Crx HF motor rebuild question (pistons)
 

I am in the process of rebuilding a spare d15b6 (HF motor) and I have ran into an issue with one of the cylinders having a slightly larger ridge than the other 3 cylinders (which are within spec).

The problem is that the d15b6 no longer has oversized pistons available :cry:

The rods/crank is different than all other USDM d-series motors (smaller/lighter).

The next closest motor (besides an EDM motor) is the 92-95 Civic Cx, which used the same pistons in 92, but 93-95 used pistons identical to 88-91 Crx Dx. The Cx head cast is the same as the Crx HF but has a different rocker assembly and camshaft.


Anybody know if the Crx Dx pistons will work on the Crx HF motor without causing any issues? Any other suggestions?

as long as the pistons are the same bore size as the ones you want to use then go for it.

rocker assembly and camshaft design has nothing to do with the pistons.

a good example is my 1.2L motor and the next model up (the 1.3L motor) have different rocker assemblys (still both pushrod design though) and you can swap them around no problem.

just my 2c

Not necessarily. Depending on how much room there is for the valves, going with a larger cam profile might get you to the point where the pistons are smacking the valves. And there is the question of the piston crown height, or the distance from the wristpin hole to the piston top, rod length, and so on.

And I don't know how the answers in this case. It sounds likely that it will work, but I'd want to be sure before spending my own money.

Is there any way the OP can take one of his pistons to the parts place and compare it directly to one of the ones he is thinking of buying?

-soD

You may want to deck the block so the ridge is evened & good seating of the head onto the gasket. if ya got nuff $$ shot peen it ect,. my $0.002

I need pistons to!
 

Hey man I'm in the same boat as you. Rebuilding my 8 valve CRX HF 1.5l motor and the bore was bad so I also need pistons. Did you happen to find a resolution for this issue?
thanks for your time,
Craig

^x2

possible fix
 

Still haven't found an oversized piston for the 1.5L HF but I just mailed my block to a guy that will resleave it for pretty cheap.... I'll reply again with final costs and a part break down after it's all said and done.

thats cool.

when you get the engine broke in i want to know the mpg, acceleration and deacceleration responce before and after the engine overhual.