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View Full Version : Early 2.5 missing #4 sealing ring?


B.Mac
05-06-2003, 05:45 PM
1989 2.5, 7 petal carbed, bottom guided, 2.4 oiler crank, small rods........

When BL & I dismantled the motor there was NO sealing ring on #4. Anybody have a clue whats up there? #4 detonated and this is bugging me about this sealing ring. The motor was rebuilt by Gene Triechel (G-Force) in '99, and #4 stuck soon after. He resleeved #4 and replaced a piston in there and gave it back to the previous owner and now she detonated #4 again on me......

Is there any logical reason Gene left this sealing ring out? Is it possible it was left out to better lubricate the lower center main?
Would this not create a lazy air condition or would this not matter once the crankcase is pressurized?
I don't get it......there's a groove in the crank for one.......but no ring?
Do I dare reassemble this thing like that?

Hurry up before BL puts it back together like that !!!!!!!
Look at him.......:eek: :D
B.MAC:D
B.Mac
05-06-2003, 05:47 PM
pic.......
B.Mac
05-06-2003, 05:55 PM
crank pic.......
Burke Kilgour
05-06-2003, 06:41 PM
This has been discussed here before and I was told by Jay and US1 to leave the sealing ring(s) OFF (above both centers if its a 9 ring) for any high RPM Merc. It does allow more oil to lubricate the center bearing. US1 even suggested the motor would not "live" at high RPM without this done.
us1
05-06-2003, 07:36 PM
Thats true.
B.Mac
05-06-2003, 09:38 PM
Is the ring missing from the right location on this crank?
No rings above the two center mains right?

(The motor is at BL's & I can't look at it)
Thanks much fellas.....:D
B.MAC:D
us1
05-06-2003, 10:31 PM
Yes it is.
B.Mac
05-07-2003, 06:05 AM
Thanks for responding.......I was lying awake at night:eek:
B.MAC:D
WATERWINGS
05-07-2003, 09:10 AM
I believe T-REX doesn't use one above the lower main (BIG) bearing also.
Talon2.5
05-07-2003, 03:07 PM
we have too

ok "Mac" get back to your nap hehehehehe

wings, get back to work hehehehehe
vector mike
05-07-2003, 04:46 PM
What do you consider "High RPM"? Also, should the remaining rings be replaced during a rebuild?
B.Mac
05-07-2003, 05:39 PM
My motor might see 6200- 6400 maximum......
I'm assuming they are speaking of 7000- 7500 and up......
It's my understanding that when it comes to the sealing rings, if they ain't broke, leave 'em alone but these guys would know better than I......
B.MAC:D
us1
05-07-2003, 05:53 PM
7000 and up. Dont bother replacing the rings unless they are badly badly worn.