43 replies to this topic

[shaun979]

I realize this is not related to F1 but that there are a lot of intelligent and knowledgable people here who can probably help me logic through some choices. Thanks in advance.

I've just started planning for an endurance engine build. I understand that racing is not cheap, but this is a private racing effort and funds are relatively limited so I seek to make this engine as practical to run as possible by maximizing mileage out of the components. The only requirements are 24 hours of racing or race level operation on a relatively high speed road course, before freshening. 98 RON (approx 94 PON) fuel. No air restrictors, no limit on displacement, bore, or stroke.

I am trying to decide between a C5R (lightweight aluminium) and SB2 block (burly cast iron). The C5R has a marked mass advantage, especially important since the likelyhood that the vehicle is going to be FR where hanging an additional 100lbs off the front end is certainly not desirable. I would gladly go with a C5R except that I would like to get a good number of races out of the engine with multiple freshenings over say 2 years and 6 endurance races. I will replace components as necessary. Does anyone have experience with high output C5Rs? Is bore stability an issue in 7 litre form (1.5 rod ratio - 6 inch rod, 4 inch stroke)? Do you think a lightweight alu block like the C5R is going to fatigue over time and perhaps lose bore stability? I'm not sure how rational this fear of mine is. The good thing is I can replace the liners if I go C5R. With the SB2 I'll have to junk the block when the walls get too thin from freshenings.

If I go C5R I'll be mirroring the Katech 7.0L C5R build. The problem is I may have problems obtaining the Nikasil liners (by Perfect Bore) they use. I have heard they are hard to find and that Katech doesn't want outsiders getting their hands on them. What do you think the effects on power/wear will be assuming I run a plain ductile iron liner at a rod ratio of 1.5?

Considering 98 RON, plain liners, no air restrictors, 7 litre displacement, how much power do you think the engine will make at an endurance-race-safe redline of 7000 RPM? Vehicle weight will be around 2900 lbs. Would you rather run a real strong block like the SB2? Or save the extra 100lbs over the front end and run less power?

[McGuire]

The C5R block won't go two years/six races with the nikasil liners. With standard liners the part number is #12480030, $6995 list, $6247.50 cost. Comes with bores in prefinish at approx 4.117"...4.124" is 7 liters and it will take a finished diameter of up to 4.160", so it's good for one full .030" overbore. This is the block I want if service life and rebuild costs are an issue.

I'm not sure I would go with the Gen III or the SB2 though...I would have to know more about the application and engine budget.

[shaun979]

The C5R block won't go two years/six races with the nikasil liners.

Thanks McGuire. I would replace the liners along with other components, as necessary. When I say 2 years, 6 races, I am concerned about the lightweight alu block itself being up to the job.

I'm not sure I would go with the Gen III or the SB2 though...I would have to know more about the application and engine budget.

The application is as mentioned, an endurance race engine putting out as much horsepower (as it can safely) for a 24 race hours before freshening. Budget for the engine is about 40K USD a year (parts alone since labour will be free). 2 or so full endurance races a year.

[Paul Ranson]

Is there not an 'off the shelf' engine that's suitable?

I think the particular engine probably isn't suitable for your use but you could afford to run a Nicholson McLaren LMP2 spec XB without any DIY engine building at all. This might give you a bottom line value/power/whatever idea.

(I'm running an NME engine in British Hillclimbing, so I know the company, and their web site has sufficient numbers on it to be useful. There are obviously many other options.)

http://www.nicholson....com/LMP675.htm

Paul.

[McGuire]

You are not going to duplicate the C5R for $40K.

[Fat Boy]

Here'a an idea. Instead of trying to re-invent the wheel, call Katech and ask them what they would sell an older version of their engine for. The Pratt and Miller Corvette's are using the newer LS7 engine, not the older C5R engine. You might be able to get a good engine that you know can do the job and stays within your budget. OK, you say you can get motor work done for free....be careful about those types of deals. They can be very expensive in the long run.

I'm going to say right off that there's going to be no engine that can do all those 24 hour races without some serious time and money put in it. You will need to freshen it up after every race. My guess is that you will have about $15k into the engine for a rebuild, but who knows.

As far as power goes, that'll depend. Katech's engines are run in the ALMS with restrictors. The RPM potential of those engines is fairly low. I would guess that they don't run 7,000 RPM even in sprint mode. Since you are running unrestricted, I'd bet you could make 700 HP easy and 800 without really stretching things, but it will only come by increasing RPM, and that will hurt the longevity. For a 24 hour race on your budget, I'd keep the RPM/HP level low. HP does not win 24 hour races. Good car preperation, competent drivers, and an easy-to-drive chassis does. Good fuel economy is more important than massive HP.

