7 replies to this topic

[sworks]

I have a 95 SPI John Cooper modified Si plus S works. It’s the 85 bhp conversion plus the S works add on and after about 20 years still happy with the performance. It’s always liked to like eat clutches even though it always gets a new crank oil seal and I think It’s on its fifth, it may be caused by crank end float as you can occasionally feel a pulse on the clutch pedal.

I'm looking at refreshing the engine as the clutch has just started to slip again and so looking at a better than standard clutch, I don’t want an on off harsh item but updated from standard. I’m also looking at cam kits as the original cams are reputed to be only good for 60k. Finally, the roller rockers I have are starting to get flat spots so looking to replace these too with either new roller rockers or something else. This isn’t a money no object rebuild and I know it will need new bearings water pump, radiator etc etc but I don’t want to do this again soon so any recommendations are welcome. I seem to remember the SW5i was the cam of choice a few years ago but I’ve not been active in the mini scene for a few years so out of touch with new stuff.

Thanks 

[sworks]

No opinions on SPI camshafts or rebuild options?

[sonikk4]

Might be worth pinging ACDodd a msg to get his take on it.

[sworks]

I’ll have a look.
Thanks 

Edited by sworks, 06 December 2020 - 04:33 PM.

[Wazzah]

Hi Sworks,

 

Just been through a rebuild/refresh and fitted the SW5i camshaft.

It's a reasonably mild camshaft and has improved mid range torque.

I already had a 36/31 ported head with 1.5 rockers so the jump up in performance wasn't huge.

Personally I think the standard SPI cam is very good.

I fitted an MED lightened flywheel with their balanced clutch pack.

When you replace your clutch I'd check the primary gear bush as I believe wear in this bush causes clutch reliability issues.

I went to town on my rebuild with an SC tough crank and SC rods.

With the flywheel, crank and rods I have reduced the rotating mass by 8 kilograms.

The engine is very smooth and spins up quickly and is still easy to get off the line with the reduced mass.

I settled for a 1310 rebore.

I'm also running a 45mm throttle body and adjustable fuel pressure regulator.

I highly recommend the throttle body.

Good luck

 

My mods have seen MEMS struggle with air/ fuel delivery and I am in the process of fitting an aftermarket ECU that will run all SPI functions including stepper, purge valve etc etc and hope to report on improvements to all of this soon.

[sworks]

Thanks for the info, I’m only thinking of replacing the cam as I read they tend to wear around 60,000 miles and thought if it’s in bits now’s  the time to do it. I’m looking more at an engine refresh than rebuild as the only issue I have is clutch wear. Primary gear Bush is a good shout and I’ll get it checked. Thanks again

[brivinci]

So the motor is already out? If not, I would do a compression and leak down test to confirm the motors healthiness. 

 

My brother has a 95 Cooper Si Plus as well here in the US. Would love to see some pix of yours.

 

On the cam, your car has the 1:5 roller rockers still, correct? This was Rover/Coopers way around having to pull the motor when doing the conversion to add a cam. It is worth noting this as you ask around for cam recommendation. In the past I have a run both the Swiftune SW5-07 and the Piper BP255, but both on standard rockers but with modified head. Both were fine choices for these motors and mine ran well. Woke things up a bit in the mid range for sure. I am now running in a refresh/rebuild and went with a new custom cam from Keith Calver but have not run the engine in enough to have gone through the rev range yet. I added a set of MED 1:5 roller rockers and I can say that the idle is not perfect. Could be any number of other things as its only just back together and I haven't scanned the motor yet.

 

As for the clutch, I hope you are able to figure out why you are going through so many. Is there any signs of oil in the bell housing? What does the clutch plate look like? Same with the flywheel. Has the flywheel been resurfaced ever? You have to take equal amounts of material off the pleasure plate mounting area as you do clutch surface.

I just replaced mine with an MED lightened, HD clutch package. It comes fully balanced which is one less thing to do...but should be done if not replacing it all. 

[sworks]

The engine is still in, id decided when the clutch started slipping again then it’s probably time to pull the engine to find out why, it started slipping last weekend when I took it out for its last run of the year. Every now and again I feel a pulse through the clutch pedal when going down the gears so crank end float is as good a place to start as any. It still has 1:5 roller rockers but the rollers are showing signs of wear, I was thinking of changing the cam and possibly moving to non roller rockers? The flywheel is as it left Longbridge in 1995. Just trying to sort a plan of what parts I need before the engine gets pulled. The car is extremely nice to drive (when the clutch isn’t slipping) and has reasonable power throughout the rev range to the point that all these years later I’m  Still happy with the JCG conversion(s)