OP: Oil Pump Quill

[Viny4]

I would never use a lipped bearing for the mains. Two flat head 10/24 are just fine, never had a failure. Using a thined spacer and full width roller bearing may allow the roller to overlap the chamfer on the outer race.

 

[oexing]

No lipped bearing - what reason ??

Vic

 

[Monkeypants]

Not a difficult thing to do at all.
This has been tested to 7000 rpm quite a few times now.

 

[Nigel Spaxman]

Funny , I have just bought a pair of Comet Cases,
And one of the inner Main Bearings is very hard to slip out !,
God knows what he's done ?,
Also the big end is as tight as anything ?, Almost no side play, ie not free !,
But the alignment is very good !,
It's like one man did one job and another did the other part ?.
Lots of strange things have been done to the cases, But I think I can get them to work.
It will be interesting to get it all stripped out , But I am just polishing and making
them look better for now and saving up for a BIG Piston and Liner.

I have a barrel Hole in the cases of 100mm !, Looks like the liner will be 96mm at it's widest,
Which will leave a space of 4 mm/ 2mm = 80 thou" each side !!, I know I will have to block off
the cylinder feed, Any body think that is NOT good ?,
I mean the "D"s have a 5 thou gap around the lower liner, ie not touching,
So I thought it might be OK ?.
Cheers Bill.

I have been running with the cylinder feeds blocked for about 7000 miles. I prefer to have that oil go to the cams. I have low expansion cast pistons 8:1 running .025" clearance. I have done long up hill runs wide open 85 MPH two up and there is no sign of any problems. The oil consumption is not noticeable. My pistons have 18,000 miles on them now and the last time I looked they were pretty much as new. I know a lot of people like to retain the oil feed but a lot of others manage without it with no noticeable effects. I think there is already plenty of oil flung off the big ends. If the oil feed is not blocked perhaps you could block the rear one and leave the front cylinder, because it must get a bit less oil. The advantage to the non lipped bearings is that they can be line lapped to the perfect clearance and alignment.

 

[bmetcalf]

.025” clearance?

 

[Nigel Spaxman]

.025” clearance?

.0025"

 

[Gene Nehring]

.0025"

I have read in old MPH magazines that if the timing cover is not mated to the cases and big end correctly you could experience aggressive wear of the quill. This could lead to the quill breaking.

With allot of engines being made of mismatched covers I guess it’s more important than ever to double and triple check that the oils quil is lining up correctly.

 

[Bill Thomas]

I was more worried about the 2 mm clearance all around the bottom of the barrel ?
It's a Comet !,
Don't know if it would give some sort of vibration or something ?,
Don't know why he took the hole out to 100mm,
Most 90 bore liners seem to be 96mm on the outside ?,
To me a gap is a gap !!, But I am only an old Mechanic, Not into this clever stuff,
The other thing is to get a very thick liner, But that might give over heating trouble ?.
Cheers Bill.

 

[Monkeypants]

Perhaps it's bored for the 92 mm pistons + liner?

Glen

 

[Bill Thomas]

Have you heard of that mod',
Maybe yours is that way ?.
Seems a bit too big for me, I was hoping to use a normal piston and standard C/Head ?.
Cheers Bill.