Is there a 12 or 8 valve head that will fit a D16?

We may earn a small commission from affiliate links and paid advertisements. Terms

J

jpoenitsch

Member
Hey guys. I have a 1990 CRX that I use as an enduro car. I used it all last season and it dominated so this year they changed the rules. NO 16 valve engines are allowed so im screwed. I have alot of $$ invested in the roll cage, etc.



The car was a DPI converted to a MPI.

PUT THE 8 valve head on the 16 valve engine.


ONLY THING IS IT ONLY SEEMS TO go to 5000 rpms and then she bogs out.
8 valve Hf's happen red line at 5000 rpms, but I thought that was a computer controlled thing??

Only thing I can think of is maybe my dizzy went bad last year after a bad accident?? See post below for more info.

Any ideas? Is 5000 rpms all i am going to get??



Thanks! :D
 
Get one out of a 90 or 91 CRX HF. They are 12 valve and MPFI. I'm pretty sure it would fit on your block including intake/exaust bolts, vacuum lines and electronics. You could probably get one at a junk yard for under $100. I'd have it rebuilt and get the ports opened up. The HF is a fuel economy car so it has alot of air restrictions.
 
:werd:

valve job, port and polish, and get the head milled down to increase compression...
should be as fast as the 16 valve :)
 
Originally posted by timEspeed@Mar 22 2005, 08:44 AM
Get one out of a 90 or 91 CRX HF. They are 12 valve and MPFI. I'm pretty sure it would fit on your block including intake/exaust bolts, vacuum lines and electronics. You could probably get one at a junk yard for under $100. I'd have it rebuilt and get the ports opened up. The HF is a fuel economy car so it has alot of air restrictions.
[post=477027]Quoted post[/post]​
Click to expand...

arent the HF heads 8 valve? i know my 89 was
 
Originally posted by ryan89crx+Mar 23 2005, 12:29 AM-->
ryan89crx @ Mar 23 2005 said:
timEspeed
Click to expand...
ryan89crx @ Mar 23 2005 said:
@Mar 22 2005, 08:44 AM
Get one out of a 90 or 91 CRX HF. They are 12 valve and MPFI. I'm pretty sure it would fit on your block including intake/exaust bolts, vacuum lines and electronics. You could probably get one at a junk yard for under $100. I'd have it rebuilt and get the ports opened up. The HF is a fuel economy car so it has alot of air restrictions.
[post=477027]Quoted post[/post]​
Click to expand...

arent the HF heads 8 valve? i know my 89 was
[post=477428]Quoted post[/post]​
Click to expand...

yes, HF is 8 valve
 
Thanks guys, I bought a whole HF engine for $150 today :D so I am going to try to put it on my D16 block cause I want to get as many horses as I can obviously. I plan on having it ported and polished and milled. I will probably use all of my SI intake and exhaust and all of the sensors.


ONE QUESTION....
CAN I USE THE DIZZY from my SI?? I would think it would be ok unless it doesn't fit or something.

Thanks for all of the help!!!!
 
you might consider the HF pistons as well as they only have 2 valve reliefs as opposed to 4 on the 16 valve...

and 150 for an HF? damn, sounds like you let them know you were eager to get the motor.
lol

definately READ THIS ARTICLE...

talks about putting a 16 valve head on an HF motor... but very important information...
the 16 valve head on the HF increased compression, so i think the HF head is gonna drop compression like a motherfucker...
might need it milled if you can clear the piston/valve slamming issue...

https://hondaswap.com/forums/index.php?showtopic=29791
 
Originally posted by reckedracing@Mar 24 2005, 05:52 PM
and 150 for an HF? damn, sounds like you let them know you were eager to get the motor.
[post=478247]Quoted post[/post]​
Click to expand...


:werd:

I literally threw one in the dumpster when I moved out of Dallas.
 
lol, i love dropping blocks in dumpsters...

i wish i could see the look on their faces when they empty it into the truck...


*clunk* what was that?? :blink:
 
PUT THE 8 VALVE head on the 16 VALVE block. Runs great, but got one PROBLEM............

It seems to bog down at 5,000 RPM's, kinda like its a RED line, which it actually is on an 8 valve engine.




Is there a way to get more than 5,000 rpms out of this head???
ANY IDEAS???



I am going to make sure my dizzy is working properly first since the car was involved in a bad accident at the end of last season and I know those dizzys are fragile.


THANKS FOR ANY HELP, I APPRECIATE IT!!! :)
 
Swapped the dizzy out, still only goes to 5000 rpms and then the engine BOGS DOWN, like its not getting enough fuel or spark??? Car seems to run fine otherwise and I do not think this problem is related to the 8 valve swap, I think it might be from the accident, the car had the same problem but I thought it was maybe a spark issue since my dizzy cap got busted. Anyways....

Swapped out the dizzy and computer, no change, swapped out the TPS, no change. Computer only throws the code for the intake intake air tempt sensor, which doesn't get hooked up.

I am thinking it might be a fuel issue?? Maybe the injector resistor went bad in the crash??? Or maybe the fuel pump cant keep up at the higher rmps????

Im scratching my head here. :blink: I drove another 8 valve today and yea, red line is at 5000 rpms, but you can go all the way to 6500 no problem. My car goes to 5000 rpms and thats it, it feels like im pulling something at 5100 rpms...... something is not working right...

ANY IDEAS??? Things I should check that im not thinking of???

Thanks!
 
your IAT could have soething to do with it, it is one of the factors that your ECU looks at for fuel delivery

plug it in and try it, it def wont hurt anything
 
Thanks for the tip, Tried the IAT sensor, didn't change anything. That was unhooked all last season and it ran fine. Also I swapped out the injector resistor and that didn't change anything. Still bogs down at 5000 rpms like the engine is under a load.

Looking at swapping out a fuel pump next, I am thinking it might not be giving anough pressure to the injectors at the higher rpms?

Everything else has been swapped pretty much. Double checked the wiring and that was all fine. I went through the whole harness, fun fun.


Any other ideas are appreciated. :)
 
I wonder if its something with the cam not being able to keep up.
 
That was my initial thought, until i drove an 8 valve HF around yesterday and found that it had more top end, you could take it to over 6000 easily. :angry:

I think the problem is from the accident last year because the 16 valve did have a similar problem. After the crash it ran to about 5000 rpms, and then it stuttered and surged to about 6000 rpms. As the race went on it began to surge less and stutter more. Eventually it felt like I was driving on three cyclinders and it had no power above 5000 rpms. I thought it was becuase one of my plug wires was bad and my cap got cracked, but obviously its something else. :huh:


Thanks though, :)
 
You must log in or register to reply here.
Back
Top