1227 cam dizzy drive

[V7 SLR]

The original SLR inlet cam has a drive lug for the distributor mounted in its rear end. The new 1227 cam doesn't have one. I tried to remove the drive lug from the SLR cam, but there's a rubber damper (I guess) built into the lug which looks fragile, and when I was lightly twisting the cam whilst the lug was held in the vice, the rubber bit didn't feel like it would stand a big twist.

 

I called Mick Smith, and we agreed that it isn't a good idea to remove the lug as it'd probably break at the rubber bit, so I need a new one (from Rover's parts dept, do you think?).

 

I believe the new one should be tapped into the cam end. That right? It appears to be held in simply by friction in a tapered "joint" - sort of the same as the top ball joint, but without the screw. Mick and I think it best to tap the main body using a socket, so as NOT to tap the part that is connected via the rubber bit. Sounds reasonable, but how do you line it up to ensure you have the correct phase? There's no markings and no locating groove. I know the ECU provides accurate timing, but it seems a bit hit & miss not to have some way of locating it.

 

One way round this is to go to wasted spark but I'd rather not because of the cost. I have heard that a VVC twin coil pack and HT leads (could I re-use my HT leads?) are approaching #100. My dizzy setup has worked OK to date so unless someone has one to sell at an advantageous price, I'll stick

with the dizzy.

 

Also, how do I recogne which cam is which... They both look the same. They both have a cam phase lug integral (I thought only the inlet would have such). I think I must have missed something. Please bear in mind that mine are not VVC cams. They (the VVC cams) are obvious which is which.

 

Stretch bolts. Unless someone has had a bad experience with re-using these bolts, I plan on re-using them without even measuring them. OK, I *might* measure them, but only if I can find the measurement I need easily. Anyone got any comments?

 

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[simon_h]

You can get the dizzy drive spigot from a Rover dealer, dont know the part number or price but I seem to remember that they are not very much. If a dealer doesnt have them then I would think that PTP or DVA (probably your best bet) would have them.

 

As far as alignment of the drive goes, they are just hit into the end of the cam, I would try to find someone with the jig made up to do it. Again try DVA or Scholar Engines in Suffolk have one, bit of a long way away for you though. I think if you look at your old cam and see where the rotor arm location flat is in relation to the cam lobe and put it in the same, that would be close enough.

 

The cams will look the same because they are usually ground from the same blank. The cam sensor lug is just for the newer EU3 engines. They are positioned correctly for the inlet and exhaust by the standard cam pulleys machining. If fitting verniers then copy how the old cams lobes were positioned with the crank on the cam timing marks as your start point.

 

I have reused the head bolts with no ill effect. Just make sure, if its the same head, they go back into the same holes. Dont reuse them if when they are screwed into the block with oil rail fitted, finger tight only, the length from the block face to the underside of the bolt head is more than 97mm.

[Jason Plato]

V7

The cams are not sided - that is they can be used on either exhaust or inlet .

 

The dizzy plug is a std rover part . I had some problems due to spark jumping terminals as a result of the plug not being quite positioned right to pass the spark to the dizzy cap at exactly the right moment .

As i recall we set the valve overlap on TDC in the usual method using a guage ,this must be done first before inserting the plug as your "new" timing will be different from the std rover timing , then positioned No1 cylinder at TDC compression . Then marked the position of the contact for No1 in the dizzy cap on the cylinder head with tipex . Then insert the plug so that you allow for maximum timing advance from the position of the tipex mark .

 

Rob Walker did some serious calulations for position , dwell and accounting for advance which we used , but even then at 8000 rpm we considered the flex of the plug could well cause timing issues as the plug is mounted on a rubber bush , this can allow flex for effective movement of upto 20 degrees , effecivley buggering your timing and all of Robs excellent calculations !!! .

 

Also be carefull to ensure that you seat the plug in the cam so that it sits 1mm or as close as you dare , off the contact in the cap .

I changed to wasted spark as I couldnt see the sense in having a 132bhp/Litre engine running a wayward timing set up .

 

Another thing is , if you hammer the plug into the cam in situ the forces will be taken by the cam carrier - not good news !!! , I had the plug drive milled down by a couple of dozen thou , then it simply slid in with a very light tap , I also used some "chemical metal" to bond it in place .

 

When I changed to wasted , emerald updated my ecu . Magnecor changed my existing plug lead ends for £20 and turned them around in less than a week and the coil pack can be had from a 2l VX Vectra from the breakers for £30 or new for about £80 from QED . Fitting takes about 30 mins .

 

The strech bolts can be re used , check them using the length method above . I fitted new ones after reusing them twice , just to be sure . Although they are far from cheap for genuine rover parts .

 

V7 ........ I would go wasted if I were you . For £100 its gotta be far more reliable , precise and maintainance free .

 

Dave

 

Edited by - Dave J on 13 Oct 2002 09:09:59

[V7 SLR]

Thanks to you both. I'll check the stretch bolts as indicated, and I was interested to hear the cams aren't "sided" as my SLR cams were marked as being "in" and "ex".

 

A local friend has given me the dizzy drive peg and some more advice about fitting. The advice you offer about potential problems due to misalignment makes perfect sense so I will carefully align the drive peg using my old cams as a "model", but will keep in mind the possible problems when I come to use the car. I wasn't aiming to hammer the peg into the cams with them in situ, which means I obviously can't go to the extremes of trial fitting the peg using the dizzy as a marker.

