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Oil pump gerotor question

Started by Adam76, June 26, 2021, 11:42:25 PM

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Adam76

June 26, 2021, 11:42:25 PM Last Edit: June 27, 2021, 12:29:48 AM by Adam76
Hey guys,

I've just put the new CR575 cams into the stock cam plate with new tensioners and full compliment of new bearings...

I was hoping to also reuse my stock '02 oil pump, but when I rotate the inside part of the gerotor around it actually manages to just slip around to the next tooth.

FSM calls for a wear limit of less than .004   I think it's called "gerotor tip clearance".

The smallest feeler I have is .004 and I couldn't get the tip of my .004 feeler guage in the gap, so I should be ok.

Should get the camchest buttoned up soon, and the reset of my top end back from the machine shop this week. 

Thanks.

smoserx1

QuoteI was hoping to also reuse my stock '02 oil pump, but when I rotate the inside part of the gerotor around it actually manages to just slip around to the next tooth.

I'll take a stab at answering.  I just recently replaced my lifters and cam shoes (99 FLHT with conversion cams and hydraulic tensioners).  I did not remove my oil pump during this service but when I removed the cam plate the feed geroter set stuck to the back of the plate and fell out.  When I put it back in the pump housing I noticed the same thing, so I am guessing you are good.  My oil pressure is just like it was before.

motorhogman

I agree with smoserx1. I've had my oil pump out several times . It was replaced under warranty back in 2006 with the updated pump that has a machined spigot instead of cast. I have checked the tolerances on it and every time apart, they have been in spec. Oil pressure is great. It has somewhere around 70,000 mi on it now.
where's the points and condenser ?<br />Tom / aka motor

PoorUB

As long as it looks good, smooth, no scoring and within tolerance, run it.
I am an adult?? When did that happen, and how do I make it stop?!

Scotty

If you can't get the feeler gauge in then it is  well within spec to run as they only have about a .002 amount to wear from new and although that seems a small amount it would take around 200k miles I reckon to get that amount of wear on a well maintained bike.

Adam76

Thanks guys, all good.

Got the camchest back together only to find out that the wrist pins that came with my Wiseco Tracker 95" pistons don't fit the wrist pin bore?

I measured the OD of the wrist pins (.926")  and they are greater than the ID (.922") of the bore they're supposed to go in... I called the machine shop to see if they can fix the problemn and they said they don't usually have any problems like this and weren't 100% sure they could fix it... Too late to send the pistons back - the cylinders were bored precisely to these pistons and the ring gaps set and installed all ready to drop in.

Adam76

Rookie mistake. Forgot to install the chain guide onto the cam plate before putting the sprockets on  :oops:

Is there a way to get the plastic chain guide on when the sprockets are already in place? Or am I looking at pulling them off again?

Scotty

Quote from: Adam76 on June 27, 2021, 09:09:41 PM
Is there a way to get the plastic chain guide on when the sprockets are already in place? Or am I looking at pulling them off again?

No - well not to my knowledge anyway but then again have never had to  :nix:

Hossamania

Really only takes a few minutes to pull the sprockets to install the chain guide.
Don't ask me how I know...
If the government gives you everything you want,
it can take away everything you have.

Appowner

Quote from: Adam76 on June 27, 2021, 09:03:17 PM
Thanks guys, all good.

Got the camchest back together only to find out that the wrist pins that came with my Wiseco Tracker 95" pistons don't fit the wrist pin bore?

I measured the OD of the wrist pins (.926")  and they are greater than the ID (.922") of the bore they're supposed to go in... I called the machine shop to see if they can fix the problemn and they said they don't usually have any problems like this and weren't 100% sure they could fix it... Too late to send the pistons back - the cylinders were bored precisely to these pistons and the ring gaps set and installed all ready to drop in.

I'm no machinist so I'm just throwing out the thoughts that would go through my head in such a situation.

First of all, you did measure the bore in the pistons in several places to make sure it isn't something funky with that?

Next thing I'd do is contact the piston manufacturer and see what they have to say.  Do they make that piston for different pin diameters?  That is, maybe you somehow got or even ordered the wrong version?  And could they hone these out to fit your pins?  Then again, couldn't a decent machine shop simply hone the bores for the pin?  Four thousandths of an inch isn't very much and I can't see where that would structurally compromise the piston in any way.  The important thing would be to make sure it's done with precision.

Alternative would be a new pin that does fit the piston along with a new properly sized bushing in the small end of the rods.  Done properly though that would probably call for removing the crank and all that involves.


koko3052

I would just have the person that I ordered the pistons from deal with it, to get the correct pins.

smoserx1

QuoteGot the camchest back together only to find out that the wrist pins that came with my Wiseco Tracker 95" pistons don't fit the wrist pin bore?

