i was looking at heads and one guy on ebay has it listed as 1.90" intake is for stock pistons and 2.02" intake is for aftermarket pistons is this true cause all i know is im getting a freshly rebuilt 306 from a guy with forged pistons will i be okay with afr 165 edelbrok or twisted wedge. can somone explain this stuff do know much in this area. also could somone explain the different pistons to me like flat top and dished what comes in a stock 302 thanks alot.
do you have to have special pistons to have 2.02"
- Thread starter murphmaster5
- Start date
Using 2.02 valves with stock pistons requires flycutting of the pistons for clearance. I believe the exception is TFS heads, as they have the valves positined in such a way that they will clear stock pistons, depending on the cam size. Most aftermarket pistons have larger valve reliefs for use with bigger valves I believe. Make sure that you check piston to valve clearance regardless of what heads you go with
Yes, you either need to flycut(notch) the pistons or go with aftermarket pistons that already have the reliefs. TFS heads cant the valves so they dont contact, but that is up to a certain lift and duration. If you call Trickflow they'll let you know what your limits are with that. Also know that not all aftermarket pistons with reliefs will work with TFS heads because the angle of the valve is different. If your getting new pistons, make sure you tell them what heads you are going with.
pb_paulie_b
Founding Member
I had a buddy who bolted on a set of performer RPM heads without fly cutting the stock pistons. His car used to run with them until it got hot and shut off
. After that he threw on a forged 347 kit to match the heads
.
. After that he threw on a forged 347 kit to match the heads .
pb_paulie_b
Founding Member
I'm with you. He swore they were the 1.90's. They got beat to death by the pistons. HBH had them repaired and ported for $800. My buddy learned an expensive leason...PBSmockDoiley said:
Michael Yount
Mustang Master
There is not a one-size-fits-all answer to the original poster's question. 2.02" intake valves may clear a stock piston depending on the cam that's used. 1.90" intake valves in an AFR165 head may interfere with the stock piston depending on which cam is used. In any event -- the identical parts may offer enough clearance in one engine, but not another.
You must measure your particular set up to determine if you have adequate p to v clearance -- what happens with someone else's engine even with identical parts isn't predictive of what's gonna happen with someone else's combo. If you have insufficient clearance (.080"-.100" intake; .100"-.125" exhaust for most hydraulic roller street motors) you can have the valve notches altered to provide the additional clearance needed.
You must measure your particular set up to determine if you have adequate p to v clearance -- what happens with someone else's engine even with identical parts isn't predictive of what's gonna happen with someone else's combo. If you have insufficient clearance (.080"-.100" intake; .100"-.125" exhaust for most hydraulic roller street motors) you can have the valve notches altered to provide the additional clearance needed.
pb_paulie_b
Founding Member
Michael Yount
Mustang Master
The B has 224 @ .050"; the E 220 @ .050" -- however, the .006" duration is even closer -- 282 for the E; 284 for the B -- meaning the E has even lazier ramps than the B. Also the B's LSA is 112 and the E's is 110. If you look at the .050" valve timing on the cams -- the overlap on both is identical -- 0 degrees overlap at .050". Many folks look at overlap as one factor in boost compatibility -- the cams are identical in that respect.
In any event, if you're gonna invest the money for boost, you'd be wise to invest a bit more and get one of the custom cam designers to help you. No sense in guessing at an off the shelf cam when you can actually model the outcome and have a cam designed for your needs. And the specs aren't likely to be close to either of those (very old) offerings from FRPP.
In any event, if you're gonna invest the money for boost, you'd be wise to invest a bit more and get one of the custom cam designers to help you. No sense in guessing at an off the shelf cam when you can actually model the outcome and have a cam designed for your needs. And the specs aren't likely to be close to either of those (very old) offerings from FRPP.
ChuckFoxLx
New Member
hey guys im almost in the same case.
just bought afr 185cc head with 2.02intake valve and 0.600 lift with 59cc chamber
im using a f303 cam
6.25 pushrod
stock piston
do my valve will kiss my piston ? do im better to shim ? or buy some dish piston ?
i cant check ptv cose i dont have the head ..im waiting them.
and i want to drop my compression ratio a little cose im gonna install a 89mm vortech v1 s trim
what to do im kinda new in this world
thanks in advance
just bought afr 185cc head with 2.02intake valve and 0.600 lift with 59cc chamber
im using a f303 cam
6.25 pushrod
stock piston
do my valve will kiss my piston ? do im better to shim ? or buy some dish piston ?
i cant check ptv cose i dont have the head ..im waiting them.
and i want to drop my compression ratio a little cose im gonna install a 89mm vortech v1 s trim
what to do im kinda new in this world
thanks in advance
Foxslider
im not that much of a idiot
What was the word? ^^^^^
From what ive read, a 2.02 intake wont clear a stock piston with an b,e,f cam.
How much material is there. Ill just notch them myself?
From what ive read, a 2.02 intake wont clear a stock piston with an b,e,f cam.
How much material is there. Ill just notch them myself?
HemiRick
I'd be looking at jacking under the house
the stock notches need to enlarged 2mm I've done it w a carbide cutter on a hand grinder
Foxslider
im not that much of a idiot
Ok, cool. Ill look for a youtube video of it.
Im sure id be able to see it after i playdohed it.
Im sure id be able to see it after i playdohed it.
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