shop work

[usheral]

What did you use for seats (ie what material/supplier)?

[mike90045]

I have this as a possible part for a off the shelf seat:
"Detroit Diesel series 92 valve seats are a very close replacement"  for the 6/1's and their family.  it's what the machine shop put into my head.

[usheral]

Thanks, will look at those.

[Tom Reed]

I have this as a possible part for a off the shelf seat:
"Detroit Diesel series 92 valve seats are a very close replacement"  for the 6/1's and their family.  it's what the machine shop put into my head.

I used the seat cutter on the factory seats. If you do inserts you might as well just have the machine shop do the whole job. I did a head with the seats Mike suggested and it never did seal right. there maybe a crack in it though. Had the same problem before doing the seats.

[mobile_bob]

been a while, had some time so i thought i would read a bit on the forum and catch up a bit.

as for indian bent cams, seats that are too wide, etc... don't think for a moment that is limited to indian manufactures

i remember all too well in the mid 70' into the early 80's the cummins big cam engines that would shake your teeth out
at idle, it was so bad you couldn't see out the side rear view mirrors at idle.  you had to bring the idle speed up to about 1000rpm
to be able to get the mirrors to stop vibrating so you could see out of them.

turns out it was sloppy cam follower/timing,  each pair of cylinders had shims under the cam follower to set the timing, and cummins apparently just
through in the standard set of gskts, and get 'er out the door.

it wasn't until late '81 while working for a very well respected shop that i found out what the problem really was, and what they did about it.
they would fuss with those shim gaskets until the got a quarter thousands between all cylinders.  the result was an engine that ran silky smooth.

wasn't just cummins

detroit diesel 71 and 92 injectors, from their reliabilt line were dreadful, and we didn't know what that problem was for years, rough running very difficult
to get the rack set stable, and having to use more buffer screw at times than you would like.

it wasn't until '83 i found out the problem, i had an aftermarket rebuilder come in to my shop and sold me a set of Krody/Colyer rebuilt injectors.
what they told me was that the "reliabilt" injectors for instance if they were N65 brown tag (typical of an 8v71 nat) they might in actuality be N63 to N68 and would pass
inspection as good enough.  so in a set of 8 you might have 7 that were N63 and 1 that was N68, if so then you had an engine that was very difficult to get to run smoothly.

i installed a set of his injectors, and they were so well matched that the only reason i used the buffer screw was to catch the rack on deaccelleration from full throttle to idle.  those engines that used those injectors were as smooth as silk.

its hard to find an excuse for sloppy work, especially when they charge top dollar and are a first world oem manufacture.

i can't begin to tell you how many mechanics thought they were to blame for engines after overhaul that just didn' want to run right. little did they know it was the crap parts they were working with.

bob g