As far as getting that 100 pounds off the nose of the car, well, it's a no-brainer. If you can possibly do it, then do it. It makes the car handle better, it makes the car easier on the front tires, it makes the car easier on the brakes, and you get better fuel economy. That's an easy decision. How to do it....well, that's a bit tougher.

[Paul Ranson]

You are not going to duplicate the C5R for $40K.

Looking back at the posts it's unclear what the required lifetime in years is. If the OP is looking at 3 refreshes per year plus financing the engine for $80k over 2 years then it's hopeless. If he's looking at a refresh after 24 hours running at 4 6 hour races in two years then it's a very different equation.

Is liner/ring wear really an issue over even 24 hours at such a low rpm? The mileage is relatively trivial.

Anyway I think that finding an 'off the shelf' engine deal within the budget will pay dividends in reliability and time, and consequently results.

Paul

[shaun979]

Originally posted by Paul Ranson
Is there not an 'off the shelf' engine that's suitable?

I think the particular engine probably isn't suitable for your use but you could afford to run a Nicholson McLaren LMP2 spec XB without any DIY engine building at all. This might give you a bottom line value/power/whatever idea.

(I'm running an NME engine in British Hillclimbing, so I know the company, and their web site has sufficient numbers on it to be useful. There are obviously many other options.)

http://www.nicholson....com/LMP675.htm

Paul.

Thanks Paul I looked at some of the prices on those things and they are quite a ways beyond our budget. What engine did you get from NME and for how much? How much to freshen each time?

[shaun979]

Originally posted by McGuire
You are not going to duplicate the C5R for $40K.

How far beyond 40K do you think the C5Rs are? Roughly which components are the real killers? I don't see them being far beyond at least hardware wise. I forgot to mention that control system will be Motec standalone and installation and tuning will be free as well - by a dealer friend of mine.

Even then I still seek to build something close as possible to a Katech C5R, given the budget. If you could suggest the best ways, in your opinion, to work with the budget, I would appreciate it.

I just talked to one of my partners. Things are more specific now regarding required liftime. In 1 year, we have..

- One 12 hour race
- 6 short races each lasting about 2 hours each.

So required liftime is considerably less than originally thought - about half.

[Paul Ranson]

We have the 3.5XB, we've got a 'lease' deal for 12 hours running over 3 years between two of us (this is not an endurance type motorsport....). A refresh would be expected to cost $25000.

It struck me that if you were talking about 24 hours running over 2 years then your engine budget would be extremely plausible, $55000 to finance $90000 over two years. A refreshed engine would clearly be worth more than $35000. An 'existence proof' that DIY might not be necessary. Assuming that DIY wasn't the objective?

Our backwater sport has a web site at http://www.top12runoff.co.uk, good luck with your proper motor racing...

Paul

[shaun979]

Originally posted by Fat Boy
[B]Here'a an idea. Instead of trying to re-invent the wheel, call Katech and ask them what they would sell an older version of their engine for. The Pratt and Miller Corvette's are using the newer LS7 engine, not the older C5R engine. You might be able to get a good engine that you know can do the job and stays within your budget. OK, you say you can get motor work done for free....be careful about those types of deals. They can be very expensive in the long run.

Thanks Fat Boy. Do you, or does anyone else, think there will be any block strength / bore stability issues in second hand lightweight alu racing engines? If not, that is something I am willing to do.

Thanks for the concern over the free motor work. Rest easy, because I am doing the work myself. It is what I do for a living.

As far as power goes, that'll depend. Katech's engines are run in the ALMS with restrictors. The RPM potential of those engines is fairly low. I would guess that they don't run 7,000 RPM even in sprint mode.

I recall reading that they make peak power around 6500rpm, so it follows that they would shift somewhere beyond that.. I'm guessing somewhere around 7000rpm.

Since you are running unrestricted, I'd bet you could make 700 HP easy and 800 without really stretching things, but it will only come by increasing RPM, and that will hurt the longevity. For a 24 hour race on your budget, I'd keep the RPM/HP level low. HP does not win 24 hour races. Good car preperation, competent drivers, and an easy-to-drive chassis does. Good fuel economy is more important than massive HP.

Wise words. I am pushing for power that will finish, not just power alone.

As far as getting that 100 pounds off the nose of the car, well, it's a no-brainer. If you can possibly do it, then do it. It makes the car handle better, it makes the car easier on the front tires, it makes the car easier on the brakes, and you get better fuel economy. That's an easy decision. How to do it....well, that's a bit tougher.

I was trying to weigh the pros against the cons. Pro being less weight over the nose of the car, potential con has been the issue of block longevity over multiple freshenings and bore stability. No one has commented on this yet.

[McGuire]

If your annual engine budget is $40K, IMO you should forget the ALMS engine. (The 2005 "LS7" race engine is the C5R. Branding.) That block is $20K and when it needs new liners they throw it away. In fact if this were my deal I would probably not go with the Gen III.

