4-30-20 day for the 430 CanAm aluminum big block Chevy

[EZ Nova]

Now back to these 430 ZL1's. Like I said, I don't see a 430 cresting 700Hp back in the early 70's?

Grumpy's '68 BEST pass for the 1970 season according to Draglist times was 9.845 and @ 3010 IF he was only 430 inches would have been 623Hp. YET most go by MPH when looking at Hp at the track. The BEST that car went in 1970 was 138.03 and @ 3010 would have been 609.9Hp.

Now the thing is, It doesn't look from all accounts the Grumpy ran the CA 430 ZL1? I not only have the magazine from July of 1970 where Grumpy built the 70 with a GM 430 inch RAT motor. So the size isn't in dispute, BUT it does say he used the GM 427 crank.

Therefore he would have the normal "052" 4.250 block ZL1 as the engine wouldn't have been 430 with the 3.75 stroke crank and 4.440 bore, more like 465 inch. There is also mentioned out there that for match racing, Grumpy would use a mountain motor and take ALL the weight out of the car. The stories I've heard was a 4.44 block and 4" 454 crank for the old 495 inch but the weight was out, so who know what that motor would have made. I seem to doubt that even Grumpy's 495 IN 1970 made 700Hp? His best match race time was 9.40's but was there 100lbs out or 200 lbs out. It wasn't 3010 legal weight to make the 700Hp.

[Carleen]

https://bruce-mclaren.com/can-am/

[JoeC]

from what I read Bill Jenkins ran a few different engines in 1970 and 1971
the articles are not always accurate so its hard to say what the engine and HP was but I have read that the 1970 and 1971 Pro Stock cars (Ford Chevy Chrysler) were over 700hp

In Super Stock and MP Bill ran the ZL1 and L88 and L72

In Pro Stock he ran the CanAm 430 engine
in match racing he ran the CanAm 494

here is a screen shot from Drag List 1971 PS Mountain (match race) Can Am 494
where Bill ran 9.265 at 141 mph

says the 1971 record was 9.265 at 149.76 mph


John Greenwood ran the ZL1 in his Corvettes for SCCA and FIA road racing
here is a quote about the #49 Corvette where they claim the Traco ZL1 was 750HP


"When it was originally converted, the #49 BFG Corvette received all the popular Greenwood innovations: adjustable suspension, above, notched rear arms, rapid replacement radiator, and quick camber adjustments. A blueprinted Chevrolet ZL1 all-aluminum 427-cubic-inch engine, producing over 750 horsepower at 6,500 rpm, was chosen to replace the factory L88. During the restoration process, the #49 car was fitted with a potent Traco 427 ZL1

Driven by John Greenwood, above, right, 1973, Bridgehampton, Dick Smothers, Bob Johnson and Don Yenko, the #49 Corvette ran in 12 & 24-hour enduro races at Daytona, Le Mans and Sebring. At Le Mans, the Traco-engined “show” Stingray was clocked at 215 mph!"

[Flying Undertaker]

Originally Posted by WILMASBOYL78

Don't forget those Buick Nail Head motors...lots of torque.

-wilma

That picture shown is of the replacement 430 cu. in. 360hp Buick engine built for 1967-1969 Buicks before going to 455 Cu. in. Buick engine of the same design. It was a totally different design departure from the earlier Nail Head Buick engines.The Last year for a Nail Head Buick was 1966 at 401 cu. in. However, your statement that Buick engines had torque in spades is quite true.

[Flying Undertaker]

Originally Posted by William

I doubt any production ZL1 engine got near 575 hp. We worked with Bill Porterfield back in the '90s on a ZL1 dyno comparison. With a good tune up, open headers, no AIR pump, air cleaner or alternator it did 523 hp.

http://www.camaros.org/copo.shtml

Camaro High Performance has rebuilt several. With racing oil and modern rings, they see 550+hp.

I just had my '69 ZL-1 engine built by Brian Tilburg at Tilburg Racing in Trout Run, PA. All original 052 engine block that was bored .030 by previous owner. All NOS GM internals used, even .030 over GM pistons. Dynoed in Apr. 2019 (2nd pull) at 601 hp @ 6700 rpm limit that I had specified because of the age and rarity of the block. Brian said that the camshaft was still pulling hard, and had not reached its peak on the curve. He said it would have maybe 15-20hp more by 7300, as he had done several ZL-1's for NHRA Stock Eliminator AA/SA cars before. Race break-in oil and modern rings used. I have both dyno sheets. Same conditions as one stated above; good tune up, open headers, no air pump, no air cleaner or alternator!

[EZ Nova]

Originally Posted by Flying Undertaker

I just had my '69 ZL-1 engine built by Brian Tilburg at Tilburg Racing in Trout Run, PA. All original 052 engine block that was bored .030 by previous owner. All NOS GM internals used, even .030 over GM pistons. Dynoed in Apr. 2019 (2nd pull) at 601 hp @ 6700 rpm limit that I had specified because of the age and rarity of the block. Brian said that the camshaft was still pulling hard, and had not reached its peak on the curve. He said it would have maybe 15-20hp more by 7300, as he had done several ZL-1's for NHRA Stock Eliminator AA/SA cars before. Race break-in oil and modern rings used. I have both dyno sheets. Same conditions as one stated above; good tune up, open headers, no air pump, no air cleaner or alternator!

Ya you would have probably made more power 5-700RPM more. Those cam were rumored to pull well into the 7500/7800 RPM range, just not sure they were making more power or just hanging on better without the drop?

