30 replies to this topic

[Magoo]

Yes, it's a hemi V8. No, it's not a Chrysler. It's a big-block 427 CID Ford hemi lashed together by Mickey Thompson in 1963. Now wait until you see inside. 

 

 

Mickey Thompson's 427 Ford Hemi V8--and its fascinating secret | Mac's Motor City Garage.com

 

[imaginesix]

Clickbait artist.

[desmo]

Pushing on a string comes to mind.

[Magoo]

Clickbait artist.

 

 

The Judges Mocked and Sneered at His Engine But What Happened Next Will Make You Stand Up and Cheer. 

[Magoo]

I would love to put a high-speed video camera on this thing and watch all those pushrod pieces trying to travel in opposite directions. 

[PJGD]

Not so very different or more weird than the straight 6 cylinder 2 L BMW/Bristol engine that was quite successful in racing in the 50's.  That had a low mounted camshaft, cam follower, very long pushrod, a rocker, another long pushrod, another rocker, and then the valve.  Neither arrangement is anywhere near ideal by modern standards, but they did the trick in their day.

 

PJGD

[Bob Riebe]

Sweet.

 

Put one of those in the engine bay of the new Mustang and that would be hot rodder's heaven.

[Lee Nicolle]

I do LOVE those pushrods! I am surprised they just did not use offset rockers ah la 340 TA Mopars and several others.  Though they are not ideal either.

Though IF the centre of the pushrod is correctly supported it should work ok. As Bill says, 6500 is probably ok. Not too much spring required either

Though those articulated pushrods I have seen somewhere else too. Pommy or Euro engine? Aircraft?

[bigleagueslider]

Don't imagine the brazed joint between the lifter and lower pushrod would last for long. Also the frictions produced by all the extra pivots in the pushrods would add to mechanical losses in the engine.

[TDIMeister]

Ugg. Open chambers all of them.  Nice if you're running unlimited octane fuel but doesn't have any squish and are forced to a less-than-great crescent shaped combustion chamber with domed pistons if you want a reasonable compression ratio...

 

If somebody came up with narrow-included angle 4V (or more...) pentroof heads for any of the Detroit-3 V8s in that era (and I'm pretty sure there were some) with compact high-turbulence chambers and generous squish, then color me impressed.

[MatsNorway]

 and are forced to a less-than-great crescent shaped combustion chamber with domed pistons if you want a reasonable compression ratio...

Such assumptions is too simple. It depends for instance on the Bore/stroke ratio, the rpm it is optimised for and so on. + I believe i read somewhere that dodge had some motor with 10:1 compression ratio as standard. Thats pretty damn good for 1960s! if it is true mind you.. Might be a special or just wrong.

[TDIMeister]

Such assumptions is too simple. It depends for instance on the Bore/stroke ratio, the rpm it is optimised for and so on.

Bore:stroke ratio of an American V8, which is good oversquare.

[Magoo]

Ugg. Open chambers all of them.  Nice if you're running unlimited octane fuel but doesn't have any squish and are forced to a less-than-great crescent shaped combustion chamber with domed pistons if you want a reasonable compression ratio...

 

If somebody came up with narrow-included angle 4V (or more...) pentroof heads for any of the Detroit-3 V8s in that era (and I'm pretty sure there were some) with compact high-turbulence chambers and generous squish, then color me impressed.

 

Two-valve hemi heads were very popular in 1963, especially on pushrod engines. A DOHC V8 based on the Ford block might be viable, but it is a totally different project from this one. 

[Kelpiecross]

Ugg. Open chambers all of them.  Nice if you're running unlimited octane fuel but doesn't have any squish and are forced to a less-than-great crescent shaped combustion chamber with domed pistons if you want a reasonable compression ratio...
 
If somebody came up with narrow-included angle 4V (or more...) pentroof heads for any of the Detroit-3 V8s in that era (and I'm pretty sure there were some) with compact high-turbulence chambers and generous squish, then color me impressed.

