John
Here are the details for the high flow heads:
Stage 4 heads - flow up to 370hp (claimed) Cost: AU$2550.00
Stage 3 " - " " " 320hp " " AU$1290.00
The stage 3 heads are unported new castings - (probably from a 4.6L?)
These heads are available by contacting Ian Wilson at Triumph Rover Spares
on (08) 8384 6933. The address is:
7 Magna Court,
LONSDALE
South Australia 5160
Paul
-----Original Message-----
From: Susan and John Roper <vscjohn@huntnet.net>
To: Paul Rakich <prakich@echidna.stu.cowan.edu.au>
Cc: Aluminum V8 List (Buick/Rover) <buick-rover-v8@autox.team.net>;
mgb-v8@autox.team.net <mgb-v8@autox.team.net>
Date: Friday, 25 February 2000 2:29
Subject: Re: Hydraulic roller camshafts
>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
>
>
|