MG T-ABC

Wondering about the camshaft which is now in MGTC 0820, while trying to sort out the overheating problem.
Not sure what is there, since it is an old version of a Crane camshaft that came from Moss Motors circa 1985, but was not installed until recently. Here is the documentation about "Grind Number 553OS Stock replacement" (circa 1985): The valve timing is very different from anything from the factory, as shown in the article from Chris Nowlan circa 1991 Also shown in WKF. Wood's book, dated 1968, Appendix III-15: -- Notably, the Wood's article discusses some relative merits of the different factory versions.

This "Old Grind" from 1985 is not even close to the current grind offered by the Moss version of Crane -- or to any previous grind.

So, what is a good camshaft grind now? Have not found any discussion about the relative merits of the "Grind" as currently offered in the Moss version of the Crane cam -- other than that it has tapered lobes.

There are comparison comments in Sherrill's books (...Forever! pp.132,133 and ...More! p.56) -- with snippets:
"...substituting a Crane Fast Road cam. ... this single act made such a difference to performance." (MS - More! p.56
-- However, there is buried, somewhere else, in MS - More, a vague reference to a presumably "street" camshaft, in another's TC,
that was even better -- but without any description or origin information.

These discussions leave aside references to "racing" camshafts, or those meant for elevated compression ratios. Consideration of the cams with tapered lobes, that are supposed to limit wear on the lifter faces, seems to be moot in light of the experience of our Site Administrator during tear down of his engine after only 9,000 miles.

Nor are we wanting to consider the ramifications of the "Roller Camshaft" -- not just due to the added cost, but also having to deal with "tricky timing".

So, we wonder whether we are searching for something as elusive as the Medieval Unicorn. Any help from the forum will be greatly appreciated.

Octagonally yours,
BOXLEY (Robert and MGTC 0820)

I understand your confusion; part of the problem is that there are many different names for many different cams. Everyone will have different names for "their" cam, and in the past 70 years there have been dozens -if not more - cam grinders, each of whom has "his favorite" grind, usually some slight variation of one of those cams above. They are far too numerous to identify. But if you rely on the identifiers used below, people will generally understand which cam you are describing.

There are 4 commonly-discussed T-series MOWOG factory cams:
Early TD 168552, more commonly called the 019 cam
Later TD and TF cam 168553, more commonly called the 012 cam
3/4 race cam AEG122,
Full race cam 168551
Y-types, TB and TC used milder variations of the 019 cam, but those will not be identified here, as they will never really be encountered today - they have long since have worn out and have been replaced by, at least, 019 cams, which have themselves generally worn out and been replaced with 012 cams.

There are two basic Crane cams for road-going cars:
340-0002, which is a somewhat-updated and slightly more aggressive version of the ubiquitous MOWOG 012 grind; and 340-0010, which would be called a "fast road cam," which feels like a slightly de-tuned AEG122 MOWOG cam. (Crane's "Grind number" is completely different from the "Part number", and is not really used when distinguishing cams.)

You clearly have the 0002 Crane cam; as much as anything, the design, materials and construction are a significant improvement over the stock cam. Nowlan's article and Wood's text only discuss stock MOWOG cams, so they will not discuss your present Crane cam which fits in between the 012 and AEG122 cams.

Does this help?

Tom Lange
MGT Repair

I don't remember reading about your overheating issue. Basically you have 5 areas of concern: internal build-up of sludge and rust to slow and block water circulation, reduced water pump function or an internal leak, overheating caused by thermostat malfunction, radiator issues, and overheating caused by engine timing.

In my experience, the majority of engine overheating is caused by engine timing and distributor function. The least expensive engine overhaul you can do is to send your distributor out to be rebuilt - I know it is common belief that an individual adequately can do that job, but there are many reasons why an expert with a distributor machine is needed to properly evaluate and tweak the functioning of a distributor. It is a small amount of money well spent to have Jeff Schlemmer of Advanced Distributor, Rob Medynski of British Vacuum Unit, or The Distributor Doctor in the UK completely re-do a distributor, and the gain in performance will be mothing short of astonishing.

Thermostat function must be determined by suspending it in a pot of water and thermometer, and watching the operation and consistency of the thermostat opening as the temperature rises. Often they will be found not to open, to open inconsistently, or to open only part-way. Modern housings have replaceable thermostats, a big improvement.

