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MG TD TF 1500 - EATON SUPERCHARGER, grins & groans
|The good news- today, I finished mounting an Eaton/Marhall-Nordec supercharger on my wife's '50 MG TD. I realize this is a farfetched request, but I would like to top it off with the adjustable oiler/sightglass fitting. I planned on installing an oil feed/drain circuit as originally designed, but would dearly love to add the icing to the cake by finishing it off with the original oiler. Any leads out there?|
The bad news- the Eaton Magnacharger on my wife's '52 MG TD started squealing like a pig today. I'll bet a bearing siezed. Only has maybe 1000 miles on it. I constantly top it up with oil, and just juiced it again day before yeterday. Maybe I'll have to adapt a decent lubrication system on it, too.
Anyone know where I can find 2 of those old oilers???
I thought a brand new unit would be reliable, but I guess I should've slapped on my fifty year old Shorrock blower after all!
And whatever you do, do not purchase the "Bando" belt from Moss Motors as a replacement for either blower. You'll spend a fortune and find it will not fit! Buyer beware.
|Quick questions...what is an "Eaton/Marshall-Nordec"? And why were you having to top off an Eaton Magnacharger every 1000 miles? Those should be good for a 100,000 miles easy.|
|Bad news isn't really bad after all. What sounded like a bearing squealing in the blower was actually the intake gasket that disintegrated leaving a section of just sheetmetal. That shrill shriek was horrendous; my wife said she was embarassed driving it yesterday because it was so loud (never occurred to her to turn around and bring it home). Someone else said he sent his Magnacharger back to Moss with a bad bearing, so I was afraid ours suffered the same demise.|
Eaton has a lot of plants here in Micigan devoted to mostly auto related manufacturing. They've been around a LOOOOOONG time. The made blowers way back when, and many showed up on MGs back in the 1930s. I've read they were used on airplanes back around WWII. My dad was Army Air Corp Crew Chief in Fassi, Itay, and recognized it instantly. "Marshall" meant the Marshall, Michigan plant. I thought I was buying an American Eaton supercharger package so screws, bearing, seals, etc. would be reasonably easy to find. WRONG. It seems (maybe I'm wrong on the precise details) that someone in England began producing those same blowers under license. They used British BA, BSF and Whitworth screws throughout and a lot of custom made studs with those threads!!! I had to use a bunch of NF National Fine thread cap screws, where necessary, many cut to length, and electric discharge machined holes through the hex head to safety wire the darn things to make sure they stay there.
Why add oil to the Magnacharger? There's a brass plug low on the extension case, that determines the oil level. Fill it until it runs out. What happens when you pull the plug and nothing runs out? Squirt more in, being more than generous, too, and screw the plug back in before it has a chance to run out.
Reminds me of my air compressor that has less than 1/2" of oil in the crankcase. Ignoring it for a few month resulted in a rod seizing onto the crank. After reaming the galled rod and polishing the crank, it is back in service, knock on wood. I've since added a few fittings to raise the oil level. I used to be an engineer with the DeVilbiss Company that designed and built that compressor (now Porter Cable)!
I've thought about adding a sightglass/oiler out of that Magnacharger thread so I can keep an eye on the oil level! I'm putting one on my wife's '50 MG so I can pop the bonnet and look at brake fluid level in my add-on fluid reservoir.
Glad your problem wasn't major.
I also have a Marshall-Nordec (clone - built in South America) on one TC with the drip-oiler and I have a modern Eaton M45 Magnacharger (not Moss) on the other. From what I understand neither the Moss version or my version of the Eaton need to have the oil filled on any type of regular basis...is there a problem with yours or is it a much older version?
Thanks for you response above, btw.
|Interesting design of the nose piece. My shorrock has a drain hole on the bottom of the nosepiece and a fill pug on the top with a very fine weep hole drilled through the plug. Too much oil in the nose piece and it squirts/dribbles out the top plug. Any thought to modifying the nose piece?|
The Marshall-Norec has been shown to have a cute needle valve/sightglass fitting to adjust flow down to drips, and drain out at the bottom. I've wondered if others have been successful just running it as a sealed package like the Magnacharger. I could believe the drive bearings would run OK, but on the other hand, they may have intended them to get lube from the drip and nothing else.
