did a compression test this weekend

[Rich]

after my rebuild of my 1.5jz end of last year and running it in the 'motoman' way i've put a few thousand miles on it by now
so this weekend i decided to check the compression:

psi:
1 189
2 189
3 189
4 189
5 184
6 189

bar:
1 13
2 13
3 13
4 13
5 12.7
6 13

i'm quite happy

 

[chopstickz]

nice numbers! what compression?

 

[c_ronius]

Interesting... I saw/read a link Tissimo posted earlier this week about that Motoman break-in. Interesting read.

Obviously you've got a really good seal, thx for sharing.

 

[tissimo]

Nice best way imo..

 

[Rich]

Interesting... I saw/read a link Tissimo posted earlier this week about that Motoman break-in. Interesting read.

Obviously you've got a really good seal, thx for sharing.

yes, after long and thorough reading i decided to go for the motoman way, i have a mechanical engineering education and this to me made good sense

i also did the head; lapped the valves and replaced one and had it leak tested which turned out with very good seal

but i must say i suspect the 1.5jz has a higher compression ratio, because the 2jzgte has a standard compression of 156psi/11bar or higher

 

[Andre]

yes, after long and thorough reading i decided to go for the motoman way, i have a mechanical engineering education and this to me made good sense

i also did the head; lapped the valves and replaced one and had it leak tested which turned out with very good seal

but i must say i suspect the 1.5jz has a higher compression ratio, because the 2jzgte has a standard compression of 156psi/11bar or higher

Yep

An 1.5 JZ has an higer compression ratio then a 2JZ are an 1JZ

 

[OneJArpus]

sweet numbers I have to do a comp test on my 1J.... What are the numbers like for that?

 

[tissimo]

sweet numbers I have to do a comp test on my 1J.... What are the numbers like for that?

compression numbers give a good indication to the health of the engine (ring wise)

 

[suprahero]

What is this break in you're talking about? I'm going to be breaking in my 1.5 tomorrow if my alternator arrives on time.

 

[OneJArpus]

compression numbers give a good indication to the health of the engine (ring wise)

Thanks, sorry i wasn't too clear with my question, but what are the comp #'s for a healthy 1J

 

[suprahero]

around 180

 

[suprahero]

I found it.
http://www.mototuneusa.com/break_in_secrets.htm

 

[OneJArpus]

Thanks!

 

[Rich]

Yep

An 1.5 JZ has an higer compression ratio then a 2JZ are an 1JZ

Yo Dre, do you have a link to someone who's measured this? I've never seen any proof of this.

 

[suprahero]

It's going to be hard to break it in like this with a new clutch installed in my car. I don't want to hurt the clutch by trying to run the car to hard. Any suggestions?

 

[tissimo]

Thanks, sorry i wasn't too clear with my question, but what are the comp #'s for a healthy 1J

with the engine warm ~ 160.. the main thing is to make sure they're all even. Some gauges may read different then others, or test methods vary.. dont get too cought up in the final number

It's going to be hard to break it in like this with a new clutch installed in my car. I don't want to hurt the clutch by trying to run the car to hard. Any suggestions?

with a new clutch the main thing is to make sure it doesn't slip.. You dont need a lot of boost (power) to seat the rings good. Just keep it on the wastegate, do a pull from 2k to ~ 4000-4500 then let out and let the engine slow you dont, do not push in the clutch and hit the brakes.. let the engine slow you down.. repeat that 4-5 times then the rings should be fairly seated.

For the clutch, just dont be banging gears @ WOT on high boost and you'll be fine

 

[Insidious Surmiser]

Yo Dre, do you have a link to someone who's measured this? I've never seen any proof of this.

it's supposedly due to the reduced size of the combustion chambers in the 1jz head, opposed to the 2jz head

 

[suprahero]

Thanks Justin. I remember seeing adds for 1jz with them hooked to a compression tester and it showed 180 and Aaron told me when we checked mine on my 1jz that they should be around 180, but all of mine read 135 across the board. I will check mine on my 1.5 once I get it broke in, but Im sure they'll be lower than the ones posted here because of my cams and my port and polish. Hopefully they won't be too dang'd low though.

 

[MassSupra89]

Jay I just broke my 7M in two weeks ago this way with a new clutch and I just kept it around 1/2-3/4 throttle pulls from 3-5k rpm. did this as many times as I could in 2nd, 3rd, and a few in 4th gear. Just rolled on the throttle, no sudden WOT, and kept my boost alittle below 10psi.

 

[suprahero]

Thanks. I've got my avc-r set to about six pounds of boost, so that shouldn't be enough to slip the clutch. I'll do this tomorrow after I get my alternator installed. Thanks again to everyone on this site............well not everyone, but you know who you are.