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Discussion Starter #1 (Edited)
Hi all, noob here, been lurking for a few weeks doing research.

I have a DOHC ZC (92-95 OBD1 "4th gen") which I'm preparing for a turbo build. The block seems to be in great shape with very little wear. Everything else looks good also so I think I have a good basis for my build.

These are the parts I'm planning to purchase very soon, the only thing I have any doubts about are the pistons. I've read a lot about this and it seems Supertech are fine for what I need. However, I contacted Supertech and they said....."you could use those pistons but they are not for turbo applications and MAY fit your engine" ..!!!

Anyway, here is my list, any constructive comments welcome.

Pistons
Honda CIVIC D16Z6 / A6 Add + 0.3:1 if used in a Y8 engine
Bore 75.50mm Oversize +0.5 Comp Ratio 10.5:1 Volume CCs -3 Head CCs 34.6 Comp Height 1.173 Stroke 3.543" Rod Length 5.394" Pin Diameter 19mm Weight 231g Piston P/N P4-HD755-N3 Ring P/N GNH7550

Eagle rods
ACL Race bearings
ARP head studs
Cometec Head Gasket (0.03")
GoAutoworks turbo kit
Larger injectors ??
PERHAPS a head shave but no more than .050"
Complete new gaskets everywhere.

Car is a '89 CRX, daily driver. Looking for around 250 - 300hp
 

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Discussion Starter #4
This is the DOHC ZC section so I would have thought with 70 views someone would have a comment. All I need is verification on the pistons, are they good, or what other options to go with.
 

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1991 Honda CRX
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The SOHC D16 pistons work in the DOHC ZC, what they meant to say was the 10.5:1 CR wouldn't work well in a SOHC turbo engine, but they probably don't know about the larger DOHC combustion chambers. With those piston specs you will be right under 9:1 CR which will be fine with no head milling necessary. Another option is the Raceengineering DOHC specific pistons. It looks like you are on the right path with your parts list and shouldn't have a problem making 300whp.
 

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Discussion Starter #6
Thanks for the reply and encouraging comments. I had considered the Race Eng. (and Wiseco) pistons but they are a little over budget IF the Supertech will be OK. If not, then I'll go with the higher priced option if I have to.

Also thinking I'll shave the head to get somewhere around 9.3 - 9.5 CR so it's more streetable "off boost".

Lastly, going to add a pair of JUN cam gears.

Going with Hondata s300 for tuning.
 

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91 CRX Si
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You're doing your homework, I like that.

The supertech pistons will work, I went with the raceeng wisecos. You'll want larger injectors and an upgraded fuel pump(255lph walbro will do). I don't see anything wrong with shaving the head slightly to increase CR. One thing I question is why Cometec Head Gasket?
 

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Discussion Starter #8
Why Cometec? From what I understand, being MLS it will handle boost pressure better. And ... I believe it is more accurate in thickness (I know when I torque the head I will have 0.03"), and easier to remove IF the head has to come off at any stage.

Is there something "better" ?

I know about larger injectors, just don't know what size ...yet.
Walbro pump is on the list of things to get.

Other engine pieces ... new distributor. The one on the engine was destroyed in shipping. All new vacuum lines, hoses,... etc.
Other things to go with this build will be a light flywheel, clutch, 1/2 radiator, new exhaust, Hondata s300, OBD0-OBD1 conversion (and DPFI to MPFI)
 

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1991 Honda CRX
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Why Cometec? From what I understand, being MLS it will handle boost pressure better. And ... I believe it is more accurate in thickness (I know when I torque the head I will have 0.03"), and easier to remove IF the head has to come off at any stage.

Is there something "better" ?

I know about larger injectors, just don't know what size ...yet.
Walbro pump is on the list of things to get.

Other engine pieces ... new distributor. The one on the engine was destroyed in shipping. All new vacuum lines, hoses,... etc.
Other things to go with this build will be a light flywheel, clutch, 1/2 radiator, new exhaust, Hondata s300, OBD0-OBD1 conversion (and DPFI to MPFI)
I personally prefer the MLS Cometic gaskets, but some will say the OEM gasket works fine.

Contact Hiprofile on here and he can hook you up with the injectors.

Doesn't hurt to bump compression up a little, but just don't go too crazy.
 

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I wasn't knocking Cometic, just curious why you chose it over OEM.

I had 440s then I got 800s from HiProfile, definitely recommend contacting him.

Looking forward to seeing your progress
 

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Discussion Starter #11
It's going to be a while before I start. Still scraping up money for parts. At least now I know I'm on the correct path. Thanks.
 
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