Jays91DXhatch

Just for fun....or, just because I can..lol..I want to take the B16 out of my car, slap my old D15 back in and turbo it (One of the main reasons going non-vtec is Turbo edit has a SWEET turbo map I can use with the PM6, PR3..no luck and I don't really want to run the AFC hack.

SO, I know that the the piston wrist pin when comparing a D15 piston to a D16 piston, the pin placement on the D16 is higher. Therefore that would result in lower compression. Since I have read that the D15 piston would stick out of the D16 block.

So, I'm just wondering if anyone knows of any factual info, IE compression ratio, or if someone could guesstimate it for me?

I don't want to hear that stock compression is good enough blah blah, I want to lower the compression, and do it CHEAP. If I blow the motor, I build my spare D16 and put that in..simple.

I'll be using a bigger turbo to get good efficiency at the higher boost levels that will be required.



Any REAL info, or insight, would be GREAT.

Thanks guys.


Modified by Jays91DXhatch at 4:05 AM 4/14/2004


Modified by Jays91DXhatch at 3:40 PM 4/29/2004

Jays91DXhatch

too stupid of an Idea?

This is what happens when you do nothing all day at work!

tilt

i remember reading somewhere the pistons cant be swapped, at least with the d15 crank.... something about it being different? im not 100% sure on it.

Jays91DXhatch

Ok, so I decided to do some research!

Using These tools:

-CR calculator http://www.knology.net/~jediklc/D.htm

-Information from this post https://honda-tech.com/zero...age=1

Namely this calculation courtesy of fastcrxsi90, Deck Height - Compression Height - Rod Length - Stroke/2 = Piston Deck Clearance

Because you can't just use the stock deck height that's in the calculator, you have to change it. One of the reasons the C-Speedracing one isn't accurate.

Values that will not change (found from that post, and also from into on the calculator, and the other page with piston info http://www.heeltoeauto.com/dseries/dseries1.html)

D15 Deck Height - 207.45mm
Rod Length - 134mm
Stroke/2 - 42.25mm

Please make sure to convert from mm to inches as the calculator uses inches (multiply the mm results by 0.03937)

So, here are my results:

P28, D16Z6

30mm Comp height

Piston Deck Clearance = 0.047244
Compression ratio = 7.35:1

P2P, D16Y8

29.5mm Comp height

Piston Deck Clearance = 0.066929

Compression ratio = 7.54:1

P29, D16A1

29mm Comp height

Piston Deck Clearance = 0.086614

Compression ratio = 9.13:1

P2E, D16Y7

30mm Comp height

Piston Deck Clearance = 0.047244
Compression ratio = 7.66:1

PG6B, D16A1 (86-89)

30mm Comp height

Piston Deck Clearance = 0.047244
Compression ratio = 8.9:1


SO, it looks like I won't be able to get the 8:1 that I wanted, either I go 7.6:1 or 8.9:1. Stock compression, if I'm not mistaken is 9.1:1..not sure if it's even worth changing to go with 8.9:1, so I'm left with 7.6:1 which is kind low for a 1.6L SOHC..I "think" trying it would be key.

Jays91DXhatch

If I go with single turbo (Slapped myself back to reality) would 7.66:1 be too low compression?

some stock boosted cars come with this low of compression.

Any Ideas?

onePOINTsix

you cant put 1.6L pistons in a 1.5L motor, the wrist pins are at a different heigh (think thats what you'd call it) in teh 1.5 the wrist pins are pritty close to the top of teh piston, the 1.6's are farther away

Jays91DXhatch

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sideout &raquo;</TD></TR><TR><TD CLASS="quote">you cant put 1.6L pistons in a 1.5L motor, the wrist pins are at a different heigh (think thats what you'd call it) in teh 1.5 the wrist pins are pritty close to the top of teh piston, the 1.6's are farther away</TD></TR></TABLE>

Umm, The 1.5L pistons have the wrist pin lower. When you put a D16 piston which has the wrist pin higher, in the D15, the compression will be lower as I stated above.

