stage 1

Author
Discussion

minipower

Original Poster:

903 posts

225 months

Tuesday 28th March 2006
quotequote all
at last made decision to go get kit. Travelled up to byfleet (hours drive) and collected bits. Gone for stage 2 lcb, decatted with pipe back to rc40 with 2 inch bore and kn filter.
All good but when about to fit it, i unbolted inlet manifold and go to pull it off and find it caste on exhaust manifold. You prob all think im an idiot but i just never thought of checkin, so bak up to byfleet and collect new inlet manifold and hope get it done this saturday.

Also once fitted will i fell a noticeable gain in power or will it just sound better? and shud i tell insurance company or just say it was on there when i bought it, or i didnt think it was a performance upgrade?

Extra 300 Driver

5,281 posts

252 months

Wednesday 29th March 2006
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With the decat you will, maybe, feel a small power increase. One thing you will notice is the difference in the sound. A mini really comes in to its own with a nice pipe on it.

Unfortunatly the only way to get serious power is through head modifications, but you are off to a goof start.

cooperman

4,428 posts

256 months

Wednesday 29th March 2006
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You'll gain a few bhp but, apart from the increased exhaust noise the reduction in timje for 0-60 will probably be more in-the-mind than in the numbers. Maybe a second or so improvement. As 'extra300' rightly says, any real improvement will come from a properly ported head with an increased comp ratio and a much better cam. Then the things you have already done will work to advantage.

minipower

Original Poster:

903 posts

225 months

Wednesday 29th March 2006
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I think its time to start saving up for some extra performance mods. Once find out what insurance company says about mods, ill then hopefully be able to move in the right direction.
Cheers for the help.

redwedge5

583 posts

267 months

Wednesday 29th March 2006
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I've not owned a mini for a long time now, but if I remember correctly to get any performance improvement with the mods you've mentioned you will need to adjust the carb settings/needle etc (I assume it's not an injection model).

If you don't tell your insurance company re mods, you're playing russian roulette with your cover!

cooperman

4,428 posts

256 months

Thursday 30th March 2006
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You can 'blueprint' an engine without informing the insurer. By this I mean optimising every part within the engine without modifying if from the design standard.
For example, I prepared a 1990 carb Cooper 1275 as a rally car in 2004. The basic output was c.67 bhp, er, maybe. So I fitted an MG Metro cam and timed it in really accurately using a duplex chain set-up. Then I fitted 35.5 mm inlet valves. Interestingly the Haynes Manual lists 35.5 as standard for a 1275 Mini of that era, whilst, in practice, it should be 33.5 mm. The engine may be service re-bored to 1330 cc and still considered standard, which I did. That's worth some 4 bhp. Then I cleaned up the combustion chambers to eliminate the 'steps' caused by the factory fitting of unleaded seats, had the block decked to bring the pistons right to the top at TDC. The compression ratio was increased by machining 0.020" from the head, this again being a max. service repair allowance. I used a rotary file to remove the 'casting flash' from inside the inlet manifold, finishing off with a flapwheel. For the exhaust I used a twin box system comprising a Maniflow 'cherry bomb' and an RC40 back box. Ignition was changed to an 'Aldon Igniter 2' which is simply a mod to the internals of the standard electronic dizzy. Power output was accurately measured as 83 bhp at the flywheel after the needle in the carb was changed and the entire lump was still 'standard' in the strict sense of the term. As regards the cam, no one seems to know which cam was fitted to the 1990-1 Cooper. In fact, there is a school of thought which believes that the wide disparity in measured power output in cars of that era is because Rover just fitted whatever cam they had stocks of on the day of buid. I think that could be correct. If Rover didn't know what cam was fitted, the insurers are also in the dark, as in fact are we. My friends who are Rover specialists can't tell me the cam spec for a late Cooper and I've just built a similar engine for their 1992 Enduro Rally Car with almost identical results.

minipower

Original Poster:

903 posts

225 months

Friday 31st March 2006
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Yes i did get a new needle also. Definetly have to consider the insurance thing, but the above post does seem very interesting (cheers for the help).
With fitting this kit, is it a good idea to get a tune up done at a rolling road or is that just a waste of money and would be best done when i move up another stage?