valve clearance opinions

Foxfan88

My Grandpa has great wood.
Sep 13, 2004
2,487
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Miami, Ok
ok i will be running patriot 185 heads, with the 2.02/1.6 valves, i will use a .051 thick HG to try and lower compression.

i also want to use an f-cam with 1.7 rockers, with this combo do you think the valves will clear enough to not cause any problems??

i will check for sure but i am just wanting to get an idea on here before i start buying parts. it it does hit i will have to get a 1.6 rocker it outa clear then. with the thicker HG i should be able to clear if it hits with the 1.7s
 
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ok i will be running patriot 185 heads, with the 2.02/1.6 valves, i will use a .051 thick HG to try and lower compression.

i also want to use an f-cam with 1.7 rockers, with this combo do you think the valves will clear enough to not cause any problems??

i will check for sure but i am just wanting to get an idea on here before i start buying parts. it it does hit i will have to get a 1.6 rocker it outa clear then. with the thicker HG i should be able to clear if it hits with the 1.7s

The Patriot 185 is a chinese made knock-off of the AFR 185. The AFR 185, just like any other 2.02 inline valve head, will almost certainly have valve interference with stock pistons. Don't fall into the trap of thinking that because you have a slightly thicker gasket that you're going to have enough clearance. Your .051" thick head gasket is only .010" thicker than a standard Fel-Pro Print-O-Seal head gasket.

The only 2.02" dia intake valved head that will not have clearance problems with stock pistons, unless you have a crazy cam profile, is the Trick Flow Twisted Wedge. Otherwise, a 1.90-ish intake valve is as large as you can go with stock pistons. Again, I wouldn't have any confidence that your .010 thicker head gaskets will clear. If you want to even attempt, you're going to need to clay the top of the piston.
 
Yeah, except it doesn't really change the problem of when there would be interference anyway.

Having a gasket that is .010" thicker than a standard gasket is kind of like artificially reducing valve lift, only in regards to how far the valve will pushed into the chamber.

But, the problem with piston to valve clearance on 2.02" intake heads, like in most situations, comes during valve overlap between exhaust and intake strokes. Your overlap won't change no matter what gasket you use.

If you are running stock pistons, go ahead and clay it and check. Typical recommended valve clearance is usually a minimum of .100.

I would, however, put my money on you have clearance problems. 2.02" dia. intake valves on inline valve type heads, such as yours, almost never work on stock pistons.
 
With my world product 2.02 heads, F cam, 1.6's and stock pistons it needed to be clearenced. Pretty sure the only 2.02 heads that will work without any notching is twisted wedges, with stock pistons of course. Your going to love your new found power :nice: .
 
Piston notching will probably be in order. And be carefull with the notcher, those things are so sharp, a couple cranks gets you quite a bit. At first sight it will look like you should put a cordless drill on it, don't let it be any more than a thought.
 
Piston notching will probably be in order. And be carefull with the notcher, those things are so sharp, a couple cranks gets you quite a bit. At first sight it will look like you should put a cordless drill on it, don't let it be any more than a thought.

sorry to bring this back up.... where can i find a piston notcher? i need to make bigger reliefs on the stockers.
 
I have cleared with the Holleys as well....

The 2.02 will clear in the center of a stock notch its the radial clearance and clearance at the outside of the eybrow that will get you. ISKY sells a notching toll you use in your exisiting head/valveguide, or you can make your own fixture and cutter like I did:)
 
I have cleared with the Holleys as well....

The 2.02 will clear in the center of a stock notch its the radial clearance and clearance at the outside of the eybrow that will get you. ISKY sells a notching toll you use in your exisiting head/valveguide, or you can make your own fixture and cutter like I did:)

right, my 1.94 valve is way too close to the inside edges of the eyebrow... and maybe pics/description of how you made yours? i have a dremel?lol
 
I actually cut up an old E7 head I had here at the shop, cut out the chamber to gain added clearance for the large valve and brazed my own cutting edges on some old valves. I use collars on the valves to control my depth and a beefy ass 1/2" drill to cut them, slow and steady.
 
Hey Foxfan, if it won't clear with 1.7's, it won't clear with 1.6's. The rocker ratio will make such little difference, I would not even use it as a variable.