22 replies to this topic

[mariner]

Wandering around the Gm sites I found this chart listing all the weights and bhp/torgque numbers for a full set of Gm performance engines

http://www.gmperform...gineQRC2008.pdf


It is the first time I have ( easily) found actual weight data from a mfr.This data is pretty critical if you are planning to build a car or do a swap but it can be hard to come by.

I do not know exactly what accesories are assumed fitted but I am pretty sure the weights exclude the flywheel as GM does not seem to supply that on crate engines. I suspect it also excludes the starter motor.

On thing that strikes me is that if you could find a STS-V engine with low milage it would be quite useful as it weighs only 37lb/17kg more than the Corvette Z06 engine and drops only 36 bhp. I have no idea if it is a good performance engine but it does have quad cams and valves, VVT plus a supercharger so it seems to have quite a high spec. I imagine not that many have been sold though.

[cheapracer]

A number of Toyota service manual include the engine shipping weight - I might presume to protect themselves if an engine lifting hoist fails.

[mariner]

I weighed all the parts of my 477 big block before assembly except the actual block whose weight I took from the Chevy power book.

The base engine came to 285kg/626lb all up including carb, alternator,water pump,starter,flywheel and clutch but no exhausts. The heads,water pump,manifold,sump pan and dry sump pump are all ally not steel. The total car weight was 5% above the sum of my individual weights. I think that was from areas other than the engine but we could say 626lb*1.05= 657lb. I have often seen the original BB qouted as 690lb so I think 626lb to 650lb is realistic.

So the ZZ502 assembled at 611lb may well be right if it has no clutch or starter as these weighed 35lb on my engine. I could not comment on any other engines.

Whether the weights include the pallet for shipping I have no idea.

[McGuire]

Good deal, now we have three numbers for our list.

If I were in charge there would be some kind of standard -- I would opt for with water pump but less other FEAD components, and less flywheel, clutch, and bellhousing, for relevance with both stick and automatic transmissions. But I will settle for any figure when at least we know what is/isn't included. Then the weight figure actually means something.

With the infamous HRM crate engine story, there was no scale available in the pit area so I had to settle for weighing the car with each engine. That was somewhat useful but not entirely, as some engines were carbureted and some were fuel injected -- the harness and controller weights add up. Also, one of the engines was dry-sump while the rest were wet. Also, we were working with a couple of different torque converter diameters.

Just as an observational note, there was a visible difference in front ride height with the various engines, an inch or more. (Front springs remained constant.) Also, with the SBC and the aluminum LS engines, the car would pull the front tires a foot or more in the air on every launch. But with the BBCs and the iron-block LSX, the front tires remained planted on the ground despite the significant increase in torque. The chassis was set up very well so it was right on the tipping point in weight distribution, naturally. I tried to take distribution numbers but the old in-ground track scale wasn't having it, bearings worn I expect.

For your amusement:
http://www.hotrod.co...ests/index.html

[mariner]

Great article McGuire - yes , I admit it I went to the 572 test first - what is interesting is that the average difference between the Chevy SB and BB car weights is 137lb/62kg. The ancient numbers I remember for the SB and BB are 540lb and 690lb respectively, so pretty close.

Also it is interesting how the Chevelle came in at 1600 kg or below for most set ups including the big block ones, shows how much safety, equipment and chassis stiffness have added over the years.

BTW in the official McLaren F1 book the 6.3 litre BMW v-12 is quoted as 585lb/266kg with exhausts and all ancillaries. That gave 627 bhp so although I am about to make a terrible generalisation if you substitute simple cubic inches for quad cams and FI etc you may well end up with about the same power to weight ratio. The Chevy 572 has 1.18bhp/lb weight, The F1 BMW engine maybe 1.15 bhp/lb less exhaust, and the Chevy Z06 1.15 bhp/lb. Of course a turbo engine might beat all these factors.

[Ray Bell]

I can probably cobble together weights of the 318 Poly and LA engines... and the Australian Hemi 6, I have most of the data here somewhere...

I think it's silly to weigh with the flywheel, as these alone can vary by a great deal. As McGuire says, you simply can't trust lists you find, they never clarify the level of completeness of an engine and they usually have glaring exceptions one way or another.

[Greg Locock]

War story on engine weights. A colleague went off to do a quality/management course, way back when. One of his projects was the mystery of the disappearing cast iron. The casting plant knew how much pig iron they bought, and they knew how many blocks they made, and what they weighed. And there was a very big difference between the two numbers.

So he looked at pilferage, he looked at evaporation and other production losses, he checked the incoming weight of iron. He spent weeks on this.

The project eventually came to a rapid halt when somebody weighed a few blocks and discovered that the weights they'd been using were from many years ago, before the dies had worn.

