Thanks for the thoughts Rich. I basically agree that there is not much point
in upgrading some of the engine as it will put undue pressure on the rest of
it. My engine's history is unkown to me as I got it from a junkyard. I know
it's been rebuilt at some stage as the mains and big ends are using
undersize bearings.
I did a compression test yesterday and the highest was 190Psi and the lowest
160psi - engine re-con books suggest a 'spread' of cranking pressures of no
more that 75% between the highest and lowest, so I'm not looking too bad
there (according to the P76 manual it should be 192psi).
I'm just going to replace the timing chain as that's pretty cheap to do and
then just carry on. There's a winter series of six sprint races coming up,
so I want to be ready for that....!
Simon
-----Original Message-----
From: Rich Atherton [mailto:gumby@connectexpress.com]
Sent: Monday, 12 April 1999 08:41
To: Simon Sparrow; 'Gregg Feldman'; 'Peter Kent'
Cc: Buick-Rover-V8 mailing list (E-mail)
Subject: Re: Cam Lobe Wear
Sorry I haven't been on here in a while, and not sure if this has been
answered yet or not. (still have 90 to read through!). I can tell you from
experience that you are working ith a tired engine, that much cam wear, and
that much slop in the cam chain indicates that this is ONE tired engine.
Speding the money on a top end job would be foolish. and heres
why.......All of the engine is worn, and is till working nicely together,
albeit, not producing a lot of power...if you rebuild the heads, slip in a
new cam and lifters it will help in many ways, but it will also cut short
the life of what is left. All of those fresh parts will up the compression
becasue of increased flow due to the correct cam timing and lift, less leak
down thanks to a fresh valve job gaskets and resurfacing of the hed, and a
slight reduction in combustion area due to the resurfacing of the head as
well. now this all sounds good, and it is, except for the fact that you
will be asking old sloppy pistons and heavily worn rings to keep this all in
the combustion chamber, and not leak past the rings... In fact what will
happen is that even MORE will leak past but now it will be burning hotter
than before, and will have more preasure and volume than before......Bottom
line here is that this stress on the rings maybe more than they can
handle.....and then they will fail shortly after the rebuilt top end is
installed.
This happen axactly this way to me in my Sunbeam's 1592cc four banger.
It was very tired, and all I did was the valve job and resurfacing. it
brougt the compression back up, and more power too, but also more blow by
for the rings. It ran for less than a month after that. While going up a
hill in 3rd gear with wide open throttle (it's what it took to get up the
hill at speed), the blow by was too much for it, and the rings and piston on
the exhaust side "Melted". The moltant aluminum and iron cooled quickly as
it landed on top of the remaining piston whic then slamed into the the
freshly rebuit head destroying both the head and most of the remain top of
the piston, which then tilted and weged in the cylender punching a small
hole and a big crach through the wall into the water jacket..........Boom!
she was dead....All becasue I didn't want to do the whole engine...that car
never saw the street again, it became my Buick 215 project car, which I
never finished, and sold it later
So take HEED.....drive it till it quits, or do it all.......if it only had
50- 75 thousand miles on it, maybe you could get away with it, but it sounds
more like 150 to 200 on it already.....Just let it die with the parts that
it has, then dump it for the Rover block ......I wouldn't spend a dime on
it!...
Just my thoughts.....Maybe it helps, maybe it doesn't... But that's what I
would do...
Rich
-----Original Message-----
From: Simon Sparrow <Simon.Sparrow@wang.co.nz>
To: 'Gregg Feldman' <theaterwiz@worldnet.att.net>; 'Peter Kent'
<pkent@skynet.net.au>
Cc: Buick-Rover-V8 mailing list (E-mail) <buick-rover-v8@autox.team.net>
Date: Tuesday, April 06, 1999 9:06 PM
Subject: RE: Cam Lobe Wear
>As with my situation, its tricky to know. You can check out your engine
like
>I've done (check timing chain slack, valve lift, compression etc.)and if it
>all looks reasonable go for the low-buck approach.
>
>My thoughts are if part of the motor is worn to some degree, then there is
a
>better than even chance that the whole thing could do with looking at. So
>there may not be much point in upgrading the heads if the bores & bottom
end
>are a bit tired.
>
>However, replacing a stretched timing chain is relatively cheap and easy,
>and should help prolong the life on the engine. (this is what I've
convinced
>myself of anyway...:-) )
>
>Ever since I've had the engine I've regularly changed the oil, and always
>warm the engine up for 1 minute before driving away. These two little
things
>should help get the most life out of it.
>
>Simon
>-----Original Message-----
>From: Gregg Feldman [mailto:theaterwiz@worldnet.att.net]
>Sent: Wednesday, 7 April 1999 15:13
>To: Simon Sparrow; 'Peter Kent'
>Cc: Buick-Rover-V8 mailing list (E-mail)
>Subject: Re: Cam Lobe Wear
>
>
>Those are my thoughts exactly..only in US Dollars...;-)
>How ever , I have 150,000 miles on my 1988 NAS Range Rover
>and figure the bottom should be good for another 100,000 , so if
>I spend a grand now , for the tune up , maybe its not such a bad Idea
>Whats the reality of my engine going to 250,000 ? any thoughts?
>Gregg Feldman
>1988 DERANGED ROVER
>AA Yellow
>http://hometown.aol.com/theaterwiz/page/index.htm
>
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