Usually if a waterpump has any play or movement of the blades, the pump bearings are on the way out. Any water drippling from the pump shows a bad seal. A fully re-manufactured pump by Butch Taras is cheap insurance, and guarantees a long life.

Sludge and rust will block the internal water-passages, large and small, and prevent efficient cooling. A temporary fix is to remove the manifolds, knock out the (probably rusty) Welsh plugs, remove the cylinder-head rear plate (probably also rusty), and flush out the build-up with a hose. I made up a nozzle with a valve and small copper line, to be able to get deep into the engine and flush it out with a high-pressure wash. You may be surprised how much comes out; I even still find and pull out bits of support-wire left over from the block's foundry casting process! Be sure to use brass Welsh plugs when you close everything up. If this is a severe problem, the engine must be pulled and rust and contaminants boiled out by a proper machine shop.

The radiator. Look through the cap: there are often bits of rust or debris sitting on the top of the visible tubes. If so, your radiator function is diminished, and you need to at least remove the radiator and back-flush it upside down. Or, better, take it to a radiator shop to be dismantled, and have the passages rodded out. The worst case scenario is that the radiator is too thin to repair, and a new 3-core radiator core will need to be installed. (I have no experience with fit, quality or function of the the Chinese aluminum radiators sold on eBay).

Go through the system, well, systematically, and you will find and be able to resolve the problem or problems - there are often multiples.

Tom Lange
MGT Repair

The discussion in this Post so far is a great help, particularly about solutions to overheating problems. The listings in this Post above, about troubleshooting overheating, is exhaustive of the classic measures that have since been pursued with MGTC 0820. We previously posted some of this problem in “TC Overheating – Another Question” dated May 7 and May 12 2019. Therein was described the list of measures that have been taken to date with MGTC 0820 -- and now also listed above by Tom Lange, to whom I owe a great depth of Thanks.

Specifically, though, the queries are in regard to the influence of the camshaft upon performance in an attempt to reduce overheating. The description by TL, of the various factory camshafts in relation to the Crane Camshaft profile that we installed, is very helpful. Somewhere there must be more information about the camshaft influencing the overheating problem.

The distributor rebuild by Advanced Distributor (Jeff Schlemmer) was done with specific reference to this particular Crane Camshaft, and was returned with the suggestion to “Advance 16 degrees BTD @ idle”. However, the problem with overheating persisted. The advance was increased even more than recommended and some reduction in overheating was noted, but still not satisfactorily.

So, with seeming to exhaust all the classic avenues, this attempt at understanding the specific camshaft profiles and designs was launched.

What is sought is a “Street Cam” or even a “Fast Road Cam” that does not require raising compression higher than 8.3:1, has reliability without excessive wear of the lobes, but which has better acceleration than “Stock” and does not cause excess heating. Quieter Tappet noise would be a “plus”.

Octagonally yours,
BOXLEY (Robert and MGTC 0820)

Sorry - I just re-read the 6-month old post on overheating, and see that I covered much the same ground then as now. At least I am consistent!

Your early description of spluttering and boiling might have led me to suggest the head gasket is incorrectly installed - it looks the same both ways, but you need the large water opening at the back of the head. You can remove the cylinder head plate and feel if there is a hole in the gasket. But if the other fixes have cured the problem, that is unlikely to be it.

Tom Lange
MGT Repair

Overheating is unlikely to be caused by the 0002 cam, or by ANY cam alone - it's a function more of how the distributor is set for ignition at the proper moment.

And everyone will have their favorite cam - mine is the RV re-grind from Delta Cam. But ask 25 people and you will be 19 different answers...

To return to the answers to yoyur original questions, overheating is NOT inherent in T-series cars. If a car overheats, there is something wrong.

Tom Lange
MGT Repair

I've found the two primary causes of overheating to be a clogged up radiator and timing issues. Be sure to check your timing at full advance, not just at idle. I had an issue once where the car ran fine at low speeds but overheated badly as soon as I reached high enough speeds to require a little more throttle. Turns out the weights were getting jammed so the advance wasn't changing as RPMs increased. I've also seen radiators that appeared clean and free-flowing but we're actually blocked internally. It's always worth having a professional check it. And the only way to truly be sure it's clear is to remove the top tank and rod it out.

