Paul, I have recently been sniffing around in the area of roller lifters and am
told by people that I trust that the lifter bores are too short to allow use of
currently available roller lifters. Tell us about the aftermarket heads that
are available. John
Paul Rakich wrote:
> Hi List members
>
> I've been scouring this list for some time now and have found that it
> contains very little information (if any!) relating to hydraulic roller cams
> that can be used with the Buick/Rover alloy V8 (or its derivatives). This
> seems a little strange (if they are, in fact available), as I would suspect
> that this is definately an area that would be of concern to the performance
> enhancement for these engines - especially the bigger capacity variants of
> these motors that are close to 5.0L. High flow heads for these motors are
> horrendously expensive (approx. $2000.00 in Oz anyway) and there aren't too
> many good porting shops with expertise knowledge in this area either. The
> final product would probably cost almost as much as a set of new high-flow
> heads anyway - especially to get close to the flow numbers of Buick 300
> heads. So how can you make these motors perform without taking out a second
> mortgage on your house?.......
>
> Enter roller cams..... Roller cams allow a larger volume of intake charge to
> enter the cylinders when utilising standard cylinder head ports, relying on
> the faster opening ramps of the cam design (usually at a higher valve lift),
> all this adding up to improved performance. The Australian Commodore V6
> (Buick variant) is one such engine which benefits enormously from the
> advantages of an OEM hydraulic roller camshaft - having an almost flat
> torque curve throughout the entire rev range, resulting in a very tractable
> engine. A high capacity Buick/Rover V8 however, has very good low end torque
> but dissapointing top-end power due to standard heads inability to flow
> sufficiently for the increased engine capacity. A hydraulic roller cam could
> compensate for this by increasing the flow but not necessarily the cam
> duration, resulting in a flexable engine throughout the operational rev
> range with good idle characteristics. Sound too good to be true? Believe it!
>
> It appears that instead of relying on a possibly suspect porting job, or
> purchasing a pair of expensive heads, there could be another more reliable
> cost effective alternative. I'm certainly not saying that a hydraulic roller
> cam alone will be sufficient to achieve all the breathing requirements of a
> high capacity engine - but it would certainly come close. After all, nearly
> all current performance OEM engines with pushrods use roller cams nowdays.
> As there is also a need to develop larger capacity versions of the
> Buick/Rover V8, there would also be a requirement to overcome the standard
> engine's breathing limitations without resorting to high dollar techniques
> like turbocharging and supercharging.
>
> ......and finally to my questions: Is there a hydraulic roller cam available
> for the Buick/Rover V8? Who is the supplier and at what cost? Can one of
> these cams be fitted to this motor or are the modifications required to the
> block too extensive (i.e. lifter gallery oil passages)? Can the lifters,
> retaining plates etc. from the Buick 3.8L V6 (late 80's) be adapted to fit?
> Remember - the lifters from the old Buick V6 will fit the V8 (I heard that
> somewhere!) and if that's the case, what mods were done to the Buick V6
> block to fit the roller cam and lifters. Since the V6 block is (or was)
> basically cast in the same mould as the V8 (minus 2 cylinders), can the same
> mods be applied to the V8 to fit the roller cam and lifters?
>
> Mmmmmm - I wonder if the Shadow knows?
>
> Paul Rakich
> Rover SD1 V8 SE2
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