Gurney-Weslake heads for the SB Chev were 4 valve.

[desmo]

Honda certainly showed that a practical production single cam, pushrod, vee engine can work with four valve heads with the CX-500/CX-650 design.

[Magoo]

Gurney-Weslake heads for the SB Chev were 4 valve.

 

Indeed they were, used forked rocker arms and rather long pushrods. The 4V Weslake Chevy head (Gurney was not involved here) has a sort of modern day successor or variant sold under the Arao name. They're not terribly practical or effective either. I do believe we could pull a set of bargain-priced aftermarket SBC heads straight off the shelf and they would outflow any of these exotic castings of yesteryear, including the M/T Hemi and the 4V Weslake. And of course, for durability and overall usability there's no contest. 

 

This is not to knock these early efforts in any way. The reason we are so smart today is folks like Thompson and Weslake---all the things they tried that worked and didn't work. And they didn't have CFD or analytics or sometimes, even flow benches. They were flying blind. Even while we criticize their technical ignorance, we are standing on their shoulders. 

[Canuck]

"After we had conducted thousands of experiments on a certain project
without solving the problem, one of my associates, after we had
conducted the crowning experiment and it had proved a failure,
expressed discouragement and disgust over our having failed to find
out anything. I cheerily assured him that we had learned something.
For we had learned for a certainty that the thing couldn't be done
that way, and that we would have to try some other way."
- Edison


If we are smart, we build upon the knowledge gleaned in failure as well as success.

Edited by Canuck, 10 November 2014 - 15:07.

[TDIMeister]

Not a V8, but American and very early.

http://www.museumofa...alve,21396.html

 

Anyone know more about this?

[Lee Nicolle]

Ugg. Open chambers all of them.  Nice if you're running unlimited octane fuel but doesn't have any squish and are forced to a less-than-great crescent shaped combustion chamber with domed pistons if you want a reasonable compression ratio...

 

If somebody came up with narrow-included angle 4V (or more...) pentroof heads for any of the Detroit-3 V8s in that era (and I'm pretty sure there were some) with compact high-turbulence chambers and generous squish, then color me impressed.

409 Chev

[Lee Nicolle]

Such assumptions is too simple. It depends for instance on the Bore/stroke ratio, the rpm it is optimised for and so on. + I believe i read somewhere that dodge had some motor with 10:1 compression ratio as standard. Thats pretty damn good for 1960s! if it is true mind you.. Might be a special or just wrong.

Mats, many US engines had 10-1 in the late 50s on. Late 60s they were at 11-1. Z28, LT1, LS7, Boss 302 had more than that even. They had good hioctane leaded fuel then.

These days the performance engines with those massive numbers are up ther too,, on unleaded. Better chambers, better fuel atomisation and far better ignition all helps.

Even with aftermarket heads. A mate has a 377 Cleveland with '3V' heads with 12-1 on 98 octane. With 500 hp at the wheels. And while wild it is streetable. That is with a carby. Avgas is good for a couple more degrees of ignition and more useable mid range power. But no more maximum power.

[Lee Nicolle]

Not a V8, but American and very early.

http://www.museumofa...alve,21396.html

 

Anyone know more about this?

There was several different conversions for those engines. Talking to a chap on Sat nite who is building a B model engine with a Riley head. A period style conversion. I have a pic of a OHV Alec Rowe [ a very smart man with engines] conversion on a midget. Unfortunatly on my phone. A Post war conversion evidently still being made.

Ofcourse the Ford V8 also had a pile of conversions too. The Ardun being the best known. No OHC conversions I know of though

Edited by Lee Nicolle, 11 November 2014 - 09:00.

[Magoo]

Not a V8, but American and very early.

http://www.museumofa...alve,21396.html

 

Anyone know more about this?

 

 

The Ballenger was one of the lesser known examples among the huge variety of conversions for the Model T and Model A Ford -- F Head, OHV, SOHC, DOHC, two-valve, four-valve, etc. Most every conceivable configuration was offered. 

