alright...it seems as though some people on h-t have been saying this isn't possible...

i'm the one who wrote this article...and a friend of mine did this setup exactly...and made 112whp, 109 tq. the dx head works, i'm almost positive the ex/si head doesn't work.

link: http://hondaswap.com/articles/viewer.php?id=52

Creating an HF All-Motor Monster


Overview:

This is dedicated to everyone driving around in an 88-91 CRX HF getting 50 miles to the gallon. Honda’s little 8-valve motor is great for fuel economy, but as you HF drivers will attest lacks the power to chirp the tires when driving spiritedly. For those wanting a very inexpensive solution, keep reading. For fewer than 500 dollars you can transform your CRX HF into an all-motor beast that’s capable of running high 14’s.



The Setup:

For starters, you’ll want to find a DX head off of any Honda motor. Newer heads are better for the obvious reasons and they can be found everywhere. Look to spend no more than 50 dollars on a clean DX head. Next, search the local junkyards for a 4th Generation Si intake manifold. This should cost around 25 dollars, although friends with Honda’s will probably have a few lying around so this could be had for even less. Ideally you’ll want a CRX Si Distributor, CRX Si Ecu and CRX Si transmission for the setup, along with a timing belt the same year as the head. For example, if it’s a 95 DX head, you’ll want a 95 DX timing belt. Other belts will probably work, but its guaranteed to work if you use this setup, although you can match parts numbers to make sure everything is to OEM specs.

What Makes the Power:

Well, if you’ll remember the HF motor has an 8-valve head, which is great for fuel economy and miserable for performance. The 16-valve head will raise compression substantially creating a surprisingly powerful hybrid. Now, what kind of numbers can you expect from this setup? A friend of mine recently used a similar setup and put down 112, 109 to the wheels. With this type of power, look to be pulling on GSR’s, Civic Si’s and even the occasional unsuspecting Type R owner.



Conclusion:

Remember, this setup should cost no more than 500, and if you have a CRX Si parts car sitting around this should cost no more than 150. Using Si parts will yield the best parts but if you’re trying to keep a budget a DX transmission/ECU will work if their readily available. And the best part, when you blow up this motor you’ll have saved enough money to buy a ZC, D16Z or even B16A.

 

LOL!!! That's great!!

 

Guess what, its an 8 valve piston. 16 valves. you do you math. no valve reliefs Pulling on a 200hp R/GSR, I doubt that. You cant use the DX ECU cause its DPFI, not MPFI.

Blaze

 

with his setup, the si ecu was used, si intake manifold, si distributor, si transmission...

hf bottom end, 97 dx head...

the valves do clear the pistons...and he made 112, 109. do you think i could make something like this up?

and yes, in a 1900lb car 112whp will bring you high 14's. obviously thats not faster than a type R under most conditions, but GSR's did fall to the little rex on several occasions...

 

Bump that, jus grab a d16a6 for 300 and call it a day.

 

the point is the hf bottom end with dx head makes higher compression...

i don't know of any Si motors that make 110whp in near stock form...

 

chet, has your friend ever measured the compression after the swap?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chet &raquo;</TD></TR><TR><TD CLASS="quote">the point is the hf bottom end with dx head makes higher compression...

i don't know of any Si motors that make 110whp in near stock form...

</TD></TR></TABLE>
True but its jus IMO I'd rather jus drop the d16a6 rather than go through swapping heads. And for $500 I'd go for a ZC. Course the project could be done for cheaper. But I do give props on a very different project and would like to know how well it really performs.

 

as far as measuring compression...he didn't...basically he just looked at a newer dx head (all 92+ probably flow equally as well) and assumed it would make better power compared to the 8valve hf head which is designed solely for economy. then, he just bolted it on...saw that there was clearance between the pistons and valves and went from there. i think this swap is great if you have a lower mileage or clean running HF...and have an older si swap laying around that doesn't have great compression due to shot rings. my guess is compression is in the mid 11's...

and he went high 14's all day in a 1900lb shell...which isn't too bad considering i've seen some b16a swaps run low 15's in 5th gen's.

 

wow ....14s suck..

whats the point really/?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by hybridvteceg &raquo;</TD></TR><TR><TD CLASS="quote">wow ....14s suck..

whats the point really/?</TD></TR></TABLE>

the point is for 400-500 dollars, you can have a setup that is both fun and unique...and occasionally surprise people with it.

ie civic si's, gsr's, nissan spec v's, etc...all run low 15's at best in near stock trim...