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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - Project engine

I guess I have to start a project next winter. Blowby gases with oil sucking distributor, high oil consumption, oil loss, decreasing oil pressure during idle (2 psi after warm up) less compression on cylinder 2 (-22 psi), oil contaminated with petrol are signs of wear which let my eyes get full of tears. The fun seems to be over after 30 years. An overhauling by a machine shop will solve the problems. Unfortunatly the near by machine shops do not have experience with the XPAG. They should know how to do the job - but what are the best sources for spares. I do not have interest in increasing power. After all the engine should be reliable for a long time. How can I support the machine shop?
W_Mueller

Winfried,
Before you jump the gun and start getting a machine shop involved, I would do compression and leak dow tests and then whip off the head and inspect and measure the bores. It might be just the top end issue. The pistons can be removed from below without engine removal. A full XPAG rebuild will cost you an arm and a leg if you leave it to an engine builder.
Start saving now!
Regards
Declan
Declan Burns

Thank you Declan for your first assessment.

You guess that all items are related to the top end. I agree - but what may be the reason for decreasing oil pressure at idle? During running it is between 25 and 40 lbs.

And where shall I buy parts? Brown & Gammons?


W_Mueller

Winfried,
I am only hoping for your sake that it is top end related. The low oil pressure could be caused by many things. Is the engine smoking, knocking when cold?
I do not buy from any one particular supplier. It depends on what I am looking for, the price and how quickly I need it. I always shop around and sometimes split orders.
Check the postage!
Some suppliers are OTT!

Regards
Declan
Declan Burns

No - no knocking when cold and no smoking. Only soot if you put the hand near the exhaust and a little bit oil burned smell directly after start. The spark plugs have a little bit oil coal at the opposite of the electrode but they are light brown.

W_Mueller

Winfried, Do a compression test wet and dry and then the leak down test. I am not convinced you need a full engine rebuild.
Regards
Declan
Declan Burns

Winfried, I agree with Declan, there are many reasons for the symptoms you describe. Maybe just worn piston rings ?

As for spares, I also shop around. So far stuff was ok, no negative experiences.

Rgds, Mike
Mike Fritsch

okay
the wet compression test is waiting. For the leak down test I must ask a friend with a workshop due to absence of that equipment.
W_Mueller

The leak down test shows a leak between 2 and 3. I'll stop driving an the head will be dismanteled.
W_Mueller

Hi Winfried,

Not sure how you leak-down gauge is marked. Is that 2% and 3%, or 20% and 30% (I assume the latter)?

Could you tell the location where the pressure was leaking?
WHTroyer

I think he may be referring to leakage between cylinders 2 and 3, but I could be wrong. If so, likely blown head gasket.
John Quilter (TD8986)

I agree with John-sounds like the head gasket to me too.

Regards
Declan
Declan Burns

Head gasket gets my vote too. Might be a good opportunity to also replace the head studs and nuts, if that hasn't been done in living memory. If so, deal with the possible stretched (raised) areas of the block surrounding each of the studs. Cheers
Peter TD 5801
P Hehir

Thanks @ all

Under pressure of cyl 2 there was a hissing through the spark plug hole of cyl 3.

W_Mueller

Winfried-off with his 'ead!!!
Regards
Declan
Declan Burns

The workshop will start at Nine Eleven. I'm not superstitious.
W_Mueller

Head gaskets leaking between cylinders is a common problem with these engines. It is due to detonation, Inaudible in the XPAG XPEG engines.As such always use premium fuel. Pressurizing the radiator may help as it keeps the coolant from boiling at the exhaust valve pocket. IMO Manley Ford has the best custom head gaskets for our engines.
Len Fanelli
XPAG XPEG Camshafts
Abingdon Performance Ltd.
Len Fanelli

Hello Len

Manley Ford? Can't find such a product.
W_Mueller

https://www.freewebs.com/manley776/
Lew Palmer

Okay - that's an other than I'd found. Thank you Len!
W_Mueller

Here is a foto of his custom head gaskets with copper "O" rings or the fire ring.

