Cheeky cheap cams???

[Rob Bell]

Excellent, thanks Andy! ;D

BTW I've been chatting to Simon Erland quite a lot - might look into building a new 1.9-litre engine...

[dave]

Rob,

I spoke to Roy Ford the other day and he told me that TS were just trying to do this cam swap on Steve Ratledge's car. Apparently it isn't as simple as it sounds. You might want to give Roy a call and get the low down.

Regards,

Dave

[Rob Bell]

I've already had a version of the "low down" from Steve.

Roy's done a little research - I hope Steve doesn't mind me summarising it here:
1. the 135 cams will make the engine idle rougher than a 'badger's arse' unless the cams are properly timed (source: Dave Walker)
2. The cams only have 8.8mm lift but a longer duration - so not really worth fitting (source: unnamed Rover development engineer)
3. The cams have a too-steep actuation ramp, increasing the probability that the standard valve springs will become coil-bound: the valve springs should be replaced with up-rated items (source: unnamed Rover development engineer)
4. The 135 cam has no distributer drive - and it's difficult to remove it from the existing cam (everyone's experience)
5. The 135 cam on Steve's head could lead to fuelling problems on his Race-speed ported head (source: PTP)

So with the best intentions, Roy elected that caution was the better part of valour, and put the standard cams back in.

HOWEVER

In the most part, all the above fears are completely unfounded.

Dealing with the above, point by point.

1. Dave Walker's opinion I would implicitly trust. However, I suspect that he was thinking about the cams used in the original Lotus 135 kit - and these were indeed a nightmare, and did give an awful idle. The cams in the TF135 are full production items and the cars idle perfectly well with a standard timing pulley. Yes, the car may run better with more accurate timing, but I don't believe this to be completely necessary.
2. The statement from the unnamed Rover development engineer is bizarre. It flys against what is published in the TF workshop manual as the cam timing and lift data required to correctly time a cam. Moreover, if you actually MEASURE the lift on one of these cams, as I have done, the LIFT really IS 9.5mm!!!!
3. The unnamed Rover development engineer's opinions have already been partially discredited by imperical measurement, I thought I'd better check the EPC to see whether the valve springs had been re-specified for the high-performance MPI derivative (the 135 engine). They haven't. There is just one part number for all valve springs in all K4 MPi engines. Moreover, Dave Andrews fits BP270H and even BP633 cams to heads with standard valve springs - and as the table earlier in the thread shows, these are a good deal more aggressive than the TF135 cam. The valve spring argument is a complete red-herring.
4. The distributer drive spindle is a problem that I recognised some while ago. A replacement is available. More details here: www.mgf.ultimatemg.com/group2/engines/index.htm
It's a surmountable problem.
5. According to DVA, the 135 cams should cause no problem with Steve's spec head despite using MEMS1.9. In fact, from G-force, we know that Steve's MEMS is overfuelling - so a more aggressive cam could actually be of some benefit! LOL

So - a very very long post - but basically, I remain of the same opinion that the 135 cam is a simple, direct swap. No worries.
I'll have a chat to Roy about this - but he'll just think that I am mad. As usual

[dave]

Rob said:

So - a very very long post - but basically, I remain of the same opinion that the 135 cam is a simple, direct swap. No worries.
I'll have a chat to Roy about this - but he'll just think that I am mad. As usual

LOL - we know that Roy will always err on the side of caution and naturally enough he will go by whatever his MGR contacts tell him. Human nature being what it is, even MGR employees can turn out to be mistaken :-)

It all boils down to taking input and making up your own mind - something that you are ably demonstrating :-)

[Rob Bell]

Absolutely - but unfortunately, I wasn't able to come up with the answers for Steve in time for him to try and persuade Roy to go ahead and fit them. So now Steve's stuck with a couple of 135 cams sitting impotently in the boot of his F!

I've suggested a cam swap session!! Need to do mine in any case.

Unfortunately with bambino on the way, I was beginning to think that I was going to give this job over to Techspeed to do - now I am not so sure... Do it myself - with the able assistance of the Knitting circle team! ;D

[dave]

Rob said:

Unfortunately with bambino on the way, I was beginning to think that I was going to give this job over to Techspeed to do - now I am not so sure... Do it myself - with the able assistance of the Knitting circle team! ;D

Both choices are still valid.

Ask TS to do it regardless of their reservations on the outcome, as you're convinced it's OK. The result will hopefully prove your point and has the merit of showing Roy and team that they may need to be more adventurous!

DIY with some helpers (or is that voyeurs in my case ) from the KC just for the fun and the learning curve of doing it

[Rob Bell]

That's true Dave. It's as much a question of time, day light hours and fair weather! Ideally, I'd like these cams fitted in time for the track days beginning next year.
Also I have a Sprint Championship class to win! ;D

[TimW]

First thing you need to do is check the lift on the cams. At last you'll be able to put that gauge you bought at silverstone to good use, rather than merely being a rather attractive ornament

[Rob Bell]

It's got a magnetic base Tim - not an awful lot of use for an alloy engine. anyone got a lump of steel I can steal? ;D

[TimW]

When I used the gauge to measure cam lift the engine was insitu so plenty of steel around. Out of the engine bay it may be possible to use a metal angle (those used to reinforce internal corners on cupboards) screwed to the block and then screw the gauge to it. You will need a bent tip for the gauge. A piece of welding rod is ideal and if you can get your neighbour to put a thread on it you'll be onto a winner.

tim

[Steve]

Hello Chaps,

I have just taken up knitting.

As Rob has stated I now have a set of 135 cams waiting so I am up for a cam swapping session. I am happy to have a go at this ~ as long as there is some good technical backup.

Basicly I will be spanner man if someone directs the show!

[Rob Bell]

Tim, I rather liked Peter Carmichael's solution: a smallish rectangle of mild steel that he was able to bolt to the cam ladder to rigidly mount in place. If you have a bit of steel that could be used, that'd be great ;D

Steve, welcome aboard! Come along and watch what's involved. Mine will be the first one we've attempted, although Tim has gained a fair bit of experience with cam belts and cam timing (he's got 633's on verniers)

I've chatted to Bob about his gaff - we'll arrange a date ;D

[dave]

Don't forget to let me know the date - I want to join the voyeur gathering ;D

[Steve]

In preperation do we have:

1) a parts list
2) a very detailed procedure of what to do.

My Parts list (mostly without part No.)

TF135 cams Tick
Single vernier timing pulley, Piper Tick
Bush-drive Spindle Distributor [£28 +VAT Rover Dealer - Part No. NJJ10001]
2x red cam seals
2x black cam seals
Bottle of the cam rail sealant
Cam cover gasket
Additional vernier ?

(Rob, some of this list was from our email exchange)

Steve

[Steve]

Just to set the record straight, the above reference to the rear of a badger was my wording not that of Dave Walker. He did stated that the cams would need to be "properly timed".