MG TC Roller Camshaft Project and Moss Rear Seal

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MG TC Roller Camshaft Project and Moss Rear Seal

Post by Steve Simmons » Thu May 07, 2015 8:27 am

NOTE: This is being re-posted from here after the project is mostly done.

Day One


As my new (9,000 mile) engine ate its lifters, and the cam is already a regrind, I've decided to take extreme measures and replace it all with a roller camshaft. It's an expensive way to go at roughly double the price of replacing a standard cam, but it should give a slight performance boost and last much longer. Parts to be replaced are cam, lifters, push rods, springs and retainers.

I'm also going to address a significant oil leak at the rear of the engine which I suspect is the lip seal conversion I so carefully installed. Something must have gone wrong, unless it's the rear oil galley plug leaking which would be far easier to remedy.

Step one is to remove the engine. Actually it's step two, but I forgot step one which is to do a compression test before pulling it all apart, just for info. I decided to pull the engine alone since I find it easier than crawling under the car to remove the drive shaft and dealing with the nearly inaccessible gearbox mounts. I may pull the gearbox also, not sure yet.
engine-pull.jpg
engine-pull.jpg (76.06 KiB) Viewed 7749 times
Since I forgot to do a compression test, I ran a leak down test instead. To my delight, this engine averaged only 3% leakage. One of my concerns is valve to piston clearance because I'm running high compression pistons which stick WAY above the block. To make measuring the new setup easier, I've measured the current setup with a dial indicator on top of both intake and exhaust valves, and then rotated the engine until they opened fully.
measurements.jpg
measurements.jpg (61.65 KiB) Viewed 7749 times
I've lost my 8x1 bolts to attach the engine to my stand so I'll be working on the floor and using a hoist while removing the oil pan, at least until I can order a replacement set of bolts. Tomorrow the head comes off and gets disassembled, followed by the oil pan and timing cover. I'd like to tip the engine on its rear to look for leaks but on an XPAG engine you can't remove the flywheel until the oil pan is off. :roll:
1949 TC8975 / XPAG 9609
1948 TC6011 / XPEG1182 (XPAG6472)
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Re: MG TC Roller Camshaft Project

Post by Steve Simmons » Thu May 07, 2015 8:30 am

DAY 2

Disassembly has started. First to come off was the head and everything looked good there. Gasket looks good, rockers are excellent, chambers are clean enough. Then the lifters came out and they look even worse than the last time I saw them. This is roughly 9,000 miles of wear. You can see how a couple of them weren't rotating, and it's interesting that the ones that were rotating also have the most pitting. All of the lifters look terrible, which is why this whole project started.
head.jpg
head.jpg (58.7 KiB) Viewed 7748 times
lifters1.jpg
lifters1.jpg (63.86 KiB) Viewed 7748 times
lifters2.jpg
lifters2.jpg (63.93 KiB) Viewed 7748 times
Before going farther into the engine, my next step was to investigate the rear oil leak. First the oil pan comes off and then the flywheel. It's difficult to tell for sure but I think my problem is a leaky rear core plug. Oil could have pooled there after being slung up by the flywheel, but looking at the rear seal, it has no more than the lightest mist of oil on it. The rear of the flywheel is basically dry, with slight dampness in the outer half. I don't want to put it all together and still have a leak, but I feel confident that I can leave the seal alone. The rear plug will be pulled out and a replacement put in. On top of that I plan to smear some epoxy putty around the rim and then hammer a second plug on top of the first.
rear-plug.jpg
rear-plug.jpg (74.45 KiB) Viewed 7748 times
flywheel.jpg
flywheel.jpg (54 KiB) Viewed 7748 times
1949 TC8975 / XPAG 9609
1948 TC6011 / XPEG1182 (XPAG6472)
http://www.mgnuts.com

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Re: MG TC Roller Camshaft Project

Post by Steve Simmons » Thu May 07, 2015 8:33 am

DAY 3

This morning's progress. Pulled the old cam and as suspected it was toast. All of the lobes show damage.
lobes1.jpg
lobes1.jpg (43.76 KiB) Viewed 7748 times
lobes2.jpg
lobes2.jpg (48.42 KiB) Viewed 7748 times
lobes3.jpg
lobes3.jpg (41.84 KiB) Viewed 7748 times
The old cam bearing was never good because the only source was a type that didn't fit correctly. The result was a bad bearing surface once pressed and reamed. So I fitted a new bearing and it looks much nicer. The center and rear bearings seem ok but I will inspect further before re-using. And yes, I tabbed the bearing after I took this photo. ;)
cam-bearing-front.jpg
cam-bearing-front.jpg (53.4 KiB) Viewed 7748 times
And then the jewelry was unboxed. I hope they work as good as they look.
roller-cam.jpg
roller-cam.jpg (59.61 KiB) Viewed 7748 times
1949 TC8975 / XPAG 9609
1948 TC6011 / XPEG1182 (XPAG6472)
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Re: MG TC Roller Camshaft Project