I looked at my ZL1 dyno sheet, @ 6700 I was at 785.1 Hp but it should have been higher. And you "probably" left 50 or so Hp on the table with you deal using the GM piston design and not pulling to 73/7500 range. Modern piston with 1/16 rings or better rings and not the 5/16 would have picked it up nicely too.

THEN one can look at the heads/valves and see what "could" be found there? I don't know what you did with your stuff, like better modern valve, back cut and valve job, but there is POWER there too.

[big gear head]

I have found that the dyno has a lot to do with peak numbers. I took my 427 to Dale Mears Racing and used his dyno. It would have shown another 75 HP if I had taken it to Tommy's Auto Machine and another 100 HP if I had taken it to the dyno in Evansville. Apparently there is another dyno close that would have shown about 150 more.

[Flying Undertaker]

Originally Posted by EZ Nova

Ya you would have probably made more power 5-700RPM more. Those cam were rumored to pull well into the 7500/7800 RPM range, just not sure they were making more power or just hanging on better without the drop?

I looked at my ZL1 dyno sheet, @ 6700 I was at 785.1 Hp but it should have been higher. And you "probably" left 50 or so Hp on the table with you deal using the GM piston design and not pulling to 73/7500 range. Modern piston with 1/16 rings or better rings and not the 5/16 would have picked it up nicely too.

THEN one can look at the heads/valves and see what "could" be found there? I don't know what you did with your stuff, like better modern valve, back cut and valve job, but there is POWER there too.

EZ Nova: That's some nice power for the ZL-1 Combo. Mine was totally stock, no headwork, ALL NOS GM factory stock internals with stock stroke and a .030 overbore. I was very happy with the results as it will be a trailer queen. If I were building one for power, I'd use a new ZL-1 block with some aftermarket heads with
headwork, pocket porting, etc., a bigger cam and a holley dominator! Don.

[Flying Undertaker]

Originally Posted by EZ Nova

Now back to these 430 ZL1's. Like I said, I don't see a 430 cresting 700Hp back in the early 70's?

Grumpy's '68 BEST pass for the 1970 season according to Draglist times was 9.845 and @ 3010 IF he was only 430 inches would have been 623Hp. YET most go by MPH when looking at Hp at the track. The BEST that car went in 1970 was 138.03 and @ 3010 would have been 609.9Hp.

Now the thing is, It doesn't look from all accounts the Grumpy ran the CA 430 ZL1? I not only have the magazine from July of 1970 where Grumpy built the 70 with a GM 430 inch RAT motor. So the size isn't in dispute, BUT it does say he used the GM 427 crank.

Therefore he would have the normal "052" 4.250 block ZL1 as the engine wouldn't have been 430 with the 3.75 stroke crank and 4.440 bore, more like 465 inch. There is also mentioned out there that for match racing, Grumpy would use a mountain motor and take ALL the weight out of the car. The stories I've heard was a 4.44 block and 4" 454 crank for the old 495 inch but the weight was out, so who know what that motor would have made. I seem to doubt that even Grumpy's 495 IN 1970 made 700Hp? His best match race time was 9.40's but was there 100lbs out or 200 lbs out. It wasn't 3010 legal weight to make the 700Hp.

The 430 cu.in. CanAM engine had a lot more going for it than the ZL-1 combo. The CanAm block with the siamesed cylinder walls made for a more rigid block by tying together all the bores, less block shift at high rpm. Also the 4.440 cylinder bores had the effect of unshrouding the valves just by virtue of the larger diameter bores. The short throw crankshaft of 3.47 stroke (think 350 sbc size crank) allowed a better rod length/stroke ratio of 1.768 versus a rod length/stroke ratio of 1.631 for the 3.76 stroke crank, which places the piston at the top dead center for a longer period of time than a longer stroke AND results in less side loading of the cylinder walls by the pistons to ensure cylinder block stability. Also by the shorter stroke, one can rev the motor higher as it would be in a Pro Stock car. NHRA had a 7 lb per cubic inch rule not hp rule. So theoretically, the car would weigh very little between the 427 smaller bore/long stroke and the 430 larger bore/shorter stroke combo ( 21 lbs). This reasoning was the main push behind the 430 CanAM engine combo in Pro Stock. Jenkins used the same reasoning with the '72 Vega. It was true that the 350 sbc made just a little more horsepower than the 331 sbc, but the additional weight (@ 140 lbs) it had to carry would make the combo less viable, competition-wise. I think the heads for the 430 CanAm motor used 2.30 intake valves also.

[EZ Nova]

Undertaker, funny you were mentioning ProStock! My crew chief has been involved in PS since the late 80's and there team since 1991. I also own a 498, 4.84 Borespace Pontiac 427 headed EX ProStock motor. I have personally had my hands on 3 old chevy PS engine from that era, 1 AMC and a couple of the Ford Clevends from 75 or before. Umm never a Hemi???

Anyway the shop I'm associated with built my PS 498 with 1 or 2 other back in the 90's. So we put a lot of that tech into this ZL1. You wouldn't know it with the valvecovers on and intake on.

I have seen 2.25 valve in those old motors but never really paid much attention to see IF the 2.300 would fit??? My "074" were originally done by AFR as a PS head I located off the old serial #. These were 2.25 valved. Now we did some more work to them to get them to work as good as they do. I can post some pictures if you would like to see these.