Compression question

[TRDemon]

I have a 4A-F engine, what is that highest compression you all think the stock internals can stand.

Remember the standard 4A-F engine compression is 9.5:1.

[Kwanza]

compression doesn't really put extra stress on the internals, at least not enough to make one worry. The older bigport 4AG internals are nearly identical to the 4AF internals (40mm versions), and people have run some pretty high comp pistons and such in them. What you should worry about is making use of increased compression (more agressive camshafts, better induction, etc), and fueling.

[Flashmn]

If I dont go turbo, I think I might get 11.5:1 pistons for my 4A-F.... if I dont boost, I'll make the mofo scream for mercy

[TRDemon]

can the stock carb push enough fuel to use those 11.5:1 pistons flashmn

[TRDemon]

have anymore tried planning the head before?

[Flashmn]

can the stock carb push enough fuel to use those 11.5:1 pistons flashmn

Most likely... but then again, I dont have the stock carb remember.

have anymore tried planning the head before?

Yes mines shaved I think about 1mm or 1.5mm

[TRDemon]

after shaved did you feel a difference in perforamance

[Flashmn]

not really.... The power you get from it is so small... maybe takes revs easier, but thats about it.

[Pineapple]

You don't need more fuel to go higher compression. In fact you may need less cause cylinder volume decrease with the crowned piston. Make sure you got new head gasket, metal one if possible and torque the head bolts correctly.

[Flashmn]

pineapple, yeah, thats what happens when you shave the head, your stock settings are gonna be rich, mines hella rich now .... I get like 15mpg

[TRDemon]

thanks guys