Compression test on 2.7i

[hakop_e30]

Hey y’all just finished the swap
cars currently turbod I let it warm up for 30 minutes and did a compression test

Is this to much of a difference

readings are without touching throttle


Cylinder 1 110

Cylinder 2 140

Cylinder 3 140

Cylinder 4 130

Cylinder 5 130

Cylinder 6 130

[hakop_e30]

Update with wot on cylinder one it goes up to 115

[TobyB]

It's a bit off. If you squirt a few pumps of oil into it, what happens?

Next would be leakdown, to see if it's the valves.

t

[packratbimmer]

Do you have a 200 or a 885 head on there? Those numbers are low for a stock early eta engine. Is it a super eta? If the engine has been sitting, try a small amount of marvel mystery oil in the low cylinder and see if it improves the seal. Just a little corrosion with throw off a reading. The marvel will help dissolve it. If oil, as suggested above does not improve the readings, it is likely that your valves are not sealing well.

[e30davie]

But what about WOT on all the others?

Cause if its now 115, 140, 150,150,150,150 then that's even worse!

If they improve drmatically with a bit of oil down the cylinders that tells you its rings, if no improvement then its vales.

And if you get to that point then its a head off and down to the machine shop with the head ($$$), new head gasket and whatever "whilst your in there" jobs need to be done. or forget about it and drive it like it is. but if you have just turbod it you might want to get the head in good shape before giving it a pounding.

but if it is the rings....well.....youve got some thinking to do.

[hakop_e30]

But what about WOT on all the others?

Cause if its now 115, 140, 150,150,150,150 then that's even worse!

If they improve drmatically with a bit of oil down the cylinders that tells you its rings, if no improvement then its vales.

And if you get to that point then its a head off and down to the machine shop with the head ($$$), new head gasket and whatever "whilst your in there" jobs need to be done. or forget about it and drive it like it is. but if you have just turbod it you might want to get the head in good shape before giving it a pounding.

but if it is the rings....well.....youve got some thinking to do.

Hey sorry for the late reply
I drove it around the block
car was turbod previously on a b25 block just got a good deal on a eta block so decided to swap blocks since the b25 had no compression in one of the cylinders
after taking the car around the block it
I went ahead and measured again
but again forgot to do wot


Cylinder 1 110

Cylinder 2 115

Cylinder 3 115

Cylinder 4 110

Cylinder 5 110

Cylinder 6 105

I believe it’s a 1985 eta block
with 885 built head
possibly the valves do need to be adjusted I will do that next

I just wanna enjoy the car till I turn this b25 block to 2.9l

Let’s say it’s the rings would 400whp be fine or should
i I have it get tuned for less power

[packratbimmer]

That short block and head combination will lower the compression so those numbers might not be so bad. The 200 eta head does not have an open combustion chamber like the 885.

[e30davie]

those results are good, +/- 10% seems fine, being close together is more important than the number itself. especially with some sort of oddball combo where there aren't any oem specs.

How does it drive? good? if so do the valves and keep on motoring.

[hakop_e30]

those results are good, +/- 10% seems fine, being close together is more important than the number itself. especially with some sort of oddball combo where there aren't any oem specs.

How does it drive? good? if so do the valves and keep on motoring.

driving way better then my b25 setup ever did and it’s not even tuned 😂
it’ was asking me to go into boost when I took it around the block

[hakop_e30]

I havnt had time I’ve been busy with a family emergency
once I have some time I will do the valves and take it for another spin and retest compression and I will also try a wet test as well on all 6