Post by Steve Simmons » Thu May 07, 2015 8:37 am

DAY 4

There were several problems at the rear seal. First, the holes in the seal housing were a bit off so it wasn't holding the seal perfectly centered over the crank flange. The way the housing is designed, it cannot be repositioned because the screws are countersunk so they self-center as they tighten. Beyond that, the crank flange itself was not round! It varied by 5 or 6 thou as it spun.
flange.jpg
flange.jpg (65.13 KiB) Viewed 7748 times
I paid a machine shop to correct the problems, which took two weeks, and all he did was loosen the bolts, move it a little and re-tighten. He said he opened up the holes a little but I now know that isn't true, because you can't get the screws all the way out with the crank in place, and the crank was still safety wired in place. Two weeks and $40 wasted. I also asked him to machine the crank flange and modify the housing to take socket caps, but he didn't do either and I was tired of waiting on him. To add salt to the wound, he forgot to work on my flywheel also, so that's still there with him to be doweled and re-balanced, and he dinged the speedi-sleeve on the crank.

So today I took it all apart and milled the housing myself. At this point I discovered that the housing isn't perfectly round. Just great. It's close and I have no way to correct it, so I'll just let it fly. The flange may be ok with a light sanding and a new speedi-sleeve but I'll know more tomorrow.
milling.jpg
milling.jpg (57.73 KiB) Viewed 7748 times
Next I used a centering jig around the crank flange. It was touchy with the crank flange not quite right, but with a lot of patience and several re-assemblies I got it spot on... I think.
centering1.jpg
centering1.jpg (64.58 KiB) Viewed 7748 times
Last, I removed everything, put some sealer on the upper housing (bottom of photo, engine is upside-down) and put it all back together and tightened up the bolts. Normally you seal both halves at the same time but I'm doing it one side at a time because I don't want to remove the rods from the crank.
centering2.jpg
centering2.jpg (56.68 KiB) Viewed 7748 times
Tomorrow when the sealer is dry, I'll attack the crank flange, the new speedi-sleeve and the second half of the housing, along with installing the seal itself. Wish me luck!
1949 TC8975 / XPAG 9609
1948 TC6011 / XPEG1182 (XPAG6472)
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Re: MG TC Roller Camshaft Project

Post by Steve Simmons » Thu May 07, 2015 8:40 am

DAY 5

This morning I cleaned up the rear flange with my custom engine spinner invention thingie and some emery cloth. With the speedi-sleeve removed I put the indicator back on the flange. The machinist told me it wasn't as bad as I thought, maybe only 2-4 thou out of round. Again he was wrong. It's just over 5 thou. I'm not entirely confident in the seal's ability to deal with this but there isn't a lot I can do about it so hopefully the other adjustments I've made will be enough to make up for this issue.
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flange-clean.jpg
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1949 TC8975 / XPAG 9609
1948 TC6011 / XPEG1182 (XPAG6472)
http://www.mgnuts.com

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Re: MG TC Roller Camshaft Project

Post by Steve Simmons » Thu May 07, 2015 8:43 am

DAY 6

Some progress to report. After doing what I could to the crank flange, I installed a new Speedi-Sleeve for the seal to ride on. Hopefully sleeve retaining compound will hold it in place because that's what I had on hand. Great care was taken to get it lined up perfectly. I measured a .028" gap all around although in hind sight I should have closed that up a little tighter. But it should be ok.
Measuring clearance to seal housing
Measuring clearance to seal housing
gap.jpg (56.89 KiB) Viewed 7749 times
Completed Speedi-Sleeve
Completed Speedi-Sleeve
speedi-sleeve.jpg (36.25 KiB) Viewed 7749 times
Next up was the rear core plug. This was a suspect in my oil leaks so I went full bore on it. With a perfectly clean bore, I installed a steel plug with sleeve retainer and hammered it tight. Then on top of that I put a brass plug and hammered that tight. I resisted the urge to JB weld a third one on top of that. ;)
Rear core plugs, one on top of another.
Rear core plugs, one on top of another.
plugs.jpg (71.57 KiB) Viewed 7749 times
Finally I installed the rear seal. Unfortunately another problem cropped up - the seal doesn't sit flat in the housing. It rocks top to bottom. Also the housing is not round, another lovely issue, but nothing I can do about that. So, I lined the seal up as best I could and because the top stuck out a bit away from the housing (and therefore was not seated flat on the inside), I used some RTV to help keep the seal - and the engine oil - in place.
Very un-round.
Very un-round.
oval-hole.jpg (43.83 KiB) Viewed 7749 times
And here is the rear end, ready for oil pan and associated gaskets.
Done!
Done!
seal.jpg (57.71 KiB) Viewed 7749 times
1949 TC8975 / XPAG 9609
1948 TC6011 / XPEG1182 (XPAG6472)
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Re: MG TC Roller Camshaft Project

