[DeTomaso] BBORR engine failure clues

Fri May 1 01:36:02 EDT 2009

John,

    A lot of companies are now making solid roller lifters with a internal oil circuit to the roller bearings.  It's suppose to help.  I think it's a fairly new development with most companies, other than Jesel lifters that have had it for years.  The lifter tech guy at Jesel also claims that a little bigger roller (that comes in larger dia lifters) makes a big difference.

Ken

--- On Thu, 4/30/09, John Taphorn <jtaphorn at kingwoodcable.com> wrote:

From: John Taphorn <jtaphorn at kingwoodcable.com>
Subject: Re: [DeTomaso] BBORR engine failure clues
To: "Kirby Schrader" <kirby.schrader at gmail.com>, "Gray Gregory" <rgg at gregorycook.com>
Cc: "Asa Jay Laughton" <asajay at asajay.com>, detomaso at realbig.com
Date: Thursday, April 30, 2009, 9:32 PM

Kirby, that is so little lash.  Hopefully, when combined with slow initial 
ramps on the lobe, the needles will live longer.  In comparison, my solid 
roller recommended .028" lash.  I believe the initial acceleration on the 
ramp was so steep that the lifter was accelerating very quickly when the 
lash went to zero.  Those needle bearings had no chance.

What I learned, only too late, is that when you have to readjust your valve 
lash because it has increased, it is time to pull the lifters and inspect 
the roller needle bearings.

Crane and Sig Erson cams (both bankrupt) told me, after the fact, that the 
lifters should be pulled and inspected every 4,000 miles. Both companies 
informed me that this practice was common knowledge.  Yet, none of their 
written info apprised me of this exercise and other owners who I have met 
running these cams don't seem to be aware either.

I've heard several positive durability experiences from people running solid 
roller lifters.  My experience was in the mid 90s.  Less lash and better cam 
ramps may be the reason.  I do know that I loved the roller before it 
tanked - it made for the freeist revving engine I've ever owned.

In an effort to recapture that experience, I know run a hydraulic roller 
with fingers crossed.

Godspeed

JT

----- Original Message ----- 
From: "Kirby Schrader" <kirby.schrader at gmail.com>
To: "Gray Gregory" <rgg at gregorycook.com>
Cc: "Asa Jay Laughton" <asajay at asajay.com>; <detomaso at realbig.com>
Sent: Thursday, April 30, 2009 9:33 AM
Subject: Re: [DeTomaso] BBORR engine failure clues

> You guys certainly aren't making me feel warm and fuzzy... JT has been
> preaching the same sermon to me. The lifters now in my GT40 are solid
> rollers. Clearance set at 0.008. They are supposed to last... Crane 
> claimed
> ramp design and technology improvements help them live.
>
> One thing the solid rollers did solve was the pump down issues I was 
> having
> with the hydraulic roller lifters. Both the engine builder and Crane could
> not figure out why that was happening... even after the second set of
> lifters... Both sets were supposedly examined by Crane and they claimed
> there was no problem with them.
>
> I am certainly keeping a close eye on the solid rollers though.
>
> My Pantera engine has Crane hydraulic rollers in it... one day, sometime 
> in
> the distant future, I may find out what it's like to drive my Pantera
> again... and see how the hydraulic rollers work in the Cleveland.
>
> FWIW,
> Kirby
>
> On Thu, Apr 30, 2009 at 9:17 AM, Gray Gregory <rgg at gregorycook.com> wrote:
>
>> 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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