trouble shooting frustration
#2955162
08/18/21 08:33 PM
08/18/21 08:33 PM
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Joined: Feb 2017
Posts: 566 Texas
RustyM
OP
mopar
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OP
mopar
Joined: Feb 2017
Posts: 566
Texas
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Hey Guys: The 65 satellite 440/512 race car was doing great all season- then it wasn't. End of a 6.32 pass, it didnt want to idle down. Kill car and restart- no idle issue. Checked "everything " for vacuum leaks- none found. Checked carb- noticed some black material starting to form on carb blades, but it seemed "hard" would not easily clean off with carb cleaner- then they called our index. Car repeated the run with a 6.33, idled up again coming down return lane. we won the night with that pass, took pics, loaded up.
Next race was to be in bad air,i wasnt going with the car, threw a tune in it- car didn't run for crap, thought: how the heck did i miss a tune that bad? Guys just backed up an index , did well. Pulled data when car got back- tune wasnt that bad, but drivers bank and little lean and should not have been- what the heck? Pulled carb, black material on edges of blades might not let carb blades close correctly and, perhaps its a intake gasket- sure enough, pulling oil through intake bolt holes going through to rocker area- but carb has this oil all up in it- sigh, Tear Carb down, give it a good bath, get it ready, new intake gaskets, use thread sealer on bolt holes- we should be ready to go, cars sounds "right again".
we go to races, have a t&t friday night - jetting not good, get jetting squared away- car will not run the number, in fact, it keeps getting slower, even when Da's are getting better. Check everything, check everything- rinse and repeat several times- plugs look great, carb clean, afr's are dead nut for both banks. Qualifying saturday- car makes a decent run on Q1, slows down again on Q2- but we cant find a dang thing causing it- now im pulling out whats left of my hair- I dont miss tunes very often and unusual i cant see in my mind whats not right or, a good theory anyway. Plugs staying nice. Back up an index, slow car down, make rounds, car starts belching smoke out the valve cover breather on passenger side bank after the run, when we kill the car- tiny bit on passenger side- but i notice both filters are now oil soaked- i think we have lost ring tension , cracked a ring- but the plugs look fine! We decide to try and make a round, maybe two to protect our points lead, lose out but, its ok, we were in first place, now 10 points behind- not a problem.
Get car home, do a compression check- passenger bank is 200, 200, 208, 198, drivers bank is 197, 187, 187, 200- so, ok, maybe, maybe we have lifted the head between 2 and 4 a little but, nothing for sure. Pull the rockers, do a pressure test at tdc and btc .
Number 1 -5% loss NUMBER 2- 10% LOSS NUMBER 3- 10% LOSSS But, on cylinder 1. with no valvetrain on the car, i can hear air leaking Number 2- more air leaking Number 3- same as 2
air not in intake, not in header- - its coming out the lifter galley - you can actually feel the air moving if you put your hand between the pushroad galleys.
We pull the heads- cannot find even the slightest indication of a bad head gasket, and i mean- nothing.
These are cometic mls gaskets- can this leak be between the layers and just gets worse with heat cycling? Needless to say the heads are going to machine shop for a cleanup for straight/flat but i sure would like to know- for sure- whats happening here and, im wondering if crankcase pressure "pushed" oil up the intake bolt holes, wetting the inatke gasket, softening it and thats how we pulled in the vacuum leak that pulled oil up into the intake/carb?
Im just puzzled how the head/ gasket/block can look that good, but be leaking and, plugs stayed looking great. The oil is what was screwing up the tune- i get that. I figure the smoking was because the carb was no longer pulling the crankcase pressure out , it had to go somewhere, yet i still don't "know" why it was smoking after we kill engine unless its draining back oil into a cylinder one we kill it and lose crankcase pressure.
Can these MLS gaskets breath between the two layers , let oil flow back and yet still hold almost 190 lbs of cranking compression?
Puzzled guy that just really wants to know.
Thanks guys- hope you are all well.
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Re: trouble shooting frustration
[Re: RustyM]
#2955178
08/18/21 09:41 PM
08/18/21 09:41 PM
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Joined: Nov 2003
Posts: 36,040 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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strickly just thinking out loud/giving you a BTT. Are the rivets out of the MLS gaskets?
live every 24 hour block of time like it's your last day on earth
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Re: trouble shooting frustration
[Re: dvw]
#2955278
08/19/21 10:31 AM
08/19/21 10:31 AM
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Joined: Jun 2006
Posts: 5,161 CT
GTX MATT
master
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master
Joined: Jun 2006
Posts: 5,161
CT
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Did you ever leak it down before the issue to compare?
Last edited by GTX MATT; 08/19/21 10:37 AM.
Now I need to pin those needles, got to feel that heat Hear my motor screamin while I'm tearin up the street
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Re: trouble shooting frustration
[Re: NITROUSN]
#2955299
08/19/21 12:36 PM
08/19/21 12:36 PM
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Joined: Dec 2011
Posts: 201 Texas
Chief
enthusiast
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enthusiast
Joined: Dec 2011
Posts: 201
Texas
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It sounds like ring sealing issues to me, sorry Thats the only way air is going to get in the crankcase. Dave
Dave Covey
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Re: trouble shooting frustration
[Re: Chief]
#2955318
08/19/21 01:26 PM
08/19/21 01:26 PM
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Joined: Feb 2017
Posts: 566 Texas
RustyM
OP
mopar
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OP
mopar
Joined: Feb 2017
Posts: 566
Texas
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Yes, we have done leak down prior, no, its not the rings, cylinder walls are fine, crosshatch looks good. After doing some more research and making a couple calls, Apparently this IS a known issue and , yes, MLS gaskets can leak between layers if the head lifts slightly . Top of the gasket/head leaks into the lifter galley area around/through the head gasket at the top of the block . Never ceases to amaze me the odd things i run into. Now, that said- if the heads don't show to have lifted between 3 and 5 ,,,, im back to square one with this troubleshooting nightmare. Rings appear to be fine from an upper inspection, walls all look good and no- the smoke is not steam- steam doesn't fill the breather filters full of oil and there is no indication of water vapor in them, the oil or oil in the water. Near as i can figure- engine is turned off, back pressure stops, oil rolls back down the leak path and lands on hot piston or, something HOT and viola, the smoke comes back up and out the breather.
Best i can come up with- everything looks great, tests great except for hearing air come out the lifter galley with a pressure test and its not coming out both sides per say- its coming out right above 3 and 5. You can stick your finger in there pretty good and feel it better- stick a piece of paper in it and it will blow the paper around. Going past the rings, it would be pretty well diffused to the whole internals i would imagine.
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Re: trouble shooting frustration
[Re: jwb123]
#2955616
08/20/21 10:29 AM
08/20/21 10:29 AM
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Joined: Jan 2003
Posts: 10,702 North Dakota
6PakBee
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,702
North Dakota
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This may be a stupid suggestion but old school test for rings was to do a compression test and then do another with oiled up cylinders to seal the rings. Is this approach of any value with a leakdown tester?
"We live in a time when intelligent people are being silenced so that stupid people won't be offended".
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Re: trouble shooting frustration
[Re: RustyM]
#2955637
08/20/21 11:52 AM
08/20/21 11:52 AM
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Joined: Aug 2011
Posts: 2,853 Pattison Texas
CSK
master
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master
Joined: Aug 2011
Posts: 2,853
Pattison Texas
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I have seen broken compression rings pass a compression & leak down test, but when running they would expand & seal & the let loose & blow oil out the breathers
1968 Charger COLD A/C Hilborn EFI 512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim 2020 T/A 392 Stock 11.79 @ 114.5
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