[DML] Re: Red Oil Herring (B27 vs B28)

["content22207" <brobertson@xxxxxxxxxxxx>]

No one's disputing massive changes in the ~1987 redesign. My complaint
is reports in DeLo community of massive changes circa 1980. Is the
only place I've ever seen such. 

What is your source of 1970's camshaft changes? Volvo factory
literature is totally mum. Volvo newsgroups are mum (example:
http://www.swedishbricks.com/faq/engpvr6.html. Business about "face
only" hardening is silly -- all production camshafts of that era,
including American domestics, are made in layers. Only the lifter face
is steel. Inner metal is gold in color (brass?)). My version of Darren
Bowker (German PRV mechanic in Columbia SC) claims B27 and B28 are
internally identical except for certain component *SIZES* (material
composition was not only unchanged, but used simultaneously between
Renault 2.7 and Volvo 2.8). The only Volvo Service Bulletin Re:
camshaft issues is the late 1984 change in oil spec
(http://www.alldata.com/TSB/64/79643149.html. My 1985 B28F manual has
what I believe is this bulletin as a supplement -- I'll get it scanned
and upload to #5939's photo album).

Bill Robertson
#5939

>--- In dmcnews@xxxxxxxxxxxxxxx, Martin Gutkowski <martin@xxxx> wrote:
> The PRV's external design specs changed very little but the internals, 
> with respect to the crank changed massively, roughly around the time of 
> the Z7U Renault 2458cc single turbo unit, of which I have one. 
> Subsequent Renault units, normally aspirated or forced unduction, 
> carried this same bottom end and only the pistons were changed. This 
> helped with the PRV's reputation as a very sturdy engine - The most 
> desirable still being the 24 valve 3 litre engines which were sold
as an 
> option in the Citroen XM, Peugeot 605 and various big Renaults (eg the 
> Laguna and Espace) but it's very easy to confuse with the later PSA 3 
> litre 24v engine which is completely different and 60 degree. The PRV 
> was around till 1997.
> 
> The camshafts very definitely were changed due to high rate of failure 
> in the Volvo 260's in the late 70's
> 
> Martin
> 
> content22207 wrote:
> 
> >Oil passages are identical B27 to B28. Douvrin produced 2.7 and 2.8
> >liter blocks side by side through 1987 (Renault Z7 series alongside
> >Volvo B28). Volvo literature makes no mention of ever modifying the
> >oil passages (I have both B27 and B28 manuals through 1985). Volvo
> >newsgroups make no such mention either (nor do they mention "soft" B27
> >camshafts). For some reason DeLorean owners love to tout their engines
> >as new & improved. But the simple fact is: Douvrin only made one basic
> >block unchanged 1974-1988 (dimensional differences in some components
> >to accomodate varying compression ratios, cylinder displacements,
etc). 
> >
> >I previously thought Volvo instigated redesign of the PRV into even
> >fire B280 (Chrysler 3.0) for the 1988 model year. But a Peugeot
> >website claims that honor goes to their 1986 Model 505.




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