602 engine on bench because of lack of power and slow to stop when ignition turned off. It does not seem to be glowing carbon because it does it when the engine is cold. Then found one piston with a black burnt oil area.
So, I took off one head and noticed that as I turned the flywheel there was a donking noise from the crankcase, it was at TDC and at the same point the flywheel was moving out of true, across the crankshaft not in line. I took off the other head and it was the same.

I then replaced the head, without pushrods and the donk has gone, together with the flywheel problem. Replaced the second head and no donk!

I am about to try to split the cases for a look-see. Does the bob-weight plate, which appears to be crimped in position, have to be removed?
Also, any tricks for actually parting the cases.

Any suggestions greatly appreciated.

No, that plate is fixed. Just split the case. Judicious use of a soft (or wooden) mallet on the 'horns' I would think.

Thanks for the info- I've now separated the cases and quickly found two suspect areas.

The pix show the cam and I'm guessing it is badly worn, not only the surface pitted but the colouration doesn't look very healthy.

There is almost 20thou end float on the crank. I assume this accounts for the flywheel movement.

Time to scrap or is the engine a realistic repair?

Thanks for any comments

Make a coffee table out of it..

Interested to see what the experts think about this engine. How worn do the cams have to be before they're considered knackered?

I guess it's tied to their ability to lift the valves?

From those pictures, it's evident that this engine has been sorely neglected, with the camshaft lobes being the most obvious casualty.

The photograph of the piston isn't too clear, but that looks as though it's suffered a partial seizure, which is usually the result of over-advanced timing or a problem with engine cooling, however running with ancient, dirty oil won't have helped much.

As regards 'fore and aft' crankshaft play, I've found relatively low mileage échange standard engines with that much play, which suggested that's how they left the Vege plant and they ran well with no noticable reduction in longevity.
As to whether this crankshaft is serviceable, there is a method of checking for big end wear, but I cannot find the video at the moment.

ken

edit. http://www.youtube.com/watch?v=JCPi5cFtpTQ

I had a cam looking like than in the Visa engine - I sent it to Kent cam and they reprofiled and hardened it for me. I think it was around £80.

Thanks for your replies. This is a very active forum!

Kent Cams is near me so that would be a consideration.

To lay the blame elsewhere, I should explain that this 'badly neglected' engine is the result of previous owners. I've the car a short time.

I have another engine in now which runs well apart from a rattling noise when the engine revs over a certain speed. I don't think it's pinking so I suspect small-end wear. Apart from taking that engine out and stripping, does anyone have a method to check with engine in situ?

Regarding the crankshaft end-float, can it be shimmed, and if so, would be on the flywheel end?

no it cant be shimmed, they do keep going these little engines - Cam looks bit crap but ive seen as bad keep giving decent service the pitting is on the ramps rather than the nose. No point in splitting the cases as unless you've got new stuff to go in there isn't much you can do about it all.

clean oil and well set up ignition the secret to a long and happy life