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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 - TD 4834 shakedown test drive

I finally broke down and took my car for its first shakedown. Initial impression was wow! Talk about cornering ability, it held the corners and was totally predictable even on vintage Pirelli racing tires. Acceleration was fair because of the timing issue as expected. Transmission up and downshifted smoothly and was quiet in all four gears. My only gripe is this big stock steering wheel in my chest that was difficult to work given my long arms.

I drove the car about a half mile and as I was nearing home disaster hit. Sudden loss of power had me limping the last several hundred feet back to the house. A noise emanating from the front of the engine. I think the cam timing has fully shifted within the vernier gear. In any case the engine is done til I investigate further.

I pulled the plugs to read them and they were greyish/ black. Pulled the valve cover to find mayonnaise. The ARP head studs are leaking. Need to find a sealant other than the silicone that Lawrie had hooped them with as they will not stay torqued in place as well. Tom Lange, what do you recommend?

So I now have no other choice but to get the front of the car torn apart and check my cam sprockets. Before another restart but it was fun for a moment. To you gals and guys driving your cars , I get it. I would have loved to seen a smile on dads face

Cheers

Bill Chasser jr
TD4834



Bill Chasser Jr

I don't know if I ever shared this photo with the group. That's my dad ca. 1952 with his TD/C. I just found this photo several weeks ago. It is the only one with a view of the car that I have found. Several over the wings of scenery but this is the only one of the car
Bill Chasser Jr

Great picture Bill. I bet you were so happy when you found this vintage family photo. I was when I found mine!

Frank Cronin

Sorry to hear it, hope it's a (relatively) simple fix...
Geoffrey M Baker

I enjoyed reading your first paragraph Bill, but sorry to read what happened later. Please let us know what your findings are and what lessons can be learned. Hopefully nothing too expensive has occurred.
Michael
M R Calvert

I will let everyone know what I discover once I trailer the cat back to Sacramento tonight. Very disappointing with regard to the mayonnaise issue. I was hoping I wouldn't have to pull the head back off until I got the Laystall repaired. I guess I better send it off to see if it can be fixed. If not, I am going to break down and order a new one so I can get my compression ration back up to 10.5:1 and the porting back so it will breathe. I am certain the water is from head studs in the block not sealing. Updates to follow
Bill Chasser Jr

Sorry to hear about the cat. How did the car fair though? :-)
Christopher Couper

The lug nut rule prevailed over the cat. 😄 No dogs were injured. Lol

Cheers

Bill Chasser
TD4834
Bill Chasser Jr

Sorry test drive didn't go well. Just curious as to why you think your coolant leak into the oil is from around the head studs. The headgasket should seal any leakage past the threads if they go into the block water jacket(not sure they do?), there is otherwise no coolant near them. I would suspect head gasket, cracked head or something else. Not staying torqued? Very strange- ARP bolts don't stretch and if the nuts do not back off, the gasket is compressing or the head moving. I would make sure the head slips over the studs without any binding- use a feeler gauge to make sure. I think there is a drilled passage in the back of the head under the cover plate that should have a slotted blanking screw in it, make sure that it is in place. George

George Butz

George. The studs were weeping at the threads in the block. Water was expressing itself at the top nut and washer both externally along the exhaust side and under the valve cover as well. The studs themselves were not staying torqued in the block because of silicone that was used to "seal " the studs.
Bill Chasser Jr

George, are you thinking of this slotted head brass blanking screw just below, (above in the picture uploaded), the camshaft core plug in the block?
Michael


M R Calvert

Michael there's also the one that George is referring to in the back of the head. Cheers
Peter TD 5801
P Hehir

Thanks Peter. I will have a look at the next opportunity.
Michael
M R Calvert

Peter, George. I found a photo. It is not very clear, but just below and to the right of the top left bolt hole is what I suspect George is referring to.
Is this the blanking screw (to the oil gallery) in question?
Michael


M R Calvert

That is it, if missing or loose oil and coolant can mix. The brass plug in the block plugs the main oil galley drilling. George
George Butz

Don't let the mayonnaise sit. It'll pit the journals, lobes, tappets very quickly as the mixture separates in situ.
MAndrus


Bill, How were you able to tell the studs were weeping at the threads where they go into the block?
This is something new to me because all of my engines did not have stud threads going into the water jacket. In fact, when I used ARP studs, the threads were so tight in the head I had to go slow in tightening them to allow air to escape around the oiled threads. I hope others can confirm what I believe to be true.
Richard Cameron

Here's a clear image from Gene Gillam's cooling system files that shows the plug's location. Bud
See http://www.ttalk.info/XPAG_Cooling_System.htm for the whole set of images.


