Matched Tappets

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I have an opportunity to pick up some used tappets that came out of several different Norton engines, both Atlas and Commando.
I am aware of the official advice: "new tappets are machined in pairs and must be re-fitted in the same order as they were removed. They do not interchange".
Back to reality and the cardboard box of used tappets. Aside from the obvious, such as avoid the lifters with chips, scores, and grooves, etc. what advice would you give about putting together a good used set of lifters?

I assume the main point of the "matched" reference is a stacked width of about 0.001 inch less than the bores.
I have good measuring tools and know how to use them.
And yes, buying new is always an option. But perhaps not the only option.
 

baz

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Sounds like you know what you are about
If you can match a pair up in the bore I see no reason to not use them
So if it were me I'd match up both sets if possible
And then get them refaced
 
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Wassell used to sell hollow tappets which were designed to be adjusted with an Allen key. In one of my bikes I used those and cut the steel lock nuts in half.
 

baz

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Wassell used to sell hollow tappets which were designed to be adjusted with an Allen key. In one of my bikes I used those and cut the steel lock nuts in half.
We are talking about tappets
Not tappet adjusters
 

johnm

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There were after market tappets (followers) being made in the 1980s and 90s that had a nasty habit of losing the stellite pad. An engineering friend who worked through that period said you must carefully inspect the joint to the pad. Any sign of oil seeping or poor brazing then reject them. I say brazing because I think that was the method but happy to be corrected if I'm wrong. It was more than 20 years ago we talked about it.

He used to reject about 50 % of used tappets and refaced them before use.
 
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RoadScholar

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If they fit, as a pair, in the tappet bore and slide without being able to move sideways, oied of course, then they are candidates. As has been mentioned above the stellite "podia" checked for any sign of cracking or separation. Additionally I weigh intakes and exhausts pairs to see what the weight difference is, equal is best assuming you have equal installed valve spring height/seat pressure.

Jim Comstock (Comnoz) wrote, possibly the definitive oil thread, about new tappets or a modification, that had key like holes in the bottom such that the brazing material could flow in and further lock the stellite foot.

Best.
 
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:eek::eek::eek::eek::eek:

I will start by stating that the vast majority of my tappet/camshaft experience is with US V8 engines. But since the fundamentals are the same, I would throw away any lifter that I wasn't re-using using in the same engine/position/camshaft. Used tappets/different engines/cams can ruin a cam profile in the same way as improper break-in of a new camshaft/lifters. I have seen it occur in less than 500 miles.

However, if you really want to do this, check the profile of the tappet surface where it contacts the camshaft. A new tappet surface has a slightly convex profile. If any of your used tappets still have a convex profile, they MIGHT work OK. Commonly, tappets take on a flat or concave profile as they wear. This, of course, depends on how many hours of use they have seen. Tappets can be very concave after years of use but they will continue to work perfectly with the same cam/same location. Installed in a different location or with a different camshaft OR a different engine with same camshaft, they can carve up a cam in short order. IMO, it's not worth the risk but, as we say, do what you are comfortable with!
 

baz

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:eek::eek::eek::eek::eek:

I will start by stating that the vast majority of my tappet/camshaft experience is with US V8 engines. But since the fundamentals are the same, I would throw away any lifter that I wasn't re-using using in the same engine/position/camshaft. Used tappets/different engines/cams can ruin a cam profile in the same way as improper break-in of a new camshaft/lifters. I have seen it occur in less than 500 miles.

However, if you really want to do this, check the profile of the tappet surface where it contacts the camshaft. A new tappet surface has a slightly convex profile. If any of your used tappets still have a convex profile, they MIGHT work OK. Commonly, tappets take on a flat or concave profile as they wear. This, of course, depends on how many hours of use they have seen. Tappets can be very concave after years of use but they will continue to work perfectly with the same cam/same location. Installed in a different location or with a different camshaft OR a different engine with same camshaft, they can carve up a cam in short order. IMO, it's not worth the risk but, as we say, do what you are comfortable with!
Personally I would never fit a new camshaft without re facing the tappets
But the question here is how well the tappets fit the bore
 
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Yep - they are ground flat

Interesting - I gotta say, my experience won't let me get my head around using a lifter that has a flat profile on a new/different cam. ;) In any case, if they are flat per OEM spec, be sure the used ones are perfectly flat before use (I still wouldn't use them but that's me) or, as recommended, reground to the correct profile.

Re the tappet bore...We would never have taken a cam and lifters out of one engine and installed them in another engine for the same reason we would never reuse lifters. The lifters may "sit" differently than they did in the previous bore so, again, there is a good chance of tearing up a cam.

I can't see any good reason to take a chance on re-using a valve lifter in a different engine/cam. It's a lot cheaper to buy new lifters than to disassemble an engine to sort out the damage caused by a lifter wiping the cam lobes/depositing all the metal bits throughout the engine.
 
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Lots of good thoughts here.
MexicoMikwe says he can't see any reason to use a valve lifter in a different engine/cam. Here are two possible reasons. One, you can inexpensively resurface the lifters before they are used, which addresses the cam issue. Two, a set of new lifters cost $1200 US.
 
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I admit/agree that reason number two is a pretty good one based on reason number one! ;)
 
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Any further thoughts on making up a set of serviceable tappets from a collection of used Norton and Atlas tappets? From some research on this site and others, it seems that there were a variety of tappets available over the years: flat, radiused, chamfers or bevels on various sides, different hard surfacing materials, etc. It all seems a little confusing.
Is there a preferred tappet, or ones to avoid?
 
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