Piston and rod size of the D14A3/A4/Z1/Z2

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mynameisowen
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Re: Piston and rod size of the D14A3/A4/Z1/Z2

Post by mynameisowen »

So the A9 has the biggest dome then the A4?? Is this true it doesnt seem to make sense as the CR for D14's is quite low, obviously the head makes a difference but why have high comp pistons and not high comp head?
1996 EJ9 Civic
1998 BB8 Prelude Motegi VTi
1998, B16A2 EK4 Civic VTi

Aims:
EJ9 - Now my GF's car.
BB8 - Rebuild after crash damage to front end.
EK4 - Daily driver. Strip and track prep once prelude project complete

hondaNickx
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Re: Piston and rod size of the D14A3/A4/Z1/Z2

Post by hondaNickx »

mynameisowen wrote:So the A9 has the biggest dome then the A4?? Is this true it doesnt seem to make sense as the CR for D14's is quite low, obviously the head makes a difference but why have high comp pistons and not high comp head?
A4 has a Dish and A9 has a Dome.Why the difference because there's a difference in the head most likely.Look at the PM7 pistons of the d16a9 engine.Those have a huge dome but their head has 43.80cc ,and they only have 9.5 :1 Cr.Also on a D14 you need more Dome to gain as much compression on a D16 engine.Cause a D14 engine has less displacement.
Quote from Endyn:"The combustion chamber is a better shape than the DOHC.So don't chunk those 1.6 SOHC engines, they can make really good power. For a pure performance application, regardless of application, I'd choose the SOHC. No bull!"

CarteluL
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Re: Piston and rod size of the D14A3/A4/Z1/Z2

Post by CarteluL »

Hy guy's ..i am new here and want to learn about d14..in the past i had an crx d16a6 with pm7 piston's and z6 head and i saw some nice power 183 bhp...but to use these pm7 piston's in a d14a4 can you use the oem d16a9 rod's? Or the oem d14 rod's? For begining...:@

Law_
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Re: Piston and rod size of the D14A3/A4/Z1/Z2

Post by Law_ »

Hello and welcome ! Nice power output !
Please do a former presentation on the right place if you can x)
About the pistons i dont know but others will.
Cheers.

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Dodo Bizar
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Re: Piston and rod size of the D14A3/A4/Z1/Z2

Post by Dodo Bizar »

Using other rods than D14 or D13 is not possible unless you start changing the crankshaft. Big-end bearings are smaller. PM7 piston, dangerous since it can touch the head at high rpm since it has 0.5 mm more compression height from the top of my head? Somebody spoke to my by email with this setup or similar in a D14 (CR 13.1) and it ran terrible bad. Only go there if you know how to built extreme engines.

CarteluL
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Re: Piston and rod size of the D14A3/A4/Z1/Z2

Post by CarteluL »

It's not an extreme engine...somebody did it...you can search in google to see it.. Whrite d16a8 in d14a4 and you'l see..cheer's

hondaNickx
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Re: Piston and rod size of the D14A3/A4/Z1/Z2

Post by hondaNickx »

Pm7/P29 pistons have 27mm compression height
D14a4 pistons have 29.5mm compression height.
Pm7 pistons will sit under deck ,and they are not the best pistons to use in any D16 D15 or D14 block.The domes Don't work well with the combustion chamber design.You'll get better result (more hp) if you use either flat top pistons like PG6 or aftermarket pistons for your specific Head.Domes are made to work with an engine's combustion chamber.

It's like using a fork to eat soup.It will work but it isn't the best solution.
Get it ? ;)

Like i said before your best bet is to get aftermarket pistons for a D16y8.
And i could recomend Arias to get high compression ~11,5 :1
Quote from Endyn:"The combustion chamber is a better shape than the DOHC.So don't chunk those 1.6 SOHC engines, they can make really good power. For a pure performance application, regardless of application, I'd choose the SOHC. No bull!"

CarteluL
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Joined: Thu Nov 05, 2009 12:25 pm

Re: Piston and rod size of the D14A3/A4/Z1/Z2

Post by CarteluL »

)) ...every one think's what he want's...i used those piston's (pm7) in another build of my'n..those piston's came from a DOHC and i used them in a d16a6 SOHC (105 hp stock) and reached 183...and it was not tuned !

hondaNickx
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Re: Piston and rod size of the D14A3/A4/Z1/Z2

Post by hondaNickx »

Pls read ,you were asking to use them in a D14 .You said you used them in a D16a6 ! Those are 2 different engines!And those pm7 pistons don't work well in a D16a6 either.If you reached 183hp with that engine you left something like ~8-10 hp on the table by using the wrong pistons.I'm not saying it doesn't work ,it will but it isn't the best for your engine.You can't just mix and match things up and expect it to work perfect with the highest gains possible.It ain't that easy to build a Proper engine.
Quote from Endyn:"The combustion chamber is a better shape than the DOHC.So don't chunk those 1.6 SOHC engines, they can make really good power. For a pure performance application, regardless of application, I'd choose the SOHC. No bull!"

Law_
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Re: Piston and rod size of the D14A3/A4/Z1/Z2

Post by Law_ »

True. Best Honda Pistons for Ej9 NA Setup?
Regards

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