Len Fanelli

Thank you Len!

Would it be advantageous to dismantle the oil pan first and after that make the leak down test again or can all be seen after dismantling the head?

I suffer under the low oil pressure while idling. What kind of diagnosis is possible?
W_Mueller

Winfried. Oil Pressure: Check the tolerances in the oil pump if there is too much wear,the
pump will deliver low pressure at low RPM.
Whith increased rpm the pressure will rise.
Compression:Pressure leak btween 2 and 3,
check and if change the top gasket
IMHO No need to consider a mashine shop
before you havegone truh this simple tests.

Thoralf. Norway TD 4490
Thoralf Sorensen (TD4490)

Hi Win, Low pressure at idle used to be commonly caused in these engines by worn rocker bushings and/or worn rocker shaft. That gave less resistance to oil flow up there, and would be OK at increased RPM. A "shade tree mechanic" solution was to put a restriction in the oil line to the head. I suppose you could block that line temporarily somehow and see if the gauge pressure at idle increased greatly.
Back in about 1963 I just replaced the shaft and it was fine for many more miles for our TD.
Hope your problem is just a head gasket.
Al
1954 TF "Emma"
Al Parker

I would still consider plastiguaging the bearings. Not tough to do even with the engine in the car. That will give a better picture o wear, and a good time to examine the bearings.
Bruce Cunha

Thanks for the hints!

@ Thoralf

I've seen tolerances are shown in A.4 of the workshop manual. I guess it would be hard, to pull the pump. The PO had used allen srews which end directly in front of chassis parts.

@ Al

Blocking the line temporary is a good idea. How long can I let the engine run without that line?


@ Bruce

What does "plastiguaging the bearings" exactly mean?
W_Mueller

to remove the pump you will have to disconnect the radiator hoses and jack up the engine.
before you do that, remove the relief valve (WSM Fig A7) and check its condition (ball and spring).Hold the ball against its seat with a brass drift and gently hit it to seat it and re-assemble.
I cannot remember the spring length but somebody on the site will know.

For the rocker supply just disconnect at the head and use a nut,bolt and 2 fibre washers to seal it, a few minutes running will do no harm.
As a rule for oil pressure around 10 psi/1000 revolutions seems to be OK. My own engine when really hot ticks over at 10psi and 50psi over 3000 revs and has done for many years.
Ray TF 2884
Ray Lee

Thank you Ray- I guess that will be done with metric threads too.
W_Mueller

Ray,
As far as I know the spring is 37.5mm long, 1.42mm thick and made from 17 wire gauge. The ball is 1/2"
Regards
Declan
Declan Burns

the bolt and washers are to go in the banjo connection at the pipe end. Any nut and bolt will do.

Thanks Declan, it was just for Winfried to have a comparison.

A friend had intermittent low oil pressure and we found that the ball had a groove worn in it. When the groove lined up with the seat all was OK, when it turned the pressure dropped. New ball, spring and re-seat gave good oil pressure.
Ray
Ray Lee

The spring and the ball have been replaced last year - but checking that will be done.
W_Mueller

What does "plastiguaging the bearings" exactly mean?

It is a technique whereby you place a thin round strip of plastic (looks a bit like a plastic wire) between the bearing shell and the journal, torque the bearing cap down and then remove. Then using the packing sleeve for the material comes in which has markings you measure how flatened out the plastic has become. This then becomes a measurement of how much clearance there is between the shell and the journal. Plastigage comes in various thicknesses. It is good to have the Plastigage span the full width of the bearing shell to get a full reading. Others, may have more to add.
John Quilter (TD8986)

Thank you John - I found the products MAHLE PLASTIGAGE CLEVITE and GENUINE PLASTIGAUGE and how it works. May be it is more commonly used in U.S.A.?