A little confused here.  When you say bore are you talking about the ID of the connecting rod bushing or the bore(s) in the new pistons themselves?  If the bore is their own pistons and the pins they supplied that is certainly an error on their part.  If the new pin will go through the pistons but not the rod bushing you could press the rod bushings out (tools are available, might could make one) and have a machine shop enlarge it enough for the pin to fit.  And pulling the outer sprockets off to install that guide is a piece of cake.  Good luck.

RTMike

How is the wrist pin fit to the connecting Rod bushing,if it is a good fit have the pistons honed out to fit the pin.The shop that fit your cylinders most likely has a pin hone.
Or call Wiseco and send them back.

kd

June 28, 2021, 07:55:54 AM #13 Last Edit: June 28, 2021, 08:05:25 AM by kd
Quote from: Adam76 on June 27, 2021, 09:03:17 PM
Thanks guys, all good.

Got the camchest back together only to find out that the wrist pins that came with my Wiseco Tracker 95" pistons don't fit the wrist pin bore?

I measured the OD of the wrist pins (.926")  and they are greater than the ID (.922") of the bore they're supposed to go in... I called the machine shop to see if they can fix the problemn and they said they don't usually have any problems like this and weren't 100% sure they could fix it... Too late to send the pistons back - the cylinders were bored precisely to these pistons and the ring gaps set and installed all ready to drop in.


You haven't said what the original pins that you took out  measured and that will also give the rod end bore size. 

You have invested in the work up to this point.  Not a shot but we all have learned the hard way how important it is to check components each step of the way before going forward.  Now you are in that club. I think you can fix this without losing the investment in parts and machining.  Any remaining costs should be miniscule in comparison to starting over.

The difference is a total of .004" too small in the bore.  That relates to .002 total material to remove from the piston (if the pins fit the rod end).  This is miniscule and very doable.  If the rod end is likewise too small, because it is an 02, they will be bushings and similarly easy to deal with without disassembly.  Block off the crankcase cavity with rags and tape.  When those bushings are serviced they have to be sized anyway so I see no problem.  In fact, you will probably end up with better fitting rod ends.  This can be all good by taking a deep breath and looking at the facts. 

Worse case scenario, on the next top end (pistons and rings) you may have to also redo the rod bushings to bring them back to the previous (yet unknown) size.  Record the present measurements so you can be sure what you now have and be able to deal with it properly when the time comes.
KD

tbird

Throw the wrist pins in the freezer over night. It helped me in the past.

PoorUB

I feel I have to ask, when did oversized pins or undersized pin bores show up? I would think if you ordered pistons tor a Harley, the should fit a Harley.

I also question the method used to measure.
I am an adult?? When did that happen, and how do I make it stop?!

rigidthumper

Hair dryer to the pistons after using the freezer overnight on the wrist pins should get you where you need to be.   Assembly lube on everything as you go together.  Should be .927" pins with about 1/2 a thou clearance. 
Ignorance is bliss, and accuracy expensive. How much of either can you afford?

Adam76

Quote from: Hossamania on June 28, 2021, 04:09:49 AM
Really only takes a few minutes to pull the sprockets to install the chain guide.
Don't ask me how I know...

:up: Yep, already done. Thanks

Adam76

Quote from: koko3052 on June 28, 2021, 05:39:46 AM
I would just have the person that I ordered the pistons from deal with it, to get the correct pins.

Thanks Koko, I've done that with no response so far. Might have to deal with this one myself.

Scotty

If the pins fit into the rod ends with no issue then they are the correct ones and would do as said above and freeze the pins and heat the pistons with a heat gun and you will be surprised at what happens.

Adam76

Quote from: Scotty on June 29, 2021, 12:15:12 AM
If the pins fit into the rod ends with no issue then they are the correct ones and would do as said above and freeze the pins and heat the pistons with a heat gun and you will be surprised at what happens.

Thanks Scotty, didn't think of that. Will put them in the freezer now.  :up:

Adam76

Quote from: RTMike on June 28, 2021, 07:45:22 AM
How is the wrist pin fit to the connecting Rod bushing,if it is a good fit have the pistons honed out to fit the pin.The shop that fit your cylinders most likely has a pin hone.
Or call Wiseco and send them back.

Thanks RTMike, the wrist pins fit the connecting rod no problems. My machine shop told me to drop the pistons and wrist pins off to them and they would be able to do something for me.

