Stuck Piston Rings

[Redcar]

1989 Daytona 2.5 T-1 Converted to T-2. New rebuild. Piston rings stuck in the lands, all four pistons, and no compression. FWD computer. Cast pistons molly rings correct clearance. No evidence of detonation. Slight heating problems, temp get high before fans turns on. Never got really hot, no boil over. This is the second set of rings that has done this.Only 300 easy miles on motor less than 7 psi.
Any ideas?

[22dodge]

could be the wrong rings (shallow vs deep grove), damage to the pistons from detonation (even if you don't see signs), ring gap too tight.

doubtful but pistons damaged in assembly or shipping or manufacturing.

have you measured clearance between ring and land (approx .001")

do the rings stick at all when you compress and release (before assembly)? have you, with your hands, compressed the ring and rotated the ring in the land to see if there is any sticky spots?

[Redcar]

The ring gap is correct, the rings are correct, they do not stick when assembled. But some thing is wrong. I just don't know what it is.

[puppet]

Poor machine work? Are the bores straight?

[allmotor]

didja clean out the ring groove b4 u put in new rings

[Redcar]

The Bores are straight and the pistons were clean both times. A machine shop on the east coast told me to break in the engine with no boost. Any one hear of this?

[Ondonti]

That is usually what someone will tell you when they used the wrong rings. Or they know its going to fail and they want to be able to blame it on you because they know you will run boost.

[Redcar]

My Mopar book says the cast pistons should have steel struts
for expansion control. I pulled up Clevite web site and it shows a cut away of pistons with small strips of steel next to the pin boss. I don't see any thing in my pistons. I checked them with strong magnets and I can't find any thing. Any one know about this?

[puppet]

As far as the break-in goes ... most guys around here will say to run it like normal. Normal for these engines is boost.

What brand pistons are you using? Who did the machine work and how do you know it's right? Don't know if the pin offset could cause this ... rods are orientated correctly?

Obviously this has to do with the cylinders and their contents. This isn't normal ... the problem appears to be something that you've said is OK. (shrug)

[22dodge]

Quote:

Originally Posted by puppet As far as the break-in goes ... most guys around here will say to run it like normal. Normal for these engines is boost. What brand pistons are you using? Who did the machine work and how do you know it's right? Don't know if the pin offset could cause this ... rods are orientated correctly? Obviously this has to do with the cylinders and their contents. This isn't normal ... the problem appears to be something that you've said is OK. (shrug)

What cracks me up is when someone has a problem and is 100% sure that there is no way they made a mistake (assembly, wrong part, detonation etc.). I've built a lot of engines and never has stuck rings, I guess I'm lucky. the fact he's had the problems 2x with what seems to be one thing in common.

forged pistons wont have steel inserts. not all cast pistons do either. however this is only for re-inforcement of the pin and has nothing to do with the rings what so ever. BTW he didn't state if its the top or 2nd or oil or all 3 that are getting "stuck". The fact that it's happened 2x says to me, go to another machine shop and have a different professional look over the situation.

[Redcar]

The pistons are Clevite cast pistons. I don't have the number I threw the box away. The first rings were Hastings the second set were Speed pros. The machine work was done by the Block shop. I have had work done there before, they do a good job. I don't have a cylinder gage, but I used a caliper on the piston and the top of the cylinder. The measurements came out correct, as close as a caliper can get. The block was bored .20 over. My machine shop looked at the pistons, and they could not come up with a possibility. I have talked FWD and Turbos Unleashed, they don't know why. They both suggest changing the pistons. I still would like to know why this is happening. I don't like to shot gun. Most often it's my fault but its annoying when I can't figure it out. And by the way Its all rings on all pistons. Please don't bag on me I came here for help.

[22dodge]

Quote:

Originally Posted by Redcar The pistons are Clevite cast pistons. I don't have the number I threw the box away. The first rings were Hastings the second set were Speed pros. The machine work was done by the Block shop. I have had work done there before, they do a good job. I don't have a cylinder gage, but I used a caliper on the piston and the top of the cylinder. The measurements came out correct, as close as a caliper can get. The block was bored .20 over. My machine shop looked at the pistons, and they could not come up with a possibility. I have talked FWD and Turbos Unleashed, they don't know why. They both suggest changing the pistons. I still would like to know why this is happening. I don't like to shot gun. Most often it's my fault but its annoying when I can't figure it out. And by the way Its all rings on all pistons. Please don't bag on me I came here for help.

so you're saying all 4 cylinders have all 3 rings getting stuck? you would have 0-30 psi max if this happened. just like everyone else you talked you. you have to be the only person to have 12 rings get stuck 2 times. you need to buy a lottery ticket! you send my all 4 pistons and all 24 rings and I'll analyze, measure and solve your problem (for a price)

[Screamin4banger]

A bit of overheating, huh?
Were the pistons and rings varnished when you pulled them for inspection?

[Redcar]

No real varnish but I think you’re on to something. I have a friend who does bikes and snowmobiles. He says people get stuck rings frequently with water-cooled super charged and turbo motors. Its because they have trapped air in the water jackets and it's hard to burp it out. My engine never seemed to get hot. The gage never got real hot but it was fluctuating more than normal. I think that may be my problem. I'll try it and let you know.