Should I be worried about my rings? Rebuild*

[talonDSMerr]

I didn't see a need to dumb it down. But you're right in that getting into boost usually means you're loading the motor. I felt the need to clarify that its not boost pressure that helps seat rings, its putting load on the motor.

 

[DSMer541]

My motor saw 15 psi on a 14b and WOT 3rd pulls the first 10 miles.... lots of LOADing the engine and engine breaking. The trick is to HEAT CYCLE, after going for your first drive and doing a couple hard accel-decel pulls, drive back to your house and let it sit for a couple hours, repeat that a few times... then CHANGE THE OIL within the first 50 miles and again at about 500 miles. Then just drive it like normal, dont baby it but dont beat on it either. Also try not to maintain steady speeds for to long if your on the freeway, vary your speed by 5 to 10 mph accelerating and decelerating without using your brake pedal.

After that method I used I had about 175 compression accross the board on 8:1 pistons after about 800 miles.... I have over 5k on it now.

But like said before it might be to late... the motor needs to be loaded up ( WOT ) within its first miles....

 

[jb2zero0six5]

Any new numbers yet?

 

[Burnett03]

Let me rephrase. While you don't have to boost a turbo motor, the rings won't be worn properly for the boost you will be running in the future. you should never baby a motor to break it in.

The bearings will be broken in upon the first 5 second of the engine running due to little or no lubrication film. The rings want to be pressed out into the cylinder walls and that needs higher cylinder compression. So, boosting it more the better.

Of course NA motors won't get boost, they are seeing their highest cylinder compression at WOT.

Do some research bud, you see the reasons why you would want to break the motor in on a track run or dyno.

Being your car, you can do it however you want. If you want a proven way that makes more power and little to no blow by then run it hard. Otherwise baby it and enjoy leaky rings and less power from not sealing the higher cylinder pressures that you now run it at.

Being that you are a "wiseman" you would think you would know how the rings are seated on a motor. The combustion gases will force the rings against the cylinder wall enough without boost. We can argue the break it in hard, break it in soft all we want, we both have done it different ways and i'm telling you that i have built a few motors and have always kept them in low boost, but varied the rpms to break them in, and i have yet to have one fail. Just like how you will say you have boosted the hell out of them and they have been fine. But tell me this, why is my way wrong? There are alot of manufactures that tell you, (turbo and non turbo) to take it easy for a while and vary the rpm to properly break in the motor. So tell me, are they wrong to? Was yamaha wrong for telling me to stay under 9k on my brand new R1 for a 1,000 miles? I don't totally disagree with what you are saying, i have broken in one motor pretty hard from the start and it seemed to do fine, but when you said you "have to do something" then that's when you are wrong because both ways work. How many motors have you broken in wiseman? Your signature says your current one has a bad #3 cylinder, maybe due to your break in method?

My motor saw 15 psi on a 14b and WOT 3rd pulls the first 10 miles.... lots of LOADing the engine and engine breaking. The trick is to HEAT CYCLE, after going for your first drive and doing a couple hard accel-decel pulls, drive back to your house and let it sit for a couple hours, repeat that a few times... then CHANGE THE OIL within the first 50 miles and again at about 500 miles. Then just drive it like normal, dont baby it but dont beat on it either. Also try not to maintain steady speeds for to long if your on the freeway, vary your speed by 5 to 10 mph accelerating and decelerating without using your brake pedal.

After that method I used I had about 175 compression accross the board on 8:1 pistons after about 800 miles.... I have over 5k on it now.

But like said before it might be to late... the motor needs to be loaded up ( WOT ) within its first miles....

This to me is the proper break-in. Not that "wiseman" beat it till it bleeds method.

10-20psi of boost will not "push" the rings for a better seal. Boost isn't what helps seat the rings. 10-20psi is nothing compared to combustion pressures.

The idea behind boosting a motor during break in isn't so much getting positive pressure in the intake - it's putting load on the motor. Loading the motor is what is important during break-in and what helps the rings seal. Combustion pressures with load on the motor reach much higher levels and this is the pressure that pushes rings outwards so they can seat.

If boost was so important to breaking in motors, you would see N/A motor builds breaking in their motors by slapping on turbos...

This man deserves the "wiseman" title.

 

[danl]

Something isn't right in that motor, its going to come apart again to make it right. I've had a full 160psi after a short 1 min idle. That was with a fresh hone and reusing old piston rings. Also I'll do a 0-100 mph pull with a 5th gear coast down, change the oil, and the car is ready to race or daily drive.

I'm willing to bet the OP's motor has vertical scratches in the cylinder walls. It's the most common low compression issue after a re-ring. Sometimes its due to dirt, debris, or not being clean during assembly. Other time it is due to improper piston ring filing. Other times its due to incorrect piston/wall clearance.

 

[ziggo0]

Something isn't right in that motor, its going to come apart again to make it right. I've had a full 160psi after a short 1 min idle. That was with a fresh hone and reusing old piston rings. Also I'll do a 0-100 mph pull with a 5th gear coast down, change the oil, and the car is ready to race or daily drive.

I'm willing to bet the OP's motor has vertical scratches in the cylinder walls. It's the most common low compression issue after a re-ring. Sometimes its due to dirt, debris, or not being clean during assembly. Other time it is due to improper piston ring filing. Other times its due to incorrect piston/wall clearance.

That's why we had it rehoned due to some vertical scratches when the motor was out. It was deglazed. My idle vac is better but my wideband is acting up. I'm gonna get a better compression tester tomorrow and a leak down test.

Turbo turbine side is bone dry. One thing I recall when I pulled this head to rebuild it - 2 exhaust ports were just covered in oil...I have a thread on it in this section. Perhaps something is wrong with the head?

Figured I would share the good news. Got to use a better compression tester today, hot engine, gas pedal all the way down, 170 across the board. Spark plugs aren't fouled, turbine side of turbo isn't leaking - it's bone dry. I'm guessing bad stem seals/guides (stem seals are brand new).

 

[ziggo0]

Figured I would share the good news. Got to use a better compression tester today, hot engine, gas pedal all the way down, 170 across the board. Spark plugs aren't fouled, turbine side of turbo isn't leaking - it's bone dry. I'm guessing bad stem seals/guides (stem seals are brand new).

Edit to the new post. I got the old head off. Valves bounce around in the valve guides completely loose. I put the valves into a known good head with good guides and it's tight as a button. Can't wait to fire it up in a few hours and hear the SIM 275s

 

[SrKegler]

Glad to hear some good news.

 

[ziggo0]

Same. I got my new head together with some SIM 275s, put about 200 or 300 miles on it now - they seem to go so fast when you want to hear it cam'in. Finally got around to turning the boost up and wow, I definitely missed my car.

Here is the news on the smoking condition. Compression is still good and equal across the board. Turbine seals on turbo are good, new valve stem seals, new valve guides - all my friends tell me I'm smoking on decel - as in if i were to run out 3rd gear then let it slow down from the top of 3rd is when it's smoking. - PCV possibly?

 

[scott90gsx420]

Pcv is very possible.. If it were rings or something in the cylinder it would due it all the time.. And usually valve seals will smoke on the initial push of the throttle especially after long idles or after sitting for a hour or so... So if its on decel then its when the motor is creating large amounts of vacuum and then sucking in oil somewhere... And there are only a few possible explanations for that.. Clean/swap the pcv and let us know man..