i spoke to jeff taylor today and he told me to get the c/r i want i should deck my head 40 thou but before i do that i need to no what will be the maximum lift i will be able to have with the h89 head on an a15 i have to know this before i go order a cam because if i order a cam and my valves hit my pistons i will say OOPS!!! shoulda checkd that out first soo if u guys could help me out that would be great cheers jacob

piston to valve clearance at max lift is not where you get piston to valve interferance. it is at valve overlap, the longer duration and how quick the valve opens. also advancing the cam also can effect piston to valve clearance. most street cams there is little chance of clearance problems but should always be checked during assembly. larger valves also can play into clearance issues. my cam specs are .508 lift and 292 degrees and advanced 4 degrees at install with 40mm valves. yes I had clearance issues.

The main thing is what the car is used for determine the cam grind. My last cam 300 degrees and .460 lift I had no clearance issues safe value is 040" clearance that needs to be checked durring assembly.

A street cam with around 420" lift you should not have any clearance issues with a decked head, but still needs to be checked

Cleance issues are usually taken care of by eye browing the pistons

Are all these "valve inteferences" and cam duration and lift done on stock pistons??...Or is it flat top pistons?

Shouldn't you order the cam first, so the cam grinder can give you all the details (like lift and clearance), then give that information to the piston builder?

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no im using the standard pistons and decking the head 40 thou to get about 10:0:1 comp much cheaper than getting new pistons. i was told flat tops in an a15 would make the comp too high to about 11:0:1 comp witch is too high because i want to be able to have it on the street not using methanol just premium

Oww...this gonna lead me to another question....if flat top pistons were to be used on a stock head, is it necessary to use methanol or some high grade fuel?

Is the regular fuel ( octane - 92 ) so bad that it will cause knocking?...

How do u check valve to piston clearance??? also i noticed small nicks taken out of the block for wat i pressume was valve to block clearence last time i had my engine apart. would they need to be ground deeper if the head was decked??