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  76 RV cylinder head hardware dimensions needed.
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   Author  Topic: 76 RV cylinder head hardware dimensions needed.  (Read 774 times)
Green and Gold
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76 RV cylinder head hardware dimensions needed.
« on: February 28, 2017, 06:16:43 PM »
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Need to fire up the lathe and turn a set of 76 RV cylinder head expansion washers (or whatever they called those things)---I believe they look like a hollowed out piece of round stock, slip over the cylinder studs,  sit between the head and the nut.    Anyone have one sitting on the bench that could send me/post the dimensions?    Looking for overall length, ID and OD, wall thickness, and depth of the pocket/hole (or how thick the top is).    Tenths or thousands/mm fine also for you north of the boarder types…..

BTW, I’ve never been in possession of an undisturbed RV air cooled motor and am not 100% sure what I described above is correct.    So feel free to point me in right direction.
Thanks  al
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Bones
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Re:76 RV cylinder head hardware dimensions needed.
« Reply #1 on: March 1, 2017, 08:52:48 AM »
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This taken from a 76 - 250 engine, I believe they are correct.
Total length ( height) .770"
OD .510"
ID .310"
Theses are just straight through, no pocket etc. The 76 engine has different head nuts / expansion sleeve than the 77/78. The 76 has the straight through sleeves then use the long nuts like the TnT F/As.
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Green and Gold
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Re:76 RV cylinder head hardware dimensions needed.
« Reply #2 on: March 1, 2017, 08:02:55 PM »
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Thanks Bones, going to be easier than I though.....just have to warm up the lathe.
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RVcrazy
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Re:76 RV cylinder head hardware dimensions needed.
« Reply #3 on: May 3, 2017, 08:23:21 AM »
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Value hardware store or Lowes, home depot in their parts bins, buy them already made, like you said, hollowed out straight stock, cut to size, washer under it, washer on top of it then the nut, done.......
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Riding new bike this summer, sleds all winter, who could ask for more!!!!!

75 RV 245, 76 RV 250, 76 RV 340, 77 RV 340, 78 RV 340, 78 Blizzard 6500,03 Mike Island MXZX 440 clone with original Island hood and panels from 03 ESPN Games, 2007 GSX 500 ss, 81 Blizzard 5500
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Re:76 RV cylinder head hardware dimensions needed.
« Reply #4 on: May 12, 2017, 08:32:46 AM »
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Finally warmed up enough to fire up the machinery.  These were pretty straightforward to punch out..
 
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RVcrazy
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Re:76 RV cylinder head hardware dimensions needed.
« Reply #5 on: May 12, 2017, 10:56:09 AM »
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sweet job, i bet you could sell sets of those to us 76 RV guys, shipping would be inexpensive i'm thinking?
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Riding new bike this summer, sleds all winter, who could ask for more!!!!!

75 RV 245, 76 RV 250, 76 RV 340, 77 RV 340, 78 RV 340, 78 Blizzard 6500,03 Mike Island MXZX 440 clone with original Island hood and panels from 03 ESPN Games, 2007 GSX 500 ss, 81 Blizzard 5500
Green and Gold
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Re:76 RV cylinder head hardware dimensions needed.
« Reply #6 on: May 13, 2017, 01:15:51 PM »
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It would be pretty monotonous to make a lot of these things on a manual lathe.  As I’ve suggested to others, this would be an ideal project to take to a local vo-tech/2 year college that has a CNC machining dept.    They are typically looking for production type projects to give students.  This one is straightforward yet still would entail using a material feeder and a few tool changes.

Easy to do, just take a sample of the part (if available) and/or a simple drawing with dimensions.    Indicate which are critical and any acceptable tolerances.  Using the RV head spacers as an example, I used ½ round stock, so the OD on mine is less than the .510 or the original.  If this isn’t acceptable indicate so and they can use 5/8 stock and turn it down.  Of course, that would drive the materials cost up a tad.   
   
I’d give them specs something like this:
Material; mild steel, cold or hot rolled
OD .510 minus .010 plus .001 (if 1/2 od is acceptable; if not call out .510 plus/minus)
ID .3125 minus .015 plus 0 (can use a std 5/16 drill bit, no reaming/boring)
Length .710 + minus .003 plus .0
Both ends chamfered (or not, your choice)
Acceptable outside finish;  Mill scale ok (for the ½ option), rough or finely turned, blued (some places can do this)

The place I attended would have charged for materials and asked for a donation to fund student activities.    Won’t find a better deal anywhere else.

I did a bunch of snowmobile projects when I was a student.  Turned 100 cable ferrule end adapters (for 70's ski doos); tapered suspension shock shafts for the 75-88 suspensions; 100 72 TNT air box standoff studs; angled aluminum mikuni to HR/HD carb adapters for the 73-75 TNT F/As; a whole bunch of John Deere HDPE suspension sliding blocks, replacements ski shock bushings (graphite/nylon composite); late 80 scissors shafts and other stuff.    Here’s a pic of what I had handy:
     
« Last Edit: May 13, 2017, 01:19:38 PM by Green and Gold » Report to moderator Logged
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