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

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?

 

HF left ~ DX right

i dont see why they wont work but you might lose compression.

could you use a D15b2 block with HF internals?

 

Bummer. Can you ****** a nice CX bottom and put your HF head on it?
http://www.crxmpg.com/

 

Looks like I will have some measuring to do with the pistons.

 

And I currently have a z1 in my 91 Civic wagon.

 

What do you mean they no longer make pistons for our engines?

When I was rebuilding my D15B6 the problem I ran into is finding the right bearings. Every place that I went to told me they had the right ones, but literally every shop I went to ordered the Dx or Si bearings. And the rings I got from the machine shop were for the Si which are different from the HF.

So finally I just went back to the machine shop and he had like 10 machine parts books and we found the correct bearings and rings. he was very helpful. If you live near Olympia I would advise you to go there.

 

Or Arias can make them for you....

...for $160 a piece....

 

I still have my spare D15B6 in my shed. I put a tarp over it and filled the pistons with oil. When my current rebuilt engine finally bites the dust in 2045, maybe I will rebuild it.

 

Yeah my current HF has 350,000. The one I'm rebuilding will sit until the current one dies.


Honda no longer carries pistons for the HF motor. I've yet to find an aftermarket supplier. I still need to figure out the bearing issue (I'm aware they are a one of a kind (besides d13 edm motor))

Should be fun ;-)

 

I believe you when you say Honda no longer carries it. But why exactly to do you need new pistons? Has the block been bored out too much? So stock HF pistons would not seal properly?

 

I'll probably need to have it bored do to the top of the cylinder (the ridge) is out of spec. .15". So I am stuck at whether or not I should have it bored.

 

I know that on Ebay you can buy D15B6s for way cheap. Many Honda guys after they do the first swap on their HFs to something with more power, they just throw the D15b6 away.

 

yeah, thats how I got this d15b6 (from a local guy)