Hi I am new on here and Im not sure where to post

[69Torino]

Originally Posted By: Vailshred
Thank you everyone, never had so many helpful and quick replies ever on any other forum! You guys are great

Ok... so I should be getting compression test numbers at around 160-170ish. I was thinking that they were low because of rings not seated yet. Thoughts?

I will start a leakdown test next week. Im leaving town Tuesday and im full till then. I return on the 11th and will get right to it.

Im not leaking any fluids at all nor have I lost any coolant yet.

Should i drive it for a bit and see if power starts gaining with milage?


If you are significantly down on power and slightly down on compression, I have 2 questions/recommendations;
1: Are you 100% positive the cam timing is correct? One tooth off will affect compression numbers. Off at crank, all cylinders affected, but also not likely to run at all. Off on one bank, that bank's compression will suffer a bit.
2: During engine assembly, were the piston ring gap clockings staggered? In other words, if there are two compression rings and an oil control ring pack, were the end gaps stacked on top of one another or equal thirds around the piston? Stacked ring gaps can and will create compression leakage. Do you have access to a cylinder leakdown tester? This will help pinpoint a compression loss.

My comments aren't meant to scare, just some things to think about, in an effort to solve or diagnose the lack of power you mentioned.

 

[Vailshred]

Originally Posted By: 69Torino
Originally Posted By: Vailshred
Thank you everyone, never had so many helpful and quick replies ever on any other forum! You guys are great

Ok... so I should be getting compression test numbers at around 160-170ish. I was thinking that they were low because of rings not seated yet. Thoughts?

I will start a leakdown test next week. Im leaving town Tuesday and im full till then. I return on the 11th and will get right to it.

Im not leaking any fluids at all nor have I lost any coolant yet.

Should i drive it for a bit and see if power starts gaining with milage?


If you are significantly down on power and slightly down on compression, I have 2 questions/recommendations;
1: Are you 100% positive the cam timing is correct? One tooth off will affect compression numbers. Off at crank, all cylinders affected, but also not likely to run at all. Off on one bank, that bank's compression will suffer a bit.
2: During engine assembly, were the piston ring gap clockings staggered? In other words, if there are two compression rings and an oil control ring pack, were the end gaps stacked on top of one another or equal thirds around the piston? Stacked ring gaps can and will create compression leakage. Do you have access to a cylinder leakdown tester? This will help pinpoint a compression loss.

My comments aren't meant to scare, just some things to think about, in an effort to solve or diagnose the lack of power you mentioned.


Yes, 60 degrees on each ring. Im sure they may have rotated a bit on installation so I cant say that they are perfect but odds of them stacking with gaps above eachother are low.

I have a leakdown tester and will perform the test and let you guys know.

As for the cams, they are keyed and locked along with the crank to set timing. I have done a half dozen timing chain services on these engines and have never had a issue BUT I am open to anything at this point.

I have driven motors with lower compression than what my results showed and they had more power/torque then this fresh ringed engine....

 

[Trav]

Compression test = warm engine with WOT. Cold numbers are almost meaningless other than telling you some compression is there and will result in higher leak down rates.

 

[kschachn]

Originally Posted By: Yah-Tah-Hey
Avoid engines with aluminum bores like the plague.

What happens? Should my BMW be dead by now?

 

[Nick1994]

Originally Posted By: kschachn
Originally Posted By: Yah-Tah-Hey
Avoid engines with aluminum bores like the plague.

What happens? Should my BMW be dead by now?
Your BMW died a long time ago kschachn, didn't you know!?

 

[kschachn]

Originally Posted By: Nick1994
Originally Posted By: kschachn
Originally Posted By: Yah-Tah-Hey
Avoid engines with aluminum bores like the plague.

What happens? Should my BMW be dead by now?
Your BMW died a long time ago kschachn, didn't you know!?

No way, I just put new power steering hoses and new oil lines on it last month!

Way too much money and time into it now to let that happen

 

[bbhero]

That's just awesome. Yeah your BMW is on death's door

 

[BlueOvalFitter]

Originally Posted By: Vailshred
all temps seem normal. Compression test with block cold were between 135 and 145 on all 8. Tops of pistons were damp when I peeked through plug holes, 1 cylinder was dry. I do remember when I took it out for the 7 mile spin it started to gain a little more power towards the end of the drive. Maybe that 1 dry piston was beginning to seat?

What were the wet (oil added) compression test numbers?

 

[ARCOgraphite]

Rings upside down? Ill go with cam timing 1st then mechanical ssy issues 2nd if build by and experienced individual. Also,
Don't forget that GROUND wire you left off

 

[SilverFusion2010]

Run it hard for a couple weeks and make sure to get the rpm up. I like the mototune USA break in method. Basically you warm the engine up then run the [censored] out of it with plenty of engine breaking and WOT. Otherwise I’ll defer to those who have actually torn down and rebuilt engines

 

[BrocLuno]

I'm old school and never break in an engine on anything advertised as "Synthetic". The exception being the blower drag motors that get broken in on Redline and last maybe five runs before they get a complete o'haul.

I used to use Chevron Supreme (dino) and it worked well for me. But when the ZDDP numbers started going down, I switched up to Chevron Delo 15W-30 SD (severe duty) because it's for "off-road" equipment and has no CAT design issues to worry about. That is my current go-to break-in oil

Valvoline VR-1 10W-30 is pretty much the standard hot motor oil used by many engine guru's. The silver bottle is the semi-syn product and what I'd use in your situation. It's been used in hundreds of thousands of engines with serious HP. Assuming they got the honing pattern right(?), it should seat rings in 500 miles.

I prolly would not have used the OEM Audi low tension rings. They are good up against aluminum, but they have many internet stories about poor sealing and further loss of tension as they age ... For Audi it's an engineering trade-off. For a rebuilder with an alternative cylinder surface, there are other options ...

So the real test of poor sealing is blow by. Run the motor hard with the oil fill cap off and see what it is doing? If it's puffing like a steam train, you have loss of cylinder sealing. If it's not blowing oil vapor you have issues elsewhere ...

Timing is number 1 including ignition timing. Maybe the pick-ups got moved ...

 

[Vailshred]

Hey everyone, just wanted to update the thread on where Im at.

Power loss was due to a knock sensor being bolted upside down. As soon as it was attached properly the motor started producing power.

All the synthetic oil was drained and conventional was added. Now I just need to drive it for a while and hope that the rings seat properly.

Im thinking of adding some zinc additive to the oil....

Thanks for all the help