Contaminated oil system

[martinlaw]

Can someone help please?

I have just bought a GTR with a broken engine (a push rod has snapped and a cam lobe is badly worn).

I am taking the engine out this weekend to have closer look at the damage.

What is concerning me is if the cam lobe is badly worn, all the metal must be in the oil system. The filter will have sorted some of it but I don't want to fit a new engine when there may still be contamination in the oil.

Any suggestions on the best way to clean the system and what to use?

The car has also got a accusump fitted.

Cheers,
Martin.

[Steve_D]

The cam wear will have produce small particles over a period of time which for the most part will have been trapped in the filter.
Buy yourself a few gallons of paraffin to wash bits in and add some fairy liquid.
You are looking to clean anywhere oil could sit and allow particles to settle out. There will be places in the valley of the block, parts of the heads around the tappets and rockers, strip and clean hydraulic lifters if you have them, fill the oil cooler and leave to stand for a day or so then flush with more clean wash, Accusump can be dismantled and cleaned (something we should all do from time to time but never do), sump and all its trapdoor compartments.

I would not concern yourself to much with the actual oil-ways as the flow will have kept anything moving on.

I would expect to replace all bearings apart from small end as any particles will have picked-up in the white metal.

My worry is why the rod bent. Is it the same one that had the worn lobe?

Steve

[martinlaw]

Steve,

Thanks for the advise.

Unfortunately the lobe and pushrod are on opposite sides of the engine so it is difficult to understand how they could be related - any ideas anyone!!

[TuxMan]

Martin any spec on the engine ??? are you sure its only one lobe on cam ?? best to strip engine completely and send it to be checked ,i used a company at soham but can recommend a engine builder if you need one . simon

[Builder]

martinlaw said:

Steve,

Thanks for the advise.

Unfortunately the lobe and pushrod are on opposite sides of the engine so it is difficult to understand how they could be related - any ideas anyone!!

If it is a solid lifter engine, maybe a bad adjustment? What are the specs for the engine? Do you know who built it? How much time was there on the engine before the damage? How are the cam bearings?

Any indication of the valves hitting the piston? There may have been a clearance issue.

Or, when an engine stops suddenly, like when an airplane propeller tip hits the ground on landing (prop strike), the engine frequently has to be rebuilt and all kinds of odd damage can happen. If the engine froze up, or there was a foreign object in there from the build-up, or a loose component, that kind of damage could be expected...apparently unrelated.

I would suspect a clearance problem crank, case, or cam. Cam bearings or a really bad rocker adjustment are suspect. Where did the pushrod break?

[martinlaw]

Thanks for the feedback.

I have not had a close look at the engine yet.

The info. I have is from the previous owner.

I am in the process of removing it and will have it stripped and rebuilt by Huddart Racing.

I will let you know what may have caused the problems.

Martin.

[MattYorke]

I would absolutely, without question, replace all external oil system components.
Otherwise you'll be very likely to be rebuilding it again next year.