[DeTomaso] BBORR engine failure clues

asajay at asajay.com asajay at asajay.com
Thu Apr 30 12:21:25 EDT 2009 

Well... get the lifters out of their bores and inspect the cam.  Try  
to move the cam with your fingers, or a screwdriver.  If it moves,  
it's toast.  This is what most of us suspect at this point.

Collateral damage?  Maybe, maybe not, or at least, nothing that should  
require a whole new engine.  Here's my thoughts:

- possible cam bearing damage... replace (could also be a cause of  
failure if the bearings were not sized right to the cam)
- possible cam bits floating around in the system....  take it all  
apart, clean, inspect, reassemble.
- possible bent valves on those two cylinders... remove heads, have serviced
- possible breakage of valve guides... ditto
- pushrods you already know about
- possible damage to rockers... inspect, replace as necessary
- cam plug at back of block
- possible damage on the cam retainer... inspect
- possible damage on the back side of the cam gear and chain... inspect
- possible damage to the distributor gear... inspect

That's about all I can think of off the top of my head.

If you need 12 other bent pushrods to match the new ones you recently  
found, I can probably help you out there.  :)

Asa Jay

Quoting michael frazier <red3644 at hotmail.com>:

>
> Ok, now back to my problem.  This engine does NOT have roller   
> lifters.  Everytime I open a post hoping someone has
> great info about my failure or is willing to give me a new engine or  
>  parts I see...JUST KIDDING, JUST KIDDING!
>
>
> I'm pretty sure it looks like a broken cam with 2 cylinder's lifters  
>  down and oil in the bell housing area.  I don't have any
>
> experience with this.  Are there any common causes for this.  I   
> assume it's a result of torsional loads, but?  What kind of
>
> collateral damage is likely?  I can imagine some block damage, bent   
> valves etc.  Thanks for any info...and that was good info on roller   
> lifters too.  :)
>
> Michael
>
>> Date: Thu, 30 Apr 2009 07:58:53 -0700
>> From: asajay at asajay.com
>> To: detomaso at realbig.com
>> Subject: Re: [DeTomaso] BBORR engine failure clues
>>
>> Very good point Gray, thank you for clarifying.
>>
>> Asa Jay
>>
>> Quoting Gray Gregory <rgg at gregorycook.com>:
>>
>> > Asa,
>> >
>> > You can add me to that list too. I agree with John that solid roller
>> > lifters are a problem waiting to happen and are not worth the extra
>> > hp for a street driven car, of course that's just my opinion!
>> >
>> > It's important that we separate solid roller lifters and hydraulic!
>> > The modern engines you talk about all have hydro roller lifters and
>> > the shock absorption effect the hydro lifters give you eliminates
>> > the problem of the needle bearings failing from the shock as the
>> > lash is taken up.
>> >
>> > Gray
>> >
>> > -----Original Message-----
>> > From: detomaso-bounces at realbig.com
>> > [mailto:detomaso-bounces at realbig.com] On Behalf Of Asa Jay Laughton
>> > Sent: Wednesday, April 29, 2009 11:43 PM
>> > To: detomaso at realbig.com
>> > Subject: Re: [DeTomaso] BBORR engine failure clues
>> >
>> > I don't see them as a "frequent" source of engine failure. I've seen
>> > more engine failures talked about due to broken valves, overbores that
>> > "windowed" a cylinder wall, broken cams, worn mechanical lifters,
>> > sheared distributor pins, and the list goes on. I've only heard of one
>> > failure due to a roller lifter going out, and that was today from John
>> > Taphorn. So I'm not really seeing any data that roller lifters are a
>> > frequent source of failure.
>> >
>> > For what it's worth.... most modern engines only use roller lifters now,
>> > which is why most cam grinders now have lower profile grinds for use
>> > with roller lifters. It used to be if you wanted to use roller lifters,
>> > your cam selection was very limited, usually to strip and track only
>> > grinds. Nowdays you can get a good street grind for everyday driving.
>> >
>> > Is it worth it? Heck yea... reduced friction, reduced load, both of
>> > which lead to better gains in HP. Modern components last a lot longer,
>> > etc. What's not to like about them?
>> >
>> > Asa Jay
>> >
>> > Asa Jay Laughton, MSgt, USAFR, Retired
>> >
>> > & Shelley Marie
>> > Spokane, WA
>> >
>> > 1971 Mach I Mustang [ASA JAY]
>> > 1973 Pantera L 5533 [ASASCAT]
>> >
>> > ******************************
>> > http://www.asajay.com
>> > http://www.teampanteraracing.com
>> >
>> >
>> >
>> >
>> > pantdino at aol.com wrote:
>> >> To admit my ignorance:
>> >> Seems like these roller cam followers are a frequent source of engine
>> >> failure.
>> >> Is it really worth it? Do you really gain that many HP?
>> >>
>> >> Jim
>> >>
>> >>
>> >>
>> >> -----Original Message-----
>> >> From: John Taphorn <jtaphorn at kingwoodcable.com>
>> >> To: michael frazier <red3644 at hotmail.com>; pantera list
>> >> <detomaso at realbig.com>
>> >> Sent: Wed, 29 Apr 2009 8:16 pm
>> >> Subject: Re: [DeTomaso] BBORR engine failure clues
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >> Michael
>> >>
>> >> I believe that you stated you were running a solid roller lifter cam.
>> >> The
>> >> excess lash occurs as the needle bearings in the roller's wheels turn
>> >> to
>> >> dust. The base of the roller then rides on the cam lobe and the wear
>> >> rapidly against one another.
>> >>
>> >> Welcome to solid roller hell from one who has made the journey.
>> >>
>> >> JT
>> >> ----- Original Message -----
>> >> From: "michael frazier" <red3644 at hotmail.com>
>> >> To: "pantera list" <detomaso at realbig.com>
>> >> Sent: Wednesday, April 29, 2009 9:36 PM
>> >> Subject: [DeTomaso] BBORR engine failure clues
>> >>
>> >>
>> >>
>> >>> I had a chance to pull the distributor, intake and valve covers
>> >>>
>> >> tonight.
>> >>
>> >>> The dist. gear is pinned tight where it should be. The rockers
>> >>>
>> >>> (intake and exhaust) for the back two cylinders, 4 & 8, are loose and
>> >>> almost off the springs. Lifters are down. That's as far as I've
>> >>> got...any new thoughts? I'll keep you posted.
>> >>>
>> >>> Michael
>> >>>
>> >>> _________________________________________________________________
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