ok so i have a problem.

D15, D16, D17 and Mini-Me swaps
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By AutoXCivic
- Fri Sep 03, 2010 1:38 am #211909
eg84dr wrote:do a oem rebuild and boost it or do a mini me and shave the head .020


This would be the way to go if you want to up compression. The b7 piston design is actually really nice for quench/combustion and the z6 head (IIRC) is the best flowing d series head. Just by swapping on the z6 head you will bump CR to ~10:1 and gain about 40 whp (at least I did). I would also recommend swapping to the EX tranny for some extra wheeee factor.

By jdmjunkies
- Fri Sep 03, 2010 2:18 am #211923 ok the point for this build was for it to be an oem build.


this is where you guys confuse me.
ive read in other forums that the d16a1 pistons on the d15b7 rods sit like the picture on the left. with the d15b rods from what i was told in another forum the pistons will sit like the picture to the right that is what i want. vvv
Image

By AutoXCivic
- Fri Sep 03, 2010 3:21 am #211932 Ok, first off I think we established (my idiocy aside) the the d15b rods will not work in your block. I'm going to assume at this point you mean z1 rods because they are the same length as the d15b rods and will fit on your crank.

With the different piston design of the a6 pistons on a b7 rod the piston will be 0.049" (1.25 mm) below deck.

On a z1 (d15b) rod the piston will sit 0.069" (1.75 mm) above deck.

The location of the wrist pin in the b7 and 16 pistons is about a 1.3 mm difference. b7 pistons have a 30.7 mm compression height and the a6 pistons about 29.5 mm compression height.

You can find all of this out using the compression calculator at zealautoworks.com, at the bottom there is a section that says "piston to deck height" ... any negative value in this field is the piston sticking out of the hole.
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By d-mon
- Fri Sep 03, 2010 7:08 pm #212019
jdmjunkies wrote:ok the point for this build was for it to be an oem build.


this is where you guys confuse me.
ive read in other forums that the d16a1 pistons on the d15b7 rods sit like the picture on the left. with the d15b rods from what i was told in another forum the pistons will sit like the picture to the right that is what i want. vvv

usdm d-series rods come in 2 sizes.
135mm = d15
137mm = d16, jdm d15b vtec
unless you had a jdm d15b vtec crankshaft the rod journals will be too small for d16 (137mm) rods.

By jdmjunkies
- Sat Sep 04, 2010 12:43 am #212049 why does everyone keep saying d16a6 pistons???
i have d16a1 pistons 2 different pistons.

so what will happen if i just put the pistons on the d15b7 rods?
will i gain anything ?
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By eg84dr
- Sat Sep 04, 2010 1:26 am #212054 you are very insistant on not beliveing us on this forum so try whatever the hell you want and find out what happens
but dont come crying if it doesnt work
it will work but you loose compression not much
and it sits in the whole quite a bit
imo there is no point to have a domed piston sit low in the block
if you wanna get crazy you could deck the block .030 and that would make the piston sit at deck height but it would barely reach a 10. to 1 compression

By jdmjunkies
- Sat Sep 04, 2010 1:51 am #212057 i do believe the ones that posted the write stuff. other were talking about a6 pistons i have no idea why...

and then some were saying other stuff and that is why i was confused and didnt know what to do!
but thanks for that i guess ill just find me a d16z6 block and put the a1 pistons in there.

By AutoXCivic
- Sat Sep 04, 2010 2:41 am #212065 Well shit, my bad, I guess I missed the a1 and read a6.

Now ... pertinent information based on not failed reading.

The a1 pistons have a slightly lower comp height than the b7 pistons (0.7 mm) and will sit slightly in the hole. The dome makes up for the loss of compression due to the lowered height of the piston (on a b7 rod), however this will mess up your combustion because it won't be happening in the right place in the cylinder. They will also maintain pretty much stock CR. So this route is not very viable as you are maintaining the status quo for CR while messing up the whole combustion process.


With those pistons on a z1 rod they will be sticking way too far out of the block (2.25 mm) to do you any good, the pistons will start making out with the head/valves and that's not going to make anyone happy.

By jdmjunkies
- Sat Sep 04, 2010 2:58 am #212071 cool thanks ill just let them continue to get dusty in my garage since i wont have any use for them :(

question how much spray can a super healthy d15b7 hold with intake and exhaust??
since the high compression is out of the question and the nos was going on anyways lol

By jdmjunkies
- Sat Sep 04, 2010 5:42 pm #212177 lol naw im good on selling them.
i did some more research and found out that they will work real nice in a b7 block with b7 rods and a z6 head with a thinner head gasket so ima just do that :)

By AutoXCivic
- Sun Sep 05, 2010 12:30 am #212238
jdmjunkies wrote:lol naw im good on selling them.
i did some more research and found out that they will work real nice in a b7 block with b7 rods and a z6 head with a thinner head gasket so ima just do that :)


Just use the b7 pistons. It will give you the same CR and a better flame front/combustion event/quench area. And you won't have to tear the engine apart.
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