[DML] Re: PRV Oil/Camshaft Problems

["content22207" <brobertson@xxxxxxxxxxxx>]

Those camshaft part numbers simply denote differences in lobe lift:

B27A 1976-79, B27E 1975-1978, B27F 1976-79:
Part #7910245522 (left) 5.144 mm
Part #7910245412 (right) 5.059 mm

B28A 1980, B27E 1979-80, B28F 1980:
Part #7401269138 (left) 6.004 mm
Part #7401269139 (right) 6.004 mm

B28A 1981-82, B28E 1981-83, B28F 1981-?:
Part #7401269615 (left) 5.96 mm
Part #7401269616 (right) 5.96 mm

Get an official Volvo produced B27/B28 rebuild manual -- doesn't
mention a word about differences in material composition, only lift
height.

You're also welcome to search all these links for any mention of
camshaft material differences:
http://members.fortunecity.com/douvrinprv/id30.html
http://members.fortunecity.com/douvrinprv/id31.html
http://members.fortunecity.com/douvrinprv/id32.html

For some reason DeLorean owners seem to be the only ones keeping the
camshaft rumor alive -- making lemonade from an engine they aren't
terribly thrilled to have in back of their cars to begin with?

Bill Robertson
#5939
 
>--- In dmcnews@xxxxxxxxxxxxxxx, "DMC Joe" <dmcjoe@xxxx> wrote:
> 
> 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@xxxx] 
> 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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