Thank you again for more information.
Now beginning to think that this "Old Grind" (from Crane 340-002) might be worthwhile after all and that it, by itself, is not contributing to overheating.

However, sure would like to know some more about the durability of the current version of a Crane Cam that has the sloped, or tapered, lobes and which is designed for rotating the slanted tappets. The intent was to increase lubrication of those surfaces and therefore to prolong the wear surfaces of the Cam Lobes and Tappet faces.
Why did the Cam fail after only 9,500 miles, as recounted by our Site Administrator.?

Octagonally yours, BOXLEY (Robert & MGTC 0820)

My cam that you mentioned was a regrind, and I suspect the shop didn't harden the lifters after resurfacing, which caused them to deteriorate and take the cam with them. I think I posted a photo of them somewhere in an older thread. I also never figured out what make or model that cam was. It had no markings that I could find, and my measurements didn't seem to match any cam that was on the market at that time.

I thought Steve had that problem running Len's special roller rockers?

Clogged radiator on the TC is tricky to diagnose, as they get crudded up from the bottom. Look fine from above. Ask me how I know

I have a different problem with the roller cam (I have standard rockers) where it seems to be wearing prematurely after only 10K miles or so. Len offered a replacement but honestly I don't want to pull the engine out and tear it apart because of a little wear. I plan to keep an eye on it over the next few thousand miles. I haven't been putting so many miles on the TC this year for obvious reasons, so it may take a while to get enough miles to see if there is a change.

Duncan M wrote: ↑

Sun Nov 29, 2020 2:55 pm

Clogged radiator on the TC is tricky to diagnose, as they get crudded up from the bottom. Look fine from above. Ask me how I know

Probably the same way I know.

Not sure whether reground camshafts are any good unless they are surface hardened, or "nitrided."
Does the cost of hardening makes the regrind not cost effective?

-- The radiator was given a new core, but maybe some cores are better than others.

Properly hardening and treating the reground cam is a part of the operation, as it is with re-done tappets. The last cam I had re-ground was $225, and has some 10,000 miles on it without a problem. It is always possible there was a bad one in the batch, but I've never had one.

Tom Lange
MGT Repair

Tom (lange) are there 19 different cams ?

I call it the 019 cam because the valve setting is .019", just as the 012 cam uses .012" valve setting.

With many cam grinders out there, both past and present, there are far more than 19 different cams!

Tom Lange
MGT Repair

There may be a discussion of the relative merits of some of the multitude of Camshafts and their grinds, and if so, where?

Would like to research some of the merits of several camshafts, including listed in this Post as well as those that are not previously listed in this post.
Particularly need enlightenment about those camshafts which are durable, resistant to wear, with good acceleration and do not require increasing compression above 8.3 to 1.

Below are photos of some marks on a camshaft that came out of an MGTC or early MGTD. Not sure what the marks are -- and whether the camshaft may be identified from the marks.
Have no way to measure whether the Lobes profile, lift, dwell or angle could be similar to those of a .019 or .012 camshaft. Maybe there is a way to measure? Octagonally yours, BOXLEY (Robert & MGTC 0820)

MOWOG cams are identified by a series of rings on the end. Crane cams are golden in color. That's about all you can identify.

Ask people which tires you should get, which motor oil, which electronic ignition, etc. etc. There are so many cams and grinds that you will get dozens of opinions. And there is no one standard by which to measure, since so many variables are in an engine, and a driver. Worn distributor? Down on power. Timing off? Down on power. Higher CR? Up on power. Overbore? Up on power. Carbs off tune? Down on power.

One recent owner asked me to drive his car, he loved it so and was so delighted with the performance. When I drove it I could barely make it move - it was down by half! My tune-up gave him faster acceleration and much improved performance all around. He had no standard of comparison.

Stick with the 0002 cam is my advice.

There is lots in the two archives on cam ID - search for "Cam identification" as a start. Try this: http://www.ttalk.info/CamshaftID.htm
and this: http://www.ttalk.info/Camshafts.htm for starters.

Tom Lange
MGT Repair