Our Magnacharger has no external oil leaks, so I have to wonder if manifold vacuum is sipping traces of oil over extended periods. All I can say is when I pulled the plug this spring, nothing came out.
From all I've seen & read, the Shorrock uses a pressure feed to dribble a bit of oil to the tune of about a quart per 1000 miles. I believe mine is missing the pin they described, but it isn't on a vehicle, so I've got no hands-on experince, yet. Actually, I always desired a Shorrock blower since it is a pretty large vane motor, it might make a decent prototype steam engine.
Are you using the GM supercharger fluid that Moss recommends, or something different?
My shorrock consumes about 16-20 oz every 1000 miles, really not a lot of oil. It does make for an interesting motoring experience as a start of the engine leads to a cloud of blue exhaust wafting around your head. My wife waits a bit before she will get in the car!
The metering pin is located under the inlet for the oil feed from the engine. Remove the plug and it sits there. Different diameter pins will regulate the amount of oil that drips into the blower. I use SAE30 in the nose piece as per the shorrock manual. The nose piece has no connection to the oil from the engine that feeds the blower portion of the shorrock.
No problems over the last 10 years. Oil starvation will kill a shorrock in 2 seconds flat so I always check the engine oil level and keep it at full and I pull the pin at least once a year to inspect and wipe clean.
I doubt the Marshall-Nordec can run with a sealed reservoir. The way it works now is the small amount of oil that's dripped in is vaporized in the snout assembly...that vapor is the oiling mechanism. Any that isn't vaporized is drained back to the sump. Trying to operate it as a sealed unit will oil soak everything and you'll end up with massive leaks and oil blow-by.
I originally used either 10 or 30 straight weight nondetergent they recommended in the instructions. Since then, I grab a small bottle of 2 stroke oil set up with a small tip, convenient for a good squirt. Never got that bulletin about GM super fluid! Does that mean the new GM & Ford Eatons run sealed? I never paid any attention.
I elected to go with my Marshall package rather than the Shorrock because of that blue plume of smoke that most would attribute to a worn out engine.
I wasn't aware that the nose has its own oil sump. My thoughts were the shaft was hollow and lubes both sides of the drum & vanes, along with the nose piece. Haven't really studied it very carefully. I think someone before me changed the oil fittings on the back and goobered it up; it doesn't look original & I found no pin anywhere when first checking it out. After I get my wife's 50 customized and back on the road, I may pull the Magnacharger off the '52 and rig up the Shorrock.
Without tearing apart the Magnaharger, I can't see where that CAN run sealed and the Marshall SHOULDN'T run sealed. The Marshall has a depressed sump region between the two drive bearings, so it is pretty clear the oil drip fills this cavity first and runs out to the blower. The Marshal has a very interesting roller bearing out by the pulley, that runs in flat races. I have to believe they intended this to allow the rollers to float in the outer race with differential expansion between the steel shaft and aluminum nose. This is the bearing that MIGHT not get its fair share of oil running sealed, but I'd have to believe with the gears slinging hot oil around, surely it would get enough in and through the inner drive bearing to eventually wet the outboard bearing. I'm chicken! I'm going to added a couple of stainless lines to & from Mr. Marshall; just wish I could run across that vintage oiler.
By the way, I see no vent anywhere on the Magnacharger, so I assume the expanding gasses must relieve out through the shaft seal as it heats up, and draw air back in as it cools back down.
More fun and games!
See attached photo...is this what you're looking for (not that you can have this one).
I found this on the internet several years ago and never used it (see photo). If you think it would help you give me a holler...it's cheap. It's aluminum, not brass but can probably be polished up nicely.
You can see the original- http://www.oldclassiccar.co.uk/marshall_nordec.htm
Those look close enough. I think they'd have to be great conversation pieces! What do you want for the aluminum one? It has a tapered pipe thread, whereas the blowers have a British straight parallel pipe thread. Gotta do some weird conversion to fit.
I see you blanked off the bypass on the thermostat housing. There's a thread in British-Cars.net archives, "occassional overheating." I've tried logging onto that website to no avail. No one ever mentioned whether they had a thermostat, the CORRECT thermostat for their housing, no thermostat, blanked bypass or wide open bypass.
