Streetwiseguy said:
I'm just not a huge fan of great big engines, although a 632 in an old Camaro might be interesting.
I regularly worked on/drove a '68 that had first a 468, then a 496, then a 540. It was nice.
The funny was the 632 in a, I think, '69 Nova. The tall deck block meant nothing fit. I ended up having to use some combination of solid motor mounts, and then I had to section the trans crossmember because the headers wanted to point directly at it. Apparently nobody MAKES headers for tall deck BBCs in Novas, so regular headers exited too high. Lowered the trans mount and heavily notched the crossmember for exhaust clearance.
It was funny because the guy who commissioned it was like 90 years old and he was afraid to drive it a half a block to his car hauler, so we had to ferry it for him. Why did you have us build it if you won't drive it?
Someone one described the sound of an idling hot cammed 600+ engine as "a bowling ball in an industrial clothes dryer" and that description is APT.
ShawnG
MegaDork
4/5/24 9:15 p.m.
In reply to Pete. (l33t FS) :
Setting the valves on Y-block Fords is a treat too.
ShawnG said:
I watched some stupid T.V. special, shot in the 2000s a while back where they dyno tested all the big dog engines from 1970.
If I remember correctly, they all scored a fair bit above the factory specs.
They ran the 426 Hemi and claimed some ridiculous number like 600-ish from a supposedly stock engine.
Guys, if you're going to lie about it, at least make it believable.
I know everyone lied to get the insurance companies off their backs but that much more? Come on.
The big three (maybe four) weren't all that far apart on their numbers.
In the late '60s Dan Gurney had a monthly Q&A column in Popular Mechanics. Once someone wrote inquiring as to why all 3 manufacturers made 7 liter engines but Ford's 428 Cobra Jet was weak sauce at 335 hp rating compared to Chevrolet and Mopar's 425 hp rating (427 and 426 respectively). Dan's answer: All 3 will make 500 with the correct parts and tuning.
I'm not old enough to remember that. Grandpa had an attic full of back issues.
In reply to A 401 CJ :
There are a few simple complications of course. Chevy built the engines with crappy log manifolds because the racers would just install headers anyway. With headers an L88 would do 550hp.
Chrysler, according to a line engineer back in the day, tended to have way over spec deck heights, which killed compression, because they could run the engine block machining line faster if they ran the blocks through taking the minimum of material off.
Ford, from one of the powertrain engineers at the time, had very strict rules regarding drivability. Engines HAD to meet certain guidelines for cold start and hot start, whether it was a base Falcon or a Galaxie 500 or a Talladega. This limited how "hot" they could be for production engines, if you couldn't hit the throttle once to set the choke, turn the key, and drive away, it wouldn't fly.
There was of course a lot of "derating" done with the numbers, for marketing and homologation reasons. Marketing, because they didn't WANT anybody but racers to buy the hottest things, since they didn't want to have warranty claims. If Engine A was 400hp and Engine B added 25% of the price to the car for only 25 more horsepower, would you buy it? Also, the NHRA classed vehicles by rated power so there was definite sandbagging involved.
But very curious that all through the 60s, engines got bigger, cylinder heads got way better, cars got faster despite getting heavier, and yet they never made more than "425hp" from 1962 to 1969. You can't tell me that an old low riser FE and a Boss 429 made the same power, or an L88 versus an old 409.
