Main Bearings (again probably)

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storm42

storm42

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I was involved with pulling a recently rebuilt Combat motor apart yesterday to investigate a rattle. There were a couple of issues that made it prudent to strip the motor fully, It looks like all the bits that were declared new and replaced had been, but, one of the oil pump nuts was in the bottom of the timing chest and the other was nearly off the stud, the pump was being held in place by the rubber seal, the cam sprocket nut was also nearly off the end of the cam so we felt the need to check everything else.

The main bearings were NJ306E M1, we thought they needed to be the C3 so we looked at RGM's site and see that they still list that bearing. So the question is, do we need to change them? are the non C3 bearings just old stock that cannot be shifted because nobody uses them?

Also should the oil pickup be moved to the back of the engine whilst the motor is apart? (CNW rear mounted reed valve)

Thanks
 
Move the oil pickup. I would not recommend doing it the way I did. And definitely a reed valve on the back.
 


www.accessnorton.com

Plugging Timing Case Holes

I noticed that although the cases I'm going to use have the mods done to the windage and oil pickup, the holes in the timing case haven't been plugged up. Does it matter how you plug the holes? Should the holes be tapped and a short set screw with locktite be used...
www.accessnorton.com www.accessnorton.com
 
Thanks Dave, I had watched that vid last night, didn't realise it was you. Just to be clear, are you saying you would plug the front pickup differently or the machining of the windage? I have the cases on the mill just now.
 
Ok, thanks,
I did read the whole post and whilst Bill did say do not do not do not etc, there wasn't really a clear explanation of what to do, no problem I can work it out, I was just looking for a definitive do it like this picture.

Now, any thoughts on those bearings?:)
 
They should be C3's, RGM mistakingley sent me the non C3 that they still have listed so I had to return/exchange.

Dave provides a good link, you can also refer to the Old Britts page on the pick up modification:
 
We think they need to be C3 as well, just thought I would check.

Yes Dave's link is good but the Old Britts page shows the windage cut away, as does Andover Nortons notes on the subject, You see my confusion.

I am struggling to understand why the windage is necessary I don think Steve Maney's barrels have any shield in front of the breather. does it matter how the oil gets back to the tank?
 
storm42 said:
I was involved with pulling a recently rebuilt Combat motor apart yesterday to investigate a rattle. There were a couple of issues that made it prudent to strip the motor fully, It looks like all the bits that were declared new and replaced had been, but, one of the oil pump nuts was in the bottom of the timing chest and the other was nearly off the stud, the pump was being held in place by the rubber seal, the cam sprocket nut was also nearly off the end of the cam so we felt the need to check everything else.

The main bearings were NJ306E M1, we thought they needed to be the C3 so we looked at RGM's site and see that they still list that bearing. So the question is, do we need to change them? are the non C3 bearings just old stock that cannot be shifted because nobody uses them?

Also should the oil pickup be moved to the back of the engine whilst the motor is apart? (CNW rear mounted reed valve)

Thanks
Click to expand...

Hello Storm 42
The M1 designation refers to the brass cage type used in the bearing. C3 refers to the internal clearance being greater than normal.
I'd suggest you re-examine the bearing for markings.
This image shows the markings on the type of bearing usually fitted. As I understand it, if there is no designation after the M1 then the internal clearance is 'normal' .
Andy
Main Bearings (again probably)
 
The pix shown is for todays bearings. A long time ago you would see it on the box but not the bearing,
New box marked C3 and now bearing marked C3 gives me hope,
If installed and the crank resists easy end play measurement, I don't use them. 3 times installing and removing bearings taught me...
If you think C3 is not desired I have a few new sets to sell.
I am NOT a fan of old brits/INOA tech digest oil pick up mod.
My method is on this forum somewhere. It reduces the oil pump disasters from eating washer tabs among other bits. open hole pick up is bad IMHO.
 
DevonNorton said:
Hello Storm 42
The M1 designation refers to the brass cage type used in the bearing. C3 refers to the internal clearance being greater than normal.
I'd suggest you re-examine the bearing for markings.
This image shows the markings on the type of bearing usually fitted. As I understand it, if there is no designation after the M1 then the internal clearance is 'normal' .
Andy
View attachment 16832
Click to expand...

Thanks Andy, defiantly no C3 marking
 
dynodave said:
The pix shown is for todays bearings. A long time ago you would see it on the box but not the bearing,
New box marked C3 and now bearing marked C3 gives me hope,
If installed and the crank resists easy end play measurement, I don't use them. 3 times installing and removing bearings taught me...
If you think C3 is not desired I have a few new sets to sell.
I am NOT a fan of old brits/INOA tech digest oil pick up mod.
My method is on this forum somewhere. It reduces the oil pump disasters from eating washer tabs among other bits. open hole pick up is bad IMHO.
Click to expand...

Thanks Dave, I think we know the bearings need changing, the spanner in the works is RGM still listing the ones we have so I thought I would ask the question.

I have read through a load of post re moving the oil pickup but it seems everyone has their own ideas, I have just managed to find your fix and I see the logic.

I have just come in from the garage and I have done the job as follows and as far as I can see, it looks like we have another way now, thanks for all the answers.

I was going to put a blank in the pickup hole and then changed my mind when I realised the drilling had to come from the front, so I removed the blank from the front of the engine and extended the threads and made a longer blanking plug that when screwed in went past the pickup hole. I covered the blanking screw in JB's finest and that was that.

oil3.jpg


oil4.jpg
oil5.jpg


oil6.jpg


I then took into account that there is a fair amount of negative comments re removing the windage so I removed a small amount of material from the timing case to expose the oil drilling at its lowest point leaving the windage in place.

oil2.jpg


oil1.jpg


Are there any thoughts on if this is good enough? I want to be sure because this isn't my engine.
Thanks.
 
That looks fine. I did like the solution of drilling a series of small holes at that end, but you should be just fine.
 
SteveBorland said:
Hi Ralph, perhaps you can try asking RGM? Roger has always been very helpful with my queries.
Click to expand...

Hi Steve, hope all is well with you and yours. I think we know the bearings need changing, but you are right, I may ring Roger just for peace of mind, they are probably used in something less stressed.
 
I have removed the lip at the rear of the cut so the cut doesn't have so much of a sump now but in any case, why would sludge collect there as opposed to any where else?
Do we get sludge in engines now days? I remember spending hours cleaning sludge out of Ford rockerbox covers back in the day, but modern oils seem to have done away with that problem.
I agree the depth is a bit unnecessary and was un intentional, I started the cut just above the bottom of the hole and didn't take into account the angle of the oil way but I cannot see sludge being a problem with modern oils and the frequency we tend to change the stuff these days.
 
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