I'll try to remember to look at my Shorrock, but one remedy to spitting oil out the vent hole might be a "sintered bronze" plug or sometime referred to as vent or filter. They are rather cute. There's an example on Ebay, http://cgi.ebay.com/ONE-Pneumatic-Muffler-Filter-Sintered-Bronze-1%2f8%22-NPT_W0QQitemZ260471074699QQcmdZViewItem for $1.50 with an 1/8" pipe thread, probably not what the factory drilled & tapped.
All I need is the postage...send me your snail mail address and I'll get it off to you.
As for blanking off the bypass I've never had a problem with it overheating...I drilled a couple of small holes in the thermostat so it's always bleeding some water through it...plus the car runs without the bonnet side panels anyway.
When I first installed the Magnacharger, I filled it with fluid before I installed it. Naturally, I did this while the supercharger was on its side and the fill plug was situated straight up, so it filled the whole reservoir area. After running it for the first time, I removed the plug out of curiosity and the fluid literally blew out. It was obviously pressurized. I then filled it in situ to the bottom of plug opening and it's been fine ever since.
I bought the supercharger with some 500 miles on it. At least that is what the seller said. I picked the installation instructions off the Moss website. Moss originally recommended the use of the GM fluid that is used in Monte Carlo's and Pontiac's. But I notice that they have changed this to 20/50 Castrol GTX or the equivalent.
That's very generous. My honey & I thank you.
Ypsilanti, MI 48197
My wife wants a heater installed in the customized '50 so I've studied the cooling system and just now realized most of the time we've run with no thermostat & bypass open. Never had an overheating problem, and living in Michigan doesn't hurt in that department. But, even with a new themostat, it doesn't fit the housing correctly and would be in backwards- no bypass closed/wide open bypass hot. I'm putting in the heater circuit which will serve as a bypass and I ground off the tiny brass air check plug from a conventional stat so it'll have a small flow through the it, like yours.
I gave wife a Motometer for radiator cap and it is a cute, functional thermometer, but I had to add a short copper tube to it so it reaches down to the coolant!
|Shouldn't you be running a thermostat?...Thought all cars needed them. I still have the original which I tested when I got the car running...still worked. I find with the thermostat closed I still get heat coming into the heater quite fast (blows hot air within a minute of two)...|
I'm not sure what you mean by using the heater as a bypass?
Not necessarily, especially down here in the south...the engine warms up so quickly that the thermostat is open within minutes, if not seconds, of starting. On cold days it might be helpful but I just let the car sit and idle a little longer to build up the engine temp just as you would with a thermostat.
If you look at the first photo I posted (above) you'll see that I have the bypass hose area blocked off (not needed because I have added holes to the thermostat to act as a bypass. JRN can add a hose connection in that area to bring hot water back to the heater (the water is hotter there than at the rear of the engine where the hose connection is normally made).
Sorry to hear that you are having problems with your Magnacharger on your MGTD. Your Magnacharger will work fine with a engine supplied oil source. Just be sure you fill the reservoir nose with motor oil first.
Just so we all understand each other. Never put "Eaton supercharger oil" in your Magnacharger or motor oil in your Eaton supercharger. Each supercharger has different requirements from its oil and you should never mix the two!
Eaton has been around a very long time, however they did not start supercharger manufacture until about 1980 for GM on the 3600 series V6 engines. Marshal built blowers since the late 20's for aircraft. These were primarily used as cabin blowers to pressurise the cockpits and later the engines. The Marshal-Nordec MG T blower came about when the NORth Downs Engineering Company (NORDEC) bought blowers from Marshal and added their own componants to fit the MG engine. These are comprised of the nose assembly, and manifolds etc. Anybody who has rebuilt one will be mystified by the mix of metric bearings in the blower (Marshal)and imperial sizes in the nose and idler etc (Nordec). Marshal stoped business in the fifties, however they still exsist in a way as they are are now part of the Howden Group Ltd in Scotland. I was a engineer for them years ago and was startled when I came across blueprints for the blower for our cars in their archives! Sadly they had no parts or other information available.
