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Re: Running on four cylinders....(instead of six)

To: Michael Noerregaard <ngaard@utxvms.cc.utexas.edu>
Subject: Re: Running on four cylinders....(instead of six)
From: "Michael D. Porter" <mdporter@rt66.com>
Date: Wed, 07 Aug 1996 21:34:05 -0700
Cc: triumphs@autox.team.net
References: <2.2.32.19960807120040.0069b634@utxsvs.cc.utexas.edu>
Michael Noerregaard wrote:
> 

> OKEY - OKEY

Sorry, but sometimes, one can't refrain from reminding the unfortunate. <g>
 

> Well, I got new valves, valve guides and valve seats in the spring sometime,
> so it is likely the piston rings - either they are 'gummed' up - or $$$$ -
> so I thought it would be worth it to try the Restore (that is only $8 a can)
> - and hopefully that will turn it around - otherwise we are talking about an
> engine rebuild since it will probably include a rebore, new crankshaft, new
> bearings, .....

I would have realized this had I been visiting here earlier.  The price is 
cheap 
enough that it's worth a try....  My former sister-in-law came to me years ago 
with a clapped-out old Plymouth which sounded as if every lifter in it was 
permanently frozen, and after explaining to her the cost of the parts, I 
suggested a little Motor Medic down the carburetor (without much hope it would 
do any good).  I made clouds of smoke thick enough to kill mosquitos for three 
miles around, but after about 15-20 minutes, every lifter freed up and started 
pumping up again....  She was ecstatic that the fix only cost her (then) about 
$4.  But, perhaps, first time's a charm, because I never had that kind of luck 
with the stuff again.    

As for all the parts you would imagine having to replace to do the job 
correctly, you may be able to get away with a bit less without compromising any 
quality.  It depends on the maintenance of the prior owner, to a considerable 
extent.  Unless the previous oil changes were few and far between, the crank 
can 
probably be turned without taking too much off the journals, so a new crank may 
not be required.  When I tore down the engine for my GT6+, I was fairly 
surprised by its general health.  And more surprised that the journals are not 
hardened, and still they survived well.  One rod journal had scored a bit 
because the big end of its rod had stretched a couple of thousands, but a 
regrind to 0.010 under cleaned everything up.  

The rebore might be necessary if the oil changes were infrequent.  But, 
remember, the older Triumph blocks are very heavy--thick walls and a very 
densely-grained iron.  All in all, with proper maintenance, they wear 
relatively 
well, compared with the iron used in contemporary thin-wall castings.

However, if you've had valve work done already, and it's still pumping oil, 
there's a great likelihood that the several of the rings are cracked.  I've 
disassembled a number of older Triumphs with high miles and found broken top 
rings in most of them, and cracked oil control rings in a fair number of 
cylinders.  That's probably a function of cooling systems undersized for the 
temperature extremes of our climate as opposed to GB, or of a lower level of 
ring technology from then to now.      

> 
> Thanks again for the advise - I am still learning, and it is great to have
> such a pool of knowledgeable people to learn from <g>

Well, none of us start out knowing much, if anything.  In the first Triumph 
engine I rebuilt, in my very early and cocky twenties, I managed to get the rod 
caps installed on the rods in reverse order (i.e., #1 on #4, etc.).  Regularly 
ran the engine to 6600 rpm for brief periods.  Didn't catch it until I tore the 
engine down several years later (when I knew better and noticed the prior 
mistake <g>).  Much more a testimony to the ruggedness of the construction than 
to my indifference to detail. <g>
Cheers. 

-- 
My other Triumph doesn't run, either....


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