Bud Krueger

Bill is talking about a Laystall head.
D mckellar


Sorry I misspoke above--- When I said "threads were so tight in the head" I meant to say they were tight in the engine block.
Richard Cameron

No actually I have my OEM iron head on the engine at the moment. The Laystall was shelved due to seized valves that pulled the guides and was porous. I had water weeping from the washers and nuts on the arp studs. Which tells me it was pushing up from the base threads


Bill Chasser
TD4834
Bill Chasser Jr

Bill: As the supplier of your ARP head studs, I do indeed have a few (actually more than a few...) thoughts:

1) If your head studs are coming loose, they were either improperly torqued, or were inserted in damaged stud holes that require thread repair. I use Chrislynn Rock Solid inserts, and have a great preference for them as literally rock solid - FAR better than Helicoils, which frequently unscrew on their own.

2) If you are finding water seeping out by the stud, the head is loose and the gasket is not seated properly (see above), or there is some incompatibility between the head and block surfaces. The stud holes do not extend into the water passages or oil galleries, so there can be no problem there.

3) I include instructions with my head studs, that clearly state to use engine oil on the threads. Silicone will do absolutely no good, and is definitely NOT recommended. Torque seals the threads, NOT silicone!

4) If you find "cottage cheese" you are mixing oil and coolant, either from an improperly torqued head gasket, or a missing grub screw in the back of the head.

5) If you are running 10.5:1 on pump gas, well, then you are on your own. Had I been the rebuilder of your engine I would give you an ironclad 50/50 guarantee under those circumstances - 50 feet or 50 seconds, whichever comes first. The more HP you try to get out of an engine the less tractable it is - I think you have gone too far beyond the pale. I get as much as 65-70HP from a stock engine, and see no reason to push the engine for more - beyond that drive-ability and reliability drop off precipitously. It's fine if the engine is raced because it gets torn down as frequently as the wallet allows - not so with a street engine.

I repeat what I have said before - the ARP head studs I sell are simply the best and strongest head studs available, which is why racers like Manley Ford insist on them.

Tom Lange
MGT Repair

t lange

Thank you Tom for your comments . I'm in no way faulting you or the products you sell. ARP is the best specialty hardware on the planet in my humble opinion. I am pretty sure my stud holes did break through into the water passages but I will verify that in the tear down. Lawrie did the initial setup and he used silicone to seal from the water passages. Which wasn't my preference or the manufacturers. I do know that the threads in the block were chased and the studs did not have a real tight fit going in but did hold there torque values. I mean to say that the threads did not pull. That may or may not be the case now. I hope to begin the tear down tomorrow. But at this point I want to use a compound to ensure the studs stay put in the block. It may be that when I took the Laystall off that the studs may have backed off while removing the top nuts. It is very possible that I didn't recheck the stud seat torque values when installing the ironhead.

I know you and I have had the conversation over stock and modified engines. And I do agree with you on many points that we discussed during the build. The car is going to be seeing track time eventually as well as street time. I built this to be reliable at 6500rpm using the best products available to achieve that end. The sorting out process can be frustrating at times when working with so many variables out the gate. The Laystall failure being one of them from contaminated race fuel. The Laystall will be going out for a final opinion on its salvagability before it becomes a paper weight and I order a new one. But it will get sorted and will perform as expected in due course.

Of course I may simply be a gluten for punishment

Cheers

Bill Chasser
TD4834
Bill Chasser Jr

You need to be put on a glutton-free diet, and then WALLAH! All should be well...


But seriously, I've never seen a block where the stud holes have broken through into water passages - I am very interested to hear if that is the case. I would use a rubber-tipped air gun in each hole, and see if you hear air escaping. I just can't imagine that the studs are loose in the block; it's unlikely the holes have become hogged out or oversize.

[As an aside, despite the desire to be aggressive and clean the daylights out of threaded holes, I NEVER use a sharp tap to clean out engine holes, as the tap WILL remove precious metal necessary for a tight fit. I have an old dedicated 8x1 tap that I have thoroughly sandblasted to remove the sharpest edges, and that works just fine, removing crud but not metal. It may be that you and people before you removed too much metal, and the studs just don't have enough bite. See my previous post about Rock Solid thread inserts.]

No dab of silicone would make the slightest difference under your circumstances, and would certainly not have held the stud in place under any pressure. Maybe one of the Loktite products? Isn't there a thread restorer?

Sorry.

