My Compression figures....

[peterako]

Hi all,

Just checked my compression figues. Engine hot, throttles fully open (we're at 200m above sea level):

Cylinder

1. 155
2. 60
3. 150
4. 150

With a squirt of oil:

1. 190
2. 80
3. 160
4. 160

So....cylinder head off time....rebuild time???

Oddly enough...car is performing very well (with the exception of warm starts). Accelerates very well and smoothly. Cruises at 130km/h (about 80 mph) with easy and will accelerate well from there....

Doesn't seem to be burning oil....gives me approx 40 mpg...

What will it be like when the cylinders are matched and at proper compression

Peter 73 +2S 130/5

[john.p.clegg]

Peter
Better..........


John

[pamitchell]

I'd advise a leakdown test in addition to the compression test.
Phil

[Otto]

I am thinking, that maby it could be your valveclearens that is off on the week cylinder. In my opinion there should be more "improvement" with the squirt off oil you made on the second test.
Regards
Otto

[peterako]

Hi Guys,

Thanks for your replies/comments.

I wasn't actually expecting any, so much appreciated!

Otto....yes I think there is a valve problem there. I acually posted the wrong figures for piston 2, they should be 65 and 80. So only 15 psi. All cyliners built to their pressure very quickly. But piston 1 is a bit worrying.

In any case, I recently had the engine out for a Sump Gasket and Crank seal.
While it was out we tightened the timing chain to recommended tension/movement.

Since then my warm starts have been horrible.

Hopefully it's all related.

I was just going to pull the head next week, but will now do a leakdown test as recommened by Phil. (Thanks Phil!)
I read up a bit on them last night and this could be quite interesting!

I'll post those results too.

Thanks again guys!

Peter 73 +2S 130/5 that's still respectably quick despite it all!

[memini55]

Peter,
Sorry to be a little late on a post but as Phil has suggested the leak down will tell all if down carefully. I have recently done this on my sons +2 which was also running well and showed no sign of oil burning. It had a very low cylinder and another down some. I was able to hear air leaking out the exhaust on one and the other was leaking out the oil stick. The exhaust was burnt valve and the other was weak rings. So out it came and a major rebuild was done. It only had about 4K miles from a previous owner rebuild. Even had the reciepts which goes to show not all work is up to standards.

Now what a difference!!! We have now been able to tune everything and it all makes a huge change. I hope you have similar success. Good luck.

Mark

[memini55]

Peter,
Sorry to be a little late on a post but as Phil has suggested the leak down will tell all if down carefully. I have recently done this on my sons +2 which was also running well and showed no sign of oil burning. It had a very low cylinder and another down some. I was able to hear air leaking out the exhaust on one and the other was leaking out the oil stick. The exhaust was burnt valve and the other was weak rings. So out it came and a major rebuild was done. It only had about 4K miles from a previous owner rebuild. Even had the reciepts which goes to show not all work is up to standards.

Now what a difference!!! We have now been able to tune everything and it all makes a huge change. I hope you have similar success. Good luck.

Mark