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Replacing timing chain tensioner and more

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Michael Oritt

Michael Oritt

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A while back I dropped the sump of my car to R & R the oil pump and rod bearings due to low oil pressure. That was a successful procedure.

When I went through the oil pan I found what I finally determined to be the remains of the timing chain tensioner ring that had at some time in the past failed. Tomorrow I am pulling the radiator, front pulley and timing chain cover to install a new chain and tensioner and perhaps an upgraded front cover that has a lip seal rather than a felt seal.


Questions:

1. Does the lip seal conversion require machining of the crank?
2. Is the DW timing chain worth getting?
3. Should I convert to a harmonic balancer and if so what source should I use?
4. What else should I do and/or look out for?
 
The lip seal is correctly sized to the crankshaft when you exchange your timing cover with someone who installs the seal. I don't have the part number off hand but got mine through British. Car Specialists in Stockton, CA. I'm sure are other sources. I installed that and a garloc type rear seal and so far they are both still good. It must be that the rodents that frequent my outbuilding mess with me by pouring small amounts of oil on the floor.
I'd think that almost anything from DW is worth doing if you can justify the cost. A timing chain isn't too dear. I wasn't aware of a dynamic balancer available for the 4 cyl.. My reaction to the rubber band thingy found in the 100 was "huh, that sure looks useless and will undoubtedly fall apart". Don't know about the effectiveness but they do fall apart.
 
I was/am very impressed with the fluidamper-type ProRace damper I put on the 6-cyl, and if one is available, I am sure that looong stroke 4-cyl could benefit from it.

I suppose one day I should edit the spelling__damper, not dampener__but that would require finding the original raw images, and if you can imagine how many pictures I've taken...

dampener.JPG


I don't know what size nut is on the Big Fours, but I could only find this size__to suit the 6-cyl__in an impact socket. I think I was able to remove the nut from the stock damper without issue, but had to mill down some of that heavy wall-thickness to get it inside the recess of the ProRace damper.

dampener_socket.JPG


You may already be thinking about these, but new motor mounts could be considered, depending on the age and condition of the current ones.
(thinking like a 6-cyl owner, you'd have to have them half undone anyway; maybe not required to lift the 4-cyl engine to clear the xmbr...?)
 
100's did not come with dampeners (thanks Randy) but I am under the impression that some folks have added them though I do not know of any sources. Guess I will check with DW.

And yes John R. that rubber thingie that I found in pieces is pretty crappy looking but my running without one is certainly a risk I do not want to run so if there is no timing chain that eliminates the need for it I will have to stick with that design. Again I will ask the guys at DSW as perhaps their upgraded (and more expensive) timing chain eliminates the questionable rubber tensioner.
 
Update: I removed the timing chain cover today and sent it off to DW as an exchange for their modified cover that has a lip seal versus the felt seal. Tomorrow I will be ordering a new chain and tensioner and new gears for both cam and crank as though I cannot see any wear on the present ones they are the same age as the chain: about 14 years/60,000 miles.

DW does sell a dampener but I am going to pass on it as aside from being quite expensive it would require me to also change both the water pump and alternator pulleys from the present 5/8" to the narrow one DW uses on the dampener.

BTW things came apart quite easily given the length of time they have been in place though I did have to borrow a socket for the big nut and also a steering wheel puller to get the main pulley off the nose of the crank. I am also getting a special nut that DW sells for that pulley--it is supposedly made of better metal and does away with the spiral design left over from the days of hand-crank starting.
 
When i was working on my engine and had an issue with some part, Moss had a guy who does engines for them call me. really nice guy and offered a number of suggestions on different things. at the time i was just getting ready to install my timing cover. he suggested i clean any paint off the cover in where the seal pushes in. then put sealant in there before i put the seal in. makes it easy to push the seal in and it stops the seal from leaking there. he said most times when he has had to go back and fix a leak at the seal, it is around the seal and not where it meets the shaft.
 
I don't know what size nut is on the Big Fours, but I could only find this size to suit the 6-cyl__in an impact socket. I think I was able to remove the nut from the stock damper without issue, but had to mill down some of that heavy wall-thickness to get it inside the recess of the ProRace damper.

It has been a while now since I did mine and a few beers have passed the lips, but I have a feeling that I had my big nut turned down to get into that space on the Pro Race damper, I do not recall having to reduce the socket, which by the way was an ordinary one, not an impact one.

:cheers:

Bob
 
Drone Dog--

No matter how well a felt seal is installed a lip seal is by its very nature superior. Ultimately we are talking about eliminating versus minimizing an oil leak and I am simply opting for the former.
 
