[DeTomaso] This ought to be fun...

Tue Apr 17 14:47:17 EDT 2012

Dan,

See below.

On Tue, Apr 17, 2012 at 13:15, Daniel C Jones <daniel.c.jones2 at gmail.com>wrote:

> > 1) Two bolt main iron block
>
> Still a 2 bolt main block?  With a solid roller cam and the way you use it,
> it should be converted to 4 bolt mains.  Is there any evidence of cap walk?
> I'd be installing something like the Bessel main caps if I were you.
>

Yes, it's still a 2 bolt block. That's all I've ever used... and never had
a problem.
Previous engine was routinely revved to 7200rpm and an occasional 7500...
It lasted for 26,000 miles before I ran it lean and fried a piston. All my
fault... fully to blame.

I have a set of 4 bolt caps and had planned to use them, but the register
was way off.
Will gave me a set of 4 bolt caps, too. I dropped them off yesterday and
I'm waiting to see if he says they will fit or not.

I need enlightenment... How do I see if there is cap walk? They all fit
tight into the block.
I will look into the Bessel main caps.

> > 12) The machinist thinks he can salvage the block with another line bore.
>
> Another line bore?  Each time you weaken the caps and move the crank closer
> to the cam.
>
Yes, sir. I'm aware of that.

>
> > nodular iron crankshaft from Quella
>
> Is this still an offset ground 351C crank?

Yes, it's what I've been using for years. This was a new one.

>  Was it crack tested?
>
No, it was not. I can have him do that. Good point.

>
> > 6) I pulled the pan and found bearing material.
>
> For future refence, you can just cut the filter open to look for bearing
> material.  Had to do that recently on my sister's Isuzu which spun a
> bearing
> (towed it from Cincy to St. Louis so I could rebuild it only to find the
> frame is terminally rusted).
>

I did not mention that, but I did cut the filter open first. There was
bearing material and a little brass shiny stuff which I assumed was from
the distributor gear. The bearing material was what led me to pull the pan.

>
> > 8) All the other rod bearings and main bearings look just fine.
> > 9) The front one had not only spun (when I pulled the cap, both had
> rotated
> > by about 40 degrees), but one half was actually partially canted out of
> the
> > web towards the front of the engine. I have pictures if you're desperate.
>
> How tight is the main cap?  They should be interference fit.  When
> they start to walk, they can loosen up.
>
They were all interference fit. I am using ARP studs for the main caps.
Based on your statement, if they are 'walking', I should see some shiny
places where it has moved?
I should note here that I had not tracked the car nor had I really hammered
it much. I went to 7000 maybe 5-6 times during the tuning process. The
engine was hardly used in my mind. I was getting the EFI tuned in.

>
> > 13) The crankshaft journal needs turning, obviously, and can be saved.
>
> Have it magnafluxed for cracks.
>
I will do so.

>
> > 15) I had an Accusump plumbed into the back of the block where the stock
> > oil sender usually resides. Accusump was set at 30psi.
>
> I wonder if something caused the bearing clearance to change (loose cap,
> cracked crank, etc.) or a piece of debris in the oil passage leading to
> the front main and the Accusump saved the back bearings?
>
Possible.... When I pulled the main and rod caps, they were all tight
though.

>
> The downside to restrictors is the small passages are very easy to clog
> with a bit of metal or RTV.  That's why Ford made them so large in the
> first place (so they'd still flow even when people never change their
> oil).
>

I will check the passages and make sure the restrictors are not plugged. I
need to confirm, but I don't think he put the restrictor in the front
bearing.... been awhile since we talked about that and I don't remember
seeing it when I pulled the engine and was examining things.

I will check.

Thanks very much for your feedback.
At least I have some more things to check.

Kirby

> Dan Jones
>
> On Tue, Apr 17, 2012 at 10:40 AM, Kirby Schrader
> <kirby.schrader at gmail.com> wrote:
> > Personally recovering from major depression and lack of motivation on the
> > Pantera front in Magnolia...
> >
> > The Space City guys already know about this and we've discussed it a lot,
> > but for some reason, I'm in the mood to throw it out to the rest of the
> > collective.
> >
> > My new 377 Cleveland engine build with less than 400 miles on it spun the
> > front main bearing.
> > I have never seen this happen, ever... and I've run the same combination
> of
> > block, crankshaft, rods, etc. for years and beat the crap out of it with
> no
> > problems.
> > Daily driver, track events, etc.
> >
> > Facts for your consideration follow. I can get more detailed, but I think
> > the following is enough to start you thinking.
> >
> > 1) Two bolt main iron block, lifter bores bushed, line bored, J&E
> pistons,
> > Eagle rods, nodular iron crankshaft from Quella, Moroso restrictors (I
> > spent a lot of money on this block!)
> > 2) Iron 4V heads, new valves, springs, etc. etc. etc.
> > 3) Comp Cams solid roller cam, lifters, pushrods, rockers
> > 4) Symptoms were that my oil pressure started dropping gradually when I
> was
> > driving home from the annual SCP pig roast. By the time I got to the last
> > stoplight before my house, I was down to 10 psi hot at idle. Oil pressure
> > is taken from the port just above the filter. You know it was less at the
> > back of the engine.
> > 5) There were no knocking, banging or otherwise nasty noises. Main
> bearing
> > problems make distinctive noises. I know. Been there, done that. Got the
> > scars. But I did not hear anything this time.
> > 6) I pulled the pan and found bearing material.
> > 7) Pulled the oil pump and it had obviously done some trash pumping.
> > 8) All the other rod bearings and main bearings look just fine.
> > 9) The front one had not only spun (when I pulled the cap, both had
> rotated
> > by about 40 degrees), but one half was actually partially canted out of
> the
> > web towards the front of the engine. I have pictures if you're desperate.
> > 10) Nothing is blue or shows signs of getting hot.
> > 11) The main cap is worn badly and has to be replaced.
> > 12) The machinist thinks he can salvage the block with another line
> bore. I
> > hope so...
> > 13) The crankshaft journal needs turning, obviously, and can be saved.
> > 14) The machine shop put the short block together, I assembled the rest
> > 15) I had an Accusump plumbed into the back of the block where the stock
> > oil sender usually resides. Accusump was set at 30psi.
> >
> > Proposed failure modes
> > a) The main bearing was put in upside down - The machine shop is adamant
> > that is not the case. 'Hell, no! No way!' was the response to that one...
> > b) The crankshaft is bent - He's checking this week, but that would have
> > been very apparent during assembly, so he believes strongly this is not
> the
> > case.
> > c) Not enough oil pressure - On start up and later, 65psi hot at rpm,
> 30psi
> > hot at idle.
> > d) It ran fine while I was tuning the EFI. Other than running rich
> > initially and some issues with the ECU, I had no problems.
> >
> > Fortunately, no other damage occurred.
> >
> > So..... my questions....
> >
> > Why did it fail?
> > What do I do to make sure it doesn't happen again?
> > Why me?
> >
> > Who am I and why am I here?
> > :-)
> >
> > Let the fun begin.
> > Regards,
> > Kirby
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