No matter which way you go, the dry sump, EFI and engine electrical, cooling system and other "incidentals" are going to eat up a quarter to a third of that $40K just to start. Then you need to take a look at your operation's engine-building capabilities. If you don't have a dyno and machine tools, there is no way you can possibly build an engine as good or as cheap as you can buy it. The most you can hope for is to carefully copy someone else's proven combination and then hope you don't eat up too many track days getting it dialed in.

But then on the other hand, we do this because we want to do it eh. And we can leverage our sweat equity into machine tools, dyno, etc. we can carry into the next deal down the road. That is the only way you get ahead in this racket. Race teams end, usually with someone owing everyone else money. Always hang onto your end of the stick.

So build or buy, I would go with the SB Chevrolet, good old v1.0 rather than the SB2. It's the best value in horsepower in the world: the info is everywhere and the parts are cheaper than dirt. You can buy an engine that will fit well within your budget and needs, and if you do build your own you stand the best chance it will actually perform as planned. True, you will not be turning over any new earth but that was not going to happen here anyway. If weight is a big concern and the rules allow it, you can go with an aluminum block from Donovan, Brodix, World Products etc, with 4.125" liners. It will come in within a few pounds of the Gen III, wear like an anvil, and make 650+ bhp/550 lb ft without breaking a sweat. And if you want more it's there; it's just a question of service life.

[Fat Boy]

Originally posted by McGuire
If your annual engine budget is $40K, IMO you should forget the ALMS engine. (The 2005 "LS7" race engine is the C5R. Branding.) That block is $20K and when it needs new liners they throw it away. In fact if this were my deal I would probably not go with the Gen III.

other "incidentals" are going to eat up a quarter to a third of that $40K just to start...The most you can hope for is to carefully copy someone else's proven combination and then hope you don't eat up too many track days getting it dialed in.

So build or buy, I would go with the SB Chevrolet, good old v1.0 rather than the SB2. It's the best value in horsepower in the world: the info is everywhere and the parts are cheaper than dirt. You can buy an engine that will fit well within your budget and needs, and if you do build your own you stand the best chance it will actually perform as planned.

1. The LS7 is a completely different engine. Trust me on this one. Used C5R engines are floating around.

2. I got to thinking about this one. If you just bought a C5R long block instead of the whole she-bang and then added on the extras, you might be able to stay within budget. They run a Bosch engine management system that by itself would eat up your entire budget. Katech probably wouldn't just sell a long block, who knows unless you ask, though. If you did take this route, it still might not be the best way to go. You're going to be a 2nd or 3rd class citizen at best.

3. I'm going to have to agree with Mac on this one. Go with a a standard SB Chebby and get some good aluminum heads (that'll be 30 or 40 pounds right there). You can get 1 of 1000 reasonable engine builders to do the tricky stuff (this includes the dry sump and pan) and then do the intake and engine management yourself. You can probably start out with a used late-model circle track engine and save yourself some of the $$$ up front.

You should be able to put together a very solid package for $25-30k. Use your extra budget to get a good engine tuner to the track with you to do some 'at the track' tuning. You can only do so much of that stuff on the dyno, and the rest of it has to happen at the track. If anything is left over, you can spend it on something that will actually allow you to go faster, like shocks.

[shaun979]

Originally posted by McGuire
If your annual engine budget is $40K, IMO you should forget the ALMS engine. (The 2005 "LS7" race engine is the C5R. Branding.) That block is $20K and when it needs new liners they throw it away. In fact if this were my deal I would probably not go with the Gen III.

I get the rest of what you are saying, but just to clarify - which block is $20K? By block do you mean long block?

No matter which way you go, the dry sump, EFI and engine electrical, cooling system and other "incidentals" are going to eat up a quarter to a third of that $40K just to start. Then you need to take a look at your operation's engine-building capabilities. If you don't have a dyno and machine tools, there is no way you can possibly build an engine as good or as cheap as you can buy it. The most you can hope for is to carefully copy someone else's proven combination and then hope you don't eat up too many track days getting it dialed in.

But then on the other hand, we do this because we want to do it eh. And we can leverage our sweat equity into machine tools, dyno, etc. we can carry into the next deal down the road. That is the only way you get ahead in this racket. Race teams end, usually with someone owing everyone else money. Always hang onto your end of the stick.

Yes I've free access to Superflow flowbenches and SF-902 dyno, and Sunnen machines.

