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tanjulio

Rules regarding DOHC ZC.

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tanjulio

Hello everyone that reads this post.

I have a DOHC ZC engine with original ZC transmission in a 1990 Civic Hatch (yes, I know ZC trans is slower than Si trans).

I read 2014 rules and I only found very limited information regarding ZC.

There appears to be NO distinction between SOHC ZC & DOHC ZC.

But

then there regarding "10.3 H2 Limited Preparation Vehicle Engine Preparation section a"

 

" ...JDM SOHC ZC may not use pistons from a JDM DOHC ZC engine and a head from a D16Y8 because this involves putting parts together from 2 different engines."

 

Does this mean that Honda Challenge considers the DOHC ZC & SOHC ZC the same engine?

Otherwise section would have said "... from 3 different engines."

So, If I am reading it correctly, by default I am in H2 'Limited prep Vehicle '

 

Anyway I can remain in H4 with DOHC ZC as an "JDM si" ?

 

thanks in advance.

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ILIKETODRIVE

I can't answer your question but...ZC gearing is better than Si gearing. Use the Si 4.25 final drive with the ZC gearing and it's miles better.

(Or use an aftermarket 4.7 )

 

Si__ vs __ZC

3.25____3.25

1.894___1.944

1.259___1.346

.937____1.033

.771____.878

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AZELISE

In the list of H2 engines in the 2014 rules it has "cam(s)" with the list for mods. That seems to imply that it applies to engines with one or two cams. And since the DOHC ZC doesn't come stock with VTEC, it makes about the same power as a SOHC and most D16's. Plus, there are some D16's that have DOHC (D16A1 for example). My guess would be that it is included in the same category.

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ILIKETODRIVE
In the list of H2 engines in the 2014 rules it has "cam(s)" with the list for mods. That seems to imply that it applies to engines with one or two cams. And since the DOHC ZC doesn't come stock with VTEC, it makes about the same power as a SOHC and most D16's. Plus, there are some D16's that have DOHC (D16A1 for example). My guess would be that it is included in the same category.

I just remembered that someone did a write-up about swapping a DOHC head onto a SOHC block: http://www.thezcr.com/forums/showthread.php?t=14474&highlight=DOHC+zc+head+d16a6

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tanjulio

So, nobody know for sure.

Does anyone here run a DOHC ZC or SOHC ZC to give some feedback

I can see the SOHC ZC making the case for H4, but not the DOHC ZC ...

 

This makes me want to ditch this engine and get a SOHC ZC or D16A6...

 

Perhaps someone knows someone with a built D16A6 engine.

Thanks.

 

Thanks.

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AZELISE

Are you asking if you can remain in H4 with your engine?

 

Please post exactly what engine code you have and what specific chassis you have it in plus what class you want to run in. Then we might be able to help.

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Karl

no motor swaps are allowed in H4

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tanjulio

Okay,

I guess i'll be classified in H2 ; might as well do some allowed parts swap.

 

Thanks for those who replied.

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Jeremy C.

ZC engine is definitely a H2 motor. Not permitted in H4.

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LoBuk 517

I ran both ZC engines in my CRX in H2. There is not nearly as much support for the DOHC as there is for the SOHC. I was able to get some good power out of it with a set of Gude cams in it. At the time I didn't have enough resources to develop the engine to the point I needed to so I gave up and went with the SOHC.

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tanjulio

Thanks everyone for the input on rules.

I Especially appreciated LoBuk517's feedback. .

 

I think I'm going to work on the DOHC ZC because of the great compression it has. I am not sure how much I'd have to spend to have similar hp from a SOHC... I haven't gotten my quotes from 2 shops.

 

Cheers.

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ELO168

I went with the D16Z6.

Unlimted cam. You can build close to 160Hp and with 2000 lbs for Crx it will be a rocket.

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ILIKETODRIVE
I went with the D16Z6.

Unlimted cam. You can build close to 160Hp and with 2000 lbs for Crx it will be a rocket.

This is true.

 

Also, you have ZC gears. Add a 4.7 and it'll fly lol.

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ELO168

I have the 4.7 with Mfactory Lsd.

