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Discussion Starter #1 (Edited)
more oil pump issues

:beat: If the moderators think this should be merged, go ahead. Figured I'd start a fresh discussion.

started with an M55. got a poor welding job and found out how many people don't care for this pump but as you can see, no probs on the install clearance.



Next, tried a Milodon 18755. Tech said dowel alignments may be off and the crank was hitting the pump a fair amount. Can't spin motor all the way around. He sent me a new one right away




Here's the latest Milodon I got yesterday. Crank spins all the way and clears but there is an ever so slight rub. I can not believe all their pumps are this tight and not sure if i am doing anything wrong. My short block was professionally done by a long time reputable guy who works alone. My crank is a stock GM steel unit I bought a few years ago from the dealer.





Aside from there still being a slight clearance issue (which I could probably take down a bit on my own) , notice the obvious CRACK around the Milodon logo. wtf? Is this acceptable? I think not. I'm going crazy here. And the guy at Milodon called me on the phone, said he pulled 3 pumps off the shelf, tried them all out and sent me one he went over. Did he not see the crack or see it and its no big deal????



Guess my next move is to either get a Melling 10553 select or have milodon send me another but one that has been thoroughly inspected, adjusted as needed, maybe even ask them to shave down a bit at my clearance issue. all good ideas right? Any thoughts on why I am running into so many snags with the pump? I know it can't be bad karma. thanks

p.s. the good news is, I'm starting an oil pump collection. Kinda like collecting stamps but more fun.

EDIT - I am sure this will all work out and in no way am bashing Milodon for anything. Their pump is solid and stout.
 

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Never seen that--I'll have to pull one of my new Chinese pumps and see how they fit. I opened one up and it looks pretty decent; nice heavy piece too--unlike some of the ones by M.......never mind!
 

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if you go with another pump from whom ever and your still running into clearance issues i would grind, file , or whatever to the pump housing so it will clear let me ask you this call your motor builer and see how much crankshaft endplay he uses iy should only be about 5 thousanths. stick a big flat head screw driver between the main cap and crank throw and pry it forward ( you dont need to give it much just a quick jolt really ) and then see what happens. im using a m55hv ( melling high volume ) and have no clearance issues on my 355 i would definetly send the pics with an email to milodon about that pump thats a manufacturing defect and is not exceptable im sure milodon does not want a bad reputation at all
 

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There should be slight amount of adjustment so you can center the pump before tightening.
Do you think the crack might have been caused when you tightened it up while binding against the crank?

Do you still have your original pump? Does it hit the crank too? If not, then the Milodon pump is probably mis-machined. Put the two together and compare the hole alignment.
 

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That crack looks like improper casting temps...
You may be right. It doesn't look recent. If it's a casting flaw, then it's troubling on several levels. Have we forgotten how to cast things and who's inspecting the pumps?
 

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What weld was poor on the M55? I've been using Mellings HV for 20 years on many racing motors and Never had any issues what so ever. Stock Chevy pumps work just fine too if your not spinning over 6000 rpm all the time.Just shim the spring with a washer.
 

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What weld was poor on the M55? I've been using Mellings HV for 20 years on many racing motors and Never had any issues what so ever. Stock Chevy pumps work just fine too if your not spinning over 6000 rpm all the time.Just shim the spring with a washer.

The NEW M55 pumps have a thinner casting and are prone to failure in performance applications.

http://www.jalopyjournal.com/forum/showthread.php?t=143630&highlight=melling

http://www.nastyz28.com/forum/showthread.php?t=65870
 

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I've been using Mellings HV for 20 years on many racing motors and Never had any issues what so ever.
A quote from Mellings about the M55 pump: "Not recommended for use on high performance or off road vehicles."
 

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Guess I'm just a lucky guy,but then again,I haven't bought one in about 4-5 years.Maybe the issue is younger than that?
 

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Discussion Starter #12
Racer, the poor weld on my M55 was referencing my poor weld attachment of the pickup. After posting pics and getting feedback about it being a cold weld and not all that desirable, I decided to pull that oil pump apart and in doing so, damaged the relief piston. Around that time I learned of some issues with that pump so I decided to try a Milodon.

I will talk to my machinist about crank endplay but when I try to budge it with a large screwdriver, there is definitely some SLIGHT play but no real movement. It is not totally locked in place 100%. I can't really describe if its in the .005 range or not.

Milodon pump #2 came that way out of the box. I sent them pics and a link to this thread and am waiting to hear back.