Director of Sales
|I'm thinking of tapping just in the thermostat housing as well...not very hot on really cold days....|
I like that "Visit vehicle profile" link you have after your name...that's neat.
I used to have a spare thermostat housing that had had a hole drilled in it and an outlet added (brazed piece of pipe). That seemed to be the best of both worlds since you could leave your thermostat (and bypass) stock which you might need up north where you are.
| The "bypass" is a 7/8" hose running from the thermostat housing (the engine coolant outlet) right back into the pump intake. Theoretically, with the right thermostat in the right housing, the coolant will circulate coolant through the engine while cold, through the bypass circuit (good insurance against hot spots in the head and giving the thermostat a good feedback on engine temp). When the thermostat opens, a sleeve closes the slit in the thermostat housing so virtually all the coolant then runs through the radiator. With no thermostat or incorrect installation, the bypass will short circuit hot coolant right back into the pump suction side, mixing hot water with cooler water from the radiator.|
I am knowingly sticking a conventional thermostat in with a small hole in it. This hole should 1) vent air out when filling 2)move water slowly through the front of the head 3)pass coolant though the thermostat for proper opening.
I'm installing a heater that can serve as a bypass, thus I'm blanking off the housing bypass. I'm tapping hot coolant out the back of the head and running it back to the front of the engine into the pump suction side. I could run it back into the housing bypass, but prefer circulating hot water back to the engine, because pumping it into the radiator could mean it would never heat up.
I should never have asked if she wanted the darn heater installed, but riding in the MG in cold weather is almost as bad a riding a motorcycle in the cold!
First off, false alarm, our Magnacharger didn't sieze a bearing, it was an intake leak shrieking like a banshee so it sounded like it was originating from the blower.
I'm grateful a manufacturer would pay attention to it's customers, but we need to sort fact from fiction. I just reread my Installation Instructions from Moss wondering if I missed something!
"Marshall" came from the Eaton plant in Marshall Michigan, right? ...or is that some amazing coincidence?! Marshall superchargers were made under license in England, right? South America now, too, under license or illegitimate clone?
"Your Magnacharger will work fine with a engine supplied oil source. Just be sure you fill the reservoir nose with motor oil first." There's no provisions for supplying pressurized engine oil to the Magnacharger. There's only about 6 ounces setting in the bottom that gets splashed around.
"Never put "Eaton supercharger oil" in your Magnacharger or motor oil in your Eaton supercharger." This statement seems totally incongruous. I now read above to put GM supercharger oil in the Magnacharger, when the instructions said 30 wt or 20W-50. The Marshall is fed a trickle of engine oil.
I'll just tell my wife to drive it and don't ask questions.
Looks like the Shorrock has a #2 British Straight Parallel Pipe thread for the vent plug. If you care to try that sintered bronze vent, there's an adapter with that male thread to female pipe, 7042-02-02. My supplier is out of stock, so you may search the intetrnet for availability. They're less than $10, but you can kiss about that much away for shipping, too.
Alternately, you might adapt the vent to fit. The British straight thread are 28 thrads/inch and a major dia.of .383" whereas, an 1/8" NPT is 27 threads/inch with a "nominal" major dia. of .405. The 1/8th in pipe thread runs in about 1 thread, so if you cut the vent threads through the back side of the pipe die, you'd cut a straight thread nearly identical to the BSPP. A wrap of teflon tape and presto.
I'll have about the same challenge adapting an oiler with an 1/8" NPT into 1/4" NPT bushing and sinking that into my Marshall blower.
Ignore the response directly above.
It appears you can get the vent with the 1/8" BSPP vent ready to go, for $1.50 and $2 shipping- Ebay auction, http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&_trksid=p4506.m7&item=260471074699&viewitem=&_trkparms=algo%3DLVI%26itu%3DUCI%26otn%3D3%26ps%3D5&category=50928&ih=016 .
BSL-01 Cone Muffler/Filter Sintered Bronze/Brass 1/8" BSPT
I'm going to order one for mine.
|For anyone with heaters, I should've stressed that the bypass would circulate most of the coolant before the thermostat opens, and once the thermostat opens, that'll take most all the coolant.|
Blocking off the bypass would flow most all coolant through the heater(except what passes through holes in the thermostat). On a cold day, I'm willing to bet the thermostat might not open with the heater running.