[Lee Nicolle]

I can probably cobble together weights of the 318 Poly and LA engines... and the Australian Hemi 6, I have most of the data here somewhere...

I think it's silly to weigh with the flywheel, as these alone can vary by a great deal. As McGuire says, you simply can't trust lists you find, they never clarify the level of completeness of an engine and they usually have glaring exceptions one way or another.

That would be interesting Ray, the 'heavy' V8 may come out well.In years past i was told that there is 9lb difference between a slant 6 and a 318. Whatever I doubt wether there is much difference and would not be surprised if the hemi is heavier.
Though with all those engines they will have minor variance in weight as the specs and castings change.

Edited by Lee Nicolle, 18 January 2010 - 04:44.

[Lee Nicolle]

I am highly skeptical of those numbers. For example, I don't know how a ZZ4 partial engine could weigh only 223 lbs, especially when the 383 partial (identical except for the crankshaft and pin heights in the pistons) is listed at 335 lbs, which seems fairly reasonable. Also, there is no way a 572 tall-deck iron-block BBC weighs only 580 lbs. These could be shipping weights and how those are derived who can say. The next time I see the GMPP people I will ask where the catalog numbers came from. Bet you anything nobody knows.

In my life I have never seen a reliable listing of engine weights. Problem #1 -- engines themselves can vary significantly throughout production. For example, older SBCs tend to run heavier than newer ones because the castings are thicker. As years went on they took some trouble to get weight out of the castings -- unless you have one of the high-nickel bowtie blocks which run heavy. Problem #2: There is no recognized standard for just what is included in "engine weight." Any given number you find may/may not include flywheel, starter, alternator, fan, water pump, carburetor.

There is a similar problem with engine dimensions due to a similar problem -- water pump, accessory drives, bell housing, intake manifold, oil pan, and other configurations can vary quite a bit among various years and applications.

As a point of reference, recently I weighed an all-aluminum (aftermarket block) SBC. Less flywheel, water pump, alternator, and starter (dyno config, essentially) and with intake manifold and carb, it weighed 366 lbs. For comparison, I then took a late model all-iron Vortec SBC (with one unusual feature for a late-model, cast-iron intake -- industrial) and put it on the same calibrated scale not two minutes later. It weighed 476 lbs in identical trim. Okay, there's two numbers for our own list.

Having weighed numerous 4" bore SBC the bare blocks vary about 20 lb from a heavy 69 4 bolt to a early 80s 2 bolt. Thogh I reckon the later block is stronger around the main webs. But are defenitly thinner in the bore. Those early blocks are thicker bored .060 than the late ones at .030. In fact the late ones strike water at .040 on occasion. [And not a rust block either]

283 small journals are lighter than any 350, though a 307 weighs about the same as an early 350.

[SimonW]

The project eventually came to a rapid halt when somebody weighed a few blocks and discovered that the weights they'd been using were from many years ago, before the dies had worn.

I'm sure the casting weight had increased over time but not because of tooling wear. Iron blocks being sand cast, wear on tools means more sand and thus less metal. However the easy answer to many to many casting quality issues end up as more metal. Moulds and cores sticking > more taper > usually more metal as you can't make the other end thinner. Core shift and other dimensional problems means thin walls or non-cleanup in machining > more metal as a fix. Difficult to make sharp edges on cores and moulds fixed by bigger fillet radii > more metal. Cold laps and pouring problems fixed by thicker walls. Very rarely does it go the other way.

Simon

[Ray Bell]

Originally posted by Lee Nicolle
That would be interesting Ray, the 'heavy' may come out well. In years past I was told that there is 9lb difference between a slant 6 and a 318. Whatever I doubt wether there is much difference and would not be surprised if the hemi is heavier.
Though with all those engines they will have minor variance in weight as the specs and castings change.

I'm not sure what you mean by the 'heavy'...

The difference between a 318 Poly and a 318 LA is less than 30lbs, though that's without checking the inlet manifold. I'm not sure what year LA block I weighed, but both blocks were still original bore and in the same state. Heads likewise.

The slant 6 is certainly a heavy engine. Its crank alone is 25lbs heavier than that of the Hemi 6. It does have a small win on main bearing cap and web weights, however.

[Greg Locock]

I'm sure the casting weight had increased over time but not because of tooling wear. Iron blocks being sand cast, wear on tools means more sand and thus less metal. However the easy answer to many casting quality issues end up as more metal. Moulds and cores sticking > more taper > usually more metal as you can't make the other end thinner. Core shift and other dimensional problems means thin walls or non-cleanup in machining > more metal as a fix. Difficult to make sharp edges on cores and moulds fixed by bigger fillet radii > more metal. Cold laps and pouring problems fixed by thicker walls. Very rarely does it go the other way.

yes that sounds more like it.

