MASSIVE D18Y8 Head Onto D15B7/8 Block MiniMe Swap Writeup!!!

[Dasfinc]

Originally Posted by 24TEN Hmmm you didn't have any extra coolant lines? Yes I did, Lol, found out the hardway I think: *Attached from another thread of mine* I found one of the problems, The DX manifold has an Extra line coming off of it opposed to my CX Block Here's a CX Manifold: Here's a DX Manifold: To the left of where hose 6 attaches to the intake manifold, There is an extra line coming out of the intake manifold on the DX manifold This may not answer my prayers for the coolant in the oil unless I managed to attach a Coolant line to a vac line somehow, but I don't see how I could have done that unless that extra line on the DX manifold is Vac, and not Coolant.

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[Dasfinc]

Originally Posted by de la sol 951

which crank pulley is that?????? oem or aftermarket? you'll be fine with a light weight pulley,you will lose a lil valuable torque,gain a lil hp.might want to think about what im doing is putting 2 and 2 together lighten the crank pulley,and the same on th otherside-the flywheel!take weight off both sides and try to even it out! and for me to make up the torque i have a jrsc awaiting


good job!

the Crank Pulley is a Megan Racing one, but I brought it to my machine shop to have them check the quality of it, and machine off the AC and PS Pulleys so it was completely bare, just a Alt pulley.

I have a D16Z6 Tranny waiting for me to be picked up, I will be placing a Stage 2 clutch and a lighter flywheel when this is installed as I also have a small 13G Turbo in the mail to me right now.

Thanks for the props!

[Dasfinc]

Please check the pictures of my motor bay "My Sit back and take a drink" picture, I already have a header, 'high flow' cat and a N1 Style exhaust. CX's stock header has the Cat mounted infront of the block up top.

[24TEN]

That's exactly what I was wondering about. I was like "He didn't have any extra lines? Am I trippin?" LOL I capped the extra line, it doesn't really do much anyway. Unfortunately, I have a bad head so I have to undo everything now. Compression readings were 0, 60, 190, and 205 (in order).

[Dasfinc]

You must not have read the extra line I included in my buildup "HIGHLY RECOMMEND NEW HEAD" Lol Too many scammers on Honda-tech

[24TEN]

I actually had started on Z6 head first. Machined the mating surface and lapped the valves. When I was ready to swap it, I noticed two broken bolts. Instead of having them extracted and rethreaded if needed I ended up getting a second head, a Y8. Had it machined but didn't bother with the valves. It's my own fault really. I'll figure out what happened when I disassemle the whole thing (AGAIN) over the long weekend.

[Ron454321]

Here is the write-up I made for wiring the O2 into the 92 hatch, this is done right into the shock tower connectors, would've been easier to use an ex/si harness but the one I had was cut up pretty bad.

http://www.honda-tech.com/zerothread?id=2098796

[Dasfinc]

I did the same thing, couldn't get ahold of a EX/SI Harness, I bought one, but it was a lie *$35, too good to be true* and just hacked it up for the connectors and wiring.

[93.2]

so any idea why the headgasket blew? i got a guy on sohchonda.com that says you can't use a 8 valve bottom end with a y8 head how long did it run before it blew the headgasket?

[Dasfinc]

Originally Posted by 93.2

so any idea why the headgasket blew? i got a guy on sohchonda.com that says you can't use a 8 valve bottom end with a y8 head how long did it run before it blew the headgasket?

There has been alot of Controversy on this swap, You CAN use an 8 valve block with a Y8 or Z6 head, but you have to check that it has 4 valve pistons *As sometime in 93 they changed the pistons from having 4 valve reliefs to only 2 Mine was a 92, so my block and pistons are identical in every way shape and form to a D15B7*

If you have a D15B8 with 2 valve pistons, you'd destroy your valves instantly.

but onto the headgasket, the reason why I blew the headgasket was for a number of reasons.

It only ran for maybe 5 min, and it wasn't running well at all because I had an Automatic Intake manifold and tried running the car with no IAC *Problem 1*, Also, I was using an Egay Headgasket because it came in a set I had purchased *Problem 2*, and Lastly I am using ARP head studs, and My GF's dad Torqued it down for me *Skilled mechanic, but my Haynes manual says 47ft-lb for the B8 block, and he believes he only torqued them to that, while ARP studs on a Y8 need 60-65ft-lb (Torque wrench we had wasn't accurate below 50, so I'm sure we probably boned the gasket to begin with, so upon the Compression stroke, the pistons were pressurizing the coolant system causing the Rad to blow, and gasket to totally give way.

