L48 upgrade advice
Thread Starter
Heel & Toe
Joined: Mar 2012
Posts: 17
Likes: 0
L48 upgrade advice
Hey guys, I have a 79 L48 that I've had for 10 years and ready to do some engine mods to this sorry excuse of an engine. I have a general idea of what i'd like to do but i'm not sure of the best road to take. The engine is bone stock aside of hedman long tube headers and true duals with flowmasters. I've done quite a bit of research on L48 ( used to work at gm garage and was able to get all original spec/build sheet for car) and I was leaning towards the gm performance vortec heads ( 64cc...1.94/1.50 valves with .475 lift) and edelbrock performer intake with spread bore to use existing qjet carb and leaning towards a lunati voodoo cam 10120702lk (262 adv dur and .468 lift dor 1400-5800 rpm. Its a 4 speed with 3.36 gears....which im considering 3.55 or lower if needed. Any guidance would be greatly appreciated. Btw....my choice of parts is based on a tight budget. Factory head spec 1.94/150 75.47 cc flat tappet cam .390/.410 adv dur 194-206 with lobe lift of .260-.273 amd 1.5 rocker ratio. Spec sheet is very detailed if more info is needed its probably in there
Le Mans Master
Joined: May 2007
Posts: 5,025
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From: North tonawanda NY
268h is a pretty good choice I had that cam but ended up finding a recently rebuilt block with flat tops and the 268h builds too much compression to use with 64cc iron Heads so I went with the voodoo 262 cam with the voodoo 262 which showed about 5 HP gains along with like 15lbs of torque with my combo on dyno 2000... it also had a wider power band with over 350lbs of torque and 150+ HP as low as 2000 rpm. It also builds power to 6000 rpm and drops off slower.
I have iron eagle heads for reference... keep in mind the voodoo and extreme energy 262 cams are bigger that the old school single pattern grinds lime the 268h. Also the voodoo series is the improved upon versions of the comp extreme energy life e which can be noisy and harder on the valve seats.
I have iron eagle heads for reference... keep in mind the voodoo and extreme energy 262 cams are bigger that the old school single pattern grinds lime the 268h. Also the voodoo series is the improved upon versions of the comp extreme energy life e which can be noisy and harder on the valve seats.
Last edited by augiedoggy; Aug 16, 2013 at 04:32 PM.
Pro
Joined: May 2008
Posts: 582
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I have had quite a few different set ups with my 79 Vette and at one time I had a Comp 268h with World Products S/R Toquer heads. It was never dynoed with that set up, but later I tried a small roller cam by erson that was slightly larger by 1 degree at .050 that killed power. It was dynoed with that cam and was just over 400 flbs of tq and 250 hp at the wheels. Later same engine but with Sportmen II heads and comp roller cam with 224 degrees at .050 made 420 flbs and 335 hp at the wheels. Now AFR heads but have not finished getting it together yet.
Thread Starter
Heel & Toe
Joined: Mar 2012
Posts: 17
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Ok....so voodoo is out?. I want mostly low end. This is a cruiser and rpms are rarely past 4500. This thing is a dog off the line. I also considered roller rockers too. Would comps 268h get me the low end im looking for with other components listed?
Last edited by 79vettecrazy; Aug 16, 2013 at 12:55 PM.
Le Mans Master
Joined: Feb 1999
Posts: 8,351
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From: Tampa Bay FL
Le Mans Master
Joined: May 2007
Posts: 5,025
Likes: 1,120
From: North tonawanda NY
I did not say the voodoo is out! In fact its a better choice . The voodoo line is the closest you can get to a roller cam without actually converting to a roller... they use newer advancements to squeeze extra power that the older cams like the 268h leave on the table (the comp 268h is a very old cam designed by the same guy who later created the voodoo line for lunati.... plus a dual pattern cam usually makes up more for the weaker exhaust flow that's common with SBC heads. The voodoo slightly outperformed the. 268h as well as all the crane and other common old school grinds like the summit cams. This was of course in software but still.
