Magnafluxing is a method of looking for cracks in a forged steel item.
Using special equipment, you magnetize the part and squirt a mixture of
fluid and metal particles on. The metal particles will align themselves in
certain patterns around particular defects. Not something you can do at
home. Shot peening is when a piece of metal, usual thick i think, is
blasted with "shot" balls of some sort. This reduces stresses produced in
the production of the part and makes it much stronger. Used in the landing
gear of Cessna aircraft, and brother are those strong for their size.
Now about the your engine. I'm one of those sick guys that if I'm this far
into it I say screw it and drop the pan, inspect the bearings, yank the
pistons, check the rings & their clearances and generally go WAY to far
overboard. All the tolerances are in the Haynes manual, and I'm sure others
on the list will help with any questions. But you probably shouldn't listen
to me......
Geoff Branch '74 Midget "Yellow Peril" and wants a bugeye
-----Original Message-----
From: William M. Gilroy <wmgilroy@lucent.com>
To: mgs@autox.team.net <mgs@autox.team.net>; spridgets@autox.team.net
<spridgets@autox.team.net>
Date: Thursday, November 26, 1998 11:39 AM
Subject: Heads off, what next
>Now that I got the head off my 77 Midget (1500cc) I have more than a
>few questions about what I am seeing. Just a recap, I took the head
>off because I had very low compress cylinders 2 & 3 (something like
>40 & 60 psi dry) and about 120 psi dry in 1 & 4. I also had high
>crankcase pressure. Oil was coming out the dipstick hole. I was hoping
>it was a blown head gasket between 2&3 and one of the oil galleys.
>
>Looking at the head gasket it does not look like there is a problem
>there. I don't see anything obvious (not that I am sure what I should
>be looking for). The color of the gasket is the same i.e. no black
>traces or worn looking areas.
>
>Other things I am seeing. If you into the cylinder head where the
>intake and exhaust manifold attach you see the following; dry soot
>on the exhaust, and black oily deposits (sort of like oily carbon)
>on all of the intake ports. These deposits are rather lumpy, you can
>rub them off with your finger. What would this be? Worn valves guides,
>rich carb, maybe?
>
>The combustion chamber on the cylinder head looks ok. Not very much
>in the way of deposits. The valves themselves are black, with some
>of the exhaust valves being gray at the center. I guess they get
>hotter?
>
>The tops of the pistons show the following. 1,2, & 3 have quite a bit
>of hard black deposits on them. I cannot see any of the original piston
>top. Number 4 has much less and I can see most of the piston top.
>
>I am trying to decide how I should proceed. I could just put a new
>head gasket, put most of it back together and see if I get any
>different compression figures. This would be the cheapest way. What
>are the other logical routes to take? The closest I have come to
>rebuilding engines is the 2 cycle dirt bike I had as a kid. That was
>quite a bit different.
>
>If it looks like a rebuild, where should I look for some helpful
>information? I mean what is required, what machine shop services
>would I need, boring cylinders, fittings cams, checking cranks and
>rods, etc.? What can I do myself, what should I check and re-check?
>
>Two other beginners questions. 1) what is magnafluxing (sp?) 2) what is
>shot peaning (sp?). I have seen both of these terms used when
>discussing whether a part can be reused.
>
>Looks like I might have bit off more than I wanted for this winter.
>Oh well. Sorry for all of the questions, but this area is completely
>new to me, and I am not even sure what I should be seeing. Thanks
>for any advice.
>
>--------
>Bill Gilroy
>77 Midget (got it for free, and final cost still not in)
>90 Shar-Pei (got him for free, and over priced at that)
>No cats
>
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