ok so i have a problem.

D15, D16, D17 and Mini-Me swaps
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ok so i have a problem.

By jdmjunkies
- Tue Aug 31, 2010 2:29 am #211333 i am trying to do a d15b7 high compression built but have real trouble finding some d15B rods for cheap or even for sale.

are there any other pistons i can use for my d16a1 pistions so that i get them to hit the tdc right no the money and not be 3mm away like i think teal said in one of the threads?


someone please help me out!

By jdmjunkies
- Tue Aug 31, 2010 3:12 am #211338 damn all those views and nobody can help me out!! :x
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By HondaHoe187
- Tue Aug 31, 2010 3:16 am #211340 give some more info!!!!!! :thumb:

By jdmjunkies
- Tue Aug 31, 2010 3:19 am #211343 im doing a d15b7 high compression built with d16a1 pistons.
i think teal said that you need d15B rods (jdm d15) cus then if not , the pistons will sit 3mm too short and will be a worthless build.
and since i cant seem to find any d15B rods i was wondering if i can use any other vtec rod that has the same measurements!
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By HondaHoe187
- Tue Aug 31, 2010 3:20 am #211344 there you go!!!! lol so your saying you cant find the oem ones????

By jdmjunkies
- Tue Aug 31, 2010 3:22 am #211345 yes! and i wanted to know if i can use some other rods cus the jdm d15b's are a rare motor to find and much more rare in a junkyard lol.
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By HondaHoe187
- Tue Aug 31, 2010 3:44 am #211349 yea def ummmm idk let me ask around to see but i dont want to give you an answer and have it not be right

By jdmjunkies
- Tue Aug 31, 2010 3:50 am #211352 whatever gets me on the right track
id really appreciate it :woot:
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By HondaHoe187
- Tue Aug 31, 2010 4:12 am #211357 no prob ill update when i figure it out if i dont reply soon pm me

By AutoXCivic
- Tue Aug 31, 2010 6:07 am #211383 You can NOT use the JDM d15b rods in a USDM d15 block. The rod journals are different sizes (and the rods are the same length). You can use the rods out of a d15z1 which are 137mm (same length as d16 rods) and have the same BE bore as the d15b7 rods, however having a rod this long WILL make any piston you use sit above the block deck (except the d17a2 piston, but that will give you a low CR). With stock length rods ANY of the d16 pistons will sit WAY below deck and give you a very low CR and make the combustion happen in a place it shouldn't. Your best bet is to mill the head. There really is no good OEM piston to swap into the d15b7.


As far as aftermarket rods go, there is currently only one option ... Crower rods which are stock length and cost $700 a set (and they're heavy apparently). There is another option in the works though, through a company called FJ-distributors, he's currently working on some USDM rods (and has some JDM forged rods) however as far as I know these will be custom length rods designed specifically for use with vitara pistons.

Your best bet to bump the CR on a d15b7 is to mill the head or find one with smaller combustion chambers, however the only smaller combustion chamer head are VTEC (which I'm guessing you don't want to do). If you don't mind going the VTEC route the z6 head is a good option. Just swapping the head will bump your CR to ~10:1 (if you use the z6 head gasket which is a little thinner than the b7 and made of better material). With a slight mill (~0.025") you can bump the CR to 11:1.

There aren't a whole lot of options out there for the d15b7 at the moment. Even with milling the head and using a thinner head gasket you'd be lucky to get 11:1 CR. The only forged pistons on the market are geared more towards a turbo build (-4.3cc dish w/stock compression height).
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By eg84dr
- Tue Aug 31, 2010 6:57 am #211394 hate to tell you this but the b7s just rent built or made to be built and theres very little aftermarket support
this i shwat i would do
get a d16 short block and put your a1 pistons in it and shave the b7 head like .030 that will give you a 11.6 to 1 with very little work
except for tunning have fun with that :thumb:

By jdmjunkies
- Tue Aug 31, 2010 9:11 pm #211503 ive heard that you need to use the d15b vtec rods on the d16a1 pistons because if you do use the b15b7 rods the piston will sit 3mm too short and will be a waste of a build.
i dont care for sturdy rods since im going to be all motor and dont think the rods will snap.
i just care on getting my pistons at TDC on the money.

but my problem is that the b15b rods are card to find so they said that the z6 rods are the same exact rods.
i will be going vtec later on but i want to put those pistons in my b7 because it is possible.

if anyone can find out for me if the z6 rods are the same exact as the d15b vtec rods i would appreciate it.

By AutoXCivic
- Tue Aug 31, 2010 11:48 pm #211527 Read my post the d15b VTEC rods are not the same as the d16 rods. They are different lengths. The d15b vtec rods with NOT fit in a USDM block. The rods are the same length but the part where they attach to the crankshaft is a different size. The d15b VTEC rods have the same size bit that attaches to the crankshaft as a d16 rod.

Did you think the d15b VTEC rods were longer or something thus making the piston sit higher in the block. Seriously look two posts up I already gave you all of the information regarding rods for the d15b7.

To recap ... d16 rods will not fit on a d15b7 crank, JDM D15B rods ... will not fit on a d15b7 crank. D15z1 rods will fit on a d15b7 crank, and are the same length as a d16 rod. There really are NO options for doing a high comp N/A build on a d15b7 you are pretty much limited to bolt ons and boosting at this point in time. Unless you want to shell out some serious cash for custom parts.

As has been said there are very few options for building a d15 ... none of which really cater to an all motor build. In a d15b7 you can ONLY use d15b7 rods.
Last edited by AutoXCivic on Tue Aug 31, 2010 11:49 pm, edited 1 time in total.
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