Compression ratio of hybrid JZ engines.

[The Real Roadrunner]

has anyone measured the comp of a 2j block, crank and rods fitted with 1jzgte pistons and head using a std thickness 2jzgte gasket?

wouldnt mind knowing so i can sort out an engine upgrade for the rolla later on.

cheers
linden

[1jzDan]

Hey guys. I just purchased a 2jzge motor with intentions of putting a 1jzgte head on it. However because the 2jzge bottom end is like new, I was hoping to avoid pulling it down simply to install 2jzgte pistons if the 2jzge pistons will provide a turbo friendly C.R.

Does anyone have any figures for such a conversion? I plan to use a standard 2jzgte head gasket.

cheers, Dan.

[Norbie]

Methinks you'll end up with a pretty high compression ratio, however you can easily do what the NA-T boys do and use a thicker headgasket. There are a variety of gasket thicknesses available for JZ engines.

[Wildsupra]

has anyone measured the comp of a 2j block, crank and rods fitted with 1jzgte pistons and head using a std thickness 2jzgte gasket?

wouldnt mind knowing so i can sort out an engine upgrade for the rolla later on.

cheers
linden

im reviving this thread
basically because i am looking to do exactly the above with my current 1.5jz build.

Does anyone know what the compression ratio will be using the above setup?

Cheers
Matty

[wilbo666]

I'm also looking into this...

I haven't measured anything myself as yet, but I can do 1JZGTE and when I get around to it 2JZGE...

>Calcs assume that the piston is flush with the top of the block...
>Calcs assume that all JZ heads are 42cc
>Piston CC is calculated from head CC and quoted factory compression ratio...




Cheers
Wilbo

[Wildsupra]

man you are a legend!!
Most helpful post ever!!!!

Do'h cant give you rep

Someone rep him on my behalf

Matty

[Wildsupra]

hmm i wonder if 10.02:1 is a tad high for a medium boosted 1.5jz like up to 20psi

[big_zop]

I know a Charade (yes - dont laugh) that runs 10:1 compression and 1.9bar boost - makes 246kW@wheels from1.6L capacity (although this is with Martini 110 unleaded race fuel) so i think with 3L it should be able to still make some power but probably not at your proposed boost if you choose to stay on 98RON.

[wilbo666]

hmm i wonder if 10.02:1 is a tad high for a medium boosted 1.5jz like up to 20psi

Yes, 20psi is prbly too much boost in my thoughts.

lol

Tho the 9.1ish of the stock 2JZGE pistons looks nice to me

Cheers
Wiblo

[big_zop]

Tho the 9.1ish of the stock 2JZGE pistons looks nice to me

Cheers
Wiblo

They as strong as the GTE ones?

[Enchanter]

I played around with a similar spreadsheet for a while too. My plan was to use 1jzge pistons in my 2jzge to up the cr for a club car.
Iam still howerver looking for a ma61 shell in Tassie to replace my bent hillclimb victim

[wilbo666]

They as strong as the GTE ones?

I can't say that I have first hand experience.

In the USA there seems to be a lot of NA -> T conversions and I don't recall hearing of piston failure being common... then again I take USA info with a very large grain of salt

If someone has a 2JZ-GTE / 2JZ-GE pistons to donate I can donate a 1JZ-GTE one and we can check

Cheers
Wilbo

[Wildsupra]

wilbo how do you propose to check the strength of the pistons??

[wilbo666]

Chop them in half and check dome thickness

One could also measure the dome thickness with some micrometers.

And one could also measure the ring land thicknesses.

Cheers
Wilbo

[big_zop]

Chop them in half and check dome thickness

One could also measure the dome thickness with some micrometers.

And one could also measure the ring land thicknesses.

Cheers
Wilbo

The material properties and construction method are going to affect this somewhat.