pushrod length
Le Mans Master
Joined: Mar 2004
Posts: 7,493
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From: Little Rock AR
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
The quick and easy way to approach this is with the Lunati pushrod geometry checker and an adjustable pushrod.....https://www.summitracing.com/parts/m...+5ba26aeb79650
Then order the correct length from Trend or Trick Flow.....DO NOT use the $29.95 three piece pushrods with the ball tips fusion welded on. You want the $90 one piece units from Trend/Trick Flow.....do not touch Proform pushrods either, they should be sued for selling them.
I also do not recommend the 12-242-2.....I do not like XE cams for break in. I like this cam and it has been a staple for many years: https://www.summitracing.com/parts/cca-cl12-210-2
Is this a low compression 350? What are you driving?
Jebby
Last edited by Jebbysan; Oct 14, 2021 at 07:59 AM.
Pro
Joined: Jul 2021
Posts: 719
Likes: 156
224* intake duration WAY too much (OE ~ 30* Less) for a low compression (~ 8.2:1) '80 street L48;
throttle response in traffic will suffer and will be Worse than OE cam. Sluggish; Not Crisp.
In addition to a more reliable break-in, the High Energy cam profile suggested above will be much more satisfying in traffic.
This one ain't so shabby either: https://www.summitracing.com/parts/cca-12-208-3
these 3 as well:
https://www.summitracing.com/parts/sum-k1103
https://www.summitracing.com/parts/sum-1785
https://www.summitracing.com/parts/sum-1065 (compares to CL12-210-2 BUT even slower, gentler ramp, less intensity, even more reliable break-in)
OE '80 specs
https://www.gmheritagecenter.com/doc...t-Corvette.pdf
throttle response in traffic will suffer and will be Worse than OE cam. Sluggish; Not Crisp.
In addition to a more reliable break-in, the High Energy cam profile suggested above will be much more satisfying in traffic.
This one ain't so shabby either: https://www.summitracing.com/parts/cca-12-208-3
these 3 as well:
https://www.summitracing.com/parts/sum-k1103
https://www.summitracing.com/parts/sum-1785
https://www.summitracing.com/parts/sum-1065 (compares to CL12-210-2 BUT even slower, gentler ramp, less intensity, even more reliable break-in)
OE '80 specs
https://www.gmheritagecenter.com/doc...t-Corvette.pdf
Pro
Joined: Jul 2021
Posts: 719
Likes: 156
If yours has common, Thick, composite, head gaskets, you can swap to Thin steel shim gaskets; that'll raise compression about 1/2 point and improve throttle response & efficiency.
When you swap cam & lifters, you'll have intake off anyway; that's the "opportunity" to R&R heads & check them as well as swap head gaskets.
When you swap cam & lifters, you'll have intake off anyway; that's the "opportunity" to R&R heads & check them as well as swap head gaskets.
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Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
I disagree. You will not feel any difference in the "seat of your pants" going to all the trouble of a head gasket swap.
In fact you might introduce other issues later on if the block or head is not perfectly flat without flaws. And that is something a shim gasket will not seal.
Valve job, seals, new springs, mill the heads? Then yes. Otherwise its not worth the effort.
In fact you might introduce other issues later on if the block or head is not perfectly flat without flaws. And that is something a shim gasket will not seal.
Valve job, seals, new springs, mill the heads? Then yes. Otherwise its not worth the effort.
Last edited by HeadsU.P.; Oct 17, 2021 at 02:21 PM.
Thread Starter
Navigator
Joined: Jul 2020
Posts: 9
Likes: 2
From: Eastern Canada
Thanks for input. Now redoing cam plans. Is there somewhere I can find complete ORIGINAL cam specs ....50 lifts for intake and exh , Intake durations , valve lift ratios , lobe separation so I can do a comprison with aftermarket cams
Le Mans Master
Joined: Mar 2004
Posts: 7,493
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From: Little Rock AR
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
The factory cams don't compare at all to aftermarket cam specs. The GM lobes are VERY long, slow lift, and low lift. The numbers are published but trying to use them to pick out an aftermarket cam is a waste of time. Duration in particular is WAY different. Apples vs oranges.
The 262 Comp cam is a proven power maker for the low-compression L-48. That cam with headers, 2101 Peformer intake and a proper tune is worth over a second in the 1/4 mile......
Jebby
Tech Contributor
Joined: Aug 1999
Posts: 15,175
Likes: 3,986
From: Connecticut, USA
Not to mention the L-48 is .390/.410 lift, 196/202 duration @ .050 which is pathetic.....just about ANY aftermarket cam will make more power.
The 262 Comp cam is a proven power maker for the low-compression L-48. That cam with headers, 2101 Peformer intake and a proper tune is worth over a second in the 1/4 mile......
Jebby
The 262 Comp cam is a proven power maker for the low-compression L-48. That cam with headers, 2101 Peformer intake and a proper tune is worth over a second in the 1/4 mile......
Jebby
Le Mans Master
Joined: Jun 2019
Posts: 7,657
Likes: 2,470
From: Indiana
lars timing and l82 specs (vacuum advance) are pretty impressive desmogged.. even without headers to me
Last edited by interpon; Oct 21, 2021 at 10:05 PM.
Drifting
Joined: Oct 2020
Posts: 1,567
Likes: 576
From: Wisconsin
The L-82 cam seems to be sensitive to CR. GM Performance slapped a L-82 cam in the 8.0 CR crate engine I have. Sure, it will make 290 hp, but it’s pretty lazy getting there. The 1.94/1.5 heads aren’t helping either.
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Easy low 14 second car with grandma driving it.....
Jebby
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
I stick with the Magnum line of cams for street engines and sometimes the Howards pieces.......but for 4-speed L-48, I go with the 268H High Energy cam....it was specifically designed for low compression 350's in the 80's and it works well.....Comp sent a lot of kids to College on that one......best seller for years....still in the top 5.
Whatever you do.....use the Z/28 spring, lock, retainer kit from Elgin and umbrella type seals........this is a must do. They can be installed on the engine if you know what you are doing but better with the heads off.
Jebby