Why wouldn't I be able to do it?

D15 pistons in a D16 could potentially cause a problem..but that's not what I'm doing.

Jays91DXhatch

I'm bringing this back up, because I'm going to build a low compression D series..for SINGLE turbo. :D

I just recalculated something:

PM6, D16A6

29.5 mm Comp height

Piston Deck Clearance = 0.066929
Compression ratio = 7.88:1


BUT If you use the D16Y8 2 layer head gasket.....it yields 8.22:1 compression

So, this would be a VERY cheap option to get super low compression yet still usable using STOCK parts.

If this blows, all I did was waste a D15 motor, I still have a D16 that I can build with "real" parts if this one doesn't last.

So, in conclusion, D15B2 engine + PM6 pistons + D16Y8 head gasket = 8.22:1 compression = 20PSI on pump gas..here I come.

kyle h.

why would you want that low of compression? out of boost power is going to suck real bad. i was also under the impression a6 pistons/rods cannot fit onto a b2 crank, so you'd have to swap the cranks, and the piston/rod, which would give you an a6................................................ .................................

single cam powa! rock that b2 till it blows.

Jays91DXhatch

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by kyle h. &raquo;</TD></TR><TR><TD CLASS="quote">why would you want that low of compression? out of boost power is going to suck real bad. i was also under the impression a6 pistons/rods cannot fit onto a b2 crank, so you'd have to swap the cranks, and the piston/rod, which would give you an a6................................................ .................................

single cam powa! rock that b2 till it blows.</TD></TR></TABLE>

I stated at the beginning that I didn't want to have to explain or answer about the compression.

It's old school mentality and It's been ARGUED TO DEATH Some people prefer higher compression, lower boost, some lower compression higher boost. I'm not saying this is the best or only way to go, just that it's the way I'm going That's it.

Also, I'm using A6 pistons, on B2 rods, and B2 crank...so no problems about fitting, and the wrist pin diameter as well as the bore of the pistons are the same. So the A6 piston will fit on the B2 rod no problem.

LoSt is BlaCk

your loosing me, i want to help but i can't figure out what you want to know...

i can see that you want to do a DIFFERENT type of build up, however it might not be the best idea. it seems to be pretty clear that the z6 pistons will not work, but this is only because of the wrist pin placement... i'm going to read this over again, but those compression ratios seems a bit too low considering they are all stock pistons, maybe i missed something. anyhow running compression in the 7 ranges is going to yield a serious power issue out of boost...this really sucks, especially since you plan to run a larger turbo, meaning unless it's ball bearing it will take a lot of time to spool. just for overall performance depending on what the use of the car is this might not be a good set up, but what do i know, i'mjust another h-t member. if you are just doing this for fun and the money you spend is not an issue DO IT and prove us wrong.

please tell us exactly hat you want to know, maybe we can better help.

Jays91DXhatch

Well, that's a good question.. i wanted to do a Cheap, low compression D series build...

But thinking about it, I probably should just boost the D15B2 with MPFI swap till it blows, build up the D16A6 with forged internals (the proper way.. ) on the side so it's ready to be dropped into the car if/when the D15 blows.

It's probably not even worth the hassle to get the A6 pistons on the B2 rods etc.

And I don't know what everyone is thinking..but you can put A6 pistons on B2 rods and not have a problem....well, I shouldn't say that, they won't stick out the top, but maybe they would go too low in the cylinder...??? I dunno.

LoSt is BlaCk

don't forget that you can always use ls rods, so that you can get rid of those pencil like rods in it now...take your d16 throw the ls rods in it, shot peened or cryoed (i have some ) grab some z6 pistons (have them cryoed or ceramic coated) or forged pistons, post the block or run a guard AND GO! that would not be very expensive...

Jays91DXhatch

You're right, would be alot better for the money.

LoSt is BlaCk

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Jays91DXhatch &raquo;</TD></TR><TR><TD CLASS="quote">You're right, would be alot better for the money.</TD></TR></TABLE>

and it just might run better then you thought, lol keep us posted