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MG TD TF 1500 - Running engine off battery

I need to prime my oil system. The engine is in the car but no systems attached (electrics/water/exhaust/fuel) except the oil lines and filter.
Is it OK to just connect the battery to the starter motor directly or can that damage the starter? I'm just thinking of installing the starter and hooking the battery directly to it with cables to turn the engine over for the 200+ revs needed to get the oil pumped through the system.
What else should I do in preparation for this? I am thinking I should remove the top bolt on the oil pump (see pix) and prime the pump with oil too. Any other suggestions?


Geoffrey M Baker

Because you are supplying 12 volts to the starter directly or through a starter switch it won't make any difference. But make sure you fasten the jumper cable firmly to the starter post and connect and disconnect the other end of the jumper cable to the battery. If you connect and disconnect the jumper cable to the starter post you will harm the threads by arcing. The best solution is to get a starter switch so you can leave it connected to the battery post and the starter post - no arcing. Of course don't forget to run a cable from the negative post (or positive depending on your system) to the engine to ground it. If you have the vertical oil filter fill it also. I put oil in the top of the pump via the bolt in your picture but it didn't take much. Watch out for oil shooting out of the oil gauge connection if you haven't blocked it off (ask me how I know).

Tim
TD12524
TW Burchfield

Thanks Tim. I've got the oil gauge connected so nothing should shoot off. :) I'll fill the oil filter too as it is vertical.
I have a screw mounted shutoff switch on the battery cable, I will connect and use that to connect to avoid arcing.
Geoffrey M Baker

I'd say the only real danger would be overheating the starter. Keep and eye on it as you go. If you have room, you could spin the engine with an electric motor or even a drill. With the plugs out (which they should be anyway), the engine will spin very easily.
Steve Simmons

Yes plugs are out
Geoffrey M Baker

Geoffrey. If this is a fresh build my suggestion is to fill the oil pump gear chambers with Vasoline. This will insure excellent suction for the pump to pull oil from the pan. Certainly filling the filter is also helpful in expediting the priming process. Spin the engine over plugs out in thirty second burst and then allow the starter to cool off. You don't want to through the windings from constant cranking on the starter. Also don't hook the oil pressure gauge up and put a can under the line at the gauge end. As soon as you have oil coming out of the line hook it up to the gauge. This will get the air out of the line and facilitate an accurate reading. Then replace the plugs and fire it off keeping the revs above 1500 for the first few minutes to get windage and oil thrown about to aide in lubricating the camshaft and diminish the chance of having a cam failure. Not as critical with a roller cam Hopefully you used a cam lube liberally on the lobes and tappet faces also on the tips of the pushrods and rocker tips. I use STP as it is very sticky and stays put until the oil gets the chance to wash it off. Also insure that your rocker shaft is oriented correctly to recieve oil from the rear pedestal and distribute the oil through the shaft and to the rocker bushings. It is possible to install the shaft upside down and backwards thus occluding the oil supply hole in the shaft.

Cheers

Bill Chasser Jr.
Td4834
W. A. Chasser Jr

Probably a little late, but I used a MGB oil line fitting with a 1/8 female BSP port in the middle to substitute for the transition fitting between the flexible oil line from the engine to the oil gauge. I attached a 1/8 male BSP fitting to transition from the above fitting to the hose of a garden sprayer and put 5 quarts of oil in the sprayer, then pumped the oil into the engine via that set up. After disconnecting the fitting and plugging the now unused port on the above fitting. As soon as I hit the starter, I had oil pressure. I have used this set up on both our TD engine and the the MGB engine - works wonderfully. Cheers - Dave
PS Geoffery - your method will also work fine.
DW DuBois

I agree with David. I have been rebuilding engines of all types for over 50 years. I always use a pressure pot to oil a new engine. Reverse flow through the oil pressure outlet lets oil get to every part of the lubricated system. You can even watch it flow from around the rockers with the valve cover off without getting splashed.
Sandy
Sandy

Here's what I use every time, even when I prime after oil filter change.

http://www.walmart.com/ip/RL-Flo-Master-1-Gallon-Sprayer/13376324

Easily connects to flexible oil line banjo that runs to head with rubber fuel hose and spring clamp. After priming, reconnect oil pressure gage flex line and you will have immediate oil pressure.
Richard Cameron

Garden sprayer works great. Vasoline in the pump also usually works, but I've found you can also simply remove the top plug and fill the pump from the top with oil (TC/early TD).

