Well I'm done with my rebuilt D16A6 block complete with all new Honda bearings and brand new P29 pistons, rings, wrist pins, etc.

I had a fully worked over D16A6 head but unfortunately the valveseats are all ruined. the headwork was free and looked great, but the guy got bored one day and decided to polish up the bowls and he must have knicked all of the seats because the machine shop has told me that they all need replacing.

So here's my question for you all:

If you were me would you:

1. Pay $160.00 labor plus parts and replace all of the seats on the D16A6 head and run an Exospeed street/strip cam.

2. Take a free D16Z6 head, intake manifold, and dizzy and make it work.

These are my choices. I know that the A6 head milled .020 off would have gotten roughly 11.5-11.8:1 CR and the Z6 head will be around 12.3:1 so CR is not my concern really.

In terms of power which do you guys think would make more power?

In terms of money (which I have not a lot of) I think the VTEC head might cost more in the end because of the need to get some sort of VTEC activation and an AFC for fuel tuning along with an FPR because I will not have a ghetto-VTEC motor in my car.

What would you guys do?

*If* I choose the VTEC head I have a few Qs:

Can I use the A6 dizzy, or rewire the Z6 one to work with my pre-OBD engine harness?

I was going to use a Place Racing VTEC controller ($90.00 new from a co-worker) and the D16A6 ECU and then add fuel with the FPR and trim away the fat parts with the AFC. Sounds okay, right?

The AFC is like $280.00+$90.00 for the VTEC activator so that's $370.00 just to run the VTEC motor plus about $150.00 to have it tuned.

I had already planned on an AFc for the non-VTEC head anyways and tuning, so really the $90.00 is the only extra forseeable money I'd have to spit out for the VTEC head unless you all know something I'm missing here.

Thoughts?

 

u can fit a Si dizzy into a Z6 heaad with some work.... heres the ghetto rig i had to do in order to make it fit...
i would go VTEC head.... once u get vtec u going to love it.... pulls harder, u can rev higher with that head.... and u got more tuneablity with it.. u can get crower cam into it and make more power.... a VAFC its ur best bet.. ebay has them for $275... and in the long run will be better....

 

Tom,

I am running a Z6 head with a D16A6 bottom end. To run vtec, I found a Fields SFC-Vtec controller online used for $55 with a chopped harness. I just rewired it. The great thing about it is that it is also a fuel controller too. You can add or take out up %30 of fuel. Its adjustable at every 1000rpms. I also bought a air/fuel ratio gauge as well, but I need to get on a dyno to tune it. I'm also running the PM6 Si ECU.

I also used the A6 dizzy. I just had to hack the ears a little bit and you can only run two bolts instead of the three. Its all worked fine for the past year and a half.

You may already know, but if you go with the vtec head, then don't forget to remove the oil jet in the block. If you leave it in there, vtec willn't activate.

Let me know if you have any questions.

Also, I have a A6 Civic Si complete head minus the distributor that you could have for free. The head has about 130,000 miles on it. The story with it though is that the timing belt broke on it, but it happened at idle. When I removed it, everything looked ok on it, the valves didn't look bent or broken. But the head has been sitting on my front porch for the past year and a half. My porch is covered though. Let me know if you want it.

 

mini me high compression as long as you get it tuned right you will be very happy with the set up. also you should look into a Y8 intake manifold

 

I think if you go for the A6 head with the Exospeed cam, you'll be more impressed. Ive gone through 3 different setups on 3 different motors. All being d16a6 motors. I did the d16z head setup about a year ago. While it did make some decent power, i was not as impressed with my setup against my friends d16a6 with i,h,e, cam..

The d16z head was slightly milled also. Tuning it was even more stressfull. If you go with the d16a distributor, it just doesnt sit right. your timing options will be limited. I was running a Fields Vtec controller and i was able to bump the fuel up a little bit, but it still wasnt right. The fuel mapping on the stock p28 ecu is the best you can do.

I sold the head to a friend of mine who wanted to see if he could get it running right. He got new valves and the head was machined and cleaned. We fully converted to 0bd-1 (p28 ecu, z6 distrib, injectors) It ran much smoother than my setup, but the power was lacking.. after a little tuning, it was pretty quick. but it proved no match for my setup (d16a6 w/ webcam, i,h,e and some headwork) Ive never been happier, it runs strong from 4300 - 7500.. my friend once said "hey man you got Vtec?!"

