large bore build

[minigreen94]

Hi all
Iam 19 this week and its time for a step forward from my thou
To a large bore. This is the plan and any advice\critism is appreciated.
1340
Omega pistons
Full balance
Duplex timing
286 kent cam
Mg metro ported polished head
Uprated oil pump
Oil cooler
Already have minispares clubman straight cut kit
Competition clutch
crosspin diff
1"3\4 carb or weber.
Thanks in advance

[guru_1071]

for a road car, the cost of the omegas are not really justified unless your reving it hard (7500 plus) or running more than 10.5:1 comp. id use the p21253 normal high compression powermax as they are more than up to the job.

an uprated oil pump is not required either, a new std steel backed one will do the job just fine, all your doing with a hi capacity one in a standard car is giving the oil pressure relief valve a load more work to do.

you wont need a cooler either unless your going to be doing sustained high revs, a road car on decent 20/50 oil with correct fuelling and ignition timings, fitted with a decent quality two core rad just doesn't kill the oil to need the hassle and expense of fitting one.

oh, and stick to the hif44 or go for a pair of twin 1 1/4"s - a weber is just overkill!

Edited by guru_1071 on Wednesday 20th November 17:45

[minigreen94]

Thanks for the advice :-)

[Cooperman]

For a road car the 286 is not a nice cam. It gives its peak power at 6400 rpm and to get the best from the engine it is necessary to keep the revs between about 5000 and 7000 rpm. Do you really want to be driving around at those revs.
On the other hand, if you have a 286 and are not continually using those revs, then you have the wrong cam for your application.
Why not go for a 266, or maybe a 276 and have a car which is nice to drive on the roads?
With the 286 a close ratio gearbox and a low ratio final drive are really needed to keep it on the cam and to pull away from rest. The standard gear ratios are too wide for a 286 to be effective.

[haynes]

If you want something thats a bit of an animal, noisey, hassle with emmissions etc Id go with a 296 rather than 286, head worked to match and a webber 45, as you have a SCCR box, maybe a 3.7fd. Thats the spec of my 1380, road legal hill climber. Nothing below 3000rpm, driving in traffic is just horrible.

So if its purely a road car stick with a 266, HIF etc.

On the road my 850 is so much more fun to drive than my 1380. You can have a conversation, warms up straight away, you dont have to ride the clutch, softer (hydro) suspension etc etc, altogether less harrowing and non-aggresive to drive.

[FWDRacer]

As above. Soften the cam spec or it'll be a pain in the arse to drive in town/suburban environements.