ChevyII, per your comment, what puzzles me the most is the Melling pump has tons of clearance as you can see. Are all Milodon's running this tight to the crank?

Paul, I can not see how there is any adjustment or centering factor because the pump has two dowel holes which pretty much keep it from rotating. The dowel holes in each of the two Milodon pumps are not in exact alignment. (The second one I got was better, but still close to the crank). I still have my original pump and the pics show how much clearance there is.
 

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Discussion Starter #13
I wonder.....instead of grinding a bit away at the pump itself where it meets the crank, what if I elongate the dowel holes a bit to give me a drop more rotation thus increasing clearance to the crank throw? my only negative thought of doing this is that there is a lot more "meat" on the pump itself as opposed to the mounting flange area.

just a thought
 

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I would send that pump back to Milodon. The QC person will want to see it and review the process so this doesn't happen again. Without feedback they might not know they have a problem.
 

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this is why I like to reuse oil pumps that never had any issues with fit, pressure, etc...may sound stupid but oil pumps can be service if you can find gears and if the housing is not worn or trashed.
 

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I think they switched to the thinner case in 2004.
this is correct melling was supplying its m55 pumps to gm for years and the engineers ran into some issues with the old ones :eek: so they asked melling to redesign the m55 pumps i beleive to get rid of a support rib. come to find out it needs this rib :yes: melling never switched back to its old design due to cost and production :no: it is still possible to get the old designed ones though i beleive speedpro pumps are the old ones and melling still offers them as well
 

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I wonder.....instead of grinding a bit away at the pump itself where it meets the crank, what if I elongate the dowel holes a bit to give me a drop more rotation thus increasing clearance to the crank throw? my only negative thought of doing this is that there is a lot more "meat" on the pump itself as opposed to the mounting flange area.

just a thought
i would not elongate the dowel holes due to heat expassion when the motor is warm and reving at high rpm you always want to give yourself some breathing room but i beleive the pump could slip and you wouldnt want that :no: i still think you can still use your good milodon pump if you still have it and grind, file, sand it down till you feel comfy.
 

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I will talk to my machinist about crank endplay but when I try to budge it with a large screwdriver, there is definitely some SLIGHT play but no real movement. It is not totally locked in place 100%. I can't really describe if its in the .005 range or not.



ChevyII, per your comment, what puzzles me the most is the Melling pump has tons of clearance as you can see. Are all Milodon's running this tight to the crank?

what do you mean not locked in 100% the oil pump doesnt need to be installed to check endplay so long as you have your main caps torqed to specs. if so and you saw slight movement then that should be it if you have a dial indicator you can check it yourself. i do understand if you have never done this before and dont feel comfortable doing this just tryin to help. as far as the pumps go i beleive all melling pumps are cast thin around the pump shaft due to various uses for this pump. i wouldnt know about the milodon pumps never used one but i have this funny feeling that there the same pump i bet its an old m55hv pump by melling :yes:
 

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Discussion Starter #20 (Edited)
Heard back from Milodon....

" I will be sending a call tag to get that pump back from you. I myself checked that oil pump, there were no cracks or clearance issues with it at all. Is this block a 283 or 327 small journal motor ?"

I have a 350- 3970010 block. Would his question make any difference? The crack was like that out of the box so I am not sure what's going on or what they intend to do.

per chevyII...."what do you mean not locked in 100% the oil pump doesnt need to be installed to check endplay so long as you have your main caps torqed to specs. if so and you saw slight movement then that should be it if you have a dial indicator you can check it yourself. i do understand if you have never done this before and dont feel comfortable doing this just tryin to help. as far as the pumps go i beleive all melling pumps are cast thin around the pump shaft due to various uses for this pump. i wouldnt know about the milodon pumps never used one but i have this funny feeling that there the same pump i bet its an old m55hv pump by melling"

Main caps are torqued to spec and there is slight movement. I didn't have the pump on when I checked endplay. Thie milodon pump looks and feels A LOT different than the Melling. Just look at the pics. I do not think they are the same. Milodon told me they cast all there own stuff in Cali.

Yes, Milodon pump #1 is still an option. Plus, I already have the pickup and retatiner all set up and in position.

Veno, you said you liked the milodon pump. Have any pics of the pump to crank area? Anyone else using a Milodon and having tight clearance issues?
link to Veno's Milodon pump inspection but would love to see pics installed...
http://www.stevesnovasite.com/forums/showthread.php?t=98634&highlight=milodon&page=5
 
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