 

Interested to hear you machined the peg/cam machined lightly. Would it require a large whack with the hammer to get it far enough into the cam otherwise? I had planned on holding the cam securely and tapping the main body of the peg with a hammer and socket. Didn't want to hammer the drive part of the peg because it is only fixed to the main body with the rubber dampening material.

 

I (think I) am going to persist with the dizzy though, rather than move to wasted spark. It has been perfectly reliable to date and as I'm not planning to increase my revs past my current rev limit, I am hoping it'll be similarly reliable with my new application. I reckon I may "upgrade" to wasted spark sometime in the future though. As everyone says, it's another mechanical thing to go wrong. I agree entirely with this sentiment.... unless... OK, more details needed please ...

 

... What changes to your leads were necessary to move to wasted spark? I thought the twin coil pack simply had 2 plug terminals on each side (each coil) so you just plug the leads into them instead of into the dizzy.

 

Also, I think my M3DK is already setup for wasted spark. I just need to enable the software for such and take another wire from the M3DK to the second coil. I think.

 

 

It wasn't all bad new on Saturday in the end. I am moving from the VHPD throttle bodies to a set of Jenveys (I got the Jenveys at a good price) so I had to remove the VHPD TBs. Thanks to the stupid way that the IACV rail is connected to the TB manifold, the bolts to remove the whole assy are shrouded and require the head to be off the car. Having to remove the head to have it "relived" around the cam lobe area just forced my hand.

 

In addition, I have been given a pair of dual digital Spa gauges. Last year I attempted to rationalise the shoddy engine loom cabling, but "choked" towards the end and lashed up the last bit. With the head off the car, there's room to rectify all that, and to add the Spa gauges cabling into the main loom at the same time. Problem is, I get all "perfectionist" and have even removed the damn scuttle in an effort at removing unwanted cabling from under the dash. So, from what started out as a simple cam change, the car is now in about 20,000 pieces... but I'm having fun. 😬

 

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[Jason Plato]

You can test fit the plug by lining it all up then removing the cam again to fit the plug , that is if you dont machine the plug down . The plug does need a fair bit of force as you said its an interference fit , so it very tight , It would require more force than would be wise to place on the head / cam carrier .

 

I would go the route of maching it down a bit and then use chemical metal or araldite . Mine held in place fine for many thousands of miles . Also if you do it this way you can "dry assemble " the timing and slide the plug in and out till you find the correct position . All nice and simple .

 

When I cahnged to wasted spark my leads needed different end fitments to connect to the coil pack rather than the dizzy cap . AFAIK Vx / ford / another all have different plug connections on the coil packs .

 

Connections to the coil pack are as you described .

 

Have fun

 

dave

[V7 SLR]

Thanks again Dave. Plenty to consider there.

 

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[WILL FLY]

Nig

 

There are full instructions on fitting the spigot (including the part number) on the Pope's website here

 

Hope this helps.

 

Roy

[V7 SLR]

Brilliant Roy. Thanks. Useful to see a piccy, although I confess I missed this when looking through his site over the weekend.

 

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[John Howe]

Nig

 

Will e-mail you direct a same size template for the for the fitting. Do phone me if you would like to talk it through (01444 892127 any time) - promise you its a simple and easy exercise.

 

JH

 

JH

[V7 SLR]

That's great. Thanks John. I'll have a go at fitting it, and if I get stuck I'll give you a call.

 

Cheers.

 

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[Rob Walker]

Nig,

 

fettle the dissy drive plug so that its a sliding fit into the end of the cam. This is easy done by fitting the dissy plug into the chuck of a drill and reduce using a file and emery cloth. Then time up your cams, transfer / mark the position of number one HT post onto the dissy back plate. Next set the engine to 16 DBTDC using the marks on the front of the timing belt cover. The dissy plug can then be slid into the end of the cam with the rotor arm aligned so that its centre is central on the mark for number 1 ht post. Some epoxy on the plug will hold it in this position. Its also important to set the plug into the cam at the correct depth, this is easy, simply measure the Ht cap, the rotor arm needs to be positioned to be mid way in the cut outs on the HT posts. Failure to get the depth correct will result in breaking off the carbon brush.

 

As Dave J posted we have had lots problems driving in the dissy plug without fettling. The problem is not that the rubber bush flexs its that the rotor arm only sweeps 54 degrees so its positioning is critical when you consider that you are running 45 degrees advance on your map. Incorrect positioning will result is the rotor arm leaving the HT post before the spark is delivered, this then causes an arc and a lot of RF intereference, the M3d does not like this. Misfires, Burn`t ht Caps, Corrupted Software.

 

Get it right or you will have problems.

 

Rob

[CHRIS CLARK]

Have to say I didn't do any of this sliding fit bit. It was a case of calculate the angle and tap it into place. Mind you, it was checked a good few times first though!!!!!

The thought crossed my mind (more than once!) that if I got it in the wrong place this engine ain't gonna work

[V7 SLR]

Thanks guys. I'm going to have a go this coming weekend, although I won't be able to check whethe rI've got it right for a while as I've currently got both the loom and the engine in very many pieces. Should be all back together in about 3 weeks.

 

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