Which of these camshafts will rev higher and still performs up top in a built 383 LT1?

Dur @ 050 LSA lift
-----------------------------
234/242 112 0.539/0.558
242/248 113 0.584/0.579
248/254 110 0.562/0.580

 

What type of heads are u running? RPMs aint crap with out the breathing capability.....

 

Stock LT1 heads CNC ported by TPIS.

Flow #s:
.100 64/52
.200 135/105
.300 193/142
.400 232/165
.500 251/177
.600 251/188

 

If I were you I'd go with that 242/248 cam, especially if it is going to see street time.

 

I am running A TPIS stock ported LT1 head and mine flow 276 CFM at .600... what the hell????

 

The ones I have are from the first patches they did, almost 4-5 years. Maybe they improved their CNC program.

 

It is for race only, no street driving what so ever.

Does that have to do with wider LSA 113. My understanding that tighter LSA will mean more overlap and hence shifting power band up top. I want the engine to rev higher so that it doesn't drop the RPM much when it shifts. I want to shift at 6800RPM all time.

BTW, the first cam is GM847 if you havn't noticed and specs shows it going to 6800RPM. Specs of other two shows 6200RPM. Makes me think something is wrong. Larger duration+ tighter LSA should rev higher.

 

With ported heads and a gm847, you'll be shifting pretty close to 6800 to stay in the power band.

 

Why not 248/254 110 0.562/0.580, higher duration & lift and tighter LSA?

How do you compare it to GM847?

 

to make your car rev u really have to get into cam design..... I cant tell u to much without revealing secrets but u can have a 112, 113, 114 LSA with a wide duration and get good revs. i suggest a wide lob seperation with at least a 113 or more so u have that accelerated pushed in your seat feel. i think your car wont rev that well beacuse of the head flow you are getting which is realitive to powerband broadness. my car creates a 443 HP on a 350CI LT1 but my heads flow close to 300 CFM at .600 and my car flies thru the RPM's... I have to shut it down thou becasue i am on a stock bottom end car and my opti shuts off at about 7000 rpms... my tuner told me that he was afraid of pushing anyomre but that the damn thing would pull hard thru 7000rpm... do some reasearch first and call around i can tell u were to get a bad *** custom grind for your set up send me a PM.

 

I'd say. The LE1 heads I had flowed way better than that. If your going all out I'd have the heads refreshed and the porting updated. Your a little weak on the exhaust side and really weak on the intake side.

Re'

 

Tighter LSA = lower rpm power peak.

 

I thought it is the opposite.

 

Nope. It'll peak lower, but be peaky compared to one with a WIDE LSA.

 

Then, if the 248/254 110 0.562/0.580 camshaft was cut on 112 or 113 LSA how much more will it peak compared to 110 LSA??