Cheap Junk 1971 Build

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Piledriver
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Re: Cheap Junk 1971 Build

Post by Piledriver » Wed May 10, 2017 3:17 am

Use the handle or a brass drift for contact...
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

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oprn
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Re: Cheap Junk 1971 Build

Post by oprn » Thu May 11, 2017 6:23 am

Well the hammer trick didn't do anything. I don't want to hit it any harder so some material needs to come off something. My tool and die maker friend doesn't like the sandpaper idea due to grit being left in the soft bearing material. Maybe a file is the answer.

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Tony Z
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Re: Cheap Junk 1971 Build

Post by Tony Z » Thu May 11, 2017 11:32 am

I use 600 or 800 grit waterpaper to sand the bearings. Havent had a problem yet.
I actually tried the hammer trick yesterday too and it also didnt give me the results I hoped for, so out came the sandpaper/waterpaper

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Piledriver
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Re: Cheap Junk 1971 Build

Post by Piledriver » Thu May 11, 2017 6:11 pm

Silicon carbide paper should probably be avoided due to the way it fragments, diamond coated mylar film is probably ideal..
A sheet can go for years, depending on use.

A fine diamond hone (diamonds in nickel, either over plastic or SS) is also an option, commonly used for sharpening knives etc.
I actually got a custom Webcam that was under std spec once, its like they forgot to finish the thrust.
That took a lathe to fix.
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

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oprn
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Re: Cheap Junk 1971 Build

Post by oprn » Thu May 11, 2017 8:13 pm

This is a new Webcam and yes I am wondering if it is under spec. I will compare it with the stock cam and chuck it up on my lathe if need be.

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Piledriver
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Re: Cheap Junk 1971 Build

Post by Piledriver » Fri May 12, 2017 1:52 am

Go for the best possible finish. It hit mine with film out to 12K grit...003-.004" clearance.
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

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oprn
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Re: Cheap Junk 1971 Build

Post by oprn » Sat May 20, 2017 6:48 am

Cam was fine, trimmed the thrust surface to get .003" clearance. It seems the cam bearing is just aluminum all the way through. I was expecting a soft babbit wearing surface that I would have destroyed doing this. Not so.

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oprn
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Re: Cheap Junk 1971 Build

Post by oprn » Sat Jul 01, 2017 11:57 am

My cheap junk build hit a snag. I checked the deck clearance on one of the cylinders and it was good so went ahead and put the heads on and torqued them. Next I put the rocker arms on so I could start working on the rocker geometry. Oops! Engine doesn't make a full turn now. Deck clearance issues still or are there valves hitting the pistons?

Out of time, too many spring, summer, yard, work things going on now. Old 1600 DP went back in for the summer rather than rush the good engine.

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Piledriver
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Re: Cheap Junk 1971 Build

Post by Piledriver » Thu Aug 17, 2017 3:17 am

Pull thr rockers and you'll know quickly.
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

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