I just sold my D16A6 to a friend of mine. It's pretty beat but the head has less than 5 months of use on it. My question is: Is it possible to put the Si head on the HF block and still have it function properly? The Si ECU runs the Hf with no problems as of right now.

 

If the valve clearances are good it should be fine. But the SI head has 16v and the HF has 8, so the HF pistons have 2 valve reliefs rather than 4 like the SI. I dont know if it will work though. Maybe if you get the pistons machined it will work out. But I have read that it does work, and that it dont. But I am not 100% sure.

 

Won't work. The HF pistons don't have the correct valve reliefs. Replace the pistons and it would be OK.

Sorry,

Charles

Administrator Honda D Series
http://pub34.ezboard.com/bhondadseries

 

why bother replacing pistons in that crappy HF engine? its cheaper just to swap the whole longblock in...

 

you can find the pistons from and si or dx on thepartstrader cheap. Like 30 for the set of rods and pistons. Thats all you would need. Maybe the crank is different too though, not sure.