I would leave the pressure gauge attached. If air remains in the line, it will not affect accuracy of reading at all. In fact when you shut down the engine, most of the oil in the line will run out anyway, leaving air. Connect the gauge and keep a close eye on it as you crank. If you don't get pressure in a reasonable amount of time, stop and prime the pump again. Even at low RPM with the plugs out, you don't want to crank it dry forever. Assembly lube and zinc paste only last so long!
Steve Simmons

SO......am I to understand that special action should be taken after an oil and filter change, before running the engine in my TF (with a 53 TD/C engine)?
Cheers,
Frank
Frank Bice


Since I made the comment about using the weed sprayer primer after an oil change, let me clarify a little better.

The XPAG/XPEG engine is notorious for loosing the prime in the oil pump after setting a long time, after filter change, or after engine/oil system rebuild. Anyone who would argue can review the archives to see the extent of questions/comments related to this subject. Let me say that every engine has its own characteristics due to clearance, sealing, wear or sludge variations.

If your engine is one of those that frequently looses its prime after a filter change, the weed sprayer primer will save your engine from damage because it will definitely pre-prime the oil system pump. Using your starter or running the engine with out oil pressure is not a good thing to do for any reason and could shorten its operational life considerably.
Richard Cameron

Bill Chasser - you've made many great suggestions before, but filling the oil pump with Vaseline? Really? I've never heard of this!

I picked up a garden sprayer for $9 and will use this. My thinking is the simplest way is to connect it to the end of the tube where it goes to the oil gauge (no extra fittings needed and some hose and a clamp will probably work) and pump from there.

My gauge connects to the HEAD, not to the lower block (as some recommend). Does this make a difference when pumping?

I have read that it is preferable (see archive threads) to connect the gauge to the lower connector, as that gets a better pressure reading; but I don't plan on doing that, I'm keeping the set up as it is.

But would there be significant benefits when priming the engine to pumping the oil through the lower fitting rather than the higher one?

It seems to me that if I hook up to the higher fitting which goes directly to the head I'm really not doing much different than if I simply just pour the oil into the rocker chamber and let gravity do the work.

Geoffrey M Baker

Steve, if you leave the pressure gauge installed, where do you connect the sprayer pump?
Geoffrey M Baker

Is there not a different size of orifice in the upper head banjo fitting as apposed to the lower banjo fitting? That's why the oil Pressure take off is normally fitted below - as I understood it. And yes you will get a lower oil pressure reading form the top.

Rod.


R D Jones

I tried all sorts of tricks to prime my TF's oil system all without success. I then picked up a tip from this forum. Block off the breather pipe in the side cover with a cork and then pressurise the sump by sticking a bow gun into the dip stick tube and giving it a couple of blasts. This worked for me and my brother.


Jan T
J Targosz



I don't want to hog this thread with my comments but things are being said that concerns me a little. First, I hope everyone knows to remove the weed sprayer arrangement and re-install the flexible oil gage line before trying to crank the engine!

Yes Bill, its common practice for many engine rebuilders to pack the oil pump with Vaseline to help the pump pick up oil from the sump during initial start up. Vaseline is a petroleum product and dissolves in warm oil.

