blow by?

nitrousED

New Member

Oct 14, 2003

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Jul 11, 2004

#1

• Jul 11, 2004

• #1

400 miles on the build ,i have 120lb cyl pressure on all but one cyl,it has 80.Im assuming i have a ring seating issue.Also have a fuel smell with a little smoke coming out of vc vents at idle but when i get in on it, it smokes a good bit.Is it time to pull the motor down and put a better ring in?

didnt realize they were chromeoly

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

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Jul 11, 2004

#2

• Jul 11, 2004

• #2

id do a leakdown test first.

 

nitrousED

New Member

Oct 14, 2003

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Jul 11, 2004

#3

• Jul 11, 2004

• #3

just did a test by dropping some oil in the cyl that was low,well it went from 80 to 125lb just like that,im told that is a cracked ring

 

HISSIN50

"How long does it take to get help in here?

15 Year Member

Nov 29, 1999

31,179

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129

Jul 11, 2004

#4

• Jul 11, 2004

• #4

ok, wet compression test compared to dry does help. and your results do suggest a ring problem. that works.

 

nitrousED

New Member

Oct 14, 2003

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Jul 11, 2004

#5

• Jul 11, 2004

• #5

waiting for a few more replys,then it may be time to rering

thanks

 

8

87'GTstang

New Member

Feb 16, 2004

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Jul 11, 2004

#6

• Jul 11, 2004

• #6

Like hissin said, do a leakdown test. 10% or less is good, 5% is great. Anything higher suggests you have major ring issues. Make sure you read up on the procedure as there are a lot of things/guidlines that you go by to tell what signs mean what *rings, valves, seating, ect.).

It does however seem like, no offense, cheap piston rings - either that or poor install that lead to damage upon installation.

 

nitrousED

New Member

Oct 14, 2003

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Jul 11, 2004

#7

• Jul 11, 2004

• #7

i believe they are cheap rings,i didnt do anything different than the last few times i installed rings,i guess ill see if the leakdown test fails.i have a funny feeling it will end up in a tear down

another test i ran is i took the rocker arms off on that low cyl and put about 100lb of air in the cyl and felt a good amount of air coming from the oil drain holes in the head,seemed alot less air came from the other cyl


thanks

 

bgjohnson

Founding Member

Sep 1, 2002

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johnston,iowa

Jul 11, 2004

#8

• Jul 11, 2004

• #8

well man it sounds like you may have to bite the bullet and refresh the motor a bit, like new heads (or have the valves and seats reground on the stock ones)and rings and have the block cleaned up