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MG TD TF 1500 - Have you inspected your tappets lately?

Just a little over 10000 miles and unfortuneatly 14 months ago so no attempted warranty claim from Moss. Running the Crane Cam, stock grind , oversized lobes, observed spinning after start up. Running Valvoline 20/50 VR1 ..no additional additives. 6 look like new...2 not so much.

Photo of number 5

LaVerne

Number 7

LaVerne

Did you modify the tappets so they could receive proper lubrication? There was a big to do about this about 8 or ten years ago.
The bummer is now you have to replace your cam, and that is not going to be cheap. Maybe it is time for a roller cam?
I'm sorry you have to go through this.
-David
D. Sander

This is the TF or the TD LaVerne? Is this damage or just cosmetic? What is "observed spinning"? Could you elaborate?

Also, could you post the Moss part# for these for reference? For those of us not as heavy into the guts. Not sure what I'm looking at but it is interesting.

Ed
efh Haskell

Metal termites! That sure looks like porosity in the metal from the photo. You can see spinning marks on #5 for sure, so it must have been rotating. Ed, search tappets, Zinc additives, oil type, etc. in the archives, as there are volumes about this in there. I am curious if these were some of the Moss improved/inspected tappets? George
George Butz

Off the TF Ed. Cam is still just fine David. The tappets come modified for proper oiling.

The "observed spinning" Ed is that the tappets are seen to be turning in the bores while the engine is running. In theory this will reduce the chance of wear on the tappets and cam lobes. To promote this the cam has a tappered slope lobe and the tappets are crowned. Number 5 appears to have been turning while I suspect that the wear on number 7 indicates that it was not. The damage is slight to the tappet surface at this point Ed but if left alone it will eventually cup out the tappets and grind down the cam lobes in short order. I have been told by an XPAG expert to expect to replace the tappets at about 10000 miles regardless of oils, mods or use. The very design of the XPAG does not provide sufficiant lubrication of the surfaces. Len's roller job is one option although quite pricey. Other option is to install yet another set of new tappets and expect the same in another 10000 miles. Len's also requires me to pull the engine . Real PIA in the TF.
LaVerne

LaVerne,
While I had realized that this was a weak link in the XPAG I had not realized that it was bad enough to quire tappet replacement after 10,000 miles. I guess it would be wise to pull the tappets and inspect them before a valve adjustment. I think I will do some inspections in the spring time, to get a base line, and then pull and inspect the tappets routinely before valve adjustments. Can't hurt.
I am glad your cam is OK. I can't believe there is no damage after looking at those tappets. And this happened WITH Valvoline oil? yikes!
-David.
D. Sander

When I blew the crank on my TD with about 10000 miles on the engine, the same thing LaVerne observes was true of mine. Berry Cam in MN brought mine back to specs and I had another set that I also had done. One of the local gurus here says this is quite common on the XPAG. I really like Lens system but right now I cant afford it. Would take care of this annoying problem.
Tom Maine (TD8105)

I have ancient tappets from 3 different XPAG engines in the attic, and none had other than what I would call routine wear. This destruction deal seems fairly new. I wonder if not the oil, maybe additive package in the gasoline contaminates the oil, or lousy metal? I still think something changed. If these are the new hardened Moss ones, you may want to talk to them. I also wonder if all of us that have rebuilt and rebushed our rocker shafts have inadveretly reduced the amount of oil draing out of the head down the pushrods, and eventually onto the cam? George
George Butz

Although not an XPAG this youtube video gives you an idea of what is meant by the tappets spinning. It's amazing to watch.
Gene Gillam

I run the oil that contains ZZDP (dont know if that is the correct acroynm or whatever in my car all the time. Some just use it for breaking in the engine but i figure what the heck, it cant hurt.
Tom Maine (TD8105)

Tom, the Valvoline VR-1 is just about the best ZDDP content oil that one can get. Bud (worried)
Bud Krueger

With only two of eight tappets affected I doubt it's the oil. When setting the valves you didn't accidentally tighten the rocker adjustments so much that the push rods couldn't turn on those two, did you? If the push rods aren't free to turn there's a good chance neither will the lifters/tappets.
Gene Gillam

I use the Brad Penn oil. I think that is the name of the stuff anyway. My garage is so full, I cant get to the oil to read the label. It is high in ZDDP. thanks for the correction by the way...
Tom Maine (TD8105)

Have to agree with George. I have two sets. One from my initial rebuild of the engine and and the set that replaced them (when the rod bolt broke and destroyed the engine. Neither has any marks like these.

