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MG MGA - Timing Cover Seal Leakage..neoprene type

Some 5 months ago I got hold of a late mga timing cover with the external recession for fitting the new type neoprene seal on the pulley shaft on my 1960 MGA. Fitted well and drove for 2 months with zero leakage on the garage floor. I left the car for 2 months whilst overseas, drove the car a short distance first day back with no problems and then for 2 hrs fairly hard on 2nd day. After latter the seal was leaking an oil trail and lost a load of oil on the road and on the garage floor. I have sent away for replacement seal before starting the work....would appreciate any advice or simlar experience....
Questions in my mind..
Had the seal just dried out in its external location and the hard driving damaged it ?
Could the sump be overpressuring due to piston ring wear ( no blue smoke from exhaust) ?
or ???
neil ferguson

Neil, my 1500 has been leaking oil from the bottom end just 4500 miles since an engine rebuild, all new gaskets, good mating surfaces and new felt oil seal, and it has been getting worse. I have since discovered that I have been running with air filters that are too restrictive (I thought they were the standard items but they are not). The front filter was oiling up despite the fact there were no blow-by gases to force oil into the air filter. I have temporarily disconnected the breather pipe from the air filter (until my new K&Ns arrive) and cleaned the front filter, and since doing that, I am not dropping so much oil. So it is possible that the incorrect air filter was compromising the engine breathing system.
I might be barking up the wrong tree here, but it might be worth you checking for excess oil in the front carb filter and see if No. 2 spark plug looks darker than the other three. Let me know what you find.
Lindsay.
Lindsay Sampford

Lindsay...thanks for your points re Filters...Do not think this is the cause of my probem because I replaced the standard filters with K&N units and inserted short horns inside the housings some 6 months ago. However I will not presume and when I lay my hands on the car today I will check as you advise to be absolutely sure.
neil ferguson

What are short horns Neil?!
I guess your fault could just be a damaged or out of position timing cover seal, and as you are already on K&Ns, probably not the same fault I had. Ever since I got my car about three years ago, I have been trying to find out why it had lack-lustre performance and oiled the front filter. I found many faults when I took the engine down, including a worn out cam, a bent inlet valve and weak valve springs. I was convinced that when I got it back together it would really perform, but it was only slightly better. The engine was smooth, would pull 70+ easily but wouldn't accelerate to get there, it just got faster in its own time. It had a misfire at about 3000rpm when I tried to gun it through the gears, due to the fouling of No.2 plug and would pee oil out of every joint south of the dipstick. All this caused by the front air filter oiling itself! So there was a possibility of it being the cause of your oil slick. Hope you sort it soon.
Lindsay.
Lindsay Sampford

Linsdsay....Ye gods you have been through the mill...glad to hear you finally got it sorted out.
Attached a pic of the short air intake horn I fitted to carb side of the inlet filter housing whilst changing the filters...had to pop rivet it in place. It had to be very short to fit in th filter housing so it is not like the huge trumpets you see advertised. I honed and smoothed the inside to reduce friction.
Read in the bumf ( on Barneys site I recollect ) that it may very slightly improve air flow and power.
Top of picture you can see the replacement timing cover I fitted with its external recess for the neoprene seal that was going to solve all my oil leak problems and allow me to finally remove the carboard sheets from the garage..up to 2 days ago!


neil ferguson

Oh Joy !! Checked filter and plugs as you mentioned,Lyndsay, and all ok. Then filled up to low level with oil and started up motor....and oil was pouring out of bottom seal on the oil filter banjo bolt. Dismantled and find the seal is a fibre thing rather than the copper washer recommended..off to get some better washers/seals..and then can close the book on this one .
....and best of all not even a drip from the timing cover.
neil ferguson

Hi Neil, I've got a very slight leak at that point too, even with copper washers fitted, I have to admit they are not new ones, but is on my list of things to do. It's amazing how tight you can wind that banjo up and still have it leak!
Lindsay.
Lindsay Sampford

Lindsay

The MGB air filter has a 'short horn' similar to the one in Neils photograph, but with a more rounded opening for improved air flow. They fit fairly easily into the MGA housing.

Regards...John
John Bray

I have a couple of unrestored covers with the rubber seal. Available for free.

The cover I use has the timing marks at the top, making it much easier to time the engine, rather than lying underneath. Should not be too difficult a job to relocate the markers or make new. Just requires a new notch to be cut on the pulley if the relocation is not spot on or you want to keep timing on No.1 rather than No.2.

Steve
Steve Gyles

Lindsay,forgive my ignorance, but if the front filter was oiling up , I assume the oil came from the rocker box breather. Isnt the same thing going to happen again
when you reconnect the breather pipe even with K&N's ?
David
D C GRAHAME

David, as I understand the reason the carb was drawing oil was because the filter was partially blocked. That is too much crank case gas was being drawn into the carb (because it couldn't breath in through the filter properly). Hopefully with the K&Ns the pressure drop inside the filter will be less drawing in less of the oily crankcase gases. Am I correct?
Neil McGurk

David, Neil has said it all. The air filters fitted to my car by a previous owner are heavy felt jobs. As I have never seen a standard MGA air filter, I had no reason to suspect they were anything other than standard. I now know different. There are no oily gases leaving the rocker cover breather pipe under normal atmospheric conditions.
Lindsay.
Lindsay Sampford

Neil - glad to hear you have solved your oil leakage problem.
Steve - I have a leak at my timing cover past the felt seal and could do with fitting the later plastic seal type cover - could I take you up on your offer of one of your spare covers?
Bit puzzled over the discussion of oiling up air filters - I have K&Ns fitted by PO and also have the old standard ones which I am considering refitting - the problems mentioned here make me think I might stay with the K&Ns - cheers Cam
Cam Cunningham

Cam

Email me your address and I will clean up the better of the 2 and put in the post. You should get it sometime next year with these postal strikes!!

Steve

stephen.gyles@virgin.net
Steve Gyles

Cam, I am sure mine aren't standard air filters. Mine are really thick felt on a wire base. I've seen the standard ones referred to as a wire screen, someone said they were only fit to keep out rocks and small birds! Mine almost keep out a molecule!
Lindsay Sampford

Steve - you have mail.
Lindsay - my standard ones have a combination of wire and felt behind the outer perforated metal mesh, but you can still see daylight through it - not sure if it is original though - cheers Cam
Cam Cunningham

This thread was discussed between 20/10/2009 and 24/10/2009

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