Thanks for the heads up, just ordered the vent today.
|Saturday morning, I just started to post an "amended" heads up, but my wife said it was time to go to her school reunion and 36 hours later, I'm just getting home.|
I assume you ordered the BSL-01 "cone" sintered bronze "fiter/vent/muffle." I got their email Sat AM and they mentioned they also have it in the "flat" instead of the "cone" form. The "cone" will work great and look really cute; the "flat" BBV-01 would be much more discrete/petite is all. Either would be a marvelous additiion to a Shorrock. I didn't order either. They also have a really cute "adjustable" muffler, very ornate. You could also crank it also completely shut and just crack it open to slowly vent the drive extension and virtually guarantee no oil traces. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260415839334&ssPageName=STRK:MEWNX:IT The bad news is... it cost 9 cents more!
I'm getting inspired to assemble the Shorrock now.
Do you have the installation info and the info for disassembly/re-assembly of the shorrock?
If not let me know and I can get you a copy.
|I received no info with my Shorrock. There's bits of info on the internet, but I haven't seen anything on disassembly/re-assembly, nor instalation on an MG. Any info would be appreciated.|
Like my Marshall, I procured it as an incomplete package, and would hate to see it pass into oblivion because no one cared to hunt or fabricate the necessary components and install it.
|I'm on vacation this week. Let me know your email and I will send scans next week when I am back. The disassembly instructions were hard to find. I got charged $50 for them 10 years ago, which at the time I considered worth it. However I am happy to distribute them out free as I feel they should be available to anyone who needs them.|
|Much obliged! email address is rnorthrupsr@Yahoo.com|
Today, an Australian came into my shop. We discussed the radiator/bypass/heater subject as I just finished welding a bent stainless lower radiator tube with a branch teeing off for the heater (still had it in my hand). He states the bypass was a measure to prevent sudden overheating and engine failure- basicly, it prolonged the agony by at least circulating the coolant so the driver would catch the temp gauge climbing out of sight. He says they would drill 4 small holes in a conventional thermostat to hopefully avoid meltdown.
Maybe a hole drilled in the radiator cap would issue a quick warning as one couldn't miss Old Faithful (a famous geyser in the States) blasting off a few feet in front. I think we'll stick with our temp gauge & Motometer.
|darn, I did't edit in time (not wearing reading glasses will do it every time). My correct email address is jrnorthrupsr@Yahoo.com|
The Shorrock is a veritable can of worms. It cannot be taken to pieces simply by removing the two end plates and pushing out the interior mechanism. The 9 ( I think ) inner bearings have to be removed as a separate item before the cage can be removed. This requires a special tool, a dowel, made up and then the dowel is slid into the inner part and the whole is lifted out. Under no circumstances try to force the cage out until this has been done. I am a little hazy about the details at the moment as it is 16 years since I last did my own. I do have, somewhere, some drawings and instructions but they are sketchy. If I can find them, I'll scan them and pass them on in case they may be of help.
I didn't know that Rob has some info and I hope he may read this sell me a copy as well.
Let me know how you get on. I'm thinking that the time is drawing nigh when I shall have to do mine.
|I also have a set of installation blue printes for the MN blower that I installed on my TD, and that Benito Travato refers to. I've lent them to Jim Mertz and others, and I'm prepared to lend them to any needy party.|
Again - no part numbers - just general arrangement blue prints that frankly, aren't terribly good, but thay are readable and just.
Jusr contact me at the address shown on the lhs.
|Gordon A Clark|
I will be happy to send you a copy also. No need to buy it, after all we are in this together and these parts are only getting older and harder to find. The rebuild on my blower was about 10 years ago by an 82 year old machinist who did it as a "hobby" with all new bearing and vanes. He estimated he spent upwards of 40 hours on it!
|Many thanks, Rob. |
If you care to send a confirmation to my e-mail address, email@example.com, I'll email you my street address.
When I have gone through the information, I'll compare that with what I have and, if there is anything beyond what you have, I'll gladly pass it on to both you and JRN.
This thread was discussed between 16/09/2009 and 22/09/2009
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