Adam76

Quote from: rigidthumper on June 28, 2021, 04:37:59 PM
Hair dryer to the pistons after using the freezer overnight on the wrist pins should get you where you need to be.   Assembly lube on everything as you go together.  Should be .927" pins with about 1/2 a thou clearance.

Thanks, the freezer and heat gun method did the trick. 👍👍

Saved me a trip to the machine shop and a chunk of change.

Cheers

koko3052


kd

KD

Hossamania

If the government gives you everything you want,
it can take away everything you have.

Buglet

    I think someone had the wrong measurements for the freezer and hair dryer to work. Glad it work out.

kd

Quote from: Buglet on June 30, 2021, 05:41:28 AM
    I think someone had the wrong measurements for the freezer and hair dryer to work. Glad it work out.

I do too but proof that it is worth trying things that are not bridge burning before resorting to things like machining that there is no return from if wrong. 
KD

Scotty

Quote from: Buglet on June 30, 2021, 05:41:28 AM
    I think someone had the wrong measurements for the freezer and hair dryer to work. Glad it work out.

Well it's winter here in OZ and at a guess the pistons were cold and the wrist pins were warm from handling and just shows how metal expands.

PoorUB

Quote from: Buglet on June 30, 2021, 05:41:28 AM
    I think someone had the wrong measurements for the freezer and hair dryer to work. Glad it work out.

Ya think?!

I questioned the measurements earlier.
I am an adult?? When did that happen, and how do I make it stop?!

Adam76

Quote from: kd on June 30, 2021, 06:17:06 AM
Quote from: Buglet on June 30, 2021, 05:41:28 AM
    I think someone had the wrong measurements for the freezer and hair dryer to work. Glad it work out.

I do too but proof that it is worth trying things that are not bridge burning before resorting to things like machining that there is no return from if wrong.

Yeah, my measurements might have been off.... but the fact is that under normal ambient temperatures the wrist pins would not go into the bores of the pistons for love nor money. That's why I did the measurements in the first place.

I still question whether this is right, because once I got the wrist pins in and they started to thaw out, they then seized inside the piston bore. I would imagine that for optimum function this is not ideal and may cause excessive wear on the connecting rod bushing?? I'm just guessing here. But I would be happier if they rotated freely in the bore like the set of pistons I did on my last build.  :nix:

Is a seized wrist pin anything to be concerned about?

Thanks

SP33DY


QuoteYeah, my measurements might have been off.... but the fact is that under normal ambient temperatures the wrist pins would not go into the bores of the pistons for love nor money. That's why I did the measurements in the first place.

I still question whether this is right, because once I got the wrist pins in and they started to thaw out, they then seized inside the piston bore. I would imagine that for optimum function this is not ideal and may cause excessive wear on the connecting rod bushing?? I'm just guessing here. But I would be happier if they rotated freely in the bore like the set of pistons I did on my last build.  :nix:

Is a seized wrist pin anything to be concerned about?

Thanks

You should be okay. Years ago the Sputhe big bore pistons were all shipped that way with instructions to what you did. He said that long as the wrist pin was free in the connecting rod, it was good. Once the engine fires the aluminum piston expands enough to make the wrist pin loose.

He did some other things that were a little different, like using a copper ring instead of a head gasket... R.I.P. Alan!



Adam76

Ok, thanks. 👍 good to know.

Thanks again for the helpful info guys, much appreciated. You're legends.
Cheers.

Buglet

  You should be ok. I the early days you had to heat up the Harley pistons to side the wrist pin in. I just think your measurements might of being off.

Adam76

Quote from: Buglet on July 01, 2021, 05:09:30 AM
  You should be ok. I the early days you had to heat up the Harley pistons to side the wrist pin in. I just think your measurements might of being off.

Yep  thanks 👍

Adam76

Got the pistons and the cylinders on.  All seems well.

Scotty

You didn't forget the two o-rings on the oil return dowels  part number 11273 I hope  :potstir:
Also the cylinder base o-rings part number 11256  :fish:

Adam76

Quote from: Scotty on July 02, 2021, 01:11:40 AM
You didn't forget the two o-rings on the oil return dowels  part number 11273 I hope  :potstir:
Also the cylinder base o-rings part number 11256  :fish:

Thanks Scotty, no thankfully I didn't forget the cylinder base o-rings or the 2 o-rings for the oil return dowels.

I had the full 95" Cometic top end gasket kit and once I'd actually figured out why I was a few o-rings short -- I didn't need any cylinder deck o-rings because I had the MLS head gaskets!   :doh:  then I had it sorted. For a minute there I was scratching my head thinking I was going crazy... 😂😂

Scotty