302 SBC questions

[big_truxx]

Well I will be running a lightweight vehicle A Fiero doesn't weigh a whole lot. This also isn't a drag or road racing car... But one never knows what a project will turn into later on

 

[sled_dog]

a stock 350 makes a Fiero a rocket, I wouldn't put much power to the Fiero transaxle.

As for the underrating of motors back in the day, well think about they didn't test with any accessories so lose some HP there. I know they underrated motors in the day but they weren't as hot as people make. I know a guy who has a 302 Camaro. No idea what year it is, its original.

377- 400 block bored to 4.165 with 3.48 stroke. a 350 with 3.75" stroke needs to be bored out .030 over for rod and crank clearance. You need to grind clearance into it even after .030 over.

Big_Truxx, your "dyno" of the 383 was off in that if you put bigger runner heads and a bigger duration camshaft it wouldn't lose the power you said it did. The motor setup you can was designed to max out at the RPM you said, I could build a motor that would max RPMs at 10k if I wanted. Would a 383 rev that high? I have no clue but I wouldn't try it. I have a buddy that is a 327 nut, hes been wanting to build a 10k RPM 327 for a while. My 400 blocked 327 idea was to beat him to the 10,000 mark.

 

[big_truxx]

a stock 350 makes a Fiero a rocket, I wouldn't put much power to the Fiero transaxle.

At www.v8archie.com he has been running some mean motors in a fiero with the stock axle shafts. One of them was in a drag car and made 425hp and then nitrous on top of that. And he has yet to break the stock axle shafts

 

[sled_dog]

sweet. There is a site that has a bunch of body mods for Fieros. THey had later model ones with chop tops, they look utterly SICK! I wanted one so bad... still do really.

EDIT: it was the V-8 Archive site you posted

 

[84_Chevy_K10]

I ran some #'s on the dyno and @ 6500rpm the 383 is past peak hp and has lost 80hp from its peak #. It peaked at 5,000. I don't know about a 350 @ 8,000... I guess maybe in a $10,000 crate it may still be making good power at that speed but for a home built on a budget type "normal" motor I do not see anything spinning 8 grand. I guess another thing I was thinking about is; doesn't rpm affect your speed anyway? Like wouldn't an engine that has 350 peak hp at 6,500 go faster than on that has 350 peak hp at 5,000?

If the 383 is dying at 6,500, you chose too small of a camshaft and the compression ratio is probably too low, along with the heads being too small most likely.

Nobody that is building a high revving, high HP engine is doing it on a budget so that point is moot. Forged parts, good fasteners, good oiling, and a good balance job is essential to make this stuff live.

A "normal" motor concentrates on midrange HP and maybe tops out @ 5,500 or so, which would make for a wild street motor but nowhere near the HP of spinning it like crazy.

The peak engines 6,500 vs. 5,000 RPM would likely go about the same speed if they both had matched setups, but the 6,500 RPM car would be faster if set up correctly. If the 6,500 RPM engine needs a 3,000 stall and 4.10s to work, and it has 3.08s and a 1200 RPM stall, it's going to be a dog. The 5,000 RPM car will work well with a more street friendly rear gear and a tighter converter and it'll have more giddy-up on the street, but the other car will likely catch it on the big end of a 1/4 mile. Beyond the 1/4, the 6,500 car is going to SPANK that other car. Your comparison is unrealistic however, because with the same CID, the 6,500 RPM car is going to make a LOT more HP if built correctly.

 

[big_truxx]

If the 383 is dying at 6,500, you chose too small of a camshaft and the compression ratio is probably too low, along with the heads being too small most likely.

Nobody that is building a high revving, high HP engine is doing it on a budget so that point is moot. Forged parts, good fasteners, good oiling, and a good balance job is essential to make this stuff live.

A "normal" motor concentrates on midrange HP and maybe tops out @ 5,500 or so, which would make for a wild street motor but nowhere near the HP of spinning it like crazy.

The peak engines 6,500 vs. 5,000 RPM would likely go about the same speed if they both had matched setups, but the 6,500 RPM car would be faster if set up correctly. If the 6,500 RPM engine needs a 3,000 stall and 4.10s to work, and it has 3.08s and a 1200 RPM stall, it's going to be a dog. The 5,000 RPM car will work well with a more street friendly rear gear and a tighter converter and it'll have more giddy-up on the street, but the other car will likely catch it on the big end of a 1/4 mile. Beyond the 1/4, the 6,500 car is going to SPANK that other car. Your comparison is unrealistic however, because with the same CID, the 6,500 RPM car is going to make a LOT more HP if built correctly.

I was reffering to the same setup just different peak rpms And meant in the long run ie road style racing. Sorry I am not always clear with my thought trains.