I would go with a voodoo 262..... wait I did
PS If you want to buy a slightly used 268h cam I have one for sale :-)
remember to use a good oil such as a high zinc oil and use the correct springs for your cam choice.
This of course is if you plan on keeping your gears and converter....it will give you the most power for below 6,000rpm.
I would go with a voodoo 262..... wait I did
PS If you want to buy a slightly used 268h cam I have one for sale :-)
remember to use a good oil such as a high zinc oil and use the correct springs for your cam choice.
This of course is if you plan on keeping your gears and converter....it will give you the most power for below 6,000rpm.
Last edited by augiedoggy; Aug 16, 2013 at 04:25 PM.
Thread Starter
Heel & Toe
Joined: Mar 2012
Posts: 17
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Ok sorry i misread it. Good cause i was really wanting to go with the voodoo cam. Thanks for comp offer....ill keep that in mind. Did the voodoo give a more noticeable idle? You know how much hp you gain?
Last edited by 79vettecrazy; Aug 16, 2013 at 04:30 PM.
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Team Owner
Joined: Jul 1999
Posts: 65,492
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From: Orange Park Florida
I had a dead stock L48 in my '72.....I went DPFI, L98 style with a speed density computer....~1227730, had an appropriate chip burnt, and it ran like a charm for about 3 years......FAR superior to any carb setup, and the MPG got 24 on the highway, crusing 80 mph on I95 clocking neear 4 grand it was a 336 muncie car...so no overdrive.....but back then ethanol was not in gasoline.....
Le Mans Master
Joined: May 2007
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From: North tonawanda NY
I researched cams for months comparing...
Le Mans Master
Joined: May 2007
Posts: 5,025
Likes: 1,120
From: North tonawanda NY
$2 grand can buy you a 383.....
Le Mans Master
Joined: Mar 2008
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From: Oxford MA-----You just lost the game!!!!
Unless I'm mistaken there's a lot more involved in installing a blower like cutting the hood up and building/ setting the engine It to handle it.... plus it doesn't really help make the car ant more fun for everyday stop and go driving does it?
$2 grand can buy you a 383.....
$2 grand can buy you a 383.....
Scott
Le Mans Master
Joined: May 2007
Posts: 5,025
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From: North tonawanda NY
I don't know a lot about how a blower works I'll admit.
Last edited by augiedoggy; Aug 18, 2013 at 10:47 AM.
Burning Brakes
Joined: Apr 2007
Posts: 1,039
Likes: 62
From: Kona Hawaii
Go with a 64cc or 58cc heads to boost the CR.A hyd roller cam will give you that much needed low end torque with your gearing.My L48 is pretty quick with those upgrades.Cam is a Crane hyd roller 119821,SS roller rockers top off the valve train.Check out the lobes on the roller cam..
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Thread Starter
Heel & Toe
Joined: Mar 2012
Posts: 17
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Some of the roller cams seem to have a higher rpm range than what i'll be driving in.....is that common for roller cams? GM performance shows roller that is a stock replacement for the ZZ3 and ZZ4.....duration 208/221 with .474/.510 lift.....lobe centerline 112. The vortec heads im considering say the max lift is .475. What would i have to do to make that cam work...and what is an affordable lifter to match?
Racer
Joined: Apr 2013
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http://www.carcraft.com/techarticles...t/viewall.html
Read that as it helped me alot!
I also got the voodoo 262 cam and cant wait to put it in. I also went ahead and am ordering these heads
http://www.summitracing.com/parts/dr...make/chevrolet
Good luck with your build! Ill let you know how my turns out as I will get it tuned and dynoed when it gets installed.
Read that as it helped me alot!
I also got the voodoo 262 cam and cant wait to put it in. I also went ahead and am ordering these heads
http://www.summitracing.com/parts/dr...make/chevrolet
Good luck with your build! Ill let you know how my turns out as I will get it tuned and dynoed when it gets installed.