AFR 165 Heads & TFS Stage 2 cam on Stock Bottom end

[SEB]

Just curious if I will have PTV issues. I ran a test with the Hyd lifter in it & here is what I got. This is without the head Torqued all the way down, But also with no Headgasket either. Ran a Pushrod test & it came out to 6.125 which is the lowest the pushrod tool woud go down too. I am thinking about picking up a set of TFS 6.100 Pushrods.






But I read AFR 165s are a Inline head & its not the lift that is the problem. But more the duration. Does anyone know for sure if a AFR 165 Head will clear the stock pistons with a TFS Stage 2 cam

The test came out clear. But this whole Inline head info along with duration has me double checking before I bolt up my Lower intake

Here is a pic of of what I had left between the piston & Valves without the Head bolted down to 65lbs. Keep in mind this is with no head gasket, I had binding problems running a stock 6.250 pushrod. Hence going to the shorter 6.100 pushrods. It called for 6.125 on the checker. But figure I would be safe with the 6.100 since I cant find a 6.125 pushrod that is sold

[dumpycapri85]

SEB , I like to do the test with a solid lifter (modified hydraulic) . The un modded lifter could collapse and give a false reading . The gasket should be good for a little room but what was the reading on the micrometer ?

[91CoupeMike]

Pushrod length needs to be done properly to assure good valve train geometry. The roller tip should be centered on the valve stem; no exceptions.

That needs to be checked, with head gasket on ad torqued to proper sequence with a solid lifter. Everything needs to be done with a solid lifter.

[91CoupeMike]

Also easier to do with lighter springs, which is how I did mine.

I got it all on, piston at tdc and I used my finger to push the Valves down to visually see how much clearance I had. My cam isn't big so I wasn't worried with clearance. I was just dicking around with all my fancy tools and cam degree kit. Lol

[jyro]

1.6 rockers I hope. Rocker roller centered on stem at mid lift.
Pedistol mount rockers., you'll need a shim kit.

"Keep in mind this is with no head gasket, I had binding problems running a stock 6.250 pushrod. Hence going to the shorter 6.100 pushrods. "

Shorter pushrods won't change valve clearance. they just put more slack in the rocker on the base circle. you can't run that way.

[46Tbird]

It is the combination of both lift AND duration when the piston is at TDC that can create PTV clearance issues. There's not much chance the valve will hit anything even with 1.000" lift and 300* duration when the piston is three inches down in the hole.

You want to go from a 6.125 pushrod to a 6.100, but the head gasket is going to be .035 to .045 by itself - more than the .025 difference in pushrod length.

It's impossible to read your micrometer there, but I consider .100" PTV clearance to be a minimum and would be happy with double that. I'm talking about measuring with a solid lifter too, and also talking about measuring both the intake and exhaust valve clearances.

I don't have any experience with that particular cam/head setup, but my gut says it will work but it's going to be a little tight. The TFS Stage II is pretty big. I'd call both TFS and AFR to see what they say instead of a bunch of yahoos here.

[wickedblkgt]

Not sure about the TFS cam, but back in the day I ran the 165's with a B-cam, crane 1.6 rockers, with a stock bottom end. No problems!

[dumpycapri85]

Seb , you can borrow my 2 solid lifters and my tester springs to check it right if you want .