[DeTomaso] This ought to be fun...

Tue Apr 17 15:37:13 EDT 2012

Kirby,

FWIW, my block was converted to four-bolt mains with very little line honing required.  It surprised the machinist to be that close first try with four-bolt caps.  

See it here:

http://pantera1998.blogspot.com/2012/01/four-bolt-mains-and-paint-update.html

Corey

On Apr 17, 2012, at 12:47 PM, Kirby Schrader <kirby.schrader at gmail.com> wrote:

> 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
>>> _______________________________________________
>>> 
>>> Detomaso Forum Managed by POCA
>>> 
>>> Archive Search Engine Now Available at http://www.realbig.com/detomaso/
>>> 
>>> DeTomaso mailing list
>>> DeTomaso at list.realbig.com
>>> http://list.realbig.com/mailman/listinfo/detomaso
>> _______________________________________________
>> 
>> Detomaso Forum Managed by POCA
>> 
>> Archive Search Engine Now Available at http://www.realbig.com/detomaso/
>> 
>> DeTomaso mailing list
>> DeTomaso at list.realbig.com
>> http://list.realbig.com/mailman/listinfo/detomaso
>> 
> _______________________________________________
> 
> Detomaso Forum Managed by POCA
> 
> Archive Search Engine Now Available at http://www.realbig.com/detomaso/
> 
> DeTomaso mailing list
> DeTomaso at list.realbig.com
> http://list.realbig.com/mailman/listinfo/detomaso