Actual classic Mini question!

Strange as it may seem, I have a real classic mini question. I'm about to
have rebuilt a 1098 motor. Is it worth the cost of boring it out, say, 20
thou oversize? I assume theoretically you would gain torque and low rev
power which, for a road car, seems to be what is needed. What sort of gain
do you get? Is there any disadvantage in going 40 thou?
Also, I have almost decided on a 1 1/2" SU with rich needle, improved flow
head with maybe 9.5:1 compression, 3-into-1 extractors and an RC40 exhaust.
Any comments?

On Wed, 28 Mar 2007 11:29:55 +1000, "GrahamL"
<grahamlyons DeleteThis @internode.ton.net> wrote:

>Strange as it may seem, I have a real classic mini question. I'm about to
>have rebuilt a 1098 motor. Is it worth the cost of boring it out, say, 20
>thou oversize? I assume theoretically you would gain torque and low rev
>power which, for a road car, seems to be what is needed. What sort of gain
>do you get? Is there any disadvantage in going 40 thou?
>Also, I have almost decided on a 1 1/2" SU with rich needle, improved flow
>head with maybe 9.5:1 compression, 3-into-1 extractors and an RC40 exhaust.
>Any comments?
>

if the bores etc. are not damaged, I don't think overboring is worth
the cost (of new pistons). The head and other changes wil give more
gain. Maybe worth putting a better cam in while you're working on it?

FWIW,
Theo van den Bogaard