[McGuire]

Back when genuine production-based engines were still in common racing use (NASCAR, IMSA etc) it was a common practice to weigh every engine as it came off the dyno and record it in the log. Last thing done before the engine went onto the pallet or into the crate. Engines could vary 5 to 20 lbs for various reasons (including changes in accessories, brackets, etc) which might be needful info for crew chiefs. Some NASCAR and NHRA Pro Stock teams still do it.

[Lee Nicolle]

Back when genuine production-based engines were still in common racing use (NASCAR, IMSA etc) it was a common practice to weigh every engine as it came off the dyno and record it in the log. Last thing done before the engine went onto the pallet or into the crate. Engines could vary 5 to 20 lbs for various reasons (including changes in accessories, brackets, etc) which might be needful info for crew chiefs. Some NASCAR and NHRA Pro Stock teams still do it.

The last time I rebuilt my Chev race engine i lost almost 70lbs. The alloy heads were far lighter than the previous iron, new intake was lighter as was the Moroso covers. The car turned in nicer with that reduction and the 50 hp extra helped out too!

I have seen Pro builders lose the plot weight wise, they have so many unnesecary brackets, mounts etc because they look good. An engine I rebuilt I lost about 20lb of junk from the assembly on a Chev. It was very nice inside though!

[gruntguru]

The last time I rebuilt my Chev race engine i lost almost 70lbs. The alloy heads were far lighter than the previous iron, new intake was lighter as was the Moroso covers. The car turned in nicer with that reduction and the 50 hp extra helped out too!

I have seen Pro builders lose the plot weight wise, they have so many unnesecary brackets, mounts etc because they look good. An engine I rebuilt I lost about 20lb of junk from the assembly on a Chev. It was very nice inside though!

A 0.040" rebore probably saves 2 - 3 lb on a SBC - assuming the OS pistons are the same weight.

[Bob Riebe]

Some of the after market, or semi-factory, boys now list weight for some of the bare blocks and finished cylinder heads.
Are these real numbers or not?
Bob

Edited by Bob Riebe, 20 January 2010 - 21:03.

[McGuire]

I see the same problems as with complete engine weights. With a block, does the weight include main caps and if so, which ones? Many aluminum blocks are available with both ferrous and aluminum main caps. And so on. Also, some blocks don't support wet sump oiling. With cylinder heads, does the weight include any hardware, such as rocker studs and guide plates? It's especially hard to know what to make of statements like "50 lbs lighter than the production heads." Which production heads?

[Ray Bell]

Ben's Poly 318 race engine will lose about 120lbs in the course of its build...

This is everything from flywheel to water pump. The intake manifold, crankshaft and flywheel will account for over 80lbs of this, but it will still have original heads.

The potential turn-in benefits are readily seen. What we have to do is get some weight out of the front bumper!

[Lee Nicolle]

Ben's Poly 318 race engine will lose about 120lbs in the course of its build...

This is everything from flywheel to water pump. The intake manifold, crankshaft and flywheel will account for over 80lbs of this, but it will still have original heads.

The potential turn-in benefits are readily seen. What we have to do is get some weight out of the front bumper!

Spend thousands and buy that alloy one !!

[McGuire]

If you are the industrious type (like the people who build scale models of Notre Dame Cathedral from toothpicks) there is probably 20 lbs to be milled from the block. Maybe more. I wonder... how much can you move the engine down/back in the chassis? Or you could fix it just like they did back in the day and move the front spindle CL forward an inch or three. Of course, then you will have to move the rear axle forward as well so the wheelbase will remain unchanged and the measurement will come out legal. Don't call it cheating, it's simply a production variance.

[gruntguru]

If you are the industrious type (like the people who build scale models of Notre Dame Cathedral from toothpicks) there is probably 20 lbs to be milled from the block.

As the V8 supercar teams were doing a few years ago (probably still do). Cost for this operation alone was several thousand dollars per block.

[Lee Nicolle]

As the V8 supercar teams were doing a few years ago (probably still do). Cost for this operation alone was several thousand dollars per block.

Depends on how serious you get.To do the outside on a Chev is about 4 hours on a mill [experienced people] When you start on the inside it triples the time and does not get rid of more than a bout 5 lb. A few hundred for probably 20lb is probably justified anymore is overkill.
Particularly on something that big and fat!!

[Ray Bell]

There are a couple of areas on the Poly that can be milled with reasonable return for the time, I think...

Thus far Ben doesn't plan to do it, but in the long term I think he will. There are ribs on the back of the block in early models that will simply be taken off with an angle grinder. Or reduced, at least. There would be 5lbs in those, in all probability. The 'pan rail' is basically an inch square all around, I see some good prospects for that with a bit of fairly easy milling.