i have twin 1.25" carbies but my mechanic keeps telling me to take em off and put the single 1.5 on is there much diff in performace, i'm prob gonna do it coz i the twins aint really for me coz im not really mechanically mined. when i swap them over the twins will be up for sale with manifold!!!

so yea what the disadvantages and advatanges of the swap the performance wise
(i have an 1100cc with LCB extactors and sports exhaust)

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i have a 1.5 on an 1100, it does not 'haul ass'

I would've said you already have a good setup, I dont think twin 1.5s on the 'ol 1098 will help much, especially in the milage department.

its a singe 1.5

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Keep the twins. But, to get the best from them you need to sort out the inlet manifold. Give Graham Russell a call and he'll let you know what he can do. Or get a Maniflow mild steel or mini spares twin 1.25" manifold.

Just by improving the inlet manifolding (stock twin inlet is REALLY crap) you will get more go than throwing the 1.5 on.

But; a 1.5 on a GR inlet manifold is almost as good, and probably a bit cheaper.

My 2c

Matt

ben

From what people have told me there is much more torque from twins then there is for a 1.5

I have a 1.5 on mine with 3-1 extractors and no cam work and you saw how hard mine went for what it is so if you use my mini as a comparison then you might get and idea....plus the 1100 has more torque down low anyway on a 998 so it will be much quicker ....IMHO.............. just my 2.2cents worth you know GST (bloody howard)

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Team MADMAN/Pat Rogers

Moving from twin HS2's to a single HS4 is downsizing. A single HS6/HIF44 1.75" is around identical in volume to twin HS2's. Just keep that in mind.

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Remember, coopers and cooper s's all had the twin 1.25" carbs, not a single 1.5", which would have been much cheaper for BMC to offer. So there had to be some real advantages.

Keep the twins!



Who's your mechanic?

Matt

And pretty good value, even after you needle it for your own car:

http://search.ebay.co.uk/search/search. ... category0=

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Whoops..
Keep the twins.

If your mechanic's telling you this it's cause he can't tune your twin's

twins are really great once set up properly. The art is in setting them up correctly (I mean art, it's something that takes a fair bit of know how and a fair bit of time)

keep the twins, the inch and a half wont haul..... i would say you have a good set-up. Keep it

change mechanic's if he can't tune twins. Mini's are special don't waste your time with one who pretends he know's what's going on.

I have put a single 1.75 on a 1100 and said that's a good mix or twin 1.25's better

I have heard a lot of rumors from people as to what's best for the mini's. Some good and some poor advice. But essentially it's personal advice and IMO keep the 1.5 it's a good size for that motor. if your worried about the carby then you can re-build it. Luckly SU'S are quite simple

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-doing a Degree in Mechanical Engineering,
and a few conversions:
13B Extend in a 1600
4EFTE in a mini ute (all slowly)

mechanic can tune them he's just recommending that i should have the single coz my car is just a round town car but ive had no prob with them yet, so yea i dont know i really want a weber but...

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I've got twin HS4s on the wife's 1293, I reckon twins are great. Power is pretty good, so is fuel economy. But, I know the needles are right, having run it about with an accurate A/F ratio meter on.

If twins are performing crook it's usually because they are either out of adjustment, have the wrong needles or are old and in need of overhaul.


I think twin HS4s are too big for a roady 1098 or 998, but twin HS2s are right on the money.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Have I mentioned "keep the twins" yet?

The twin 1.25s will actually give you better low down torque than the 1.5,
and will breathe better right through the range. So town driveability is better with the twins.

That said, if they are in good condition, and the linkages are in good condition, and they have been tuned right for your car, that's when they will work well for you.

Next step, getting a better manifold!

Cheers
Matt

That what my mechanic said so next week im going back to the single 1.5" performance isn't a biggy with me as my clubby is just around town car will save me on petrol anyways...But i had them tuned today and it is running so good and the power is really noticable one of the carbs was running to rich before the tune and the car was a bit sluggish all good now...still hasnt changed my mind on the swap but.

what sort on manifold should i get for the single 1.5" and were can i get one
also what sort of $$$ are twin 1.25" getting there been recond. there of a cooper s and will be sold with manifold

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