Bill, I recently rebuilt an engine for another enthusiast. He sent me a disturbing email this past week, telling me the new engine I sent him only showed only 10 lbs. of oil pressure on initial start up. I told him several different things to check related to his oil pump which he had re-used from his old engine. He also had used his original copper head oil line which he installed upside down like his previous configuration. One of the things in the list, I told him to do was flip that oil line around and connect his gage at the lower banjo area. He argued that it worked previously upside down and pressure was pressure no matter where one measures it. So here's what I said in an email to him:

First, MG changed the arrangement after problems with early engines. Look in the Moss on- line catalog and you will see the different P/N lines and different connection banjo bolts. The copper line in some cases has a restrictor orifice to reduce flow to the rockers(not all). No matter what the configuration, The rocker arm train does not have tight enough clearance or tolerances between the rocker washers to maintain much pressure so there is a better volume of oil but less pressure. If you connect the oil pressure gage at the top banjo, the gage only sees pressure that exists from that point of attachment-- It is restricted and a potentially lower pressure due to loss at the rocker arms. It is common for one to see a 10 lb. difference between the two connections.

Guess what? He chose to do the easiest recommendation in my list and turned his oil line with the gage connection at the bottom--- His oil pressure jumped up to the normal range and he sent me an email saying he couldn't believe that it made that much difference.
Richard Cameron

Vaseline is a common thing actually. Sounds crazy but it works. It will dissolve into the oil, which you will be changing shortly afterward anyway. You don't need to pack the entire pump, just use enough to coat the gears. The idea is to create suction as the parts turn so you only need enough to make an air seal.

Geoffrey, when I suggested leaving the pressure gauge connected, I was talking about cranking the engine with the starter to build pressure. Using a sprayer will never create enough pressure to register on a gauge, and yes you attach the sprayer to the lower bolt where the gauge normally attaches. After using the sprayer, reattach the gauge and crank the engine, watching the gauge carefully! I suspect that priming would work better from below but I've never tried it from the top. It just seems like it's better to push a steady stream upward to displace the air than to have it pouring down the galleys and taking air with it.

My preference is to prime the system with a sprayer or other method and then crank with no plugs until pressure reads on the gauge. There will be plenty of oil on the bearings to handle the very small load being placed on them during this process. Once pressure registers, I install the plugs and start the engine. If pressure will not build, I pour oil into the top of the pump with a funnel and that usually does the trick. Failing that, the Vaseline trick comes into play.

Never had a problem losing prime after an oil change, that's a new one on me!

Here's how I connect:


Steve Simmons


Sorry, I meant to address the last comment primarily to Geoffrey, not Bill.
Richard Cameron

Thanks for the input, lots of helpful tips.

Re upper and lower banjo connections; I don't really see an issue. So long as we all KNOW that connecting the gauge at the top results in a lower oil pressure reading, we can adjust for it mentally. It's like putting the water temp gauge on the elbow (or back of the engine) vs its original position on the TD. It will give a different temperature reading, by a few degrees... and so what? So long as we understand that the block will probably be a few degrees hotter than the reading coming from the top of the radiator, we know what to watch for...

I'm just loath to move things around on an early engine.
Can you really just flip it upside down without other changes? The fittings are the same?
I'd love to see more photos of the banjos in either configuration.
Geoffrey M Baker

Just one caveat about the Vaseline pack - don't rotate the engine backwards or the vaseline is pushed out of position and an air pocket is created. I'm with Steve, I've never lost prime from an oil change. I'll grant that it will take a bit of cranking to fill the passages and show pressure. ALWAYS done before turning on the ignition. Bud
Bud Krueger

Bud, naturally I will do all this with the plugs out and power only on the starter, until I get oil pressure.
Geoffrey M Baker

My TD has great oil pressure when running - even when hot - but every time I start it from cold it takes bloody ages to pull pressure. I'm concerned about engine damage so I've taken to spinning the engine with the ignition off for about 15 seconds before starting it. I have no idea if this is 'normal' or not, but it's certainly not normal for any of my other LBCs.
Kevin McLemore

FWIW. I started my engine sevral years ago before I had the coolant ssystem hooked up r the dash in.

Attached is how I measured the oil pressure at start up. The gage is a water pressure gage is use to check incoming pressure.

I also had my oil gear pump filled with vasoline. Its an old procedure. I have used it on several cars. In my case the pump was filled around 1986, but the engine did not start up until August 15, 2013.

As a note you will need to crank for almost 1 full minute to get pressure. I also first filled the oil filter canister, squirted some oil down the spark plug holes, lubricated the rockers and push rods and lifters and squirted some down the oil return holes in the head to try to get some lubrication on the cam.


