D15 block D16 head = what compression?

[turbo93impreza]

I have an 89 dx with the d15b2 and i'm considering swapping the heads from a d16y8 or z6 onto it and going vtec.
What compression will this bring?
higher or lower?

[91civicDXdude]

higher. depending on what head gasket and which head you use, you will most likely be in the high 9's or low 10s compression wise (9.8:1 or 10.2:1 etc.)

[d16a6crx]

here just use this.. you plug in different heads, blocks, pistons, etc and it will give you the compression yeilded

http://www.knology.net/~jediklc/D.htm

d15b7 with Z6 = 9.8:1
d15b7 with Y8 = 10.2:1

[turbo93impreza]

are there any heads, preforably vtec that will lower compression? or can i double the headgaskets up or something?

[d16a6crx]

Originally Posted by turbo93impreza

are there any heads, preforably vtec that will lower compression? or can i double the headgaskets up or something?

There aren't any VTEC heads that will lower compression, but if you use d16y8 pistons with a VTEC head, the compression would not be so high...

d15b7 block w/ Y8 VTEC head & Y8 Pistons = 9.0:1
" " " Z6 Pistons = 8.3:1

[turbo93impreza]

has anybody heard of doubleing up the head gaskets on hondas? (have heard of it elsewhere).

[d16a6crx]

Personally i havent heard of it, but even if you can do it, it won't lower compression much at all...

d15 w/ d16y8 head, double head gasket = 9.5:1

What kind of compression are you looking for?

[turbo93impreza]

low enough for a little turbo action, 9.5 is ok but 9 is better

[d16a6crx]

Originally Posted by turbo93impreza

low enough for a little turbo action, 9.5 is ok but 9 is better

like i said, d15b7 (should be close to d15b2) with y8 head and pistons yeilds 9.0:1 compression

[turbo93impreza]

unfortunatly i also dont have the means to swap pistons.

[KoRnSaQ]

Originally Posted by turbo93impreza

unfortunatly i also dont have the means to swap pistons.

you dont have the means to swap pistons, but you are goin to turbo it

[d16a6crx]

Originally Posted by KoRnSaQ

you dont have the means to swap pistons, but you are goin to turbo it

Yes, if youa are going to turbo it, you will need to swap in aftermarket pistons and rods if you plan on running anything more than 6-8psi for a period of time. Should be fine with 9.5:1 compression still with a turbo

[turbo93impreza]

what heads are on the 88-91 crx si? i found one of those motors and i could pull that head, but i would like to know the compression afterwards.

[d16a6crx]

they have a d16a6