cam selection

[Big88]

Now that the racing season is over for me, I'm thinking about a cam change. What i have now is 258 254 dur. @ 50. 110 intake ctr. line. 614 614 lift. 112 lobe seperation, Comp cam. The engine is 256 cu.in. all stage 2. Anyone out there have any suggestions? Or what they have found to work for them?

[turbolou]

Originally posted by Big88
Now that the racing season is over for me, I'm thinking about a cam change. What i have now is 258 254 dur. @ 50. 110 intake ctr. line. 614 614 lift. 112 lobe seperation, Comp cam. The engine is 256 cu.in. all stage 2. Anyone out there have any suggestions? Or what they have found to work for them?

The only thing I would change in your cam profile is maybe more lift if the rest of your combination is maxed out & you have nowhere else to look for more power. Like heads , intercooler & plumbing etc.

[John Wilde]

I agree with Lou. That cam is not that bad, but the lift seems low for a stage 2 head. I have seen Duttweiler Stage 2 cams in the 270 range at .50 with 700 plus lift. The cam was so big it almost hit the rods. What is your car's combination and how fast have you gone with it?

[TurboBob]

want to sell that cam?

Solid, hydraulic, solid roller...?

Bob

[Big88]

I should said the cam was 650 lift 614 was with 1.55 rockers I have 1.64 which would be 650 lift. The engine is 256 cu in. 4.00 bore 3.400 stroke, Pt. 88 turbo 160 injs. ATR headers 4 barrel intake conv. to FI. heads & intake are fully ported. Percision IC. 4 inch. down pipe built myself. 400 trans with brake. stock rear 33 spline moser axles with spool. Notched frame for MT. 10.50W tires. 3500 lbs. with driver. Best time of 9.37 at 149, 1.41 60ft. I think the car should be faster than that. The cam is a solid roler.

[John Wilde]

Your car sounds really cool! Do send me pictures!!!
The cam is not the problem keep it!
What is your compression?
How much timing and boost do you run?
What do your egts look like?
How are your valve springs?
If your PTE is the standard model you will be on the edge.
Is your converter any good?
The 60 foot is a little less than was your should be doing.
With a 10.5W even at your power level you should be in the 1.35 to 1.29 range

[Big88]

John Wilde:
I don't have any pics. My comp. is about 9.5. Boost at max is 30#.Timing 25-26*. No egts. Valve springs are new comp cams. 290-300# at the seat. Converter is a good one hand built by JPT. 5000 + stall. IC is a PTE standard 3 inch pipes. air inlet temps in the traps are 200* +. My tuning with the FAST could be better. I am using a weldon 2025 fuel pump. I have a duty cycle in the 55-65% range. Anything else just let me know.

[John Wilde]

Your inlet temps are too high!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
With a good liquid to air intercooler your temps should
be close to ambient. With a good air to air your temps
should still be in the 150 range max. The compression and boost your running should make a lot of hp. You may want to talk to Precision Turbo or another vendor about an upgrade.
A local racer went from 9.63 @ 145mph to 8.68 @ 158 with an intercooler upgrade and some additional tunning.

[Ted A.]

Did we meet at Milan Dragway back in Sept on the friday night street race?


I had my car there running slow that day.


Ted

[Big88]

Thanks John i got your email. I will talk to PTE. about an upgrade. When i get some pics. i will get them to you.

Ted we did meet there. I'm always there on friday night. Milan has a heads up pro tree race first fri. of the month. Last race 10/10/03 I qualified with a 14.83 but made it to the final round.