1965mustangman

Just got stock bottom end 302 roller motor with forged pistons. It has a e303 cam and twisted wedge heads already. Since the motor is out i wanted to build it while its out. Its going into a car with a c4 auto and a 2500 stall. I've heard how the tfs cams are alot better than the e303 and have heard that the tfs cams will idle better with the auto trans. I would really like to get the tfs stage 2 with a victor jr intake (carbed by the way). Will the performance be alot better than the stage 1. The reason i ask is with the stage 1 i shouldn't have to get the pistons notched. As with the stage 2 im pretty sure i will. Has anyone used the isky notching tool or should i leave that to a machine shop. thanx for any info.

jtmustang

yes u will have to get the factory pistons notched if u choose to run the stage 2 with the trickflow heads well they say atleats your fine up to a .540 of lift and the stage 2 is .542/.563 as i have the stage 2 in my 306 with the trickflow heads but i bought new probe pistons with the valve reliefs for the tw's and when i mocked up my stuff i had quite a bit of room more than enough.

u could also if u were dead set on the stage 1 is throw some 1.7 rockers on there to up the lift/duration/rpm range a little

here is a sound clip of my 9.5306 with a trickflow (crane cams) stage 2 and twisted wedges plus full boltons

FLcracker9

I don't think you'll like the TFS 2 with that stall. What gears are you running?. The only way you can be sure if the cam will work is if you check PTV clearance, but this can be expensive if you buy the cam and it doesn't work. My custom cam is .569 lift on the intake, .564 on the exhaust, and I run Twisted wedge heads on a stock block and pistons. It all depends on how the cam is degreed?.

mjr46

with the stage 2 you may wanna up the stall

tinman

IMHO, with the stage 2 you really need a 3000 converter......

jtmustang

yeah i was gonna say the same in my first post ,if u are lookin at a decently aggressive cam and the car is more of a play toy u will probably up the stall to get it in the rpm's better

5spd GT

Peak lift has NOTHING to do with piston to valve clearance issues.

You can use a simple thought process for this one...

Say you have a 3" stroke (302), which is 3 inches of travel from top dead center to bottom dead center. If the camshaft opens up half an inch (.500") at peak lift, why would they do this when the piston is anywhere even close to the top part of the travel?

There is a weak pressure differential at this point and novolume for air to displace.

At peak lift, the vast majority of the aftermarket camshafts we deal with are well past two inches down the bore at peak lift.

Good Luck!

Joel5.0

The lift specification from the TFS heads is not a PtV allowance based on lift spec...... it's the capacity of the valve springs installed on the heads based on coil bind. A higher lift cam will require valve springs that could handle the added lift, aside what the cam requires in terms of pressure rate to control those valves.

jtmustang

.....i know , but i was just saying that trickflow says u cant run over a 540 lift without hitting the pistons. i know there are ways to fudge it , but i was just repeating what trickflow techs told me over the phone.[8D]

Joel5.0

..... you could theoretically have .850" total valve lift and the valves will not hit the piston.... when max valve lift occurs the piston is >1.95" down the hole. By the same token, you could have a .450" total lift cam that will cause the valves and piston to get intimate. It is NOT the total valve lift spec that causes PtV. Maybe the following piston vs valves position graph would help you understand.......