 

Okay well maybe I wasn't clear enough, so my bad.

I have the Z6 dizzy - can it be used with the pre-OBD engine harness?

See the worked A6 head is garbage - it's ruined. Replacing valveseats is bullshit.

It's either a STOCK A6 head with a good cam, or a stock Z6 head with *possibly* a good cam as well.

See either way I was going to get an AFC for tuning, so here's another question:

Can I use the V-AFC to activate the VTEC or do I need either a P28 with jumper harness or some sort of RPM switch in addition to an Si 88-91 ECU?

Am I making any sense?

See if the Z6 dizzy works with no cutting but some rewiring then that's cool with me.

So basically it's Z6 vs. A6 head stock for stock or cam vs. cam.

 

i'd go with the stock A6 head with a good cam. i cringe everytime i see the mini-me dist. setup.

fyi, i don't really know much from a performance standpoint.

also, just the little i read/know of you, you will be happier with the A6 head and not the z6 ghetto style vtec.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by breaka_1_9 &raquo;</TD></TR><TR><TD CLASS="quote">i'd go with the stock A6 head with a good cam. i cringe everytime i see the mini-me dist. setup.

fyi, i don't really know much from a performance standpoint.

also, just the little i read/know of you, you will be happier with the A6 head and not the z6 ghetto style vtec.
</TD></TR></TABLE>

Well the thing is that I have the correct dizzy too, but nobody has confirmed whether it will work without converting the entire thing over to a 1992-1995 OBD1-spec engine harness.

As far as ghettofied VTEC, I meant I'm not running a toggle switch or anything.

I'm thinking that the Z6 head with a good cam would have to be better because for one the CR will already be higher and the Z6 head is better overall, correct?

If I ran VTEC via the Place rpm activated VTEC controller and then used an AFC and had it tuned with an FPR to get the fuel right I'm *thinking* that it *should* lay down much more power.

I've seen bone stock D16Z6 motors with only i/h/e laying down 123whp. Add to that 12.3:1ish CR and a better cam and what do you think would happen?

In order for me to properly guage this though, what kinds of whp do guys see with stock A6 heads, P29 pistons, and a good cam once tuned?

I'm really wanting 130-140whp once mine's done - thoughts?

 

What motor are P29's out of? BTW just throw a wicked cam in a6 head, and be done. That head is meant to be on that block.

 

if u buy an obd0-obd1 converter than u can run the z6 dizzy, with obd1 injectors, and the z6 manifold too,u will also need to run a 4 wire o2 sensor.

and oh yeah u gotta repin the dizzy to match up with the stock harness

forgot to say, that if u do decide to run the z6 dizzy, u will need an obd1 ecu also

 

i think that exospeed is probably better qualified to answer this but.......I *think* that 130-140 whp is acheivable w/ a good cam(w/valvetrain for obvious reasons) + the p29's & some p&p work. the apex'i safc is what i am planning on using to tune the air/fuel maps on mine- this is the setup that I am going for- I'm just waiting on parts. I say stay obdo non vtec w/ the stock a6 head. just my .02---and i'm pretty sure that you would't be able to use the obd1 dizzy w/o converting to obd1

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Ef ***** &raquo;</TD></TR><TR><TD CLASS="quote">What motor are P29's out of? BTW just throw a wicked cam in a6 head, and be done. That head is meant to be on that block.</TD></TR></TABLE>

teh p29's are from the 87-89 teg (d16a1 motor) 89 is preferable due to the piston config if I remember correctly

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dj_sandoz &raquo;</TD></TR><TR><TD CLASS="quote">

teh p29's are from the 87-89 teg (d16a1 motor) 89 is preferable due to the piston config if I remember correctly</TD></TR></TABLE>

88-89 USDM Integra and JDM ZC motor.

Has a +7.2cc dome as opposed to the -3.xx dish on the stock A6 slugs.

