Compression test with 11.5:1

I’m running an ls/vtec with b16 pistons so my compression is around 11.5:1. I was bored so I did a compression test and it came out around 185 all across. Doesn’t this seem pretty damn low?

If you think that is low, put a tea spoon of motor oil into the cylinder and try again to see if your #'s improve.

Did you do the test with a warm motor and with the throttle wide open? How many cranks?

Warm motor approx 5 cranks. All spark plugs out.

I woudl probably do at least 7-8 cranks, cause its not like it will keep going. Also make sure that you hold the throttle open.

Anyhow, Im not sure what that ompression should be for something like that. But my friends crvtec with 11.5:1 put out 190psi in all cylinders. It was a REALLY strong motor and hauled nuts. Maybe it could have been higher/lower, but I think that thats prolly ok, especially considering that they are all about the same and there is not much variance (thats a good thing).

that is stock compression on a b18a1 with 100k miles or more… for some reason my old motor stock(b18a1) had 205psi in pistons 1-3 and 200psi on # 1, and you could ask erik , hayden, clunker, angel in miami we did it at one of the park meetings that we did 1.5 years ago
now i have a b20b and is averaging 185psi all around and next weekend we are slapping a p72 head

when I was running 11:1 my compression was an even 245psi, after my rings washed out the compression dropped quite a bit and was between 185-195psi. If your compression was initially where it should be… you would definitely feel that there is now something wrong, power should have dropped drastically.

This is going to flip ya out my boy has a B18a1 ls with stage 3 ported head msd wires no came gears just the stock ones DC 2.1 headers and two P30 pistons and the other two pistons are PR3 we put them and he had 210 psi all across. :clap:

that cant be too good …:shrug:

When I had SRP 11.5:1 C/R pistons on a Lsvtec with a milled head, Bored to 81.5, re-lapped in valves, I was getting 282, 265 275, 277. (Or something along those lines.)

IMO, something is wrong with your engine. Do a leak-down test.

-Andrew