RE: [ihc] Ted's under pressure

["Steven Stegmann" <steve.stegmann@xxxxxxxxxxxxx>]

Ted,

I rebuilt my 345 a couple years ago, the camshaft died at about 80,000
miles.  The engine was built in 1979, just about the time Chevy had a run of
bad cams back then.  Hmmm....

It only has about 1000 miles since the rebuild, I'm not driving it very
often these days.  I haven't checked the compression but oil consumption
doesn't appear to be an issue.  Starts and runs fine.

And yes I did put in new connecting rod bolts/nuts, and new flywheel bolts.
Cost of those bolts was amazing.  Eldon found them for me at a IH dealer in
Nebraska.  The only moving parts to be reused were the crankshaft, the
connecting rods and caps, intake valves and valve springs.  Everything else
is new.

I had the block & heads in the machine shop.  The machinist did a valve job
on the heads and wanted to replace the exhaust valves so we did new stellite
exhaust valves.  He would only swirl polish the cylinder bores to seat new
rings.  He pretty much refused to do anything else said it would be a waste.
I didn't want to bore it out, it has all the power I need.  Checked the
block & head mating surfaces, excellent condition, checked the crank bore
alignment, excellent.  Magnafluxed the head, excellent.

I cleaned and assembled it myself.  I spent probably a month, evenings,
cleaning that thing.  Like to drove Mark crazy watching me.  I went through
a couple gallons of engine oil but it came clean.  I brushed every oil
passage in it and pumped oil through the passages quite a while before
assembly.

But...  Always seems like there's one "but" doesn't it.  I have one lifter
that sometimes collapses when it's parked.  This has been aggravated by not
running it for weeks, sometimes.  I'm running it daily again and the
collapsing when off seems to be much less.  It always comes back to quiet as
the engine warms.  Comes back much faster if I've been running it daily.
Actually, when running it daily it doesn't always collapse.

My hot idle oil pressure after running on the highway 20 mi is about 18 psig
with 10w-30 Castrol.  I have a real gauge in it.

Any comments.

Steve

-----Original Message-----
From: owner-ihc@domain.elided [mailto:owner-ihc@domain.elided]On Behalf Of Jim
Grammer
Sent: Friday, February 06, 2004 9:34 AM
To: ihc@domain.elided
Subject: [ihc] Ted's under pressure


Date: Thu, 5 Feb 2004 18:43:42 -0500 (EST)
From: Ted Borck <tborck@domain.elided>
Subject: [ihc] Re: SII 345 compression test

Looking at a SII with a low mileage rebuilt 345.

Compression varies from 90 - 98 - 100 - 110.

I don't remember what is considered to be OK.

I RTFM and was unable to find compression specs.

Anyone know?

Thanks

Ted -

I've compression tested *lots*(like a couple dozen at least) of IH SV-8's
over the years. I write the #'s on the valve cover in Marks-a-lot or paint
pen so I don't have a piece of paper to go missing years later. Consistent
with the other responses, engines in reasonably good running order(whether
266/304/345/392) clocked 125-160PSI. All tests warm, throttle/choke plates
blocked fully open, and a freshly charged known good battery. 4-6
compression strokes to make sure the #'s have peaked. A little lower than
125 I don't worry too much as long as the #'s are within 10%, the engine's
not smoking excessively and has good HOT idle oil pressure. These last 2 are
usually *not* the case when the compression is low, and I know I'm messing
with a tired motor.

The point may be moot, but you need a wet/dry compression comparison to
isolate whether it's rings or valves causing the low #'s and high variation.
'Rebuilt' means a lot of things to a lot of people, starting at just
replacing some gaskets :( Others will just do a re-ring(with or without
touching the heads), or a head job alone and call it a rebuild. A fresh set
of rings in an otherwise untouched IH SV bore is practically guaranteed to
be a 'no-seat' disaster.

To me, the hot oil pressure is even more important than the actual
compression. The engine needs to run for 20-30 minutes on a fresh oil
change(spec is 30W)so that the pressure stabilizes as low as it's gonna go.
Much less than 10PSI and I'll park the engine as not worth putting in, even
if the compression's great. Beats pulling it back out in a year or 2 when
the valve train starts making noise that won't go away ;)

Jim