11 replies to this topic

[onefasthondacrx]

I want to build my 1gZC motor with at least 11:1 compression but can't seem to find any pistons that will work. I know the engine has 9.3:1 compression and I also know that I could put in a set of 88-89 D16A1 pistons to bring the compression up to 9.5:1, but I'm looking for more of a gain then that. Does anyone know if there a company out that that makes a set of high compression piston for our old D16A1/ZC?

[DEIVIONCRX]

Many, Wiesco, Arias, JE, Endyn, SRP, CP you name it they make em. Any D-series piston will work as long as the wrist pin diameter is the same, which i think they all are(maybe not D17's).

[1gcvcb18]

You can swap a Z6 or Y7 head on the D16A1 block and bumo the compresion a bit. May have to relocate some holes for the studs on the head.

[staticchmbr]

look at www.raceeng.com ...race engineering sells all sorts of pistons

also see www.theoldone.com ...endyne also has a ton of options

if you buy any pistons for any OTHER d series, they will lower the compression ratio by 1 full point in a d16a1/dohc zc (if you buyt 12:1 pistons that are made for a y8, it will be ~11:1 in a d16a1)

[onefasthondacrx]

well, what i need is for you guys to tell me exacty what pistons to buy to get my compression over 11:1. Need exact details. thanks.

[DEIVIONCRX]

Google it.

[onefasthondacrx]

look at www.raceeng.com ...race engineering sells all sorts of pistons

also see www.theoldone.com ...endyne also has a ton of options

if you buy any pistons for any OTHER d series, they will lower the compression ratio by 1 full point in a d16a1/dohc zc (if you buyt 12:1 pistons that are made for a y8, it will be ~11:1 in a d16a1)

ive done research on the websites you told me about and others, and all the high compression pistons I can find are for a 75.5mm bore. The D16A1/ZC has a 75 mm bore and I'm looking to stick high compression pistons in my block without having to bore it out. Any thoughts on this?

[onefasthondacrx]

Does anyone know if the wrist pin size on a D16A6 is the same as a D16A1? CP pistons make a set of 75 mm bore pistons for the D16A6 with 11:1 compression. Those would work perfect if the wrist pin size in the same.

[Xspenzo]

Don't use a6 pistons they will give you crappy compression in a d16a1 (like 8:1). use p29 pistons and mill the head/deck the block to raise the c.r.. you will get to 11:1 faster then you think.

[anjin]

ive done research on the websites you told me about and others, and all the high compression pistons I can find are for a 75.5mm bore. The D16A1/ZC has a 75 mm bore and I'm looking to stick high compression pistons in my block without having to bore it out. Any thoughts on this?

You should at least have the bore honed with new pistons, so why not have it bored as well. Nice and round then. Bet you have oval cylinders at the moment.

I'm building a browntop up, and I'm using blacktop pistons. 25 thousanths off the block, and the same off the head. That'll get the cr ratio up about 11.5. I've worked the combustion chamber so call it 11.

But all that work costs, so a piston upgrade is a reasonable option to look at. Good luck

[Xspenzo]

How much are you getting charged for all this? I can have it done for $120 (Decked&Milled) But the extra pain is disassembling the head. $120 is very cheap for Horsepower gains.

[Elpimpo]

well, what i need is for you guys to tell me exacty what pistons to buy to get my compression over 11:1. Need exact details. thanks.

Youre asking alot.
compression depends on a lot of things, not just your pistons.
Deck height at TDC, Compressed thickness of head gasket, piston top volume, and combustion chamber volume.
hone your cylinders, shave your head, get a thinner head gasket, new piston rings, get YCP d16a1 pistons(like $150 on ebay), and conduct a compression check make sue everythings good and tight. And remember that really high compression requires higher octane fuel.


Some Good info:

All D-series motors run the same bore (75 mm), however most factory motor variations (i.e. D16A1, D15B7, D16Y7) have used a different piston compression height as well as a different dome or dish. In general, the older D motors have a higher compression height and a larger combustion chamber which create around a 9.1:1 - 9.4:1 compression ratio from the factory. The newer variants have slightly lower compression height combined with a much smaller combustion chamber to create a compression ratio of 9.4:1 - 9.9:1. Now if you combine an older D16 motor's piston with that of a newer D16 head you can end up with a compression ratio of about 10.7:1 with no other work (i.e. D16A1 piston, D16A6 head). There are a few websites that have compression ratio calculators for Honda motors.
D16 and D17 cranks share the same size main bearing diameters.
D16 and D17 rods all have the same major dimensions. The D15 rod is shorter (in general) and has a smaller bearing size, although the wrist pin bore is the same.
D15Z1 and D15B motors have a rod that is the same length as a D16. Other than the rod length, the rest of the bottom end is D15 spec (i.e. rod and crank bearings). D15B has D16 sized rod journals. D15B uses the same p28 rods that the D16z6 does. All other D15s have smaller rod journals.
The B18A/B Rod has the same bearing bore as a D16. It is 0.044" wider, so the sides of the "big end" of the rod have to be shaved down for use in a D16/17. The wrist pin bore is larger so a conventional D15/16/17 piston can only be used if the stock "small end" bushing in the rod is replaced with one of the proper size. These affordable rods are generally considered to be able to handle up to 300 hp (220 kW).
There is a D16 motor that runs on compressed natural gas (96-98 Civic GX). The pistons from that motor have a 12.5:1 CR. The wrist pin bore in the 98-00 D16B5 is 21 mm, like the B18B rod. D17A7 01-05 Civic GX uses 19 mm wrist pins.
Interestingly enough, the Suzuki Vitara has a 75 mm bore as well, so engine builders have occasionally used these pistons in the D16 motor. These pistons are commonly referred to as Vitaras, and they provide an 8.5:1 compression ratio, and thicker ring lands. Lowering the stock compression ratio lowers compression heat, which raises the detonation thresh-hold and is useful when employing forced induction. There have been reports of over 400hp to the front wheels utilizing these.

Edited by Elpimpo, 17 June 2008 - 11:09 AM.