Oil Presure passages

[Klingbeil]

I bought a tractor with a set of new crank and rod bearings in it. The oil pressure was low, so I just rebuilt the pump and did gain some pressure. But, the pressure drops to near Zero after the engine comes up to operating temperature. I begining to believe that the crank may not have been ground and match fit with the new bearings. I really do not want to take the engine out, now that the tractor looks good. I would like to know if the oil pump provides oil to the cam first or does it provide oil to the crank main bearings first. I will pull the engine if the cam bearings need to be replaced. If the crank mains are the first, I may consided a small size main bearing to compansate for the crank size. Tell me what you believe. This is a very early 1940 model.

 

[HCooke]

No cam bearings in a 9N originally. Of course no telling what is in there now. Oil goes to the mains and rods first. Have you checked the oil relief valve?

 

[Den N Ms]

Klingbeil,The proper tool,(jig) is needed when rebuilding an oil pump to correct clearance specs.A oil pump with excessive clearances is the same as a worn out pump with little to no oil pressure.The pump should be rebuilt by some one with the proper tool and knowledge such as a good machine shop. Check the main and rod bearings with plastigauge to check the clearance when you have the pan off.

 

[TheOldHokie]

(quoted from post at 17:16:53 07/31/11) I bought a tractor with a set of new crank and rod bearings in it. The oil pressure was low, so I just rebuilt the pump and did gain some pressure. But, the pressure drops to near Zero after the engine comes up to operating temperature. I begining to believe that the crank may not have been ground and match fit with the new bearings. I really do not want to take the engine out, now that the tractor looks good. I would like to know if the oil pump provides oil to the cam first or does it provide oil to the crank main bearings first. I will pull the engine if the cam bearings need to be replaced. If the crank mains are the first, I may consided a small size main bearing to compansate for the crank size. Tell me what you believe. This is a very early 1940 model.

Neither gets oil "first". The camshaft and the crankshaft (rods and mains) are both direct branches (tees) off the main oil gallery where the oil pressure is gauged. The flow splits off at those tees and excessive clearances in either one will cause a drop in gauge oil pressure independent of the other.

TOH

 

[Klingbeil]

Thanks, I will check the crank to bearing clearance with plastigage, good idea. I noted noticed that I fouled a spark plug just after I repaired the oil pump. This would be an indication that the rods are spinning, too much oil off of them. Seems, like I should check the clearance on the rods, too. I am assuming that the crank is cross drilled to the rod journals. How does the rear main get fed oil from the pump?Thanks for your help.

 

[Klingbeil]

Thanks, I will check the crank to bearing clearance with plastigage, good idea. I noted noticed that I fouled a spark plug just after I repaired the oil pump. This would be an indication that the rods are spinning, too much oil off of them. Seems, like I should check the clearance on the rods, too. I am assuming that the crank is cross drilled to the rod journals. How does the rear main get fed oil from the pump?Thanks for your help.

 

[JMOR]

(quoted from post at 22:19:51 07/31/11) Thanks, I will check the crank to bearing clearance with plastigage, good idea. I noted noticed that I fouled a spark plug just after I repaired the oil pump. This would be an indication that the rods are spinning, too much oil off of them. Seems, like I should check the clearance on the rods, too. I am assuming that the crank is cross drilled to the rod journals. How does the rear main get fed oil from the pump?Thanks for your help.