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Houston.... we have a problem!

Sterling said:
Stupid question, but is it possible the engine just hasn't fully seated the rings yet? 530 k is only 300 miles, My 05 rx-1 drove me crazy when I tried to sync the carbs at about 500 k. Once I had 1500 on it I tried it again and it was bone simple. The only thing I can think, was the vacume signal was different on all four due to the low time on the engine. I now have 2200 on mine, 600 with sc boost, and I swear it still is getting stronger. I know you are not trying to sync carbs (ain't none!), but maybe something to consider. You mentioned a lot of air in the crankcase, which could mean rings not yet seated. Just my two pennies. Wish you all the best!

my rx1 has 100 miles since new pistons/rings and has a perfectly good ring seal, so I don;t think this is the problem
 

Detonation is a ugly beast, your rings could have been destroyed.

Take a look at the picture posted by jhlarsen. In this picture you see clear evidence of detonation on the intake side of the cylinder. It has been detonating around the edges of the pistons at top dead center. Such detonation will destroy rings. I have been working on detonated engines (with less cylinder damage than shown in jhlarsen's picture) with rings destroyed and serious loss in compression as a result of that. It can be hard to tell by looking at the pistons as they are often not much damaged, you have to measure them to see that they have actually deformed. If you tear your motor down please measure your cylinders to check that they are not out of round.
 
i would agree. The dyno can be too much fun sometimes and because its controlled you stay on it too long and lean on it too hard.
Remember the 809 Ski-Doo!! people would always complain that half way through the winter holding them wide open down the lake all day and running reg gas that they would get slower and slower....It was because the crap fuel would let the motor detonate just enought to blow the moly out of the rings. toss in new rings and what ya know fast agin..
 
rxrider said:
Detonation is a ugly beast, your rings could have been destroyed.

Take a look at the pics posted by jhlarsen, in this picture you see clear evidence of detonation on the intake side edges of the pistons, such detonation will destroy rings. I have been working on detonated engines with less cylinder damage with rings destroyed and serious loss in compression as a result of that. It can be hard to tell by looking at the pistons as they are often not much damaged, you have to measure them to see that they have actually deformed. If you tear your motor down please measure your cylinders to check that they are not out of round.

I am getting the motor done this time, I don't have time and all required tools for a complete tear down. Block will be reinforced as well as the head itself, oring, oil pump ported, forged. This time I will have no excuse to not run that gt28 as it should run.
 
Keep us posted on your motor build, and what you find went wrong with your engine. I'll hope you get'r done before the snow flies.
 
rxrider said:
Keep us posted on your motor build, and what you find went wrong with your engine. I'll hope you get'r done before the snow flies.

Should be!

Will keep you posted!
 
:) Thanks

BTW - cleaned up inside my garage today, finally dug out the turbo from underneat whatever junk collected since last spring. Nice to see her again at last. Time to start working on it.
 
Maudit Mulot...té partout!!!!

Une bonne place ici pour avoir la vraie heure juste sur nos Yamaha!!

Mais le problème....je suis pas perfect bilingue!!!

:4STroke:
 


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