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MG MGF Technical - Lightened flywheel & 633 cams

Is any body running high lift cams like the 633 grind with a lightened flywheel?

There is a very good chance my F needs a new clutch so always looking for the silver lining I am considering a lightened flywheel - but a tad concerned about drivability (especially at low speed) with the 633 cams.

Steve Ratledge

TF135 cams are a good deal milder than your 633s Steve - but IMO the lightened fly wheel isn't really all that light - you could afford to go lighter IMO.

I doubt that you'll have a problem - and you've got good low-down torque with your engine, so I think that the chances of stalling are low...

Definitely worth pursuing the silver lining! :o)
Rob Bell


I have 633's and a light flywheel on my 'other car' it makes for very quick revving but does rely on the timing to be correctly set to ensure that the engine doesn't stall in traffic. I would think your current timing should be adequate.

Rob has more experience with light flywheels of the F, but it does sound like a goer.

tim woolcott

I might be in the market for a pair of 633s Tim - if you see any going, let me know! ;o)
Rob Bell

So you're not interested in a set of cams from an Elise 135 then.. :o)

I'll keep an eye out on Blatchat


I'm not sure what cams the Lotus 135 head used - aren't they standard MPi profiles?

Thanks for keeping an eye on Blatchat - I'll checkout SELOC :o)
Rob Bell

The exhaust cam is marginally hotter in the 135 and more importantly it has Lotus Sport stamped on it. :0)
tim woolcott

I still have a spare set of cams from a TF135 which I need to get rid of, but I think you already run with these don't you Rob?
Steve Ratledge

Thanks Steve - yes I do. 145 bhp thanks very much :o) But obviously I want more, and am thinking throttle bodies and 633 cams...

Anyone selling 633s please let me know!
Rob Bell


I just upgraded this year to a set of Piper 633's and have recently put on a lightweight flywheel.

The car goes like a rocket. From about 3700revs the car takes off. If you keep youre foot down and change gear at around 6700 revs the next gear drops right down to about 4000 revs so you stay on the power curve.

The feeling is ace. Problem is I should really be changing gears at about 7500 revs for the ultimate hit.

But I need a new engine management system such as the emerald to do this. Anything over 7500 and u risk blowing a piston but hey ho........more money lovely omega forged pistons!!........

The car has verniers on it so its timed just right (44degrees inlet 66degress exhaust). My only issue is (and this was without the lightweight flywheel) that sometimes the car will just not idle right and will stall.

This rears its ugly head into play when as follows. If you pop out of gear above 2000 revs the car will dip below the idle limit. Some times it will recover. Others not. Its worst on short journeys after the car has warmed up. By fitting the lightweight flywheel this did not make it any worse or not. I have changed the IVAC a couple of times and played around the idle screw on the throttle body but to no effect

Dave Andrews believes that this is due to the MEMS on my car not being able to understand whats going on with my hot cams and air flow as it is pushing 160BHP. Im going to change my sparks next week to see if that might help but I doubt it.

I did have a standard mpi but now I have a

Fully ported head (DVA)
Vader induction kit
Piper 633's
Vernier Cams
Competition Ignition Leads
A VVC plenum matched to the head
52mm Throttle Body.
Lightweight Flywheel.
Daytona Exhaust

Some might not think that a vvc plenum was the way to go but as I will be ultimately upgrading to throttle bodys I believed along with Dave that I might as well get the head correctly ported for what I wanted to achieve.

The rest my goals (once the wedding using wedding cars tunbridge wells is over!!) are

4-2-1 Manifold
Emerald Management
Throttle Bodys.

The only thing I would say is that this has been very expensive. Luckily I have done all the installation myself and with the wonderful help of Dave Andrews I have now learned how to correctly time a K-Series engine.

My last note is that just after I had rebuilt my engine in June someone released the new head gasket/oil rail for the K-series. I will wait till my engine blows again!! LOL

Just dont show the other half the bill!

With the ported head, verniers and cams I didnt see much change out of 1100!

And then theirs all the rest


When will it end!!

Chris Glen

It doesn't! ;o) ROFL
Rob Bell

message for Steve Ratledge - how much do you want for the 135s? I might be interested... I rather fancy the better top end, but don't know when I'd get round to swapping them. Having just had a new gasket fitted (no failure, just a precaution while the engine was out which is another story) so I'm not in a rush to disturb things.
M Cunningham 1

This thread was discussed between 18/10/2006 and 14/11/2006

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