 

not to confuse you more...but:

did you ever consider
D16Y7 non vtec head...34.6cc (same as Z6) combustion chambers, and the 1mm bigger valve like the z6.
D16Y5 non vtec head...32.6cc (same as Y8) and 1mm bigger valves

i am not sure how the head are performance wise...ive always heard that the Z6 is better than the Y8, but i dont know about the Y5 and Y7. i dont know if the Y7 is similar to the Z6 and the Y5 is the same casting as the Y8 (just by looking at the chamber volume).

i know that probably doesnt help much...but i figured it was worth mentioning, ive never heard anything mentioned about the Y5 before. its got 115hp stock and the Y7 is 106. plus i dont know about cams...you can always call http://www.deltacamshaft.com since they are nonvtec. i got my A6 cam from them.

heres my setup https://honda-tech.com/zerothread?id=461235 , i dont know how it is power wise as its still in the garage waiting for summer.

 

I've heard that the 1996-up heads do not flow as well because of emissions - this was a comparison of a Z6 vs. Y8 on D Series.org.

I'm guessing that the same could be said for the non-VTEC versions as well, but I could be wrong.

The D16Z6 head is FREE and I do have one more free D16A6 head at my disposal too.

Has anyone ever dynoed both heads to compare them?

I would think that a cammed Z6 head with 12.3ish CR would be absolutely bad-***.

The guy who would be tuning it tuned my B18C5 as well. He got 20+whp and ft-lbs. in the midrange on my B18C5 from simple FPR and V-AFC tuning.

 

go stock a6 head w/ cam. non vtec cams "spool" faster than vtec ones anyway. plus you can get some seriouse ***** out of non vtec engines.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C5-EH2 &raquo;</TD></TR><TR><TD CLASS="quote">I've heard that the 1996-up heads do not flow as well because of emissions - this was a comparison of a Z6 vs. Y8 on D Series.org.

I'm guessing that the same could be said for the non-VTEC versions as well, but I could be wrong.</TD></TR></TABLE>

You're correct - the Y8 head is the worst flowing head of all D-series motors. I'm not too sure about all of the other 96+ heads - though it wouldn't surprize me if they were the same as the Y8...

I'd recommend using the Z6 head over the A6, simply because of VTEC. You can completely upgrade the A6 valvetrain and get excellent results - but you can the same thing to the Z6 head, and get slightly better results. The Z6 get's my vote, simply because it has a little more potential.

 

Hey Tom,

Check out post https://honda-tech.com/zerothread?id=481582

I dynoed my mini-me A6 bottom end with Z6 head. Just a little info for ya

 

id rather have the a6 head, ported and polished with a nice cam. something 270+ duration or around there.

with the a1 pistons, the valve reliefs match the valve locations of the non vtec heads, not vtec heads (their valve arrangment is different). if you started playin with huge cams and/or milling or thin gaskets, theres a possibibility for contact.

sure people have done it just fine but if gonna be taking my sohc to 8100rpm (with the pistons, big cam, etc) id like to know my valve reliefs are in the right spot.

edit: for your info, you can reach the 130 mark with a stock bottom end. wil did it.

i also think its gonna depend on your cam choice. i believe in ***** out cams for sohc. i think youd like a milled/PnP'd/270+ duration cam/valve spring equipped head more then a vtec head with a really really mild cam such as the zex.

hell if your gonna go a1 pistons thats big compression with the vtec head. a larger cam like would help with your dynamic compression ratio. something like the crower stage 3 vtec.


Modified by JaeOne3345 at 12:06 AM 4/21/2003

 

Just do a fully obd-1 convert. Instead of using ghetoo afc or some kind of fpr. That way u can run a vtec computer and z6 dist along with the z6 head. If you want a good strip/street cam get a zex cam. Running one in my turbo 1.6 sohc vtec motor and its a good cam so far

 

All of thids is great but I need this thing to be my daily drover too. I don't want a really lumpy cam or anything like that.

The more I think about it and seeing how broke I am, a stock A6 head seems to be a good choice right now.

I don't have the funds to get a nice cam and/or P&P another A6 head, and even the electronics to run the free Z6 head will set me too far back.

I'll probably just pop on a stock A6 head for now and slowly build up the funds for the VTEC head or a nicer A6 head with a nice cam.

 

wil has a 268 cam that idls just fine. you want big compression obviously with the a1 pistons. bigger cam is gonna help with dynamic compression which can then help against detonation.


Modified by JaeOne3345 at 8:04 AM 4/21/2003

 

I'd just go with the Non-VTEC setup, sell the free z6 head and buy some more goodies for the new motor... or stuff the cash in your pcket and make the project even less cheaper!