KillerKiwi

What does using longer or shorter glow plugs do? I bought some glow plugs that are a little longer than what I usually get, is there any chance it could strike this piston or something?

-Matt

125cchyperman

It could try tightening the glow plug up and slowly turning the engine over with your finger and see if it does strike. It it does then dont use them as if it does strike now it will strike when the engine is running also. You could add an extra washer under the glow plug to make up for the difference but I dont know how well that would work and is just as idea. I have used long plugs in engine that require short plugs and it didnt hit or anything like that but that was with my engine and mine may be different then your's.

gubbs3

My Feedback: (1)

I would stick to what the engine was designed for. The majority of manufactures use long plugs, or rather "standard." Short plugs I know for sure are used by O.S., and there are others that I am not sure of. But if you have an O.S. Stick to O.S. plugs since they are short reach. Using a long plug in a motor designed for short won't necessarily hurt it, but it can cause erratic running. First thing that is obvious is that the plug sticks further into the cylinder raising the compression. This is the same effect as removing a head shim and could lead to detonation. Plus the edges of the protruding plug can get hot spots on them which can also cause detonation. So far I have not seen an engine where using a long plug hits the piston.

KillerKiwi

The glow plugs are "DYN2508 McCoy MC59 Power Plugs". I noticed that they were longer than the OS 8 glow plug that I bought before.

46u

My Feedback: (3)

What engine are you talking about? OS are the only engines I know of that takes the short plug.

KillerKiwi

Dynamite Mach 427.

Philster

Use the McCoy. You will NOT have clearance issues.

KillerKiwi

Thanks.