>you might find that small block chev rods can be used in this conversion.
>
>simon
>-----Original Message-----
>From: Peter Kent <pkent@skynet.net.au>
>To: Simon Sparrow <Simon.Sparrow@wang.co.nz>; 'dkern@napanet.net'
><dkern@napanet.net>
>Cc: Buick-Rover-V8 mailing list (E-mail) <buick-rover-v8@autox.team.net>
>Date: Tuesday, February 09, 1999 6:14 PM
>Subject: RE: P76 Crankshaft
>
>
>>(The rod ratio is as you've correctly guessed, something like 1.7 and
>>above
>>is desirable. The std. P76 motor has a stroke of 3.5" and a rod length of
>>6.25" this gives a ratio of 1.78. The higher the ratio number, the longer
>>the piston 'pauses' at TDC and BDC. This has benefits for the combustion
>>process, but I can't remember the details.)
>>
>>
>>
>>
>>Reply:
>>A rod/stroke ratio below 1.5 is not ideal and a rod/stroke ratio is very
>>good, however, many successful engines have a rod/stroke ratio between
>>1.5 and 1.7. I read an article once that ran a Chev 383 strocker on a
>>dyno with 2 kits using different rod lengths. The engine produced around
>>400bhp, and the difference was 15hp max (started on come in above 4000
>>rpm). There was a correponding small increase in torque (but still in the
>>2% to 3% range). Worth considerating but not of overwhelming importance.
>>
>>A P76 crank in a Rover/BOP block has the following rod/stroke ratio:
>>
>>Rover 5.66 rod 1.62
>>Chev 5.70 rod 1.63
>>Chrysler 5.78 rod 1.65
>>
>>I have an Excel spreadsheet that allows modelling of different pistons
>>(compression height, bowl volume etc) for Rover/P76/BOP standard and
>>stroker engines (including compression calculation). If me know if you
>>would like me to email you a copy.
>>
>>(Does anyone know what the factory specification for deck height
>>(crank centerline to top surface of block) is for Rover 3.5, Rover 3.9, or
>>BOP 215?)
>>
>>Reply: The block height on the only Rover 3.5 I have measured was 8.9565"
>>
>>The Prostroke P76/Rover block 272ci kit looks like it will retail for
>>approx. AU$1800 (US$1134).
>>
>>
>>Regards,
>>Peter Kent
>
Thanks, Jan, Peter, Simon, Sandm, & others for many responses to the P76
crank question. Thanks for the education on the concept of rod:stroke
ratio. The mention of piston side-thrust was not new to me but the idea of
combining it all into a single number was. Peter--in your first sentence,
did you leave out a second number? Was it 1.7 ?
Thanks for the deck height spec. I do not have the tools to measure it
myself. I have made numerous inquiries on this and nobody else could tell
me anything. It is either a closely-guarded secret or nobody else cares.
Can anyone either confirm or deny Peter's number?
The Prostroke kit sounds great but it is way out of my price range. It's
beginning to look like I will probably end up using the stock Rover crank.
Thanks, Peter, for the spreadsheet offer. I use a MacIntosh computer and
rather doubt your program would work on the Mac. Do you have any idea if
it will ?
New question--What is the maximum practical bore size on a 3.9 block using
the original liners? More specifically, could it be bored as far as 3.736"
to accomodate the Chevy 305 pistons of that diameter?
Cheers,
Dave
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