Regarding the timing chain tensioner. There have been many stories of the remains of old tensioners found in the motor, including mine when I rebuilt. Motor seems to continue to run with no ill effects without the tensioner, though presumably valve timing is a little less precise and maybe chain and sprockets wear a little faster? I did replace mine when I redid the motor, but have heard of it being skipped, more worry about the bits floating around than the benefits of the tensioner I guess.

Perhaps the thing should be treated like a modern timing belt and routinely replaced after x years and miles (6 and 60,000?, just throwing out a reasonable ballpark number) if you are fastidious about maintenance.
 
Side note: The cam gears for the 100s also have an oil 'catcher' riveted to the front. Apparently, no one makes this type any more; Moss, for instance, sells the gear but sends instructions for de-riveting the catcher from the old gear and re-riveting it to the new gear. So, don't throw that old original cam gear away. And, if you do find a vendor who sells the gear with a slinger, please let us know.

https://mossmotors.com/media/instructions/838-020.pdf
 
Bob--

I just ordered the two sprockets, chain, tensioner and a few miscellaneous parts from Moss and you can be sure that I am going to get out my "unrivetting tool" and install the old oil slingers on the new gear front and rear! I know that DW sells the gear but without the two pieces and given that the Moss site refers to the source being in the UK it is entirely possible if not probable that DW and MM are sourcing from the same supplier.

In the meantime while waiting for parts I am removing the grill and seeing about fabricating some sheet metal baffles to maximize air flow through as opposed to around the radiator. I got a set of Ray Juncal's full-scale drawings about 10 years ago (actually forwarded to me by the late great Dave Russell who had just used them) and am just now getting around to doing the project. We don't want to rush into things....
 
Greg--

DW says they do not use the tensioner but I am going to install one, figuring that the previous one lasted for almost 14 years and only came apart recently as I found pieces of it in the sump earlier this year and I know I would have gotten bits of it when I changed the oil last fall.

It would be nice to have a better arrangement, perhaps stick with chain and a modern cam-type tensioner. I saw a site where . guy had fashioned a tensioner out of an idler gear which mounted between the upper and lower sprockets but that seems like a lot of work.

I'll keep adding to this string as the job progresses or in any case wraps up.
 
Michael
i was talking about when you install the lip seal in to the new cover. This guy says he sees a lot of leaks between the seal and the cover. Sometimes the seal will spin in the cover.
 
DD--

Unlike the six-cylinder cars 100's came with only a felt seal in the timing cover. The modification that DW performs allows the installation of a lip seal which, all things being equal, should be superior to a felt one. Yesterday I sent DW my timing cover as a core for them to modify and sell to another customer and they are sending me a cover that has been modified with a seal already installed. I understand what you are saying and it would be very disappointing if the modification and lip seal were to leak....
 
Bob--

I just checked BCS's website and wish I had done so before sending mine off to DW.

It appears that in addition to selling the DW item they are also selling one that is, perhaps, modified in house and for a lot less $$. Can you see any difference between the two except for the impressing of "DWR" on the Welch version.

Why am I always at the airport waiting for my ship to come in?
 
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Update--

I decided to wait till I had all the new parts on hand and finally received the exchange timing cover with lip seal from DW last week. Today I set out to put things back together, starting with the reinstall of the two new gear sprockets and new timing chain and tensioner.

As said in my earlier posts I am doing this with the engine in situ and I had been warned in advance that getting the chain on is a challenging job because since there is no cam tensioner (this IS a 100...) there is virtually no play in the chain to ease installation. I worked with a fellow who does some wrenching for me and it took us a couple of hours to first get the crank sprocket started and then drive the two sprockets back onto the respective shafts bit by bit with the chain in place. Finally the cam sprocket rode past the threads and onto the shoulder, stretching the chain VERY tight. Before putting on the nuts and finishing the reinstallation I am going to make sure that my cam timing is correct as I do not want to do this job more than once. Assuming it is correct the balance of the job should be relatively easy.

BTW I got the chain from Moss as though DW touts their German-made chain quite highly it turns out that the Moss chain had a similar description with an AH Spares label on it and I would be surprised if it is from a different source than DW's. I also bought an oil thrower that rides in front of the cam sprocket as when I took the engine apart I found that there was none. The engine was last rebuilt by a Healey specialist about 60K miles ago and perhaps he did not feel it an essential part but I saw no reason not to install one.

I hope to finish this job over the weekend and will post when complete.
 
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Does anyone have the torque setting for the big nut that goes onto the front of the camshaft--in front of the timing gear sprocket?
I am at that point right now and need a value.

A phone call would be appreciated if possible: 305-793-9467.
 
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