Jim B.


JA Benjamin

Ok, I need to ask. Why is the pressure measurement higher at the lower outlet position than the upper one on the head. As I see it the only reason for a pressure drop at the top fitting would be if the banjo opening was working as a hydraulic control. This would only be the case if the the rocker bushings were in very poor condition and not acting as the control.
Hugh Pite
H.D. Pite

Have to agree with Hugh there are some mysteries being expressed, I thought "Pascals Principle" was being applied in the lubrication system or am I missing something.

"Pressure is transmitted undiminished in an enclosed static fluid. Any externally applied pressure is transmitted to all parts of the enclosed fluid, making possible a large multiplication of force (hydraulic press principle)."
G Evans

After 36 years of ownership of my TD I read on this forum that the correct location of the oil gauge line is on the block, not the head. Changed mine over and immediately gained 15 lbs indicated oil pressure.
John Quilter

The pressure is lower in the upper position because in that position it is close to the feed to the rockers, which offer relatively little resistance to flow. Measuring pressure near to a pressure outlet is bound to indicate lower pressure unless there is a significant resistance to flow (and there isn't). The lower position is further away from that position and there is a flow restriction above it, so it gives a higher reading.
Dave H
Dave Hill

I guess it really dose not matter. We can do with our cars as we please. But that said, my thought are these.

The measurement of pressure you want to see is the pressure at the main bearings, big ends and cam bearings. The main gallery is the important location to monitor. You want to know if pressure is being lost due to wear on these parts that really need it. This gives you the correct indication of engine health.

Due to the restriction at the upper banjo and much looser tolerances of the rocker gear. The pressure measurement is much lower at the head connection.
You do want lots of Oil to flow through the rockers as this is the lube that gets down to the tappet followers.

The oil gauge is possibly the most important one on the panel and it is the one I always look at. 40lbs is a good number

The correct location for a TD is shown in the manual figure A1. in the engine section.

But like I said, you can really put it anywhere you like.

JMHO
Rod



R D Jones

G Evans.
The key word in your quote is "static".
The fluid in the pipe is anything but static.
There is a lot of flow through a relatively small tube.
Hence there is a pressure drop.

Jim B.
JA Benjamin

Rod, as is almost always the case, there is confusion even in the manual. If you look at the diagram A1 as you suggest, the lower connection would appear to be the place to connect the oil gauge.
But if you look at the prior diagram, on page A2, entitled "The Engine Components" the oil gauge takeoff is clearly on the upper banjo connection. (At least it is in my manual). This diagram shows the precise setup that actually exists on my engine, that is to say, the top connection has a banjo with a pass through threaded connection. The banjo goes to the bottom, and terminates in a banjo with no additional openings, so there is no way to put the oil gauge connector there. The top connection has a pass through threaded fitting which connects to the oil gauge.
Additionally, the length of the braided hose connector on the upper fitting is too short to simply move it to the bottom and reverse the banjos.
So my engine, an early 51 TD engine, is as Morris and God intended, according to their design of the time.
The "correct" placement for my 51 TD engine is therefore on the UPPER fitting.

The question is, is it better to modify the OEM setup in order to obtain a different/better/more accurate(?) oil pressure reading?

Setting aside two arguments (if it aint broke don't fix it, and the purist argument of HEY! That is NOT original to your car, what the heck are you doing?)
what do I really get by modifying this setup?
I get a reading that is 10 lbs higher.
But if I know that the lower fitting gives a higher reading, what difference does it really make to do this? I can just mentally adjust for the reading when I look at the gauge, right?
Geoffrey M Baker


Geoffrey, I also have a 1951 MG TD and like yours my gage was connected to the head and like you I believe this is correct for an early TD. The weed sprayer should work fine at the head banjo because all your trying to do is fill everything with oil and push most of the air out.

I agree with everything you said in your last posted comment. However, for those who experience low oil pressure from the head connection, it still remains true that MG changed the location for a good reason on later cars. Some people don't have a near perfect rocker arm set up and their cars will likely show lower than normal oil pressure from the head connection.