Have not touch the tranny yet.

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LoBuk 517

On my car I was running the CG transmission from the 86-89 Integra with an MFactory diff in it. The only issue with the CG transmission is that there are no final drive options available. Being that I was running 13" wheels with a 205/60 tire the gearing worked quite well for me so I didn't put much thought into changing the ratio. When I switched to the single cam I continued using the CG, it took a little creativity to get everything to work but it was a great setup. I would have liked to have continued with the single. A nice big lumpy cam also makes that car go.

 

I still have a D16a6 head with a really aggressive Gude cam in it that I'm looking to offload.

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ILIKETODRIVE
I have the 4.7 with Mfactory Lsd.

Have not touch the tranny yet.

Sorry. That ZC gears bit was meant for tanjulio lol.

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tanjulio

I am located in California...

LoBuk517....Not sure if your head is rebuilt or just slightly used... either way it won't work for my dohc block...

 

Plus my engine's stock 130 hp isn't bad. compression is even 190-192 on all cylinders!

I bought the DOHC engine and Transmission from a JDM CRX front clip with 68k kilometers.

it has the pin so it's NOT an LSD transmission,,,

I believe the stock final on a CRX ZC DOHC was 3.88 and the early LSD's are better for drag racing.

 

ILIKETODRIVE or anyone that knows....

Which type of LSD should I get for a road course? I know there are 2 types of LSD's but don't know name for the type of 'road course racing'.

 

Note: a few years ago, I bought a rebuilt L3 si transmission from "Aquafina" who is in Tennessee. I moved to Asia and it literally collected dust. I just took it out of the crate it came; Not a joke.

 

Thanks.

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ELO168

For road race I suggest the clutch type. Mfactory have served me pretty good so far.

1.5 way only not the 2 way one.

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tanjulio

I saw this link,

http://www.teammfactory.com/final-drive-gears_Honda

I only see one option for 88-91 Civic 'cable' transmission it's listed as '4.9'.

 

A: Is this the correct one ?

B: can anyone chime in suggest a site or place to buy ?

 

Thanks.

 

Sergio

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ILIKETODRIVE

Aquafina is a legit rebuilder of D stuff.

 

The 3.88FD from the ZC gearbox is terrible. 1-5 gears are not.

 

A 4.9FD *might* be a little ridiculous with ZC gearing. It would be better with the Si 1-5 gearing.

 

If you have never driven a car with an LSD a nice option might be (don't laugh) an OBX LSD. It's dirt cheap and easy as F to install and shim and drive in a D-powered car. I should know, I had one.

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ELO168

Yeah that is the link, sorry mine is 4.9 not 4.7

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Jeremy C.

4.9FD or 4.7FD will work with SI gearing, but not with ZC gearing. Use the stock SI FD with the ZC gears as a cheap alternative for H2.

 

If Mfactory or Cusco make a 1 way diff for the D series, that is what I would get.

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tanjulio

One follow up question...

Are there many standing starts or rolling starts for Honda Challenge races?

 

I looked at the transmission ratios from here.

http://www.zealautowerks.com/transcalc.php

 

I would assume IF there are rolling starts I think the ZC DOHC transmission wouldn't be so bad as the 3rd, 4th and 5th gears are comparable to an Si transmission.

but

IF there are standing starts then, DOHC ZC transmission wouldn't provide the same level of acceleration.

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tanjulio

Plz delete this post.

Edited by Guest

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ILIKETODRIVE

Are you comparing Si 1-5 gears with a 4.7 or 4.9 vs ZC 1-5 gears with the 4.25?

 

...because ZC gears are HANDS DOWN better. I've had both in the same car. It's like GSR 1-4 with a B16 5th vs LS 1-4 with a GSR 5th.

 

What I did at one point was swap around stuff.

 

Si 1-2, ZC 3-4, Si 5th (closer 2-3 shift, 5th doesn't run out so quickly; this with a MFactory 4.5 or 4.7 would work)

ZC 1-4, Si 5th (basically a GSR trans for a D-Series; this with that 4.5 FD or 4.7 would be great too)

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