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AFR 185 Question

L

Lilalaric

Member
My 302 has 9:1 pistons and the aforementioned heads, will they work together without problem or will the pistons need work so the valves won't hit?

Any experiences to share, or cautions to look out for?

Thanks.
 
Hi, this may be apples & oranges, but. I am running the same cam: XE268H / #31-242-3. My rebuilt 289 has a 302 crank and AFR165 heads. MY compression is around 9.75 and no issues. When shopping for my head/cam combo I discussed. at length with Summit reps. They ran the numbers and said I would have clearance issues at 10.0. I hope this helps. BTW, although I'm still breaking in the motor, I'm very happy with the cam. It likes to rev!
 
Keep in mind the AFR-185 has 2.20 intake valve versus the 165 has 1.94 intake. If this is a street/strip motor you might be better off with AFR-165 heads. My understanding is the port velocity on lower displacement engines increases low / mid range power. The 185s are suited better for higher RPMs.

For what it's worth, I have a 331 with stock compression height pistons, stock valve reliefs, AFR-165 64 CC chambers, 0.039" head gasket, E303 cam with 1.7 rockers which yeilds .527" valve lift and no interference.
 
@stangg. That's precisely why I went with the 165's over the 185's. They work well on the street and I have no plans to race mine.
 
Even though everyone thinks you shouldn't have any problems, the valve/piston must be checked in the assembly process. There's a lot of variables. . .

Robert
 
"66benchcoupe" said:
Even though everyone thinks you shouldn't have any problems, the valve/piston must be checked in the assembly process. There's a lot of variables. . .

Robert
Click to expand...

I actually edited my own post before submitting it and inadvertantly deleted that point... I totally agree Piston to valve clearance needs to be checked. I used the clay method without the head gasket installed and had plenty... I don't remember how much though.
 
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