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gm crate engine : its here . . . possible cam swap help needed

I was running a roller cam at 204/214 .429/.452 112* LSA on my previous engine (350, ~9.4:1 compression, Vortec heads, headers, TPI) and having swapped from that motor, directly to the L31 crate, same headers, induction, etc., there was no seat of the pants difference. Dyno is the only way I would have seen it, if there was a difference.
 
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You probably don’t have enough cylinder head and intake to fully utilize that. The aluminum head GM crate engines use cam 10185071
 
As I mentioned about press-in rocker studs, it only takes about 50 ft. Lbs. of torque to start pulling those press-in studs out. 50 Ft. Lbs. of torque starts to happen at about .480" of lift. The cam you are interested in exceeds that. Also, if you are going to run an OBD-I/ECM The dual pattern of the cam you like might drive the ECM crazy.

If you look for a cam that is under the .480" thresh-hold, and in a more single pattern (meaning INT. and EXH. having the same amount of duration and lift) with an LSA of 112 or more you would be good. Just my opinion though from my own dealings with OBD-I/ECM GM-Goodwrench crate engines. Comp Cams has the Computer Control series of cams that have the single pattern lift/duration and 112 or higher LSA's that are made to play nice with the old OBD-I/ECM's
 
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1-ton said:
As I mentioned about press-in rocker studs, it only takes about 50 ft. Lbs. of torque to start pulling those press-in studs out. 50 Ft. Lbs. of torque starts to happen at about .480" of lift. The cam you are interested in exceeds that. Also, if you are going to run an OBD-I/ECM The dual pattern of the cam you like might drive the ECM crazy.

If you look for a cam that is under the .480" thresh-hold, and in a more single pattern (meaning INT. and EXH. having the same amount of duration and lift) with an LSA of 112 or more you would be good. Just my opinion though from my own dealings with OBD-I/ECM GM-Goodwrench crate engines. Comp Cams has the Computer Control series of cams that have the single pattern lift/duration and 112 or higher LSA's that are made to play nice with the old OBD-I/ECM's
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doing holley snipper efi on edelbrock intake .
 
sweetk30 said:
doing holley snipper efi on edelbrock intake .
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The tunability of the Holley ECM solves any problems that an OBD-I/ECM would give you. I would like to do the same with my truck, but then there is the issue of controlling my 4L80E trans. That would cost a bundle to have both a Holley ECM, and a stand-alone ECM for my 4L80E.
 
sweetk30 said:
still thinking maybe a cam swap . . .

i can get this one for less than retail but not much more than the gm cam .

any feedback on if this is to big for stock swap out with no mods required ? https://www.summitracing.com/parts/cca-07-502-8
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That might be a little bit too much duration for a truck but I think the 07-501-8 would be perfect. You will probably have retainer to guide clearance issues though. Vortec heads are usually only good to about .470" lift, some won't even clear .450" so make sure and check clearances. The springs will be marginal as well.
 
I still say run it as is, and see if you like it. If you *really* think you need more cam after running the engine, then go through the hassle of doing it in the truck. But having no idea what your baseline is isn't going to give you any idea whether the cam was needed, or not. Realistically if there was zero penalty, who WOULDN'T opt for more power? Normally however, we know what we have, then seek to improve on that. Just me...and I know my thought processes are not everyone elses.

Did I miss it, or was it not explicitly covered...is this a carbed engine, TBI, or....?
 
dyeager535 said:
I still say run it as is, and see if you like it. If you *really* think you need more cam after running the engine, then go through the hassle of doing it in the truck. But having no idea what your baseline is isn't going to give you any idea whether the cam was needed, or not. Realistically if there was zero penalty, who WOULDN'T opt for more power? Normally however, we know what we have, then seek to improve on that. Just me...and I know my thought processes are not everyone elses.

Did I miss it, or was it not explicitly covered...is this a carbed engine, TBI, or....?
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He just mentioned it a few posts back.
TBI holley sniper to be exact
 
bigblock72 said:
That might be a little bit too much duration for a truck but I think the 07-501-8 would be perfect. You will probably have retainer to guide clearance issues though. Vortec heads are usually only good to about .470" lift, some won't even clear .450" so make sure and check clearances. The springs will be marginal as well.
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this is why I stopped at a .458" lift cam on my 1991 caprice police roller 350 (L05 block) with 1996 Tahoe heads. didn't want to mess with machine work and I'm very pleased with this cam... makes me question my decision on the 8.1L but will see eventually...

the cam I have is the comp cams xtreme 4x4 cam
Xtreme 4x4 Retro-Fit Hydraulic Roller Camshaft
Chevy Small Block 262-400ci 1955-98
Lift: .458"/.458"
Duration: 258°/262°
Lobe Separation Angle: 111°
RPM Range: 1000-5000


https://www.jegs.com/i/COMP-Cams/249/12-409-8/10002/-1


ive got msd rev limiter set to 5200rpms and I can burry my 5k tach and make it stick (factory one with gas gauge from c60 dump truck)... truck will spin my ground hawgs with ease..
 
1-ton said:
The tunability of the Holley ECM solves any problems that an OBD-I/ECM would give you. I would like to do the same with my truck, but then there is the issue of controlling my 4L80E trans. That would cost a bundle to have both a Holley ECM, and a stand-alone ECM for my 4L80E.
Click to expand...
www.usshift.com and mrk5 has both with bugs worked out .
 
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