advice on modding an L48
Thread Starter
Racer
Joined: Mar 2002
Posts: 287
Likes: 5
From: Northampton MA
advice on modding an L48
I just got my 77' I purchased in march for $1k driving great this week (new brakes, carpet, weatherstripping, ETC for a car parked for 7 years), now I want to park it again and mod the motor before school starts in september. I'd like to get as much HP as I can without replacing the bottom end of the motor to match too high RPM oriented parts in the top end. I was thinking Performer RPM or EPS, holley avenger 670 or 770, Trick flow SB chevy heads, comp 268/280 or 262/274 Xtreme energyw/roller rockers, and an accel HEI distributor. will this push my RPM band beyond that of the stock cast crank and rods?
Drifting
Joined: Nov 2000
Posts: 1,428
Likes: 0
Re: advice on modding an L48 (smonska)
Not if ya keep your foot off of the Gas.........See my Sig. to see what I have done. A milder cam than U want and still runnin' stock heads....I will be forwarding some G-Tech times to the Forum soon, as I just got my headers put on today.....ran abt 15 flat w/o 'em and car feels a lot stronger now that they are on.......... :cheers: :cheers: :cheers:
Drifting
Joined: Nov 2000
Posts: 1,361
Likes: 0
From: Honolulu Hawaii
Re: advice on modding an L48 (smonska)
The low compression dished pistoned L48 needs small chambered heads that bump up the comp ratio. Depending on the head gasket you use, comp ratios of 9.1-9.6 max are achievable. If you are going to limit yourself to comp ratios of this range, think about getting iron heads instead of aluminum. It is said iron heads make more power than equivalent aluminum ones. If you plan on doing total engine build up with better pistons, then aluminum heads become the better choice. My 2 cents.
Safety Car
Joined: Aug 2001
Posts: 3,685
Likes: 202
From: Waterford Mi
Re: advice on modding an L48 (nunus79)
Engine, trans, and rear gears have to work together to improve total performance. For what its worth, If I had to do it over again I might have chosen a different cam than what I bought. At the time I was told this one would be good cam for an L-48 from "the Crane Cams tech service. CF did an article about how to get 350hp from an L-48 and this is the cam they used. I am getting new heads this fall.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: advice on modding an L48 (smonska)
L98 induction, DPFI is the way to go for increased performance, depending on your electrical skills....the performance increase on my original L48 was ASTOUNDING, doubled the fuel economy, and that's with stock muncie and 336 gearset....doubled it....and the driveability was greatly improved, and the ultimate POWER was at least the same, but the torque curve was lovely...
I stuck with stock rams' horn dual exhaust, and put the O2 sensor in the heat riser valve flapper part....blocked the crossover....it runs like a charm...
GENE :D :D
I stuck with stock rams' horn dual exhaust, and put the O2 sensor in the heat riser valve flapper part....blocked the crossover....it runs like a charm...
GENE :D :D