So build or buy, I would go with the SB Chevrolet, good old v1.0 rather than the SB2. It's the best value in horsepower in the world: the info is everywhere and the parts are cheaper than dirt. You can buy an engine that will fit well within your budget and needs, and if you do build your own you stand the best chance it will actually perform as planned. True, you will not be turning over any new earth but that was not going to happen here anyway. If weight is a big concern and the rules allow it, you can go with an aluminum block from Donovan, Brodix, World Products etc, with 4.125" liners. It will come in within a few pounds of the Gen III, wear like an anvil, and make 650+ bhp/550 lb ft without breaking a sweat. And if you want more it's there; it's just a question of service life.

Gotcha!

[shaun979]

Originally posted by Paul Ranson
We have the 3.5XB, we've got a 'lease' deal for 12 hours running over 3 years between two of us (this is not an endurance type motorsport....). A refresh would be expected to cost $25000.

It struck me that if you were talking about 24 hours running over 2 years then your engine budget would be extremely plausible, $55000 to finance $90000 over two years. A refreshed engine would clearly be worth more than $35000. An 'existence proof' that DIY might not be necessary. Assuming that DIY wasn't the objective?

Our backwater sport has a web site at http://www.top12runoff.co.uk, good luck with your proper motor racing...

Paul

Those are some nice vehicles right there Paul. Looks like you're doing good in the competition too! What is the typical vehicle weight, engine power, and some of the main differences between standard formula cars and these Hillclimb ones?

[McGuire]

Originally posted by shaun979


I get the rest of what you are saying, but just to clarify - which block is $20K? By block do you mean long block?

The short block for the current race engine, with liners and main caps, dressed and finished but no internal parts. The piece is available through channels, it's just not in the book. $16,900 the last I heard.

For the old school SB Chevy, you can get a Brodix or Donovan 4.125" aluminum block for about $4500 complete, new. I would avoid used for an endurance racing application unless I really know where it's been, the price is right and I can thoroughly inspect it before purchase. I especially don't want sprint car blocks or heads -- these are often CNC-milled for weight reduction which we don't want here. World Products has a new 4.125" alumimum block for $3300. It looks like a very nice piece but I don't know about hardcore endurance racing use yet.

A beauty part of all these blocks is they can be had with .500" over decks on standard order, so you can run a 4.00" stroke with a decent rod length and ring package. I wouldn't go any bigger than that on displacement -- the service life and reliablity falls right off while the output gains are not proportional.

In cranks and rods etc. beware the the cheap offshore parts currently flooding the market. They are okay for street use or bracket racing but not here. I feel pretty much the same about used parts here too. I love used parts but not for this application. You will have plenty of used parts of your own lying around soon enough. If I wouldn't use mine why would I buy someone else's timed-out junk.

[J. Edlund]

Originally posted by McGuire
The C5R block won't go two years/six races with the nikasil liners. With standard liners the part number is #12480030, $6995 list, $6247.50 cost. Comes with bores in prefinish at approx 4.117"...4.124" is 7 liters and it will take a finished diameter of up to 4.160", so it's good for one full .030" overbore. This is the block I want if service life and rebuild costs are an issue.

I'm not sure I would go with the Gen III or the SB2 though...I would have to know more about the application and engine budget.

The nikasil liners are supposed to be good for two re-hones. The intervals between re-hones are around 1000 miles. After the second re-hone has worn out, with around 3000 miles on the engine the block should be replaced.

The C5R engine also features billet machined bearing caps instead of the powder-steel stock units.

[McGuire]

The Gen III Chevy V8 (badged as a Pontiac) is very popular in the Grand Am right now...this is sort of a special case however as the regs limit the engines to +/- 500 bhp, so the engines are nicely understressed. The builders get around $50-70K for an engine and a refresh (3 races or so) is $10K. One team owner I know who is used to footing the bill for Porsche motors was happy as a clam about this, thought it was the deal of the century.

[hydra]

Can somebody explain to this cheap bastard just why a race engine refresh costs as much as a respectable family saloon? After all, aren't they just rings, bearings, and a couple of gaskets at th end of the day?

[Engineguy]

Originally posted by hydra
Can somebody explain to this cheap bastard just why a race engine refresh costs as much as a respectable family saloon? After all, aren't they just rings, bearings, and a couple of gaskets at th end of the day?

Depends, to a small extent, on what "refresh" means to a particular program, and to a larger extent on what name is on the front of the building.

[McGuire]

Originally posted by hydra
Can somebody explain to this cheap bastard just why a race engine refresh costs as much as a respectable family saloon? After all, aren't they just rings, bearings, and a couple of gaskets at th end of the day?

Oh, he knows. Add to that list a set of rod and head bolts, valve springs, retainers and keepers, cylinder honing, valve job, magnaflux, zyglow, run-in and dyno test. But the main expense is the 40 hours of shop time @ $100+ per to get it done by someone with the expertise and equipment to do it the only way it should be done. At this level of the game a "refresh" is essentially an overhaul without the new parts. So $10K is not a bad price at all, especially if you have been footing the bill to keep Porsches running.

[hydra]

As an aside, does anybody have any data, quantitative or otherwise, as to the effects of piston speed/accel vs wear and engine longevity?

[McGuire]

Originally posted by hydra
As an aside, does anybody have any data, quantitative or otherwise, as to the effects of piston speed/accel vs wear and engine longevity?

Yes. Slower is better.

Keeping rod angularity to a minimum is good too.

[shaun979]

The short block for the current race engine, with liners and main caps, dressed and finished but no internal parts. The piece is available through channels, it's just not in the book. $16,900 the last I heard.

That is amazing. The old race engine block was little over $6000 new. How much was it sold for after doing the same to it? (Liners, main caps, dressed and finished without internal parts) I assume it would be close to the price of this current one at $16,900? If not, what is it about the current race block that justifies its high price?

I especially don't want sprint car blocks or heads -- these are often CNC-milled for weight reduction which we don't want here. World Products has a new 4.125" alumimum block for $3300. It looks like a very nice piece but I don't know about hardcore endurance racing use yet.

Brodix and Donovan have some real nice stuff for sale. Brodix claims to have broken into the sprint car racing world, but I've a friend who races them and 90% of everything he's heard of is Donovan. If anything, I will play safe and go with Donovan since it has been proven many times over.

These companies (Brodix especially) offer a whole range of lightening options such that the block weights range from 70 to 110 pounds. Are you saying to go for the 100% full weight ones?

But the main expense is the 40 hours of shop time @ $100+ per to get it done by someone with the expertise and equipment to do it the only way it should be done.

I would love to hear your views on what is the only way to machine, build, or freshen a race engine. Perhaps you could start a thread on that? Things like hone processes (hot honing, stone types and steps), tolerances, clearances, common mistakes, misconceptions, whatever.


Best regards

[hydra]

McGuire,
Slower is indeed better, but by how much? :-p
Ricardo talks about three types of wear, attrition, abrasion, and corrosion, and goes on to claim that since corrrosion wear is the primary source of wear in an engine, and that corrosion wear is independent of V, then wear is (almost) independent of piston speed. I would think that this would be the case for a slow running (

[McGuire]

Originally posted by hydra
McGuire,
Slower is indeed better, but by how much? :-p
Ricardo talks about three types of wear, attrition, abrasion, and corrosion, and goes on to claim that since corrrosion wear is the primary source of wear in an engine, and that corrosion wear is independent of V, then wear is (almost) independent of piston speed. I would think that this would be the case for a slow running (<3000fpm) engine, and that attrition wear is a function of V^2, and abrasion a function of V (I think). How does all of this translate to the engine speed vs longevity equation?

What does any of this mean if one set of pistons weighs 12% more than another? The speeds and acceleration rates may be identical, but the loadings will not be.

Originally posted by hydra
About rod angularity, how much does this matter as well? Isn't piston sidethrust, and therefore wear proportional to L/R - everything else being equal, or am I missing something? Secondly what do you suppose is the minimum L/R one can get away with on a 4500fpm endurance engine?

The r/l ratio determines rod angularity. They are two ways of stating essentially the same thing. When the crank is at max offset or 90 degrees the connecting rod, crank throw and cylinder form a right triangle, with the crank as the base and the rod as the hypotenuse. Shorten the rod or lengthen the stroke and you increase the the rod angle.

Some folks might state the maximum practical rod angle for an application is 14.5 degrees, or a rod/stroke ratio of 2:1. (My personal limit for one engine is 1.6:1 or 18.2 degrees.) But either way these are entriely relative markers -- what matters are the actual loadings encountered. There are only so many ways for me to say this: I don't believe in piston speed as a limit or indicator. It's just one of the posts along the road.

[McGuire]

Originally posted by shaun979
I would love to hear your views on what is the only way to machine, build, or freshen a race engine. Perhaps you could start a thread on that? Things like hone processes (hot honing, stone types and steps), tolerances, clearances, common mistakes, misconceptions, whatever.
Best regards

Why? So I can have rude and interminable arguments about it with people who have never done it? No thanks. Most of the published lore on the subject is pure bullshit, which ironically will form the total knowledge base for folks here to tell me I don't know what I'm talking about. I have been to that party.

There is a right way and a wrong way, everyone certainly knows the latter, and this is one subject where I do not suffer foolishness gladly. While I'm sure your interest is sincere, I'm also confident you will do fine on your own. PM me if you like and I can give you some sources of good info.

[hydra]

McGuire,
I was talking about the case of altering the redline vs longevity for a given existing engine, and not making design changes.
It would also be interesting to see the same thing for rod ratio vs longevity, most other things being equal

If an engine has a life of 30 hours at 10,000 rpms, how many hours can we expect it to last at 9000 rpms? 8000 rpms?

