more Horsepower in a std L48 [Archive] - SmokinVette.com Forums

: more Horsepower in a std L48


raceman
08-24-2007, 12:49 AM
I´m just an owner of a 350 corvettw -74 350 (L48 I guess)with 4 speed gearbox. Standard engine less than 200 horsepower, it is not good enough. My knowledge havt to be improved about V8 engines. I want 375-400. I get when I bought the car new parts :cam Erson E110421 (296° IN 228° IN .472" IN 108°. 0° .000" IN. 5750. Hi-Flow IH) A Edelbrock intake and a Edelbrock carb 650 Thunder AVS , and headers. Next step have to do something with the heads and comp I guess. What can anybody give me som support?

Thanks

chexbucks
10-02-2007, 05:38 AM
I´m just an owner of a 350 corvettw -74 350 (L48 I guess)with 4 speed gearbox. Standard engine less than 200 horsepower, it is not good enough. My knowledge havt to be improved about V8 engines. I want 375-400. I get when I bought the car new parts :cam Erson E110421 (296° IN 228° IN .472" IN 108°. 0° .000" IN. 5750. Hi-Flow IH) A Edelbrock intake and a Edelbrock carb 650 Thunder AVS , and headers. Next step have to do something with the heads and comp I guess. What can anybody give me som support?

Thanks
Get the heads port and polished would be good start.

rkyle
12-27-2007, 11:34 AM
just finished complete rebuild of 81 with 350. Bored block .030 over, decked block to 9.0, flat top pistons, hotter cam, roller rockers, World Product 2.02 heads w/ss valves, Edelbrock Performer intake, Holley 650 and put a 700-R tranny behind it all. Changed rear end gearing to 3.38. WOW what a ride. It will break em' loose shifting into 3rd. Horses estimated at 375. When weather gets better here I will take it to town for a dyno run.

gonesailing
12-28-2007, 08:27 AM
just finished complete rebuild of 81 with 350. Bored block .030 over, decked block to 9.0, flat top pistons, hotter cam, roller rockers, World Product 2.02 heads w/ss valves, Edelbrock Performer intake, Holley 650 and put a 700-R tranny behind it all. Changed rear end gearing to 3.38. WOW what a ride. It will break em' loose shifting into 3rd. Horses estimated at 375. When weather gets better here I will take it to town for a dyno run.

Man thats alot of work, who did the work you or a shop? 375HP not to bad, you plan to get her on a dyno to see what you get?

rkyle
12-28-2007, 07:20 PM
I had a local "spped shop" do the boring, decking and piston and crank assy. I assembled and installed all other upgrades. It was a lot of fun and am looking forward to doing another vette in the near future.

Grimbo
01-04-2008, 01:50 PM
my buddy has a program that you can use to punch in all the mods your going to do i.e. cam, heads, stroke, bore etc... and it does a pretty dang good job at giving you a HP TQ figures. i think its called like DYNO 2000 or something, really neat. i calculated what my build-up will be and it figures around 400hp and 430tq. :cheers:

Fly-n-C3
01-06-2008, 07:22 AM
Horsepower is made in the heads and camshaft profile. With a set of high flowing heads, your hp will increase. For a street driven car, i wouldn't go over 190cc intake runer size. Remember, the more air and fuel you can stuff into a cylinder, the more power you will make.

Personaly i like the ProTopline heads, or Pro Action heads vs Dart heads. The protopline and proaction heads will out flow a Dart head right out of the box. Also don't forget about Vortec heads. These heads out of the box will flow 170cc. With mild bowl work and a better valve job these will close to 180cc.

My set up has Vortec heads, TRUE flat top pistons (no dish at all) .488 lift with .292 dur on 112LS on a 2* advance. I'm putting out around 380hp with this set up. I could get to 400hp with a little more tweeking.

As for the Dyno programs, Yes they are close, but at the end when it pumps out your hp and Torque figures, you need to deduct around 8-10% for your results. This is 90% of the time be almost right on.

Good luck on your build-up.....:cheers:

Grimbo
01-23-2008, 07:47 PM
thats what my buddy said when he did the calculations and his BB, about 10% should be deducted off, but if i get somewhere in the ballpark i would be Very pleased :willy_nilly: