I need to do a compression test on an sc300 w/ 1jz that I will pick up this weekend. What compression should it have? and other stuff that I need to inspect. Thanks for all the help guys.

Norm

 

i believe it calls for 150ish, but that's w/ everything being right
the main thing you want from the comp check is just consistency across all the cylinders.
i personally goes #'s around the 180's

 

Post engine questions in the engine forum please.

 

150 is low. 180-190 is what i had. 190 is about right on a 8.5:1 compression motor

 

Thanks alot guys, and sorry about posting on the wrong thread

 

180-190 sounds a tad high for 8.5:1 CR...

follow the lines on the chart, a healthy motor will be somewhere between the two slopes... if it's higher, it probably has some carbon buildup, if it's lower, it's rings are leaking... higher is not horrible always, just a sign the engine needs a little cleaning internally...

 

Thanks for the chart

 

hey everyone wanted to know what the compression rate(psi) was for a Lexus.
Its a 1991 Ls 400 with 235K miles on it. The numbers I got for each cylinder were:#1-200,#2-225,#3-210,#4-225,#5-209,#6-222,#7-210,#8-225. I repeated the test twice, still same numbers. If anyone can help me with this that would be great. Thanks

 

the graph I posted above has all the info you need... if you need help reading the chart, simply follow the compression ratio (10:1) across, and you will see anywhere from 170 psi to 200 being normal... on older engines with good rings, and some carbon buildup, it is perfectly normal to see slightly higher numbers...

yours is good...

 

I just did the test 160 all cylinders cold.Are thosee numbers good

 

sounds like it's dead on... it should be a little higher when warm, so, it sounds like it's a healthy motor...

 

Thanks alot for your help....Hopefully someone could help me out with the speedcut at 106 mph, i do have a HKS SLD, but i don't know what the settings should be on. ANYONE