[McGuire]

Originally posted by hydra
McGuire,
I was talking about the case of altering the redline vs longevity for a given existing engine, and not making design changes.
It would also be interesting to see the same thing for rod ratio vs longevity, most other things being equal

And I'm just saying it's all relative...most else is never equal.

Originally posted by hydra
If an engine has a life of 30 hours at 10,000 rpms, how many hours can we expect it to last at 9000 rpms? 8000 rpms?

In terms of simple abrasive wear and piston speed, one greatly oversimplified way to look at it....If at 10,000 rpm the piston speed is 4500 fpm, in 30 hours each piston will travel 1500+ miles. If we reduce the operating speed to 8000 rpm, the pistons will cover 20% shorter distance in the 30 hours. So will the crankshaft in its bearings, etc. So in that regard it would seem we could lengthen the service interval in proportion, within the validation of a given combination.

Of course it's not that simple. For one thing, every engine and application invariably has a critical component or factor which effectively determines the service life. For another, when we reduce the operating speed we reduce the inertial loadings, but we will also increase the pressure loadings (engine now closer to peak torque and MEP) and alter the engine harmonics as well.

[hydra]

And I would imagine that in most engines, this critical component is the piston/ring/bore interface right?

Nicasil liners are supposed to last "a million miles" so I would imagine its the rings that wear out first followed mainly by the top ring land getting hammered out. Does that sound right to you?

[McGuire]

Originally posted by hydra
And I would imagine that in most engines, this critical component is the piston/ring/bore interface right?

Nicasil liners are supposed to last "a million miles" so I would imagine its the rings that wear out first followed mainly by the top ring land getting hammered out. Does that sound right to you?

In terms of wear perhaps, but I was thinking more in terms of the critical components or factors that define service intervals in general...fatigue life etc. With pushrod engines it probably will be the valve train, especially valve springs...come to think of it, for most engines with metal springs they will be a factor...with 2V engines valves are usually a problem, being so damn big and heavy.

...In an earlier thread the Cosworth XB came up. Excellent engine, but it so happens it uses chain cam drives, which had an original service life of perhaps 800 miles. Service life involves a LOT of factors, many confliciting....the greater the rod/piston assembly's mass, the more quickly it will tend to pound out the rod bearings, naturally...but a lighter rod will go oblong sooner, while lightweight pistons are more dimensionally unstable as well.

So if there is any truly reliable formula for engine life relative to reduction in rpm or piston speed, or even a handy rule of thumb I can't imagine what it might be. We have to redo all the sums one by one and case by case, or better yet, what we really need to do is test and revalidate the engine at the new operating speed. We can safely presume we can extend service life, but precisely quantifying it is another matter...and we might even be creating trouble; for example with the proverbial flat crank V8 if we lower the operating rpm from say 14K to 10K we will have a big vibration problem on our hands.

IMO Nikasil is a Whole New Day in racing engines. While it got a semi-bad rap from some of the kakhanded production applications in which it has been used, to me there is no genuine downside when done right... except the additional cost and hassle of it, which in some levels of racing is not an issue. (In those neighborhoods a true, measurable improvement can be worth virtually any dollar amount; that said, nikasil will just not make dollar sense in many applications.) While the nickel- embedded silicon carbide finish is indeed hard (90 HRC or something) its oil retention properties are so good it's not so big a problem. The issue has been likened to the chrome rings of old but it's really not. Yes, it will wear out the pistons and rings first but they were going to wear out anyway, and a tungsten carbide or similar ring can handle it. The beauty is it allows very tight wall clearances, a great thing when the piston is cooled properly.

[Wuzak]

Do Ford Racing or Mopar have anything that would be suitable?

Just asking since the discussion has concentrated on Chev products.

[desmo]

Originally posted by McGuire



The issue has been likened to the chrome rings of old but it's really not. Yes, it will wear out the pistons and rings first but they were going to wear out anyway, and a tungsten carbide or similar ring can handle it.

Tungsten carbide rings? I assume this is a coating on iron?

[hydra]

McGuire,
Being used to production engines, I had automatically assumed an infinite fatigue life - my bad
Its quite natural that you can't expect reciprocating components to live forever when you push them to the limit, so the 30-50 hour useful service life that you see on these race engines is fatigue limited and not wear limited, but reduce the redline and/or beef up the components in question and you can expect them to last tens of thousands of miles - crank TVs permitting of course... Meaning a Gen III or IV based unit (or any alloy pushrod Yank V8 for that matter) with a 7250rpm redline and a max lift of 0.650" (using Ti Valves, retainers, etc) would be just the ticket for a "somewhat practical endurance engine" I would imagine that such an engine could be built for under 10k (minus cooling, oiling, sparking and fueling), and produce upwards of 600bhp, whicle lasting semi-indefinitely...