In a box gave away by the PO I found two kind of head gaskets. One is made of copper and the thickness is 0,055" and it is used and stamped "1532". I can't see any damage. The other one has the same shape. The material looks similar to asbestos. The thickness is 0,083" and is branded with "Klinger Cilit" - I guess that the former name for ElringKlinger. That gasket had also been used - again no signs of damage. But no question - I'll purchase a new one. I'm curious which thickness I'll find in reality.








W_Mueller

update:

Oil pressure is still low after warming up wile blocking the upper line. Bad bearings? How to determine?


The camshaft and the cam followers are worn. It seems the worn prevents opening of the exaust valve. I guess that is one of the reasons for blowby? Is replacing the camshaft and the bearings possible without pulling the engine?

The gasket is toast. It is leaking between 2 and 3. Block and head are plane.

Only one of the cylinders has a good surface. There are traces of former rust.

The pistons are stamped with "STD I.D.8". That can not be a standard set because the bore diameter is 68,9 mm. That seems to be +0,100". Is is possible to drill +,120" which is the maximum or is a cylinder liner the better solution?

I tend to let rebuild engine and oil pump. Any suggestions for a workshop in Europe?
W_Mueller

To get back to your original question. It will depend on the experience of the machine shop. There is noting magical about the TD motor. Most shops that have done cast iron standard valve heads should be able to do it. You may ask them if they can contact one of the More experienced MG motor machine shops to see if there are any special items that need addressing.

Boring a block is pretty standard.
Bruce Cunha

Winfried,
The last engine rebuild I did was a 1275 A series and I used a shop in Dinslaken which is a fairly long walk from your neck of the woods. The company is called DSW Motorenservice GmbH. The owner is Rolf Erbach. His engine work is excellent and is well known around here. He usually does trucks where the pistons are the size of 10 litre buckets so an XPAG is a piece of #iss.
You bring him the block and he measures it and tells you what size pistons you need. He bores the block when you (or he) procures the pistons and bearings. You get the block back with the crank and the pistons installed correctly. In German they call it "Splint fertig".

He will also do the head skimming and insert new valve guides.
www.motorenhandel.de
Tel:02064-80067.
Ziegelstraße 122
46539 Dinslaken

It costs about 125€ per cylinder and about 150€ for the head work.

Regards
Declan


Declan Burns

Thank you Declan,

sounds good - I'm looking forward
W_Mueller

At the moment I need input about cam shaft and cam followers.

As mentioned the engine is an early one with the early camshaft 0,19" tappet clearence. The engine shall be reliable - performance is not the goal.

There seems to be more than 6 possibilities- so I'm confused:

1. Cam shaft and cam followers (tappets) like the original (MOSS EUROPE?)- what will be the mean time between failure?

2. Cam shaft X/drilled from Brown & Gammons (GB)

3. Cam shaft full race TType Brown & Gammons (GB)

4. Cam followers from Peter Edney (GB) - better than MOSS?

5. CRANE Cam (mild road or fast road) and CRANE Cam followers from FTFU (U.S.A) and valve springs for that cam shaft- shipping will last from U.S.A.

6. Cam rollers (with cam?) from Len (U.S.A.) - most expensive?

7. What would be the easiest solution for the workshop?

8. Are all solutions reversable?

9. What's about the bearings for the cam shaft? FTFU has a MOSS-warning document EN063 in the tech tips.

10. Sprocket and chain set from Brown and Gammons

11. Adjustable sprocket and chain set from B&G - what is the benefit?

12. heavy duty chain from FTFU- recommended?

W_Mueller

I can answer a couple of the questions.

Regarding camshaft selection and reliability. The biggest issue when using a flat tappet camshaft is having sufficient ZDDP additive in the oil you use to reduce wear and potential failure. The original style cams and lifters are flat faced which doesn’t allow the tappets to rotate easily while running. This eventually causes the cam lobe to constantly wear the same spot on the tappet eventually causing a groove in the tappet face preventing even wear. The hard facing is worn away and the cam lobe then begins to grind away leading to the cams ultimate failure. Valvioline VR1 has ZDDP additives as do other oils specifically formulated for classic cars with flat tappet cams. Still premature wear can occur because of the nature of the original cam and tappet design.

