Priming onan oil pump before first start up?

[seuadr 488]

I am working on putting together a replacement engine for my 520h. It occurred to me today that i should probably prime the oil pump prior to first start, and possibly even prelube the engine before starting? 

 

Would spinning it over with the starter with the plugs pulled be sufficient?

 

I'm kind of ignorant on proceedures for breaking in in general

[lynnmor 7,308]

12 minutes ago, seuadr said:

I am working on putting together a replacement engine for my 520h. It occurred to me today that i should probably prime the oil pump prior to first start, and possibly even prelube the engine before starting? 

 

Would spinning it over with the starter with the plugs pulled be sufficient?

 

You should have been using an assembly lube while installing the parts.  That should be sufficient for the first start.  The engine builds oil pressure fast when spinning the starter, so that is a good idea.  Also, you can tilt the engine to the oil filter side and install a pre-filled oil filter to really speed up the pressure buildup.  Another old trick is to put some oil in the engine and quickly roll it over to coat everything, that is particularly helpful in an old engine that hasn't been run for years.

[953 nut 55,321]

If you have used oil and/or an assembly lube on all moving parts as it went together you should be OK.

[seuadr 488]

Yeah everything has been oiled as it was put together, i just have never done this before so was not sure if that would be sufficient. I guess i should probably rig an oil pressure gauge in somehow to make sure it builds pressure too. 

 

I have the remote filter for it that i plan on using but i wonder if for initial start up i should use the normal filter instead.

[WHX?? 48,828]

30 minutes ago, seuadr said:

 

Would spinning it over with the starter with the plugs pulled be sufficient?

 

I like that idea, especially since you went with the remote. Can't hurt. Just once you get it started and after running for one or two minutes shut it down and recheck levels. 

[seuadr 488]

Anything else i need to know about starting it up?  I've read a lot of contradictory info -

 

Don't let it idle, only idle it, run it for at least 20 mins, run for no more than 15 mins, immediately change the oil and filter, don't change it until it has cooled, etc.

 

I static timed the points to open at 16 degrees per the manual, etc. So my hope is that i won't have any issues running it, but may need to significantly adjust the carb and/or governor (which i have not statically set yet - cause I don't have tins on and part of the throttle mounts to the tins)

[WHX?? 48,828]

Depends on how far you went into it. New rings? Bored? Lower end work?.  My 02 is don't let it idle for much longer than start up. Get it at say 1/4 throttle to keep the oil pressure up. Once it runs to satisfaction and you get the carb dialed in button it up and get it under load assuming you have to seat rings. Expect some smoke on start up. I would do an oil change after 3-4 hrs of run time but not the filter then at say 20-30 hrs replace oil and filter. A few guys we know run cheaper oil for run in just to keep the cost down then the good stuff. 

Others will have other ways, most likely better than mine so stay tuned. 

[seuadr 488]

5 minutes ago, WHX24 said:

Depends on how far you went into it. New rings? Bored? Lower end work?.  My 02 is don't let it idle for much longer than start up. Get it at say 1/4 throttle to keep the oil pressure up. Once it runs to satisfaction and you get the carb dialed in button it up and get it under load assuming you have to seat rings. Expect some smoke on start up. I would do an oil change after 3-4 hrs of run time but not the filter then at say 20-30 hrs replace oil and filter. A few guys we know run cheaper oil for run in just to keep the cost down then the good stuff. 

Others will have other ways, most likely better than mine so stay tuned. 

It is a NOS short block, so everything is new (but of course it was assembled years ago) so i lubed everything up and rotated it by hand while doing so, but wanna be extra through.

[lynnmor 7,308]

5 hours ago, seuadr said:

I static timed the points to open at 16 degrees per the manual, etc. So my hope is that i won't have any issues running it, but may need to significantly adjust the carb and/or governor (which i have not statically set yet - cause I don't have tins on and part of the throttle mounts to the tins)

 

Refresh my memory, what engine are you putting in since the original had no points?

[JoeM 7,874]

Put many a race engine together and the only extra step was to crank it up for oil pressure, start it up / warm it up, idle to full throttle,  change the oil, (hot), after the first start up. 

 

Do a burnout and take her down the strip.

 

Don't baby it.........run it like you stole it. Those parts will never be in better shape or tolerance. Warm it up and open it up preferably under a load. Let r eat!

Edited March 25, 2021 by JoeM

[seuadr 488]

5 hours ago, lynnmor said:

 

Refresh my memory, what engine are you putting in since the original had no points?

i'm trying to fit an N52M in there, it is a "big block" onan, but dimensionally it appears very close to the P220. of course it is an older vintage so has points instead of electronic ignition

 

i bought it by mistake a while back, thinking it was a P series.

[stevasaurus 22,764]

@JoeM  That's how we used to break in the new VW bugs back in the 60's & 70's.