As for WC coated rings, I can't say I've heard of those before... How do they compare to TiN-coated rings?

[McGuire]

Originally posted by Wuzak
Do Ford Racing or Mopar have anything that would be suitable?

Just asking since the discussion has concentrated on Chev products.

Sure. The pieces are out there...a number of ALMS cars used Ford Power; Hugues de Chaunac's Team Oreca ran Reynards with Mopar sprint car engines at LeMans a few years back. But for cost and availability the Chevy has the edge.

[McGuire]

Originally posted by hydra
McGuire,
Being used to production engines, I had automatically assumed an infinite fatigue life - my bad
Its quite natural that you can't expect reciprocating components to live forever when you push them to the limit, so the 30-50 hour useful service life that you see on these race engines is fatigue limited and not wear limited, but reduce the redline and/or beef up the components in question and you can expect them to last tens of thousands of miles - crank TVs permitting of course... Meaning a Gen III or IV based unit (or any alloy pushrod Yank V8 for that matter) with a 7250rpm redline and a max lift of 0.650" (using Ti Valves, retainers, etc) would be just the ticket for a "somewhat practical endurance engine" I would imagine that such an engine could be built for under 10k (minus cooling, oiling, sparking and fueling), and produce upwards of 600bhp, whicle lasting semi-indefinitely...

As for WC coated rings, I can't say I've heard of those before... How do they compare to TiN-coated rings?

All true, with conditions. A 450+ bhp SB Chevy that will last forever can indeed be built on the cheap. It's been a sort of hobby of mine, have built lots of 'em...I have one out there in a truck with over 200,000 miles on it. However, long-distance sportscar racing is another thing, and 600+ hp is another thing too.

[shaun979]

Thanks everyone for all the advice.

Can I summarize that that reasons you guys believe it is better, given my situation, to go with an alu SB1 over Gen III C5R, is purely because of the $1500 saving on the block, PLUS that race build info for SB1 is more abundant?

If so my last question is.. if the budget grew to cover the extra cost of the C5R block, based on characteristics of the block ALONE, would you recommend the C5R? I am not too concerned about build information because we are friends with a few Katech guys. While they may not be willing to sell us Nikasil liners for reasons unknown, I am confident they will help us with other information.

IF there is no significant merit to alu SB1 over C5R, I will build the C5R because it is a reputation builder amongst the customer base back where I'm from. People in Asia just don't know what the other good American engines are. Possibly the only American engine they know of and respect is the C5R - mainly because of its 24 hours of Le Mans winning reputation. It just helps to build stuff that gets you more business, IF it doesn't compromise the race effort and it is within the budget.

I hope you guys understand where I'm coming from. Thanks again.

Best regards
Shaun

[Wuzak]

The C5R engine also won the Bathurst 24 hours in the Holden Monaro 427 (aka Pontiac GTO). In that situation it was restricted to 5500rpm and made somewhere in the region of 550-600hp, reportedly.

I think the general gist of the advice given is that the SB1 option would be far cheaper than the C5R option, not just in the purchase of the block, but in all other areas as well.

btw, the series for which the Monaros were built ended a year or so ago. I believe 3 were built, but I dunno what they are doing now.

[Nathan]

Originally posted by shaun979

IF there is no significant merit to alu SB1 over C5R, I will build the C5R because it is a reputation builder amongst the customer base back where I'm from. People in Asia just don't know what the other good American engines are. Possibly the only American engine they know of and respect is the C5R - mainly because of its 24 hours of Le Mans winning reputation. It just helps to build stuff that gets you more business, IF it doesn't compromise the race effort and it is within the budget.

One would think if you could garner local success with a SB1 rather than having to fork out extra cash, that would be more impressive. To build success on the cheap is what gets you customers. Not many potential customers I would think could afford to have you build them an engine with a $17000 block. However show them you can build them a complete, race ready, hopefully sucesfully race proven motor for alot less, to me atleast, that would get my support and cheque. Besides, I'm sure with the money you could save going SB1 vs C5R, you could find extra speed elsewhere to help with the overall package (better brakes, extra track testing, hire better driver(s), wind tunnel time etc.). Its not just the engine that wins the race.

Be an innovator, not a follower. (granted the SB1 hasnt been developed to death, if its not well known in your area, who's the wiser?)

[shaun979]

Originally posted by Nathan


One would think if you could garner local success with a SB1 rather than having to fork out extra cash, that would be more impressive. To build success on the cheap is what gets you customers. Not many potential customers I would think could afford to have you build them an engine with a $17000 block. However show them you can build them a complete, race ready, hopefully sucesfully race proven motor for alot less, to me atleast, that would get my support and cheque. Besides, I'm sure with the money you could save going SB1 vs C5R, you could find extra speed elsewhere to help with the overall package (better brakes, extra track testing, hire better driver(s), wind tunnel time etc.). Its not just the engine that wins the race.