 

One of the more interesting was the Frontenac Stagger Valve -- a DOHC, four-valve conversion for the Model A Ford with intake and exhaust valves for each cylinder on both sides of the head in the manner of the Apfelbeck.  

[Ray Bell]

The pushrod set-up is similar to that used in the Repco-Holden F5000 engines...

According to John McCormack, who was very close to Phil Irving (the engine's main designer/analyst), Phil found that pushrods were bending. "If they want to bend," Phil said, "they want to break. So we'll break them!"

There were simple and very short shuttles between the halves in the holes bored into the heads for the pushrods to pass through. The remaining pushrods were able to be made light and were very stiff.

[gruntguru]

Sounds sensible. Small increase in valvetrain inertia, massive increase in valvetrain stiffness allowing stronger valve springs (if required).

[Ray Bell]

Perhaps a little friction too...

But if the valves opened fully and they didn't before, there's bound to be gains.

[Magoo]

Does anyone have an illustration of the valvetrain of the Holden Repco? Would love to see it. 

[Magoo]

Upon asking around, it seems some sources indicate that it was a Holden Leyland F5000 V8 that used the articulated pushrod setup. Anyone know? In any case, I am on the hunt for any photos and info. 

[Lee Nicolle]

Upon asking around, it seems some sources indicate that it was a Holden Leyland F5000 V8 that used the articulated pushrod setup. Anyone know? In any case, I am on the hunt for any photos and info. 

Having seen a few Repco Holdens in bits they used normal guide plates with a bolt down individual rocker with a adjuster for lash. A reliable enough engine but nothing overly flash. Reputedly good driveability but less power than a Chev. Though no two Repco Holdens seem to be exactly alike. 5000 engines used injection, some others only used a 4bbl. I have seen them in Sports Sedans, Sports Cars and even a speedway HT Holden.

I never saw a Leyland in bits but do remember Macs chief mechanic [then] Dale Koeneke [later K&A engineering] telling me about some weird valve train stuff in those engines. Which with the flat plane crank viabrated half the rivets in the tub loose every event. Possibly an engine with potential but never really fulfilled. I know Dale was never impressed. Chevs were simple and won! Those engines are just a Buick alloy engine enlarged to 4.4 and for 5000 about 4800 from memory

[Ray Bell]

Fully 5-litres, according to all sources, Lee...

It could be that the Repco-Leyland engine had the shuttles too, after all, Phil Irving built it on a very limited budget and would likely have incorporated things he'd learned while doing the Repco-Holdens.

It was John Goss who mentioned the 2-piece pushrods to me when he was talking about the difficulties he might have faced in developing the engine further.

A Repco-Holden of the highest development level was as good as the Chevs of the day. John Walker's engine was rebuilt to this standard for Sandown at the end of the Tasman Cup series of 1975, it had a flat plane crank and 25hp more than before, he found in practice that he could pass anyone on the Sandown straights.

At the start he recalls thinking, "There's no point in panicking here, I can take my time, I can pass them up the straight whenever I like." Then came his inexplicable crash... but Goss won the race with a Repco-Holden engine anyway.

As for winning, if you look at the Gold Star results over the F5000 period you'll see that Waggott won one title... then:

1972 - Matich, Matich Repco-Holden
1973 - McCormack, Elfin Repco-Holden
1974 - Stewart, Lola Chev
1975 - McCormack, Elfin Repco-Holden
1976 - Leffler, Lola Chev
1977 - McCormack, McLaren Repco-Leyland
1978 - McRae, McRae Chev
1979 - Walker, Lola Chev
1980 - Costanzo, Lola Chev
1981 - Costanzo, McLaren Chev

Take into consideration the fact that none of the competitive cars ran Repco-Holdens after Repco closed down their racing support, which was about 1977, and you see that the Repco-Holden did pretty well at winning. Some time in the late seventies they allowed alloy heads on the Chevs, there were none for the Holden.

