AAARGH! What has chewed up my dizzy?!

[petrolhead]

Advice please!

 

BACKGROUND: I took my dizzy out to get the advance curve altered. The car had been running well but the last dyno run indicated a slight loss of torque and on the very last drive it was pinking (which I put down to bad fuel). Rally Spec Xflow, used on the road serviced every 2500 miles with a good 20/50W oil.

 

PROBLEM: pictures speak for themselves, the driveshaft gear seems to have suffered significant damage. The teeth are worn/deformed and one of them is almost sharp. see below:

I have never seen this before on my cars. My thoughts are that I have to get this dizzy drive replaced but that won't solve the cause of the problem. The only thing I can think of is that the dizzy drive is being pushed too hard against the can, in which case shimming it further away may solve the problem (pray that the cam is undamaged)

 

OR the cam itself is the cause or has already been damaged. Quick google search indicated a 'wandering cam' is sometimes the problem. In which case it is an engine out job

[escort21]

I'd guess a dodgy cam gear

[emu]

I Cant picture how the distributor drive is supposed to look. Does the shaft normally sit so far up inside the gear section?

 

I'm just wondering if the gear has worked its way down the shaft or the shaft is moving back and forth along its own length within the distributor body??

[petrolhead]

Yes, it does look odd but it does sit like this. I have spoken to the engine builder and dizzy builder. Both confirm its highly likely to be a mis-match of metals. Steel cam should be used with a phosphor bronze dizzy drive. So they have both sorted me out and this is getting changed with no labour charge even though its not their fault.

 

On the big plus side, the cam shaft looks mint inside the block

 

PS if anyone else with a Twin Cam or Cross flow is also using a steel cam, PLEASE BE AWARE OF THIS PROBLEM.

[Fiesta Steve]

It will most likely be down to a worn cam retainer plate allowing the cam to walk as mentioned. I have just replaced my drive gear too and I didn't have a steel cam.

 

My retainer plate probably had almost a 1mm groove ground into it by the cam.

[Fiesta Steve]

Here's a pic, worn one below, new one fitted;

 

 

As said I don't have a steel cam so the deep groove in the retainer was blamed. Obviously your steel cam is not going to help matters weather your retainer is worn or not. It may be worth measuring the end float of the cam but that will mean front cover off, very difficult in a Fez, not sure about an Escort. My engine is out so was easy.

[petrolhead]

Cheers Steve, much appreciated. I'm using a Kent 244 cam, I take it they are steel?

[Fiesta Steve]

Off the shelf they won't be unless you specifiy, then they are double the money

[Toby]

The cam won't be steel if not specified - they're about £300 for a steel cam.

 

The dizzy drive usually suffers less than the oil pump - check that one as its implications are much more serious.

 

I have seen worse with a bronze gear on an oil pump. I now add a 1mm drilling through the block behind the oil pump to spray oil onto the drives. This seems to have helped. This area is not very well lubricated by splash only. I don't use bronze anymore.

 

Does your dizzy turn freely? I would think it has to be tight to wear like that, after all, there's a lot of fords out there fine. Or there is an issue with the cam gear, or some other fitting issue. I never got to the bottom of the issue on mine but it seems to be resolved with the above drilling.

 

[Fiesta Steve]

The oil drilling is a good tip, but I've just assembled my motor Thanks anyway

 

Toby, what causes the retainer to wear heavily ?

[petrolhead]

Thanks Toby, I will whip that oil pump out and have a look!

[w p e]

ive found cam thrust causes these problems also cheap after market drive gears [very soft. done the oil hole drilling a few times on short oval engines and on rover v8s that suffer the same