36 Chief Oil Pump question...

[ChiefTwoKicks]

I would like a little help with the setting of the metering screw on the oil pump on my '36 Chief. I'm thinking that I'm building up a little too much oil in the sump when I ride at high speed (over 55mph) for extended periods. I remember reading somewhere there is a way to measure how much oil gravitates to the bearings, etc. and since the return ratio of the early pump is about 3.7:1, the amount of oil seems to build up and the return part of the plunger isn't enough to return the bulk of the oil out of the sump, hence the onset of "wet sumping". Alot of early rigid frame rider bikes are equipped with the '37 or later oil pump with the return gears, (with a return ratio of about 23:1), but I want to keep my machine stock. Is there a way to measure or better regulate the oil passing into the pump, so that I may avoid the problem ? Am I asking for too much on such an early oil pump? Or is my worry just something I'm going to just have to live with. Any help would be greatly appreciated. Thanks in advance. Roger Herbison #4287

[c.o.]

Roger, I'm not sure about regulation but a couple thoughts on over oiling... is there a chance the sump valve might need a service/cleaning? Also, could it be a possibility that you have an air leak in the line between the sump and the return pump?

[tfburke3]

I would like a little help with the setting of the metering screw on the oil pump on my '36 Chief. I'm thinking that I'm building up a little too much oil in the sump when I ride at high speed (over 55mph) for extended periods. I remember reading somewhere there is a way to measure how much oil gravitates to the bearings, etc. and since the return ratio of the early pump is about 3.7:1, the amount of oil seems to build up and the return part of the plunger isn't enough to return the bulk of the oil out of the sump, hence the onset of "wet sumping". Alot of early rigid frame rider bikes are equipped with the '37 or later oil pump with the return gears, (with a return ratio of about 23:1), but I want to keep my machine stock. Is there a way to measure or better regulate the oil passing into the pump, so that I may avoid the problem ? Am I asking for too much on such an early oil pump? Or is my worry just something I'm going to just have to live with. Any help would be greatly appreciated. Thanks in advance. Roger Herbison #4287

Curious where the 3.7 to one ratio comes from.There is only one plunger for the return and feed.The return side has the disadvantage of working against gravity with a pulse pump.Thats why as C.O mentioned the disc, seat and spring,plus the screen all should be checked.The adjuster,(feed line pinch off valve),may need to go as closed as 3/4 on hot long ride.Frequent checks of oil in sump by draining while you get used to the settings will let you know when its not too much.
Tom

[bstevens479]

interesting idea about 3/4 turn I have same problem. uncle frank suggests 1 1/2 turns from bottom out I have been scared of going less than 2 maybe I will give it a try & watch it close. also would converting it to 47 early 48 scrapper help, thanks

[tfburke3]

interesting idea about 3/4 turn I have same problem. uncle frank suggests 1 1/2 turns from bottom out I have been scared of going less than 2 maybe I will give it a try & watch it close. also would converting it to 47 early 48 scrapper help, thanks

In my opinion the 36 pulse pump needs a sump valve.The scraper relied on the better, gear,continuous flow pump.
Sump valve cases have a transfer hole in the bottom of case flanges.Conversion from sump valve to scraper requires machining(filing) a notch in the case bottoms flanges to fit scraper.Not easy if engine is assembled,harder if in frame.
To convert to cast Iron and scraper you would also need correct cam shaft,cam case cover. Tom