Tom Does Berry Cam reface or do they add material to bring back to spec?
Bruce Cunha

When my engine was built, about 10k miles and 10 years ago, it had a Crane cam and unmodified lifters installed. I had to pull the engine recently to fix a flywheel problem and found the lifters in very poor condition, no doubt due to oil starvation caused by the increased base circle on the cam and the unmodified lifters. The cam was worn but not destroyed. I sent it to Iskendarian and they checked it to see how much hardness was left on it. They determined it could be reground, so that's what I did. I also sent some lifters to Rocker Arm Specialists to be hardness tested & refaced. I'm now in the process of putting it back together....

FWIW, Isky recommends Brad Penn oil.
Rob Edwards

Gene,
Do you have the link for the video?

"Gene Gillam, Mississippi, USA, anngene@bellsouth.net anngene@bellsouth.net>View vehicle profile

Although not an XPAG this youtube video gives you an idea of what is meant by the tappets spinning. It's amazing to watch. "
Mort 1950 TD1851 Möbius

Bruce - I don't know anyone who adds material to old lifters; they would then have to go through the entire hardening process, which is so much more expensive than just buying new.

I've been in touch with various manufacturers about making up some NEW high-quality lifters based on NOS MOWOG lifters, with oiling grooves and with each one harness tested. My design would include all the latest technology to try to avoid the current problems, including Teflon-impregnation and cryo-chilling to relieve stresses. It's looking possible.

Tom Lange
Bar Harbor, Maine
t lange

Hi all;
This discussion makes me want to check my tappets. Engine rebuilt professionally in '03 with about 6000 miles on it.
I can do this without removing the head, correct?
I would remove the top and side covers, remove the rocker assembly and the push rods (keeping them in order) and then I ought to be able to pull out the tappets. Is this correct?
Is a tool needed to pull the tappets up?

Tom
'54 TF
Tom Norby

Bruce, Berry Cam just reground them and then they are sent off to the cities to be hardened. When I checked mine after the engine blew there were 4 of them that were like LaVerne's. I have looked at others that have rebuilt the XPAG and they all have about the same number that are bad. Seems to be an inherent deal with the engine and the engineering that was done at the time.If I can ever afford it, IE winning the lottery, I am going to buy one of Len's roller cam setups.
Tom Maine (TD8105)

LaVerne
I guess my question would be what made you pull the lifters in the first place? Were the valves out of adjustment? It would have been nice if you had observed the oil flow on the rocker assembly. I am curious if each pushrod and lifter was getting the same amount of oil lubrication? If it was bad parts it would seem that they would all show wear. Or two out of the eight lifters bad and just got assembled on the same cylinder. I too use Valvoline VR1 racing oil in the silver plastic bottle, it even has a paper sticker on the bottle which says “High Zinc, Great For push-rod & flat tappet engines”. The Tech advisor for our MG club dose not recommend VR1 racing oil, but I think he is talking about the not street legal Valvoline VR1 racing oil in the dark gray bottle, which says on the bottle not legal for street use and is a one race use and then change. Back in the early eighties on my first TD you could not buy push rods or lifters for an xpag engine rebuild, you had to rely on buying used. So I’m wondering if you might have had 6 usable old lifters and two new ones, that might explain why two are bad on the same cylinder and not the others. I usually change all the fluids in my TD each spring, so this year I’ll add pulling the push rods and lifter just to check for wear. Keep us posted. John
John Hambleton

To remove the tappets just remove the VAE cover and the tappet cover. Back off on the valve adjustment enough to pull the push rod out, and then you can lift the tappet out from the side cover. Just remember to put everything back in the same place. The best tool to use for the pushrods is a piece of cardboard with eight holes in it. Just numer the holes 1-8. inspection is quick and cheap.
-David
D. Sander

Whoops! Substitute valve cover for VAE cover above.
D. Sander

Mort,

Sorry about not posting that link (and now I can't find that exact link again).

Here's another link though...this one shows the pushrods turning (which they won't do unless the lifters/tappets are rotating). This is an easy check without having to take your tappet cover off:

http://www.youtube.com/watch?v=MmjSou5onKc

It also goes back to my question to LaVerne above...were those two valves adjusted correctly or had they been accidentally tightened up too much?

Gene Gillam

John to answer a couple of your questions.