Be an innovator, not a follower. (granted the SB1 hasnt been developed to death, if its not well known in your area, who's the wiser?)

Thanks for the advice Nathan The $17000 block is the current block in the C6-Rs. I am talking about the older C5-R blocks that I can get for around $6500 new - close to the price of the alu SB1s.

I would agree with your strategy if we were talking about the American market where SB1s are
understood and the racers have a clue about the engines they deal with. You must understand that Asia is full of rich clueless racers that go heavily on reputation and appearance. If you were to try to sell even a good SB1 in a land where it is not known and all the usual clouds of BS/hype prevent the accurate assessment of a race engine, then you are soon dismissed ("Oh standard small block chevy.. pushrod 2Vs are no good"). For roughly the same price (or a little more), you could ride on the reputation of the C5-R and at the same time do good in races, get these rich clueless customers (it seems the richer they are, the more clueless they are), and charge a premium for this "special" internationally proven, multiple endurance race winning engine.

A couple thousand dollars is not going to make the difference whether we win or not. If anything we are going to be chassis limited since developing it swallows a whole lot more money. A few thousand dollars is not going to cover the deficit. All I aim to do is show the rich guys - "I built this engine, it made this much power for 12 hours, and I can build it for you. Put into a matchingly competent chassis, it has the potential to be very competitive." Right now, we are not going to win going up against Murcielargo R-GT and GT3 RSR teams with 300-500% our budget.


Cheers!

[McGuire]

One benefit of the Gen III engine: as far as GM Racing is concerned it is now the only road racing V8 they have. If you want their attention or assistance at any level -- which never discount-- that's what you need to run. Otherwise you may as well be racing a 318 Poly as far as they care. (Sorry Mr. Bell.)

To me the advantages of the the Gen I are significantly cheaper price on most parts, availability, and the broader experience base. However, we can't escape the fact that the Gen III is a better engine based on newer technology, so at some price point -- and I don't know exactly where that is, depends on the budget -- the Gen III must be a greater value per dollar.

And you have your future to consider too, where I expect good things, and there's no question which engine experience will have more value down the road. One engine is the future, the other is not. I guess you have to weigh all the factors that matter to you. I don't mean to dis the Gen III in any way. I'm just not crazy about trading the farm and the mule for the trick liners, if that indeed is the case. I certainly wouldn't compromise on anything else to have it.

....I don't know if this will make sense or is even pertinent, so excuse my unsolicited advice... but you may not want to look at your $40k annual budget as an engine to be built, but rather as a $40K annual business to be run. In order to satisfy its return on investment as a business, it has to meet all its performance goals, justify all its expenses, and it has to run somewhere in the black. Then like any business it can thrive and grow into something bigger and better the next year. I'm sure this will sound horrible, but getting ahead in this racket is mostly about taking care of business. As tech nerds we tend to look at racing budgets as opportunites to get hold of the trick stuff we most want to play with, which is usually not be the most strategic use of the dollar. Business.

[Engineguy]

Here's a LS2 engine that might make a good endurance racing engine... since you only have to run it at 4000 RPM to get 650 HP / 860 ft-lb.

Just kidding, but the dyno run sounds too good not to share it.

951 HP 950 ft-lb LS2 dyno run

[shaun979]

Originally posted by Engineguy
Here's a LS2 engine that might make a good endurance racing engine... since you only have to run it at 4000 RPM to get 650 HP / 860 ft-lb.

Just kidding, but the dyno run sounds too good not to share it.

951 HP 950 ft-lb LS2 dyno run

Beautiful!

[shaun979]

Originally posted by McGuire
....I don't know if this will make sense or is even pertinent, so excuse my unsolicited advice... but you may not want to look at your $40k annual budget as an engine to be built, but rather as a $40K annual business to be run. In order to satisfy its return on investment as a business, it has to meet all its performance goals, justify all its expenses, and it has to run somewhere in the black. Then like any business it can thrive and grow into something bigger and better the next year. I'm sure this will sound horrible, but getting ahead in this racket is mostly about taking care of business. As tech nerds we tend to look at racing budgets as opportunites to get hold of the trick stuff we most want to play with, which is usually not be the most strategic use of the dollar. Business.

It certainly is very good advice I will definitely bear that in mind.

With this project I believe the returns in terms of reputation and publicity in the target market back home, will pay back. Thankfully we have sufficient reserves for the business side of things.

Thanks to all. Now the technical planning and part ordering begins. I will be happy to share the machining, build, test process if anyone is interested. If it is ok, I will post on this thread when the time comes. It all should be complete by December this year.

This is a great forum!