Tom Lange
MGT Repair
t lange

I agree with Tom on all of his comments. Crucial to make sure block and head straight and all fully seats as I suggested above. The block can pull upward at the threaded holes, this needs to be check with a straight edge and filed flat, etc. Crack check head also. Other random thought: I have a friend that bought a new digital torque wrench and promptly snapped a head stud off. I forget if it was defective or set to metric vs. ft/lbs or something. So make sure your torque wrench is working correctly. The click ones can fail or become grossly mis-calibrated over time. George
George Butz

Tom and George I can't agree with you more. As the engine deck was surfaced as was the head and the run time is maybe 20 minutes total I doubt that the surfaces are problematic at this point. Tom I will investigate further tomorrow as I hope to tear into it again then will apprise. If in fact there is no break through I will use the Permatex thread locking compound to ensure the studs stay seated. Wash off the copper coat on the head gasket, anneal, recoat and put it back together again. I will clean the holes with brakleen and compressed air to remove remnants of the silicone

Cheers

Bill Chasser
TD4834
Bill Chasser Jr


Bill, I don't think you mentioned it before but hope you don't mind repeating if you did.

Are your head and block water holes on this engine matching or mixed? That is are they both oval or round, or mixed? Also, when you said you would anneal the head gasket, does that mean it is the solid copper variety? I'm very interested in what you find during your investigation.

Richard Cameron

Don't assume anything, especially that the surfaces are straight just because they were surfaced. Recheck them. George
George Butz

Richard. I have an early banana block and head and currently using the banana water passage gasket. It is a solid copper variety gasket that if memory serves me correctly was .040 thick. I shot three coats of copper coat on both sides before installing to ensure a good seal. I hope to get after it today and start the tear down. I had a problem getting my portable garage built yesterday so I'm without cover to work on it. We are expecting a storm front this Thursday so I'm working on it first thing today so the car is protected. I will report back as soon as I make inroads to the teardown

Cheers

Bill Chasser
TD4834
Bill Chasser Jr

Regarding compression ratio / camshaft duration:

Static Compression Ratio
(SCR) Intake Valve Duration
(degrees @ .050" lift) Power Range
(RPM)
8.00:1 185º Idle-4,000
8.25:1 189º Idle-4300
8.50:1 194º 800-4,500
8.75:1 200º 900-4,600
9.00:1 204º 1,000-4,600
9.25:1 208º 1,200-5,200
9.50:1 212º 1,600-5,400
9.75:1 216º 1,800-5,600
10.00:1 221º 2,000-5,800
10.25:1 227º 2,400-6,200
10.50:1 233º 2,800-6,400
10.75:1 236º 3,000-6,800
11.00:1 240º 3,200-7,000
11.50:1 244º 3,400-7,200
12.00:1 248º 3,600-7,400

So Bill is OK, as he has a 236 / 236 cam.http://www.crankshaftcoalition.com/wiki/Cam_and_compression_ratio_compatibility

Len Fanelli

I got the portable garage assembled today and began the disassembly of the car once again. Had a neighbor come by to help me with the bonnet removal. Fluids drained, header y pipe, temp gauge, oil pressure line, side cover loose. Tomorrow will pop the radiator out, water pump, timing cover and get the head off. Hoping I don't have to pull the engine

Bill Chasser
TD4834

Bill Chasser Jr

Got the head off and found nothing unusual other than I torqued studs in several positions. Pulled the radiator, water pump and tried to take off the timing cover. I hit an impass. With the updated front lip seal it is not possible to pull the cover without dropping the pan. I need to lift it up to clear the lip seal from the cover but the chain tensioner prohibits that from happening. Since trying to set a new pan rail gasket in position on reassembly is such a bear I will pull the engine. There is a more pressing reason to pull the engine. I was turning the engine with the crank handle and encountered a snapping sound that resonates through the handle when turned at a moderate speed. All the pistons are moving in unison Cw or CCW and doesn't seem to be caused by a broke crank. I hope to finish disconnecting the rest of the ancillary pieces and have it out by Friday AM.

Bill Chasser
TD4834
Bill Chasser Jr

Bill,
I don't understand your comment
>>found nothing unusual other than I torqued studs in several positions<<

Steve
Steve Wincze

Glue on on side of paper gaskets, grease or oil on the other side. Then you do not need to replace them when taking the engine apart the next time.
Len Fanelli

Thanks for the tip Len.

Steve sorry. I didn't spellcheck the spellcheck on my iPhone. Several of the studs had worked loose. Though it may have been simply from untorquing the nuts. The tops of the Pistons were a bit wet. Couldn't tell if it was antifreeze or oil. Very little hard carbon deposited. Most wiped off with a clean rag which makes me think there may have been seepage into the bores the copper gasket was in excellent shape so it will be annealed and reused

I will have more to report once the engine is out of the chassis and torn down

Bill Chasser
TD4834


Bill Chasser Jr

Engine is ready to come out as soon as I remove the oil pipe from the pump to the filter and pull the column back. Unfortunately the weather beat us to the punch with wind a driving rain coming in the open door flap to the garage. We decided to close up the garage and call it a day will wait for a dry day to proceed further. Garage was dry inside but no room to pull the engine without playing in the rain.
Bill Chasser Jr

This thread was discussed between 26/11/2015 and 04/12/2015

MG TD TF 1500 index

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