davesrex

Ok heres what i got....

I have an 89 crx si shell with an hf engine. But this is where it gets crazy, its a 90 or 91 hf block and head, si fuel rail, si inectors, si intake manifold and TB, si ecu chipped with a mugen pm7 chip(atleast thats what it appears to be when i open it up, it says mugen pm7 on this little chip about 1 1/2-2" long and 1/2" wide), si distributor, si harness, si axles, and a 4 speed dx tranny. Amazingly it runs somehow and has for a while with no problems but i want to upgrade.
I am looking at buying a d16z6 block,head, timing belt and cover, and the oil pan.
Is it possible to take the parts i would need to complete that d16 with my parts from the engine i have right now. can i wire this block with my harness, ecu, and other stuff as if it were just like a d16a6 block. And will my starter work with this as well as my alternator from my 89 si.

BlueCrxNC

The fact that you have a mix of HF and Si parts is not a problem. Just so you know.... HF and Si Distributors and fuel rails are the same, as well as 90-91 HF injectors (*88-89 are 192cc unlike most Honda injectors which are 240cc) Si Intake manifold and Throttlebody are much larger than the HF's which is a good thing.

Having that 4-speed DX transmission sucks but you can keep it with the new motor.

You cannot use the HF motor parts on the Z6 block or head. Your best route is to find a complete Z6/D15B VTEC motor or even longblock (motor, in. and ex. manifolds, distributor etc) One can be had from a local for $300-450 or you can buy one from an engine distributor like hmotorsonline.com for $495 (JDM D15B VTEC, similar to Z6) plus freight costs. I purchased mine many years ago for about $700 to my door.

Your starter doesn't mount to the motor, it mounts to the transmission... no issue. Alternators for all the D-series are the same as far as mounting... they may only differ in the amperage they put out and the belt pulleys differ (3 rib vs. 4 rib)

Lastly, do you wish to stick with OBD-0? You can convert to OBD-1 using an ECU such as the P28 or P08 which would give you easier tuning capabilities. If you want to stay OBD-0 you'll have to re-use your current Distributor and ECU.

davesrex

I do plan on running it on the pm6 ecu i have for the time being. I am short on cash so im trying to use as much stuff as i have on it so i don't have to buy all that other stuff. Can i use the harness i have or do i need to find a obd1 harness and combine them.

BlueCrxNC

If you're planning to reuse the PM6 (OBD-0) then you wont need anything OBD-1. You'll need to use the HF/Si Distributor (Distributor ALWAYS matches the ECU you use) which means only one or two bolts will hold it on. It will be functional though.

The other thing you will find is that you need to change the wires for the coolant fan switch. On your old motor you'll see a two prong sensor just above/beside the oil filter (May still have the large rubber cover hiding the connectors)... this was relocated in 1992+ to the thermostat housing and the switch connector type was changed as well. What you'll need to do is find a spare EACV/ECT/IAT Sensor plug (they're all the same) from a junkyard to use for the new style plug. The relocating of this switch requires extending the current two wires. Definitely solder your connections and cover with shrink wrap. If you really want to minimize wiring you may be able to just take the old switch off of the old motor and transplant it onto the new motor which will come with a bolt in the place to put it. In that case you'd just disregard the switch on the thermostat housing.

davesrex

I have my radiator fan on a switch for the time being so thats not a prob. I picked up the block yesterday and will start the swap this weekend. Is there anyhting else im gonna need to do. Are there any other things i should worry about.

davesrex

OK i finally got around to doing the swap this past weekend. I got it all done in about 18 hours of straight work just by myself. I basically had to strip my old engine and then i cleaned everything and put it all back together. It started after a couple times while playing with the dizzy. I couldn't be happier with the swap. Its a lot more power compared to the hf, now i just can't wait to hook up vtec. Thanks for the help.

BlueCrxNC

Cool. Enjoy!