I will be replacing it with an OEM HONDA Y8 Headgasket, and using Copper Spray and it will be fine.

[93.2]

oh cool, this whole time i thought it had 4 but i just went and verified and it had 2, but i'm picking up a set of d15vtec rods and pistons so that should fix the problem.. i'm also using an ebay headgasket (came in a set) its three layer metal so i'm hoping it doesn't blow.. i'll just check my torque specs when i reassemble.

[Dasfinc]

Mine was metal also, Throw it away, Go to a Honda dealership, its only like $40 to buy a BRAND NEW OEM Y8 gasket, Don't make my same mistake, the rest of the set worked fine.

I just got home from the Honda Dealership, and they ordered a Y8 gasket for me, Only $31!!! OEM FTW!


Modified by Dasfinc at 11:32 AM 11/21/2007

[Dasfinc]

I'd also recommend using D16A6 or Z6 Rods and pistons depending upon if you are going NA or boost, instead of D15 pistons, D15 Rods are SUPER weak.

[93.2]

oh, well my head has 8 valves, but it has the reliefs in all the pistons for 16 valves.. i'm gonna look more into it. rather not have to go buy new rods and pistons.

[Dasfinc]

If you have the reliefs in all the pistons you can slap a Z6 or Y8 head straight onto that bad-boy. if you stay Naturally Asperated, your pistons and rods will be fine, you only really need upgraded pistons/rods if you are boosting or pushing VERY serious HP numbers.

[93.2]

cool, well i'll check back in on this thread to see how yours is coming, i just rebuilt my b8 last night, took about an hour and some change, hopefully won't have any problems now, not trying to make a race car, just something with a little pep thats good on gas, i might build the d one day *still got the whole y8 bottom end* but for now esp. since i have a DX transmission, not going anywhere fast.

[Dasfinc]

Y8 bottom end is acctually not very strong, I'd recommend a Z6 bottom end.

I slapped on my new headgasket last night, the old one had completely let go *Pics later*

[rleonekc]

Anything new?

[Dasfinc]

Couple of new discoveries last night.

When using the EACV Valve off a D15B7 on a D16Y8 Intake Manifold *I picked up a Y8 manifold to replace my OBX one* you have to Grind of a piece of the back of the Y8 intake manifold as it blocks where the sensor clips in. *I have pics will post later*

ALSO when using the D15B8 Throttle Cable, you have to modify the bracket to allow for some level of adjustability on the D16Y8 intake manifold as well.

Would have driven the car home last night, but my timing was a tooth off it felt like *Missing and no power at low revs, Vtec hits and the car Instantly looses traction and takes the expletive off, It really ****ing moved in Vtec, but I assume thats because the timing being off when Vtec hits the Valves are staying open long enough for the fuel to get in.

*edit*

But CHRIST is the car loud/fast over 5 grand, Can't wait for the timing to be right


Modified by Dasfinc at 8:47 AM 11/26/2007

[24TEN]

I just blew my second head gasket

[Dasfinc]

Originally Posted by 24TEN

I just blew my second head gasket

Couple questions to help you out.

What brand/model headgasket are you using? Is your torque wrench accurate? and are you sure the head isn't warped?

Honda Headgasket was only $31, and a brand new torque wrench from autozone was $20. The ARP's we talked about helps a ton too, and pickup a can of Copperspray to make sure you really seal the hell out of your next gasket.

and are you running premium?

[24TEN]

OEM Y8 3 layer metal head gasket sprayed with copper spray both times, head has been machined to ensure it's not warped. My guess is the bolts themselves OR the torque wrench isn't so accurate anymore. Oh, filled up on 91 and ran through the entire tank to ensure no more 87 was left inside prior to the head swap.

[Dasfinc]

The Tq wrench I used the first time was off, and I'm sure that contributed to the gaskets quick failure, That and if the 1 Y8 bolt you got was used, or something it could be a problem, keep in mind the slightest diffrence in material of the bolt or wear of the bolt can cause it to need more or less torque than the rest, thats why I ended up buying ARP's

[24TEN]

ARP is what I'll try next.

[Dasfinc]

Here's some pictures of the engine carnage from when the headgasket let go.







Damn that cleaned the piston off.