Indian four oil pump adjustment.

[L Burke]

I do not know how the bottom end was sat up on your engine. If I had beaded the crank.......in my bike, I would set my spill no greater than 40 lbs at a nice fast idle.......checking the speed on my drill with a machinist tachometer, a little over 1/2 spees is about 850rpm. I am quite sure there are motor builders out there who might or might not agree with me. This is the heart of your engine, call someone who does this for a living and buy a little of their time. It will be worth you peace of mind considering the value of your bike.

[Ivor]

Hi Larry, I don't understand why the speed that the pump is turned should affect the spill rate. I can see that the pump produces more pressure when it is turned fast compared to slow, but irrelevant of how much pressure the pump produces, I thought the spill valve was just a pressure relief valve that is adjusted to open at the maximum pressure you want the oil to arrive at the bearings. I really want to be comfortable about these details while I complete this build, because I think if the previous builder had paid more attention to these details, I wouldn't be going through all this now.

[L Burke]

Hi Ivor, you are probably correct with your concern of the previous builder and the setup of the bottom end. Just remember, at lower rpm range the majority of the oil is passed throughout the system, at higher rpm oil is spilled back into the sump pan, all this is determined by the lubrication needs of the bottom end.

Some bearing materials and bearing types you will want as much oil as possible flowing over the bearing surfaces. Modern insert type bearing ran at higher speeds, demand more oil, which will be delivered at a higher pressure setting on the spill. Spill rates are set as high as 50-55lbs using modern insert bearings. With this style of pump, you can not have your cake and eat it too! It is pressure driven and not a volume pump, a volume pump in which you actually flood the bottom end with oil at any rpm.

With the 4 pump if you run a high flow of oil delivered at a higher pressure, some babbit compounds can actually be worn away or mined out with high pressure delivered oil. The rate of wear is determined by the composition of the babbit. Hope this helps.

[Ivor]

Thanks again Larry.
I have just put the new spring in from JG's and the pressure is clocking 95lbs and that's just turning it slow with cold sae50 and the spill adjuster wound out as far as I dare.
The pump looks exactly the same as Roy's. I just don't know where to go from here ?

[L Burke]

I can not tell from here, but you might try this.....take the spring to a auto machine shop, use their valve spring tester....might have to build a gig to hold this smal spring and check the compression poundage of the spring.
Your approach correct, I am unsure how you are doing the set up process. You might consider sending the pump to Roy Davies and let him set it up. This step is important. Roy can be reached by private message on the Indian4 Club face book page or pm me and I will send his contact info

[Ivor]

Thanks Larry,
I don't know what the compression poundage of the spring should be. So, going back to basics, I now understand that too much oil pressure can erode the babbit, and from all of the information that I have seen, I feel comfortable with setting the spill pressure at 40lbs. BTW, I have just found this mentioned in a Indian 4 overhaul manual ; Gear oil pump, Adjusted pressure 30 pounds.
Maximum pressure after motor is warmed up - 15 pounds minimum. Light oil.
I'm assuming that this is a pressure gauge reading on an assembled motor.( Allowing for leakage from around the bearings )
Anyway, I'm testing the pump, just as in Roy's video and the pump reaches high pressure evan when turned slowly and takes a little time to drop to zero after I stop turning the pump. No noticeable end float on the oil pump shaft and it doesn't feel like it's binding either, so 'all-in-all' I feel happy with the pump.
What I have done is, cut the spring length down, so when the adjuster is wound in half way, the oil spills at 40lbs.
Thanks again for all your help, and I hope I'm not responsible for any grey hairs ! But this site is my only life-line.

[L Burke]

Ivor,
You are tenacious like a bull dog pup! Good approach on the spring. I urge you to set spill with a modern gauge....then read with your original US gauge and note the difference in reading......and remember it...for me that is sometimes hard to do, like to many PIN numbers.

[Ivor]

Yes, I went and got a new gauge as you recommended on one of your first replies, it reads in BAR, but translates to read 5lbs less than my original gauge.

[L Burke]

Ivor,
Hope all goes well with the 4, know it is frustrating, but persistence with a 4 is important!
Merry Christmas to you and yours.

[Ivor]

Thanks for those kind and supportive words Larry. It all took a turn for the worst yesterday when the front engine mount fell off ! I explained in a reply to my torque setting post.

Here's wishing you and yours a merry Christmas and a happy new year as well !
Ivor.