Crane cams grinds there cams with a slight angle to their lobe profiles and require a special lifter that is machined to work with this design. Both work together to aid in the tappet ablitiy to spin and thus reduce the chance for premature lobe and lifter failure. It does not nullify this from happening but it’s chances for survival are increased. Again ZDDP must be used.

A roller cam will be more expensive initially but the reliability and longevity will more than pay dividends over time. The need for ZDDP
Is not necessary. Len’s roller cam offerings run the gambit from mild to full race (not recommended for street use). I believe all have the same high lift (.430” at the valve with zero lash). But check with him for advice and specs. Contact me at the link above for additional info regarding Len’s cams as it’s a bit too much info for here. The lift becomes an issue if your cylinder head has had a lot of shaving done to increase the compression ratio while using the flat top pistons. In these instances a valve relief must be cut into the top of the cylinder wall for clearance. I prefer to take minimal material from the head and instead chose to use a pop up style piston to gain the desired CR I wish to obtain. These piston types are available from many manufacturers such as Arias, JE, Jahns just to name a few. My pistons are made by Arias of my own design.

The need for a vernier (adjustable) timing gear set is not a necessity for a stock rebuild. Their purpose is to be able to either accurately set the cam to crankshaft timing exactly to the cam makers spec or to make exacting adjustments to alter the timing from the spec. Either way it requires the use of a degree wheel temporarily attached to the crankshaft and a dial indicator on a magnetic base to measure push rod rise at a given degree of rotation. This is done during assembly to set the cam to crankshaft timing. As an example for my particular engine setup using Len’s 286°/286° race cam we found the engine’s performance was dramatically improved by bumping the cam timing several degrees. The vernier is a pricey bit of kit but it is very handy to have especially when one wants to play with the numbers to gain the very best performance.

Another option to the vernier is to use what is called offset keys. These replace the standard woodruff key that index’s the crankshaft gear. By using offset keys one can advance or retard the cam timing a set number of degrees based on the amount of offset of individual keys. . In an engine using std valve springs they are an economical alternative but when using high psi rate valve springs I wouldn’t recommend them. I have seen offset keys shear off. For that reason, I use the vernier.

Hope this helps a little from my perspective

Bill Chasser
TD-4834
W A Chasser

I can answer a couple of the questions.

Regarding camshaft selection and reliability. The biggest issue when using a flat tappet camshaft is having sufficient ZDDP additive in the oil you use to reduce wear and potential failure. The original style cams and lifters are flat faced which doesn’t allow the tappets to rotate easily while running. This eventually causes the cam lobe to constantly wear the same spot on the tappet eventually causing a groove in the tappet face preventing even wear. The hard facing is worn away and the cam lobe then begins to grind away leading to the cams ultimate failure. Valvioline VR1 has ZDDP additives as do other oils specifically formulated for classic cars with flat tappet cams. Still premature wear can occur because of the nature of the original cam and tappet design.

Crane cams grinds there cams with a slight angle to their lobe profiles and require a special lifter that is machined to work with this design. Both work together to aid in the tappet ablitiy to spin and thus reduce the chance for premature lobe and lifter failure. It does not nullify this from happening but it’s chances for survival are increased. Again ZDDP must be used.

A roller cam will be more expensive initially but the reliability and longevity will more than pay dividends over time. The need for ZDDP
Is not necessary. Len’s roller cam offerings run the gambit from mild to full race (not recommended for street use). I believe all have the same high lift (.430” at the valve with zero lash). But check with him for advice and specs. Contact me at the link above for additional info regarding Len’s cams as it’s a bit too much info for here. The lift becomes an issue if your cylinder head has had a lot of shaving done to increase the compression ratio while using the flat top pistons. In these instances a valve relief must be cut into the top of the cylinder wall for clearance. I prefer to take minimal material from the head and instead chose to use a pop up style piston to gain the desired CR I wish to obtain. These piston types are available from many manufacturers such as Arias, JE, Jahns just to name a few. My pistons are made by Arias of my own design.

