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Stripped my Dizzy drive TWICE - rover 3.5

Posted: Wed Aug 12, 2009 1:00 pm
by BrettInUte
I have a rover 3.5L V8 in a offroad buggy.
Ex - race engine. Built to rev to 7000 rpm.
cam + head work. Zenith carbys.
Ridiculously fast in a 600kg rig.
Running holden v8 dissy + elect ignition. (vr/vs ?)


But - while sorting out some other buggies at top gear WOT....

Buggy stopped making power, backfired a few times and rolled to a stop.
Towed back to camp. Spent a whole day trying to figure out why. All was revealed when we noticed the rotor button wasnt spinning correctly.
Pulled dissy out to see some broken teeth on dizzy drive cog.
Drive gear on end of cam looked rough but usable.
Fitted another drive gear to bottom of distributor and continued driving for another couple days before it went bang again. (got to the last day of trip though)

Back home now and deciding if 2 new drive gears and some fresh oil is all I need.

1. Is the sprial gear on the end of cam unboltable ?
2. Could the oil pump be causing the issue ?
3. How do I make sure this isnt a repeating problem ?

Thanks for the advice - Rover V8s are new to me.

Posted: Wed Aug 12, 2009 7:39 pm
by 6.5 rangie
I've had a holden dizzy do this before, the shaft in the dizzy had siezed, the engine would crank it but you couldn't crank it by hand. Pulled it apart and cleaned the shaft up with some emery paper which got it home, then replaced the dizzy and all was good :)

Posted: Wed Aug 12, 2009 10:34 pm
by TheDato
Hi,

This might apply.

The rover V8s use the cam to run the dizzy and the botom of the dizzy runs the oil pump. The problem used to be, when revved hard, that the cam would 'walk' in the block and root the dizzy drive.

To lessen that effect a 'teflon' button was put in the end of the cam that ran against the inside of the timing cover to stop the cam 'walking' so much. You adjust it with a dial guage on the back of the cam (before the cam plug is in) to allow some thrust; but not too much. I can't remember the amount though sorry.

It's been many years but that is my recollection of the issue. It was a problem when the Rover SD1 was raced in the British Touring Car Championship. Maybe try that as a starting place for research.

There was also a couple of really good books written about tuning the Rover V8, I've lent mine and they never came back. From memory the writer's name was Hardcastle.

If my drunken memory serves that is...

I hope this helps a bit.

Cheers
Muz

Posted: Wed Aug 12, 2009 10:38 pm
by TheDato
PS. It's also possible to run an oil line from somewhere (maybe the oil pump, or a gallery...) and tap it into the timing cover so that it puts oil directly onto the dizzy drive. That also helps.

I used -3 sppedflow line anf fittings, brake line size, and it worked a treat.

Once again, if memory serves...

Cheers
Muz

Posted: Thu Aug 13, 2009 7:42 am
by red90

Posted: Thu Aug 13, 2009 8:19 am
by BrettInUte
I can tell you the dizzy is not siezed. Its spins over nicely with one finger.

The motor does pull some high revs. So ill have to look at what setup there is for cam float.

Can you tell me where you fitted the extra oil line in ??


Cheers.
(help here is much appreciated)

Posted: Thu Aug 13, 2009 10:00 pm
by TheDato
Sorry mate, it was that many years ago I can't remember where I ran the oil line from.

http://www.amazon.co.uk/Rover-V8-Engine ... 41-8324421

http://www.amazon.co.uk/Tuning-Rover-En ... pd_sim_b_1

These are the two books I had at the time.

Good luck with it.

Cheers
Muz