When I rebuilt the engine in 2008 I installed the Moss/ Crane stock grind camshaft with new Moss/? lifters. Put about 1500 miles on the engine over a few years and blew the head gasket in 2010 ( my own fault). I saw a little valve recession on one valve so I had the head reconditioned and did an inspection of the tappets and found that several were pitted. I complained to Moss and was sold another set at a very discounted price. Yes I used the recommended break in lube and the recommended break in procedures each time. Oil system was prelubed with a pressure tank both times. Used Castrol Classic ( higher zinc) 20w50 the first go around and the VR1 the second time. Change oil every 3000 miles or 6 months. She gets plenty of oil from the top end (observed). And the tappets were all observed to be spinning during the break in. Set the lash to the Crane recommendations which is pretty loose... .016 and .018 come to mind but I could be wrong there. I'd have to look at the card.

I run her hard. Sometimes hours on end at 5200 rpm. A lot of these miles were highway speed for hours on end. I can't vouch for the past history of the original tappets or the mileage the sustained but my gut feeling is that a great number of these engines rarely saw even 5000 miles in a year and maybe less. I was told to expect the need to replace these at around 10000 miles.

That combined with the fact that I wanted to address oil blowing out the Moss alloy tappet cover I installed when these were installed is the reason for inspection. My intention is to drive the wheels off it again this year. Maybe even a lot more than the 10000 plus I put on her last year.

I'm no expert ..far from it. Just saying that as a rule you might want to have a look when you get the mileage on your engine I have.
LaVerne

When these cars were new there would be few places in England where you could maintain cruising speeds above 40 mph for longer periods due to road conditions. Ever rising and falling RPM between 2000 and 3500 is the original modus vivendi of these engines. No wonder that tappets fail prematurely if one has a habit of cruising@ 5000Rpm - IMHO. Correct me if I am wrong.

Regards,

Jan
Jan Kristoffersen

I came across this company. They make solid lifters for race cars and have a line for street use. I wonder if they would consider making a run of ours?

http://www.precisionenginetech.com/products/2011/03/28/trend-offers-new-tool-steel-solid-lifters/

Tom. I know Delta Cams has a service to add material to cams. Just was not sure if it would work for lifters.
Bruce Cunha

Bruce that sounds like a great idea. although at 18 bucks each it is somewhat spendy..
Tom Maine (TD8105)

You haven't priced a set of these from Moss Tom...$330.00

Here's a shot of two from the first go around. 1500 miles approximatley and pretty mild use. No long time at higher RPMS which shoots Jan's theory down. Different bores I might add.

LaVerne

For those of you not familiar with the parts

http://www.mossmotors.com/graphics/products/PDF/451-260.pdf
LaVerne

LaVerne,

If I where you take them to some-one who has a Rockwell tester I see what the hardness is from the flat surface and how deep it is hardened. Personally I think it has nothing to do with the oil used .
For over 40 years I been playing with model A Fords and have overhauled numerous engines. You probably know that model A'S and other Flatheads also have lifters who ride the same way as a MG do on the camshaft. Have said this I realise that there are other issues could be at stake on your engine

Gerard
Gerard Hengeveld

Thanks LaVerne, never looked at the Moss Cat. I had two sets and just took them to Berry cam.
Tom Maine (TD8105)

LaVerne: When I Bought my Crane cam and lifters a few yrs. ago, There was a notice with them that said they have trouble with some TD's had lifter bores that were not bored offset with the cam. Hense the lifter cannot turn. On Checking my crankcase my lifter bores were not offsrt. I had my new cam and lifters reground to yhr original M.G. grind. My lifters spin very good. The original cam and lifters looked quite good At 68000 miles when I removed them. Your bad lifter looks to me that it contacting on the center of the cam.
Dave
DL Rezin

in regard to the comment that lifter problems are new perhaps thinking about oil formulation change...i have a set of lifters out of my engine that were ONLY run with the old oils and they were TERRIBLE. i did my engine over 4 years ago. regards, tom
tom peterson

Hardness examination by a Rockwell tester will leave small gouges in the surface. There are other ways.
It is one thing to be too soft and wear quickly, but, on the other hand, the first two images above strike me as possibly too hard. Looks like pieces spalling off- chunks popping off from subsurface fractures. I would assume they would follow up with tempering to restore toughness, but I'd be suspicious.
Jim Northrup

This thread was discussed between 20/01/2012 and 23/01/2012

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