Grumpy Chevy Book Volume 2 What If?

[lorax]

BTW, does anyone actually know what valve angle Grumpy ran on his 331, I don't think I've ever seen it published?

I haven't re read that thing in a while. But if remember correctly, he may have angle milled the heads. But I 'am pretty sure he moved the laterally in the bores.

As for the LS, am not saying the heads aren't very well massaged, but just like he did back then, it is OEM stuff.

[GARY C]

BTW, does anyone actually know what valve angle Grumpy ran on his 331, I don't think I've ever seen it published?

I haven't re read that thing in a while. But if remember correctly, he may have angle milled the heads. But I 'am pretty sure he moved the laterally in the bores.

As for the LS, am not saying the heads aren't very well massaged, but just like he did back then, it is OEM stuff.

Thats cool, thanks for setting me straight, I'll shut up now

Well, at least for now

[barnym17]

I read that book so many times you could see thru the pages, then I passed it on to another member here.Full of good info the part that really made me think was when he talked about all the ignition tests he ran, he said that in testing he could find no difference between his dual point setup and the latest electronic ignitions of the time(msd 7 is shown in the book).Until he opened the plug gap to .060 then he found 10hp but also mentioned starting could be difficult with the large gaps.
He also brought up how the stock aluminum and nylon timing chain helped dampen the harmonics from the crank going to the cam.According to him this helped high rpm valve train stability.Many little details in the book that make for good reading.

[BrazilianZ28Camaro]

If I remember correctly, Grumpy also built PS truck 358" racing engines making about 980 HP@10K rpm. That's 2.73 hp/ci against 2.05hp/ci from the older 331" engine.

So this is what Grumpy "cold" build with more modern parts, IMO.

To me he was a genious motivated by his race love. He first design and tested parts used to this day successfully.

Would be amazing have another Jenkins book , or maybe one from Black Arrow .

[vortecpro]

If I remember correctly, Grumpy also built PS truck 358" racing engines making about 980 HP@10K rpm. That's 2.73 hp/ci against 2.05hp/ci from the older 331" engine.

So this is what Grumpy "cold" build with more modern parts, IMO.

To me he was a genious motivated by his race love. He first design and tested parts used to this day successfully.

Would be amazing have another Jenkins book , or maybe one from Black Arrow .

You would need to look at at what Bills cars ran at the time the book was published, run the numbers, then compare his modern day Pro Stock truck numbers, but remember you have to take into account the FORWARD FACING HOODSCOOP. Todays 500 inch Pro Stock engines make 1500 plus HP on the dyno, thats 3 per inch, compared to Bills production engine based 2 per inch. Again remember the first year of 500 inch Pro Stock, right around 970 HP @ 500 inches, not quite 2 per inch with parts that were not quite production line parts, but when Ol Warren got in there with that dude from EPD, it didn't take long to exceed the 2 HP per inch.

[kirkwoodken]

Quote: Grumpy said that in testing he could find no difference between his dual point setup and the latest electronic ignitions of the time(msd 7 is shown in the book). Unquote.

Grumpy ran the Rochester FI dual point distributor. These are famous for being point float free up to 8000 RPM with the right fixes. Because of their rarity, nobody knows how they look and supposes they are like a standard dual point, I'm guessing. In the FI distributor, the points are mounted to a solid cast iron piece about 3/8" thick, which in turn fits into the main distributor casting. Grumpy said these were absolutely the best distributors ever at that time. These had a special point cam like the Z-28's that was shaped to keep point bounce to a minimum, much like asymmetrical cam lobes. The non street FI distributor did not have vacuum advance. These were designed for balls out racing. I would imagine these are in the $2500+ range today if you can find someone who will part it.

[steve cowan]

i just had a quick look in grumpys toys, one of the first 331sbc made 540hp with 0.020'' overbore 327. 292 turbo heads,tunnel ram with 2- 660 centre squirters,check out the photo on page 112,ron sperry refered to grumpy as the father of the bowtie cylinder head.the initial so-called 292 turbo heads were developed from ron sperry and smokey for his 209 ci sbc for the indy 500,50 sets of these heads were developed in 1971 but needed extensive cutting and shutting and brazing to be in the ball park,they run around 13.0:1 comp with a 2.06" intake valve,initial prep was carried out by afr in california.ken dondero drove grumps vega to a 8.59@159mph with the 331sbc before the stepped up to 358ci

[barnym17]

He also explained how to tune up a non f.i. dual point to get the same results, it involved a lot of epoxy.