Let's put the D15 rod issue to rest
 

I've heard plenty of people say "D15 has pencil dick rods" regarding ANY D15.

I've also heard this statement doesn't refer to all D15s, just some. Some say the JDM d15b is an exception as it has the same rods as a Z6.

My main questions:

1. Does the JDM d15b vtec have the same size rods as a d16z6? Or pencil-dick?
2. If the answer to the above question is "they're the same," does that mean mean you can use D16 forged rods in a d15b vtec? Or do you still have to use the ultra-expensive d15 ones?

I just really want the answer to #1, #2 I'm just curious about.

Re: Let's put the D15 rod issue to rest
 

jdm vtec d15b rods are z6 rods. No you can not run z6 pistons in a jdm d15b block. The height issue comes into play. I have pics of a z6 rod piston combo vs jdm rod/piston combo. Actually have them in my garage side by side

And no you cant run aftermarket rods in a jdm d15b block

Its a bastard motor with no real support.

Re: Let's put the D15 rod issue to rest
 

you kinda contradicted yourself there...you said they are the same but that the d15b has no aftermarket rods, if they were the same you could use the z6 ones. Im assuming you meant that they are of the same strength but not the same dimensions

Re: Let's put the D15 rod issue to rest
 

Basically I'm just gonna buy the motor and boost it stock, so it should be a bit beefier than my old d15b7 then.

Re: Let's put the D15 rod issue to rest
 

You can run aftermarket rods in a D15B, finding aftermarket pistons is the hard part.

You need a 27.7mm pin compression height.

PM7's in a D15 block with 137mm rods = .052" above the deck...........

http://bonespec.com/Honda/D15Baby8/P...5/PA150013.JPG

Yes they WILL fit a nonVTEC head opening the chamber edges slightly, yet to check valve clearance though!

What not take some Wiseco's or other D16 VTEC slugs and shave .060" off the top so they are flush with the deck?

Re: Let's put the D15 rod issue to rest
 

Jon I was almost gonna post the same thing this morning. What is the most you can safely bore a d15 out to? Picking up a Z1 block to ---- around with for free and you can't pass that up since for some reason these don't show up that often. Any possibility of getting it to 81mm? You can always dream can you? Ever think of the b16 rods and supra pistons setup? Don't see why it wouldn't work in the d15b since crank journals are the same I think. You'd just have to knotch the block for the rods.

Re: Let's put the D15 rod issue to rest
 

What i was saying was you cant run the d15b aftermarket rods in the jdm d15b block. And yes if you go z6 rods and pistons you already see the problem has bone has shown but, If a company ran atleast 10 sets of pistons for the jdm d15b there would be the support for them Im sure just a matter of havin someone have them built and findin someone who will sell them

Re: Let's put the D15 rod issue to rest
 

D15B vtec rods ARE THE EXACT SAME Honda rods as the D16 rods.

So why are you saying you can't run them?

Z1 block uses a DX crank, 42mm rod bearings, not the 45mm like the D15B vtec.

You can safely bore a D series to 76mm before sleeving. After sleeve job the limit is 78mm, maybe 79mm on a grenade motor.

81mm was tried once on a sleeved motor, it never made it off the dyno before spliting the sleeves in NA form.

Re: Let's put the D15 rod issue to rest
 

Or run a MrGasket headgasket? The one with the .25 mm, .50 mm, and 1.00 mm layers you can stack?

Re: Let's put the D15 rod issue to rest
 

1mm = .039", stock Y8 crushes to about .035", no info provided from MrG when I emailed them.

Cheap way = 2 Y8 HG's

else Cometic.