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MG TD TF 1500 - Line boring the block

Hi,
When a block is line bored, are the cap seatings and caps machined to close them up before boring.
The reason I ask is because a rear seal kit has been fitted on a friends car and the block section is located only by countersunk screws in the original holes. This is not concentric with the crankshaft, the offset is not enough to mess the seal. The problem is that whoever fitted the kit relieved the block section of the kit to allow the cap to seat. I WILL stop the leak even if I have to re-engineer the housing.
I checked the cap seating to crankcase bottom depth and found it 0.015" deeper than either of a pair of spare cases, is this within the tolerances of the time or because of line boring?
TIA
Ray TF 2884

Ray Lee

See this link: http://www.mossmotors.com/graphics/products/instructions/433-421_980-379_INST.pdf

I think they went away from the countersunk holes due to the problem you are having.
George Butz

Hi George,
thanks for that link.
The idiot that fitted the seal kit realised it was misplaced but filed it down to the cap seating level and the oil just ran out of the side gap.
I will remove the new parts mill off the 0.015 on the block piece and turn it true to the lower piece.
That is if there is enough meat to mill out where the C/S screws were fitted and use the original type screws
so I can re-centre it.
If not I will get some aluminium plate and make a complete new one.
Ray TF 2884

PS I used to have a modified version of my email address in my heading but it has disappeared, anybody know why and how to fix it.
Ray Lee

Ray,

Go to "Customise" (Add your comment; New thread; Invert: List threads;.....etc. up above) and change it there.
Gene Gillam

Thanks Gene,
that works ok,I tried to do it from the Enthusiasts home page with no success.
Ray
Ray Lee

Hi Ray,

If you are going to make up a seal holder I will swop a piece of 7"x7"x1" duralumin for photos and a sketch of the one you make. My engine still has the archimedes scroll and even though there are no leaks after trial running, I expect trouble after a good run. I have a Myford Super 7 lathe with a 7" faceplate. Will I be able to turn up the seal holder in this.


Cheers

Jan
J Targosz

Thanks Jan,
I already have the material to make a new one if I have to. I don't have access to the engine at the moment (pal is sunning himself in Spain!!!), but I think 7" is OK. When I get the seal housing off I will get you the measurements.
If you look at George Butz link it will give you an idea,they rely a lot on HT RTV sealant to keep the oil in but as there is no pressure at the seal they should be OK.
I don't know the make or number for the seal but I think it came from Edney.
Your scroll will not leak until you brag to other owners, then it will, just to spite you
Ray TF 2884
Ray Lee

I have now machined the crankcase seal housing level with the bearing cap seating.The next job is to set up the sump side housing in the lathe,fasten the other one to it and turn it to match.
As it was, the seal was being asked to cope 0.025" out of place.
Jan, pop me an email I don't have your address.

Photo is of the gap in the seal housing that an engine specialist deemed OK !!!!
Ray TF 2884

Ray Lee

I am trying to find a seal for this housing.
The size is 4.7" OD x 3.75"ID X 0.375" Depth.
I cant find it in any catalogue so I presume it is an Auto Industry special as it has no marks.
Can anybody help.
The seal housing is now fitted and tested all I need now is a seal.
TIA Ray TF 2884
Ray Lee

sorry OD is 4.75"
Ray Lee

A bit wide, but matches o.d and i.d:
http://www.ebay.com/itm/NEW-CR-37396-OIL-SEAL-3-75-ID-x-4-75-OD-x-43-W-/350626918770 Bud
Bud Krueger

Ray, I don't really know how to read their catalog, but I see seals that seem to have the dimensions that you are showing. http://www.allsealsinc.com/skf_seals.html Bud
Bud Krueger

The saga ends.
Re-engineered seal housing fitted, engine run up to hot, stopped and left to stand a few times, no sign of an oil leak.
I would advise anybody replacing the rear seal to do the following before putting the engine back in:-

Leave the engine upside down with the sump off, fill the bearing drain with oil and leave for a day. This will show up any leaks before fitting the engine. Not a bad job on a TD but a PITA on a TF.
Ray TF 2884
Ray Lee

When the block is line bored, no lip seal is needed!
If the sump is correctly installed, there will be no leaks from the rear of the crankshaft.
Len Fanelli
Abingdon Performance
914 420 8699
laf48@aol.com
Len Fanelli

Hi Len,
I agree that a properly fitted original set up works.
In this case the crank has had a hard life and the return scroll worn. Although we can make the crankcase oil thrower (Moss name) fit, the bearing cap clearance is too much.
No leak when running but lots of draindown after stopping.
Ray TF2884
Ray Lee

Should have kept my mouth shut. It's back!!!!.
So its sump off, gearbox out, flywheel off, sump back on and eyeball it running. I have got a horrible suspicion that it is the cam plug or the oil gallery plug.
Ray TF 2884
Ray Lee

A steep learning curve, the seal was faulty.
I learned that,
(1) you do not run the with engine flywheel off without temp fitting the flywheel bolt with some compound.
(2) do not tighten them fully in as they protrude out the back and foul the new seal housing.
Learned this the hard way.
Ray TF 2884
Ray Lee

PS
this only matters if you have fitted modern seal assembly.
I have run engines before with the original seal and all is OK as the scroll returns the oil.With the new seal oil is on the crank flange.
After 60 years an engineer and 40 years TF ownership, you would think I should know better.
Ray
Ray Lee

Ray.
I am in the dark. What flywheel bolt are you referribg to. What purpose is achieved with replacing all of them without the flywheel?
Sandy
ss sanders

Without the flywheel retaining bolts in place, oil will pour out of the holes. You will want to plug the dowel holes also.
Steve S

This thread was discussed between 11/08/2014 and 04/09/2014

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