Post by Steve Simmons » Thu May 07, 2015 8:46 am

DAY 7

Progress this afternoon. The camshaft has been timed and the bottom end is torqued and safety wired. Camshaft end float is a bit higher than I'd like at 11 thou (factory spec 3-11 thou), but I've decided that leaving it as-is would be better than shimming it. The thrust plate and pulley show no significant wear so replacing them would make no difference. The extra gap may be in the length of the camshaft journal (too short).
Camshaft Timing
Camshaft Timing
cam-timing.jpg (75.1 KiB) Viewed 7748 times
Safety Wired Nuts
Safety Wired Nuts
safety-wire.jpg (36.89 KiB) Viewed 7748 times
1949 TC8975 / XPAG 9609
1948 TC6011 / XPEG1182 (XPAG6472)
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Re: MG TC Roller Camshaft Project

Post by Steve Simmons » Thu May 07, 2015 8:48 am

DAY 8

Not as much progress today as planned, but the bottom end has been completed. Flywheel is on, sealed and safety wired (don't make fun of my feeble safety wiring skills). And the pan is finally installed which feels good. It's no small task though. There are several things that have to be sealed and aligned simultaneously, and a specific order to do them in. From memory, and I'm probably missing something... Adhere rear cork seal, seal half of front seal, seal front cover to engine, align front cover to oil pan and lock down, remove pan and glue both oil pan gaskets to block, fill front and rear gaps with sealer, seal front lip seal and rear cork seal to oil pan and pan to block, torque pan.
Flywheel installed and safety wired
Flywheel installed and safety wired
flywheel.jpg (67.51 KiB) Viewed 7748 times
Bottom end all closed up
Bottom end all closed up
oilpan-installed.jpg (73 KiB) Viewed 7748 times
1949 TC8975 / XPAG 9609
1948 TC6011 / XPEG1182 (XPAG6472)
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Re: MG TC Roller Camshaft Project

Post by Steve Simmons » Thu May 07, 2015 8:52 am

DAY 9

Three days left to get this project done and disaster has struck! I was moving along, and decided to drop the engine back into the car before finishing up. All was well.
engine-in.jpg
engine-in.jpg (68.13 KiB) Viewed 7748 times
The new springs are also installed in the head. Shiny new parts are exciting. :)
engine-installed.jpg
engine-installed.jpg (62.13 KiB) Viewed 7748 times
Then as I was cutting push rods and pressing in the ends, in a hurry and with the wrong tools...
broken-rod.jpg
broken-rod.jpg (49.03 KiB) Viewed 7748 times
So I finished as much as I could, and ordered a new set which hopefully will arrive VERY quickly. Installed the radiator, exhaust, starter, etc, etc...
radiator-on.jpg
radiator-on.jpg (53.21 KiB) Viewed 7748 times
Then I decided to just give up and buy another TC.
tc.jpg
tc.jpg (54.01 KiB) Viewed 7748 times
(Actually it's just a friend storing his car here for a while) ;)
1949 TC8975 / XPAG 9609
1948 TC6011 / XPEG1182 (XPAG6472)
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Re: MG TC Roller Camshaft Project

Post by Steve Simmons » Thu May 07, 2015 8:54 am

DAY 10

New push rods arrived and are now installed. Controls connected, battery reinstalled, etc. Time to go buy more sealer for the side cover and some oil for the sump, turn the key and see what happens!
Push Rods Installed
Push Rods Installed
engine-side.jpg (81.97 KiB) Viewed 7748 times
Shiny Springs
Shiny Springs
new-springs.jpg (83.92 KiB) Viewed 7748 times
Decided to also buy some new spark plugs. I was surprised the store had my plugs in stock, and so was the guy at the counter. He brought them out and realized they had been on the shelf back there since probably the 1980's. Check out the old packaging. Even the script is different.
spark-plugs.jpg
spark-plugs.jpg (44.39 KiB) Viewed 7748 times
So I turned the key and nothing much happened. It took quite a while to sort out the timing, not sure why. But the car did finally come to life and it sounded glorious! It revs quicker than before and runs well... until you get above 2500 RPMs at which point it stumbles and misses. I spent a few hours last night and all day today trying to figure out what's going on. In addition to the miss, the ignition lamp was stuck on and would occasionally flicker.

