[Fot] Fw: Help with Oil Pressure Problem

Bill Tobin william.tobin31 at verizon.net
Fri Mar 7 06:54:39 MST 2014


I still like good old STP as an assembly lube.
If you look at the ingrediants, you'll see ZDDP.
Been using it for 45 years.
Sun's out; warmup on the way!
Bill
----- Original Message ----- 
From: "barry rosenberg" <britcars at bellsouth.net>
To: "EDWARD BARNARD" <edwardbarnard at prodigy.net>; "Jack Wheeler" 
<jwheeler1947 at yahoo.com>; <fot at autox.team.net>
Sent: Friday, March 07, 2014 8:26 AM
Subject: Re: [Fot] Fw: Help with Oil Pressure Problem


>I have been building these engines since 1975 and have found most of these
> problems are from the pump. A good machine shop would not send a crank out
> with too much clearance so I doubt that. If you are certain the filter 
> head
> was clean then I would pull the pump out and check the end clearance. This 
> is
> more critical than clearance between the rotors. I always chuck my pumps, 
> new
> or used, in my lathe and and machine the rotors and housing flush. Then I 
> take
> about .001" off the rotors. Clean very good and reassemble. I always use
> petroleum jelly on all my rebuilds as it dissipates in the hot oil 
> completely
> and an engine can sit for years and still be primed, coated and ready for
> use.
>
> Barry Rosenberg
>
>
> ________________________________
> From: EDWARD
> BARNARD <edwardbarnard at prodigy.net>
> To: Jack Wheeler <jwheeler1947 at yahoo.com>;
> "fot at autox.team.net" <fot at autox.team.net>
> Sent: Thursday, March 6, 2014 10:38
> PM
> Subject: Re: [Fot] Fw: Help with Oil Pressure Problem
>
>
> Jack:
> Last year we
> had this problem on a new build for Bob Blake's "4" motor.
> It really had us
> scratching our heads until Bob pulled the pressure relief
> spring and ball and
> found that the thick assembly lube I used had traveled
> with the oil and
> clogged the ball and spring and caused it to seal
> erratically. I replaced the
> spring and ball at the track with one from another
> filter head and that solved
> the problem. I have not used the white assembly
> lube on another engine.
> Easy
> place to start.
> -Ed Barnard-
> ________________________________
> From: Jack
> Wheeler <jwheeler1947 at yahoo.com>
> To: "fot at autox.team.net" <fot at autox.team.net>
> Sent: Thursday, March 6, 2014
> 7:20 PM
> Subject: [Fot] Fw: Help with Oil
> Pressure Problem
>
>
> I've never sent
> a message to the FOT group before, so I
> hope I am doing
> this correctly.
>
> I
> just finished rebuilding the engine in my
> TR-3, and it is
> showing some unusual
> and disconcerting information on the oil
> pressure gauge.
> When cold, the
> pressure ranges from 60 psi at idle up to 80
> psi at 3,000 plus
> rpm.  However,
> last weekend, I took it out for a drive and
> after about 25
> miles, when the oil
> was up to full temperature, the pressure
> dropped to almost
> zero psi at idle,
> but still kept showing almost 80 psi at
> 3,000+ rpm.
>
> I have
> built these
> engines for over 40 years and have never had
> this problem before.
> The first
> thing I would think of is bearing clearance,
> and for years I always
> checked
> the bearing clearances with plasti-gauge when I
> assembled one.  When I
> was
> racing, I had a crank grinder who was so good, I
> gradually stopped doing
> the
> plasti-gauge check (I never found one that was out
> of tolerance).  In this
> case, the crank was standard size and the crank
> grinder recommended that he
> polish it, which he did.  Although this guy is new
> to me, he was recommended
> by someone who rebuilds race engines for a living,
> so I trusted him.  I guess
> he could have polished too much off the bearing
> surfaces, although I would
> have thought he would have checked that after he
> polished it (I certainly
> should have - and will next time).  The other thing
> that could cause too much
> bearing clearance would be bad bearings.  Has anyone
> seen problems with main
> or rod bearings, resulting in excessive clearance?
> The only other thing I
> could think of is a failure of the pressure relief
> springs in the oil filter
> head.  The long spring, which is used to adjust the
> pressure is still
> available, and I
> always replace them when I rebuild an
> engine as standard
> practice.  The shorter spring, which is there as a fail
> save to keep the
> engine from starving for oil if the filter gets clogged up,
> is not available,
> and I have never replaced one.  I did not use this spring in
> my race car, as I
> had a custom made filter head which excluded this oil
> pathway, but I have
> never had a problem, that I know of, with this spring in
> street car engines.
> Has anyone seen symptoms like this before, with a newly
> rebuilt engine, or
> have any suggestions what might be causing this?  Thanks
> for any ideas/help
> you can give me.
>
> Jack Wheeler
> _______________________________________________
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