It was under these rules that McCormack was able to do his new head for the Leyland engine, which never actually got a chance to strut its stuff. This was very much a privateer project with Irving involved with his friend McCormack.

As for Dale, yes he did get sick of hauling the Leyland engine in and out of the ML6 and so it became the MR6 with a Holden engine, but by the time they got the McLaren operating the engine wasn't too bad and it was repaying its relative lack of power with the light weight that enabled McCormack to use better tyres and to out-corner everyone on the track. He built up such a huge lead at Phillip Island once it was hard to believe the others were in the race.

[Ray Bell]

Originally posted by Magoo
Upon asking around, it seems some sources indicate that it was a Holden Leyland F5000 V8 that used the articulated pushrod setup. Anyone know? In any case, I am on the hunt for any photos and info.

You mean 'Repco-Leyland V8', of course... there's no connection between Holden and Leyland...

I don't know, but it's possible as I've outlined above.

The later development with the IMC heads was very interesting to me, the 'IMC' standing for Irving, McCormack and Comalco. They used an alloy that didn't require valve seat inserts.

As is probably well known, the Buick/Rover/Leyland heads were seriously lacking in port section and they addressed this with these heads, which I'm pretty sure were of the Heron type (chamber in piston, flat head surface). One of the problems McCormack had through the McLaren-Leyland period was bleeding the cooling system for some reason.

Remind me during the week (it's now Saturday morning here and I have a weekend of work away from home) and I'll see if I can dredge up some pics.

[Lee Nicolle]

Fully 5-litres, according to all sources, Lee...

It could be that the Repco-Leyland engine had the shuttles too, after all, Phil Irving built it on a very limited budget and would likely have incorporated things he'd learned while doing the Repco-Holdens.

It was John Goss who mentioned the 2-piece pushrods to me when he was talking about the difficulties he might have faced in developing the engine further.

A Repco-Holden of the highest development level was as good as the Chevs of the day. John Walker's engine was rebuilt to this standard for Sandown at the end of the Tasman Cup series of 1975, it had a flat plane crank and 25hp more than before, he found in practice that he could pass anyone on the Sandown straights.

At the start he recalls thinking, "There's no point in panicking here, I can take my time, I can pass them up the straight whenever I like." Then came his inexplicable crash... but Goss won the race with a Repco-Holden engine anyway.

As for winning, if you look at the Gold Star results over the F5000 period you'll see that Waggott won one title... then:

1972 - Matich, Matich Repco-Holden
1973 - McCormack, Elfin Repco-Holden
1974 - Stewart, Lola Chev
1975 - McCormack, Elfin Repco-Holden
1976 - Leffler, Lola Chev
1977 - McCormack, McLaren Repco-Leyland
1978 - McRae, McRae Chev
1979 - Walker, Lola Chev
1980 - Costanzo, Lola Chev
1981 - Costanzo, McLaren Chev

Take into consideration the fact that none of the competitive cars ran Repco-Holdens after Repco closed down their racing support, which was about 1977, and you see that the Repco-Holden did pretty well at winning. Some time in the late seventies they allowed alloy heads on the Chevs, there were none for the Holden.

It was under these rules that McCormack was able to do his new head for the Leyland engine, which never actually got a chance to strut its stuff. This was very much a privateer project with Irving involved with his friend McCormack.

As for Dale, yes he did get sick of hauling the Leyland engine in and out of the ML6 and so it became the MR6 with a Holden engine, but by the time they got the McLaren operating the engine wasn't too bad and it was repaying its relative lack of power with the light weight that enabled McCormack to use better tyres and to out-corner everyone on the track. He built up such a huge lead at Phillip Island once it was hard to believe the others were in the race.

And as it was flat plane it viabrated quite badly, the tub had to have a lot of rivets replaced after every meting, both the Elfin and the Mclaren too. 

Not an ideal circumstance at all.