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Re-Using Tappets...Re-Installation Position Matter?


keithb7

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As I tear down and inspect my flathead engine, I am recording the positions of some crucial parts.  I found that my tappets and cam look really good.I don't believe they need any machining work. When I remove and re-install the tappets, does their position location matter? Should I number them as I pull them out, to ensure they go back in in the exact same location they came out of.  Then the tappet exactly matches up again, with the cam lobe it was wearing with? Tappets spin, so I question, does it matter?

 

Thanks, Keith.

 

 

Screen Shot 2020-11-24 at 10.53.08 AM.png

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Yes, most definitely.   I grab a piece of 2x4, drill 12 holes of the right size almost all the way through and label board front/rear to match the engine.  The lifters go in that until reassembly.  Same thing for valves if reusing them, especially if going back into the original guides.

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You should mark the location to the lobe of each lifter.  I also recommend a a micro polish with 600 grit with oil...on the install a coat of molybdenum disulfide paste on the lobes of the cam and the flats of the lifters where they will ride on the lobes.  On using this clean up and install procedure I have never had a used cam ever to fail.  These are fairly low spring tensions on the flathead as it is and even less likely to gall.  

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4 minutes ago, Adam H P15 D30 said:

Have them refaced by the machine shop.  The one on the right looks like garbage

I had to use a mismatched set of lifters and cam on the last one I did.  A local engine rebuilder,  big business that only does engines, polished my cam and resurfaced the lifters for $60.  Cheap insurance.

Edited by kencombs
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The one on the right in the pic above,  is showing reflections in the photo. Here is the same tappet seen below. Removed. I cannot feel any imperfections with a fingernail. I like Plymouthy’s suggestion of a 600 grit polish. 
 

 

C7455D57-CCCD-4F23-945A-2740C67520D6.jpeg

Edited by keithb7
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35 minutes ago, James_Douglas said:

One of the things I am noticing is that the bore in the blocks are getting too warn. It is inducing side movement even with new lifters.  In my next block I am going to have the bores opened up and bronze lined back to specification and use new lifters.

 

James.

 

I did a Model T "in-frame" engine repair once. The lifters were something besides Model T and had the valve end brazed up to make up the clearance. Needless to say the brazing got beat down, the valves got mushroomed and the clearance was way too much. They had reamed the lifter bores as well so Model T lifters no longer fit. My fix was to get the largest oversize adjustable Model T lifters, had them hard chrome plated and ground them to fit the block (it helped that I had a machine shop and the expertise to do this). New valves (oversize stems) springs and camshaft. While I was at it I clearanced the rod bearings. Oddly I left the Aluminum high compression head off and put the stock one back on and it still ran much better!

 

I guess what I am trying to say is even if the block gets worn or abused, the lifters can be chrome plated to make up for the wear. Sleeving the lifter bores sounds expensive and means you've got to completely disassemble the engine. Hard chrome against cast iron might be better than bronze against a hardened lifter (regardless of the lifter material).

 

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I have a blunt tip chisel here for use with my air hammer. I tried it on 1 valve guide. It quickly split the cast iron guide. The impact load needs to be spread out over a wider area. I will take my chisel tool to my friend who has a lathe. We'll cut the chisel tip off and turn the shaft down in his lathe, to a nice tight fit in to the valve guide. I'll create a shoulder that will sit snug against the guide end. That ought to do it. Then I'll try again pounding out the valves guides...We shall live, learn and proceed.

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years ago I got this wild hair to get me a lathe...I decided on a Southbend with 9" swing....I do not know how I got along as many years as I did without it......just so many projects this lathe has bailed me out on....as my bud says, pulls the fat out of the fire every time.  That should drive the guides out without a bit of problem...you done good grasshopper

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9 hours ago, James_Douglas said:

One of the things I am noticing is that the bore in the blocks are getting too warn. It is inducing side movement even with new lifters.  In my next block I am going to have the bores opened up and bronze lined back to specification and use new lifters.

 

James.

 

Vintage Power Wagons lists .008" oversized tappets. might be a cheaper fix, still would need to machine the tappet bores though.

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The home made guide tool worked fantastic! The guides come out very easily. The chisel tool cost $5. My buddy turned it down on his lathe for free. Guess who's buying beer next?

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