Forum

[Dennis C]

m1ks, simple question, what do you think caused it to seize?.

[m1ks]

I retract my earlier comment Norm, having gotten Home and taken another look at the gudgeon pin, it does have a tinge of brown, kind of like a nice morning croissant,

[m1ks]

Alan, my email is
[email protected]
Tel no: 07846581349
Let me know the details and I'll pay you some Pennies for postage, and packaging too.
Again Thankyou for your kind offer.

[Norm]

M1ks,
Is this a 350 or a 500

[m1ks]

It's a 350 Norm.

[m1ks]

Had a good check of the rockers and noticed some scoring on one side of the upper ex rocker. Don't know how clearly the pics will show it.





Darn!

[Norm]

M1ks,
Slots are nice and clean, so no signs of whitemetal is good, scoring like that is fairly normal, I wouldn't be overly worried about that

[Les H]

The scoring of the Samrat bushes is a by-product of the seizing. What happens is that bore and piston particles drop down into the sump into the oil there. The very smallest particles in the oil pass right through the gauze filter in the sump as all the oil is pumped up to the rockers. I have observed this phenomenon myself. Where inspection of the Samrats showed no wear at all after thousands of miles, after fitting another piston and suffering several partial seizures I noted that the rocker bushes had become scored, proving to myself that particles from the seizure had been the cause. Some years ago I suggested that the cast iron rockers should be used on a new engine or engine rebuild as the initial larger wear particles especially from the new cylinder bore would not affect the cast iron rockers so much or indeed if they did it would not matter as they are being discarded anyway. After running in the engine the Samrats could be fitted later with the benefit of not having to suffer "large" metallic particles in the oil. Note: the fabric filter is in the feed into the big end so the oil supply is cleaned up quite well for that bearing but the cylinder head gear has to use only crudely filtered (mesh filter) for its oil supply. I also suggested some time back to attach Samarium Cobalt button-magnets to each rocker feed bolt where ferrous particles (the most abundant and abrasive) would be held onto the inner surface of the bolts. Removal of the bolts say at 1000 mile intervals will allow the metal sludge and particles to be wiped off. I would imagine this would extend the Samrats life quite a bit.

[another Allan]

I like the idea of the magnets on the rocker feed bolts....My engine has Samrat rockers, and is newly-rebuilt, so I'll fit some and look out for metallic sludge collecting on the bolts.

[Les H]

Just to add that high temperature Samarium magnets should be chosen due to the highish head temperature....noting the rocker bolts will rarely heat up more than 100c due to the oil cooling they experience: loads on Ebay: eg: http://www.ebay.co.uk/itm/Samarium-Coba ... f634....OR......
http://www.ebay.co.uk/itm/10mm-dia-x-5m ... 4ab0f2ef12