In a message dated 02/22/2000 7:57:09 AM Pacific Standard Time,
Phil.Roettjer@quantum.com writes:
<< Any advice for optimum CR for a warm street engine (CR, cam, header) --
> does 9.5:1 sound good? (no racing or autocrossing -- just spirited
> street driving)
>
> -- >>
Well Phil-- I guess I need to contribute my 2cents: Get the factory book on
tuning from moss or whoever and port the head, match the manafold to the
head, 9.5 probably will be fine especially if you add a cam with lots more
lift and not much more timing I'm going to try moving the bushings out on the
stock rockers for more ratio!. Headers won't do much for you in that the
heavy cast iron lumps are efficient. (match them up to the ports also) When
you need to replace the exhaust pipe with 2" pipe-- go to home depot and buy
their thinwall fence pipe, it's galvanised in and out.use a straight through
muffler of the same diameter. I think chopping the flywheel may help also.
I've chopped mine but haven't installed it.
There are bigger intake valves used in the latest MGs and the Austin Marina
that will help! 39cc of combustion chamber will give you 9.5 cr with your
dished pistons!
A good book for this type of information is MGB a Comprehensive Owners Manual
by S. Turner and J. Organ, it covers what was done bu the factory for racing
and has interesting pictures.
I'll put my spare copy on Ebay.
Michael Rogers
MGB-GT
MGB-V8 tourer
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