fot
[Top] [All Lists]

Re: [Fot] TR4 continued race motor problems spun # 2 rod bearing

To: Joe Boruch <jaboruch@netzero.net>
Subject: Re: [Fot] TR4 continued race motor problems spun # 2 rod bearing
From: Mike Mehl <mike.mehl@yahoo.com>
Date: Tue, 19 Oct 2010 18:27:51 -0700 (PDT)
Joe;
thanks for the note.  I should have clarified Oil temp was 210 water never went 
above 180.  No oil in the water (that happened with the first motor).   I am 
running around 10.5 to 1 compression so clearance is not really a problem.  The 
engine looks really good except for the #2 connecting rod bearing.  Weird

Thanks!!!

Mike



________________________________
From: Joe Boruch <jaboruch@netzero.net>
To: mike.mehl@yahoo.com
Cc: fot@autox.team.net
Sent: Tue, October 19, 2010 6:14:45 PM
Subject: Re: [Fot] TR4 continued race motor problems spun # 2 rod bearing again 
 
- input thoughts needed


Mike, I would suspect that your head gasket is leaking at the #2, causing high 
combustion pressures, which are beating up the bearings, leading to the 
failures.  The steel shim head gasket is difficult to get to seal.  What are 
you 
doing to seal it?  Copper coat or aluminum paint are not enough.  I put copper 
wire o-rings in the fire rings and thinner copper wire around the lifter 
valleys.  Before I started doing that I was often having head gasket problems 
and once bent the # 2 rod.
210 deg water temp seems very high to me.  My TR3 runs 195 deg even on hot 
(northeast summer) days (with 13.5 compression and a 7300 rpm rev 
limiter). Perhaps the spike was the gasket letting go before all hell broke 
loose?  Was there much water in the oil?
How much clearance do you run between the pistons and the head?  With a stock 
crank you need at least 0.030 inch.  The crank does lots of flexing.
Any cylinder wall scoring?  What pistons and clearances are you running?  
That's my 2 cents.  Joe(B)

---------- Original Message ----------
From: Mike Mehl <mike.mehl@yahoo.com>
To: Triumph Friends of <fot@autox.team.net>
Subject: [Fot] TR4 continued race motor problems spun # 2 rod bearing again - 
input thoughts needed
Date: Tue, 19 Oct 2010 10:34:18 -0700 (PDT)

Well -several of you are up to speed on my engine saga.  First it was the head 
(May), then the # 2 rod bearing (July 4th Pacific Northwest Historic's) and 
then 

new engine #2 and then # 2 rod bearing again (Columbia Classic in Portland).  
My 

understanding that bottom end problems are not normally this bad.

So what changed. 
- #2 engine had a different engine builder do the engine.  He is very 
experienced and does at least one other FOT member engine.  He had 15 engines 
in 

the SCCA runoffs.  They know what they are doing. 
- The #2 engine had a new crank and all new forged rods.  The engine was 
running 

warm around 210F pretty consistently through all 4 sessions the engine ran an 
spiked up to 270 in a big hurry and that was it. 
- The engine is equipped with an Accusump.   
-  The engine is apart and there is nothing obvious that is wrong with the 
block.  Is there something weird they need to look for?
- The crank was not Nitrited (would that have made a difference this quickly)

Is there something we are missing?  I ran the engine between 5000 and 6000 RPM. 
It had a 455 rear end gear so I was painfully slow down the straights at PIR. 
Could stroking the engine at those RPMs have hammered the bearings?   Would it 
happen after a total of 90 minutes of run time?

In the mean time I have crank #3 on the way.


Any thoughts would be much appreciated.

Mike Mehl 62 Triumph TR4 - Vancouver Washington   
_______________________________________________
fot@autox.team.net

http://www.fot-racing.com

Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums
Unsubscribe: http://autox.team.net/mailman/options/fot/jaboruch@netzero.net


____________________________________________________________
Moms Asked to Return to School
Grant Funding May Be Available to Those That Qualify.
SeeCollegeDegrees.com
_______________________________________________
fot@autox.team.net

http://www.fot-racing.com

Donate: http://www.team.net/donate.html
Archive: http://www.team.net/archive
Forums: http://www.team.net/forums


<Prev in Thread] Current Thread [Next in Thread>