The need for a vernier (adjustable) timing gear set is not a necessity for a stock rebuild. Their purpose is to be able to either accurately set the cam to crankshaft timing exactly to the cam makers spec or to make exacting adjustments to alter the timing from the spec. Either way it requires the use of a degree wheel temporarily attached to the crankshaft and a dial indicator on a magnetic base to measure push rod rise at a given degree of rotation. This is done during assembly to set the cam to crankshaft timing. As an example for my particular engine setup using Len’s 286°/286° race cam we found the engine’s performance was dramatically improved by bumping the cam timing several degrees. The vernier is a pricey bit of kit but it is very handy to have especially when one wants to play with the numbers to gain the very best performance.

Another option to the vernier is to use what is called offset keys. These replace the standard woodruff key that index’s the crankshaft gear. By using offset keys one can advance or retard the cam timing a set number of degrees based on the amount of offset of individual keys. . In an engine using std valve springs they are an economical alternative but when using high psi rate valve springs I wouldn’t recommend them. I have seen offset keys shear off. For that reason, I use the vernier.

Hope this helps a little from my perspective

Bill Chasser
TD-4834
W A Chasser

Thank you Bill for that fine introduction.
W_Mueller

None of those suppliers actually make cams and cam followers. If you want to go to a top class long established cam manufacturer directly try www.newman-cams.com in the uk. I believe they supply at least one of those on your list and maybe more.
Roller cams I can't comment on.
Dave H
Dave Hill

I'd visited some workshops but couldn't decide because none of them know the XPAG.

What's about Peter Edney in GB? Is it a recomendation? He offers a rebuild for about 4.500 GBP and runs a test after all - are the parts additional? Did he ever fail? Please use email for an answer if it should be a compromising statement.

For this send email to sweets_for_my_sweeet(at)t-online.de
W_Mueller

Peter Edney is a reputable XPAG engine builder and dealer in TType parts and cars. I have bought good quality parts from him from time to time.
Dave H
Dave Hill

I would recommend a machine shop near you that has 30-50 years of engine building experience, they will know more than enough to do the engine properly. Check with Udo Fink & Dr. Peter Zernial.
Len Fanelli

Early TDs were fitted with a flat bottomed unfinned sump of 5.1 iltres capacity. Engine to No 7575 were fitted with the oil pick-up on the left hand side of the sump but after problems with oil starvation on left hand corners this was altered to a pick-up in the centre of the sump.

My engine is an early one. Is that a reason to change the pick-up (if available)?
W_Mueller

Unless you have an aggressive driving style ie. sustained high rpms, hard cornering or braking as in fast road/ racing, hill climb events it’s an unnecessary expense in my opinion.
W A Chasser

This has nothing to help with your problem, but just a word to the wise. The PO of my 51 TD had the crankshaft break, and destroyed the engine. He took it to a local shop that was supposed to be experienced in foreign car repair. ( live in Nebraska). They rebuilt the engine, after the PO furnished a replacement used block. They did install a forged steel crank. They had the car for 6 months, and charged him $9,200 U.S. After I bought the car I went and visited with the shop owner, and he gave me a copy of the work order. I have had to do many reworks since to get things right. I think that he got way overcharged.
Gary
g parker

The engine is back from the workshop.

There was a test outside the car and nothing seemed wrong. But the bill has questions.

So I hope get some hints for the workload.

When the engine is prepared and completely disassembled - how many hours have you spent in the best and worst case for assembling all the parts together?



W_Mueller

This thread was discussed between 18/08/2018 and 30/06/2019

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