my son just bought a 1970 from his boss. it was sitting for a long time. we changed oil (50 wt penzoil, couldn't get to bike shop). it doesn't have an oil light so I put a guage on it. 30 psi cold, 0 psi hot. I can pull the gauge and the oil just sits there. pulled the line to the head and the oil just barely comes out the hose with the engine at high idle. If I pull the cap off oil tank I can see that it is circulating. I pulled the supply line to the pump, flow was ok. put a new relief spring in the pump, no change. the fact that the pressure is ok has me wondering about the oil itself. my last shovel would at least wiggle the gauge when it was hot at idle. any suggestions? thanks

 

Pull & clean the tappet screen , that's the dime sized plug just above the oil pump on the cases . Zero gauge pressure is not uncommon on a hot shovelhead and the cheap gauges can be way off on the low end . Nor Cal 50 wt is fine unless your central valley over 100 regular then 60 is a better choice .

 

Twisted is right about the pressure. I would suggest replacing the oil lines if the bike has been sitting that long. It's a pain in the ***, but well worth it. You can usually snag a good FACTORY shop manual on ebay.

 

screen is clean. full pressure cold, zero hot. NOTHING flowing out of tappet screen port when hot. pulled and cleaned tank, lines are new. pulled pump today, clean, very minor scoring. check valves and ports clear. clear between block and tappet screen. sure would like to see more pump wear before I spring for a new pump!

 

I'd run with changing the oil lines then could be when hot the inner walls are collapsing and choking things maybe , you've done the spring change already so not much else could be going on unless there's a wrong pump body gasket blocking a port on the case .

 

first question -- does the bike have the original oil pump can you tell the difference

second --- if you removed the oil pump than the cam cover is off does it still have the side oil pinion in it, and the cover is it still side oil or has some one changed it all - do you know how to check that

if its a side oil is the bushing worn out - do you know how to check that as well -- side oil motors tend to be low when they were new / they have tools and jigs to mod the pump to the evo style and that requires drilling do you know what that looks like when done --

can help but you need to fill in some of the blanks -- jz

 

Damn , you just shook some dust loose I had forgotten about the 70 -72's and the dedicated oil pump & nosecone for the side oiling pinion shaft . And your right when mine was still a stock 72 it had squat for oil pressure till I did the later conversion to her .

 

thanks for the replies. to answer your question I do not know if it is an original pump, or a side oiler. my local mech said the cases were not Harley (although he did not know what brand) and that it looked like it had 80" cyls. is it possible that it could still be a side oiler with that configuration? he looked at the pump and said the only thing he could see was the seal between the 2 driven gears did not look good, but he did not think that would make much difference. if I dropped it in your lap, how would you proceed? I've got a new seal and gsks coming. unless you recommend pulling the cone, I think i'll put it together and use a sending unit and see if the light comes on. thanks again for your input. I hate to admit it, but I was missing my shovel when he got this one (don't laugh, I have a 90 evo), but after messing with this one and kickstarting, I think I may just stick with my button equipped evo

 

Shovelhead oil pumps rely more on volume than pressure, and the two are different. The gears in the pump moves just enough oil to lubricate the needed parts.
Does the motor still have hydrolic lifters? Are the staying pumped up while the motor is running (no rattles from the pushrod tubes) I know it sounds simplistic, but when you have a pump failure, or low volume of oil going through the motor, the first indication will be the lifters collapsing. The engine will actually run for quite a while without oil, many times with little or no damage if caught quick enough.

 

anything can happen but to think someone would go to the trouble of making an aftermarket block a sideoiler is - well - even stupid people wont do that --

the seal in the pump today is put in with the lip facing you NOT in like the books show with the lip down - two reasons one it installs better ( does not get bent installing it ) and the main reason the pump side ( smaller gears ) facing the cover will blead past and into the return gears the ( larger ones ) as the the pressure side has well more pressure than the return at all times - jz