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[b]Even more 12g 295!!!!!![/b]

Posted: Thu Nov 06, 2003 7:42 pm
by biffabacon
Iam in the process of improving the performance of a standard 1098 mog.
I have collected together a number of parts including a 12g 295 head from a mini cooper, both 38 and 44 hif carbs, heated inlet manifold, K&N Filter etc. I'm off down to the NEC and hoping to pick up an LCB manifold and performance silencer along the way, either new or second hand.
My questions are these.
1) I intend to get the ports polished and new rimflow valves fitted, should i use single or double valve springs? Any ideas on guides to cost?
2) I have read the previous post about this particular head being fitted to a 948 but how much can/should be skimmed for a 1098?
3) Which of the two hif carbs would be more suitable? Any ideas on spring and jet sizes?
4) I imagine a fair few people will have taken this route, what type of differences in performance/mpg can i expect?
5) Can i fit braided brake lines from an MG midget or does anyone know if they are made for a minor?
6) Any other suggestions/ideas greatly received!!!!!

Posted: Fri Nov 07, 2003 12:44 am
by Kevin
5) These are available from the MM centre Birmingham £10:93 + vat

Posted: Fri Nov 07, 2003 9:02 am
by Peetee
Best sugestion from me would be to uprate your brakes first if you haven't already done so.
Some suspension upgrade too like telescopic shocks and front antiroll bar.

Done it now? Good read on. :wink:
Skim the head 60 thou (check it hasn't already been done)
Use a HIF38 carb
water headed inlet
As for the exhaust, My deity, Mr Vizard, suggests a LCB only if you intend to use high revs a lot as it will reduce the torque available in the mid revs.
HTH

Posted: Fri Nov 07, 2003 9:42 am
by rayofleamington
performance/mpg
Performance - the car should feel a like a standard 1300.
MPG - in theory if you drive at the same speed and acceleration as you did before you will get better mpg as the air flow is more efficient. In practice you will accelerate harder and the mpg will drop.

I really have no experience on the carbs, but my first minor was similar and ran with the marina 1.5" SU carb instead of the 1.25" SU, and this was good.
The HIF44 may be overdone for a 1098, but if it works I doubt it will be superior to the 38 (gas velocities etc..). The HIFF 44 will happily run a tuned 1275 (eg 1380 / 1440) so to get roughly the same gas velocities on a 1098, the HIF38 will do the job.

Head skimming - look on the other head posts as someone (Willie I think) posted about head volumes. You can of course skim a lot off, but the trade off to performance is that but you loose driveability (and reliability) with higher compression. You also have to worry about the valves clearing the block if the head is severely skimmed and/or you have a high lift cam/rockers. Not sure exactly about the 12G295 / 1098 combination, but if you mark up a piece of paper on the block it will show you where it all fits against the head.