Bye the way if you decide to switch banjos top to bottom later--- to get your flex hose to reach, all you need to do is move the brass union down on the firewall. The thin pipe to your gage is normally long enough to reach under the dash.
Richard Cameron

Don't trust a diagram in a repair manual. The artists often make mistakes. Even the factory line drawing of the TC has at least a dozen mistakes on it. There's even an hexagon where an octagon should be! And on the MGB sales brochure, one drawing has the indicator lamps drawn backwards.

The lower bolt is the correct location for oil pressure take-off.
Steve Simmons

The upper banjo takeoff for the pressure gauge IS CORRECT on early TDs. It was moved later. This is evidenced by numerous manuals and books.
Just because YOUR car has it on the lower banjo doesn't mean it was the correct location for ALL cars.
Lew3

I'm not saying it wasn't factory original on a particular car. I was simply stating that the lower bolt is the correct place to take pressure readings, for the same reasons already stated by others. If you want to run on top for whatever reason, go for it! It still works ok.

And my car is a TC so yes, it's in the factory correct location on bottom.
Steve Simmons

ALL,

From the TD service parts list you can deduce that the oil gauge feed pipe position was changed from the head to the block at engine number 9408.

John

52 TD
J Scragg

I'm with John on this. The same car will give a higher reading if the feed to the gauge is taken from the lower point, but this doesn't make it "more" correct or the engine any healthier. If a higher reading on the gauge is important to you then by all means use the lower pickup. Early cars like mine had the feed taken from the head. This resulted in comparatively lower readings when compared to later cars with the repositioned pickup. If originality is important to you, as it is to me, then note the engine number oil feed changeover point provided by John & position accordingly. Cheers
Peter TD 5801
P Hehir

I think the only way it would matter is if the bottom end was starting to wear. You would still have the same pressure in the top end, so there would be no indication on the gauge that the bearings were losing pressure from wear or damage. Not a catastrophic situation or anything.

Just having an oil pressure gauge, no matter where it's connected, is a good thing! Cars without them are scary to drive. :)
Steve Simmons

If all the above from early TD owners is correct, why then, if the TC took the reading from the block, would the factory have moved the fitting to the head on the TD? The only difference between the TC and early TD oil pump was the at the output of the pump - the TC fitting bolted to the top of the pump and the TD used a banjo bolt. The early TD used the same oil filter arrangement as the TC so the output from it would have (should have?) been the same as the TC.

If the oil pressure was ever taken from the head connection I'd have thought the factory would have done it when they changed to the later TD/TF oil pump.

Gene
Gene Gillam

Who knows, Gene? All we can be sure of is that early TDs came with the fitting on the head. BTW, My understanding is that not all early TDs had oil filters at all. Mine at some point had a Sears canister aftermarket oil filter assembly which a later PO removed completely, leaving no oil filtration system whatsoever. I installed Bob Grunau's spin on adapter.
Geoffrey M Baker

Lots of early engines ran without oil filters. You could buy add-on filters to improve engine longevity and decrease oil change intervals. Suddenly people were letting their oil go far longer than before, so I don't know which was worse on the engine - with filter or without! ;)
Steve Simmons

Steve,
You wrote:
Just having an oil pressure gauge, no matter where it's connected, is a good thing! Cars without them are scary to drive. :)
That's another reason why I developed the oil pressure warning light kit. This gives an optical and acoustic warning if the pressure drops. It's a simple replacement for the union to the pressure gauge and gives that bit of extra security. XPAG engines are expensive!

Regards
Declan


D Burns

Warning light fitted


D Burns

R.D. Jones wrote:

"The oil gauge is possibly the most important one on the panel and it is the one I always look at. 40lbs is a good number"

Most of the time my instrument indicates 100lbs and falls down to 20lbs at idle. Is something wrong?
Bela

Yes. Check the pressure relief valve. Too much oil pressure can be as bad as too little.
Steve Simmons

This thread was discussed between 03/10/2015 and 08/10/2015

MG TD TF 1500 index

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