The first problem I identified was a wire behind the dash that had come loose, so every time the wiring harness would jiggle, the wire would lose contact. that explained the flickering ignition lamp. But the lamp was still on. Further investigation revealed that the high current wire had broken loose inside the generator, so that had to be remedied. Finally the charging system was not only charging, but stable.
generator-wire.jpg
generator-wire.jpg (79.44 KiB) Viewed 7748 times
With that out of the way, I continued diagnosing the stumble/miss. Adjusted carbs, changed coil, reinstalled old plugs, inspected wires, etc and no improvement. I swapped the dizzy plate to try a known good condenser and the car wouldn't start. As I was cranking, the starter kicked in and out and jammed itself solid. I've pulled it back from the engine, which is a major pain on a TC and even more of a pain to get it all the way out (starter switch and exhaust have to come out, and sometimes unbolt steering box and/or carbs and manifolds). So this is how the car sits now as I decide whether to continue or give up and drive something else this weekend.
starter-gear.jpg
starter-gear.jpg (73.87 KiB) Viewed 7748 times
I've now replaced coil, condenser, rotor, cap, plugs and battery with no change. Misses badly above 3,000 RPM. I've also checked carb mixture and balance, cleaned the float bowls, adjusted float height, checked floats for leaks, etc.

Nothing changed except the cam. I even took the carbs off as a complete assembly so I wouldn't have to touch them again. I'm stumped!
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Re: MG TC Roller Camshaft Project

Post by dirk w dondorp » Thu May 07, 2015 9:30 am

Quite a story Steve, thanks for sharing!
Question; what are those plates on the lower end of each pushrod and interconnected inlet/outlet??
(picture -file pushrod connected )

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Steve Simmons
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Re: MG TC Roller Camshaft Project

Post by Steve Simmons » Thu May 07, 2015 9:57 am

The plates are the links between lifters to hold them straight. Since roller lifters cannot be allowed to rotate, these plates keep them in the correct orientation. There is a decent photo of them in Day 3.

I should have added that last night I took the car for another test drive and something in the exhaust system was rattling. I couldn't figure it out so I ignored the noise for the time being. On my third lap around the block, I gave it some gas and there was a noise. Sort of a clang-pop followed by something metal tumbling down the road behind me. The rattling noise was now gone.

When I went back to see what fell off the car, this is what I found. Must have dropped it while working on the engine, and it went straight down the downpipe and took a couple miles before it spat out the back end!
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1949 TC8975 / XPAG 9609
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dirk w dondorp
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Re: MG TC Roller Camshaft Project

Post by dirk w dondorp » Thu May 07, 2015 10:04 am

OK, got it, not familiar with those goodies!
thanks

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Gene Gillam
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Re: MG TC Roller Camshaft Project

Post by Gene Gillam » Thu May 07, 2015 1:55 pm

Steve...I have one of Len's roller cams in my supercharged TC...timing seems to be a bit touchy. I ended up getting it close with the timing light then adjusted by test drive until it felt right. I haven't rechecked with a light.

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Re: MG TC Roller Camshaft Project

Post by stephen stierman » Thu May 07, 2015 3:11 pm

So the big question, does the rear seal leak??

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Steve Simmons
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Re: MG TC Roller Camshaft Project

Post by Steve Simmons » Thu May 07, 2015 6:02 pm

Not a drop!!! The only leak on the entire engine at this point is the oil hose adapter on top of the oil pump, and that's because I had to re-use the gasket. I'll replace that soon. I've never had the engine oil tight before. I hope it lasts.

I do remember the rear leaking worse as I put miles on the car last time, but it could also have been the rear plug. I'm still not sure if it was just the seal, or the seal and plug leaking. But it's so dry now that it scares me. Like I ran out of oil or something.
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stephen stierman
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Re: MG TC Roller Camshaft Project and Moss Rear Seal

Post by stephen stierman » Thu May 07, 2015 6:21 pm

Better pull the dipstick! But glad to hear all the work was worth it, hopefully it will remain dry.

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Norman Golm
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Re: MG TC Roller Camshaft Project and Moss Rear Seal

Post by Norman Golm » Sat May 09, 2015 4:27 pm

The attached technical article is from a very old issue of the Sacred Octagon. It may apply to your problem good luck
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Norman Golm
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Re: MG TC Roller Camshaft Project and Moss Rear Seal

Post by Norman Golm » Sat May 09, 2015 4:36 pm

I am not sure the file I uploaded was uploaded but the article talks about a grounding cable from the distributor to the center camshaft bearing locking bolt. The article talks about a mysterious miss solved by this cable. The author mentioned 49 out of 50 owners won't need it but will drive some owners batty trying to solve a missfire.
Norman Golm
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Re: MG TC Roller Camshaft Project and Moss Rear Seal

Post by Norman Golm » Sat May 09, 2015 4:39 pm

I just looked at your pictures again and I did not see the ground wire in "eng side JPG"
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