RE: [DML] Re: PRV Oil/Camshaft Problems

["DMC Joe" <dmcjoe@xxxxxxx>]

Bill,

Thanks for your response. Concerning camshaft up grades in the post 1980
B28F engines here is information from my PRV-6 B28F library. Referring to
the Hanes Volvo 260 Series Manuel ISBN 1 85010 287 2 Chapter 13 Supplement
Revisions P-247 Section 3 reads: "On some 1980 and all 1981 and 1982 models
new camshafts have been installed". Illustration 13.1 indicates the new LH
camshaft as #7401269616 and RH camshaft as #7401269615. I also have
additional first hand experience on this subject.

Back in 1989 I purchased a Volvo 260 GLE with the B-28F strictly for
research proposes. At 64k miles the car was in great shape except for
excessive valve chatter. As you well know valve noise in these engines is
not uncommon. As the miles increased so did the valve noise level. I decided
I would go ahead and perform a valve adjustment but when I removed the valve
covers I noticed that the rear oil passages had a much lower oil flow volume
compared to the front, I also observed discoloration of the camshaft lobes
in that area. I in turn called an associate of mine who owns Volset Service,
a Volvo engine service facility in Atlanta. He told me that this was a
common problem and he had observed the same condition in many other B-28F's
of that era. Keep in mind that by that time I had already racked up over 60k
miles on my DeLorean. I was also several years into servicing DeLorean's at
DeLorean Services and was wondering why I had not seen this premature
camshaft ware problem in any DeLorean's.

About a year or so later, at 83K miles, my 260 GLE seized up from a chewed
up camshaft. As time passed my Volvo associate commented that it was obvious
to him that a modification was made to either the valve train oil system or
camshafts because he was no longer seeing the problem in 1981 and later
B-28F's. When I retired my DeLorean engine at over 260k miles the valve
train was still in good shape. Currently we have many DeLorean's with over
100k miles, several at 200k, and a couple at 300k. With these facts in mind,
although there is no factory documentation concerning modification of the
oil passages, something obviously changed in the post 1980 B-28F's. 

FYI: In addition to two DeLorean's I also own a 1989 Volvo 760 GLE (very
rare) with 193k on the clock and still running like new.

DMC Joe      

-----Original Message-----
From: content22207 [mailto:brobertson@xxxxxxxxxxxx] 
Sent: Tuesday, January 11, 2005 11:30 PM
To: dmcnews@xxxxxxxxxxxxxxx
Subject: [DML] Re: PRV Oil/Camshaft Problems




I respectfully disagree with your disagreement:

- I have two notebooks of Volvo B27-B28 factory literature spanning
1979-1985, none of which contains a single word about modified oil passages
or different camshaft materials.
- The only Volvo TSB dealing with PRV camshaft wear (#21112 4/84) addresses
the problem in terms lighter oil viscosity specification, retroactive to the
beginning of engine use, not enlarging oil passages or replacing early
camshafts with later models.
- The oil passage/camshaft rumor periodically rears it head in BBS's such as
swedishbricks.com and brickboard.com, only to be discredited by Volvo owners
themselves. Note that some of these owners have enlarged oil return passages
of their own volition (others claim that lighter oil alone solves the
problem).

Bill Robertson
#5939

>--- In dmcnews@xxxxxxxxxxxxxxx, "DMC Joe" <dmcjoe@xxxx> wrote:
> 
>  Nathan,
> 
> I respectfully disagree.
> 
> In my 30 years of DeLorean consulting and servicing this is the one
subject
> I've had to repeat over and over.
> Once again, here are the facts.
> 
> The valve train oiling problems and early camshaft failure are
related to
> the pre 1981 version of the PRV-6. The majority of these engines were 
> in Volvo 260 GLE's. It was not uncommon for these pre 81 Volvo's to 
> start chattering at around 40-50k miles with complete valve/cam 
> failure at
around
> 80-90k miles. As these failures mounted the engineers at the engine 
> manufacturing plant initiated a modification that enlarged the oil
passages
> and specified a harder camshaft. This modification completely
eliminated the
> earlier problems. This is one of the reasons why the DeLorean gained a 
> negative opinion among mechanics when the DeLorean was first introduced.
> 
> Your experience with cam chain problems is extremely rare. As a
matter of
> fact it is the first time I have ever heard of this problem in a
DeLorean
> engine. 
> 
> DMC Joe
> 
> -----Original Message-----
> From: Nathan Robinson [mailto:nathanrobinson@xxxx]
> Sent: Monday, January 10, 2005 1:35 PM
> To: dmcnews@xxxxxxxxxxxxxxx
> Subject: Re: [DML] Re: Piston rings + sleeves
> 
> 
> 
> The PRV-6 engine had problems with oil delivery, and consequently,
the cam
> chains wore like a mofo. Also, the cam chain tensioners are hard to
check,
> making the engine (you guessed it) develop problems 'later on' in
life. The
> blowing up bit I can only imagine is what happened to me.
> 
> The cam chains wore considerably and broke prematurely. A borked chain 
> thrashing around at the front of the engine cover is quite a chore
to fix.
> And expensive. The 'new' cam tensioners and my dad's modification to 
> the front of the timing cover (and also scoring depth marks on the
tensioners as
> well - so we can tell how worn the chains are) makes checking up on
those
> little beasts a whole lot easier.
> 
> When those chains break, it's generally cheaper to just find another
engine.
> 
> Nathan Robinson
> 
> 
> Note: On different odds and ends, an interesting tid-bit is that the
Ford
> Triton V8 and V10 are also very similar engines to our squirrelly 
> little PRV-6, which was initially slated by P,R,V to be a V8, but gas
shortages at
> that time changed their mind. While the Triton engines have more 
> displacement and more cylinders and more electronics, however the
guts (as
> far as I can tell from visiting junkyards) look to be the same.
> 
> Also, (I don't know if this has been mentioned before) another good
thing to
> do if you're having problems keeping antifreeze in the system, is
install
> spring clamps (instead of those screw clamps) on the engine coolant
tubes
> right under the intake manifold. (there are two IIRC) If (when you
take your
> engine apart) there is antifreeze on the top of your engine block,
(and it
> happens to make a mess when it gets there) run to the junkyard and
grab some
> spring clamps off a triton engine (which just so happens to have most 
> everything in the same spot, and the same size, and happens to be a
far more
> common
> engine) and it will fix the leaking antifreeze.
> 
> Also, (Boy.. i'm on a roll here) another place to get engine parts,
etc...
> is www.ipdusa.com and www.swedishparts.net. IPD is a tad expensive,
but good
> stuff, and www.swedishparts.net had dirt cheap (OEM and others)
prices (and
> photos) of whatever you're looking for.
> Just remember the same engine (based on the research I've done on the
> engine) is on a '80 - '82 Volvo 260 series car. (Different 250's I'm
sure
> are similar as well, but the engine production years are the same
for that
> particular 260 car. ('80-'85)
> 
> 
> 






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