Viton o-ring Headgasket

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Brian Rupnow

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Has anybody done this on a model engine? Sometimes I think it would make life simpler if a person could just put an annular groove in either the cylinder end or the cylinder head face to accept a 1/16" cross section viton o-ring. The annular groove would be about 2/3 of the cross section deep (about 0.041" deep), or maybe a groove in both cylinder and cylinder head grooved to 0.020" deep. I have always made head gaskets out of 0.031" thick waterpump gasket, but may change.
 

Engine maker

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I do it all the time but prefer to use either 3/32 or 1/8 inch"O" rings. Works great. I even have one engine that has no recess for the "O" ring, just put it on instead of a gasket. But if you don't have a groove and compression is high it may blow out after a while.

If you look at the build video of an Associated Hired Man someone posted it shows him cutting the groove for the "O" ring. All the Jerry Howell Farmboy's use an "O" ring for a cylinder head sealing gasket. including my double sized one.

Jim G
 

ZebDog

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I built 5 I,/C engines including the rupnow vertical which you kindly provide plans for and I have used an O ring all for head gaskets with no problems
WP_20200104_22_44_45_Pro.jpg
 

Badhippie

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Why not just use copper wire it’s done all the time on blower engines and high compression engines. You can even buy an o-ring groove tool. I have used .035-.060 copper wire for this. Some people have even have went from .020-.125 wire
 

Bentwings

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Why not just use copper wire it’s done all the time on blower engines and high compression engines. You can even buy an o-ring groove tool. I have used .035-.060 copper wire for this. Some people have even have went from .020-.125 wire
actually we used soft stainless steel safety wire. A spool is not expensive and goes a long way. We used copper sheet head gaskets with it caring the thickness to adjust compression ratio slightly hemi head gaskets in copper are way over $100 each now. Fortunately they are reusable if not damaged. Years ago there was a neat tool used to cut the grooves in the cast iron blocks. Roughly a three cutter cut off tool arrangement on a round cutter holder. It was done by hand in the shop the tool was available from idly cams . You could either buy it or rent it . I did a lot of blocks with ours.
byron
 

Badhippie

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actually we used soft stainless steel safety wire. A spool is not expensive and goes a long way. We used copper sheet head gaskets with it caring the thickness to adjust compression ratio slightly hemi head gaskets in copper are way over $100 each now. Fortunately they are reusable if not damaged. Years ago there was a neat tool used to cut the grooves in the cast iron blocks. Roughly a three cutter cut off tool arrangement on a round cutter holder. It was done by hand in the shop the tool was available from idly cams . You could either buy it or rent it . I did a lot of blocks with ours.
byron
 

Badhippie

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On the Hemi’s we built we always used copper wire just for the better crush you get from the copper wire it’s really a matter of the type of build your doing and some personal preference either one will work. I just remember having some problems using stainless wire when ever we got close to 14:5:1 it seemed as though we would always see the tell tale sign of leakage across the wire. It really never caused a problem but when we switched over to copper we never seem the line. Also on the Cummins diesel pulling engines I used to build at around 17:5:1 - 21:5:1 the softness of the copper really out performed stainless. Due to the better crush you get from the copper. But there was also 55 psl - 85 psi of boost from the twin turbos that didn’t help matters at all
Thanks
Tom
 

Bentwings

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I can see your points . The nitro motors would get really hot and detonate then burn the piston and sometimes burn under the head gasket snd melt he block recking both block and head . I used bits of copper strands on my model killer motors just as you you said there was just enough crush to seal . I had a couple ducted fan motors blow th head right off stripping the bolts out. There was another nitro called tetra nitro that was good for finishing off a weak motor. It was pretty dangerous stuff actually . Kids don’t alwasys know what they are playing with. That stuff is very illegal in today’s drag racing. I don’t think you can even buy it s civilian now. Bo I don’t have any laying around. LOL

byron
 

Bentwings

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I can see your points . The nitro motors would get really hot and detonate then burn the piston and sometimes burn under the head gasket snd melt he block recking both block and head . I used bits of copper strands on my model killer motors just as you you said there was just enough crush to seal . I had a couple ducted fan motors blow th head right off stripping the bolts out. There was another nitro called tetra nitro that was good for finishing off a weak motor. It was pretty dangerous stuff actually . Kids don’t alwasys know what they are playing with. That stuff is very illegal in today’s drag racing. I don’t think you can even buy it s civilian now. Bo I don’t have any laying around. LOL

byron
sorry spelling got me again . Double vision is frustrating
U hi
 

Longboy

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Using cylinder liners with O-rings for my gas engines. The liner supports the inner diameter of the O-ring torqueing down the head and a tapered groove recess in the block and cylinder head prevent squeeze out. Plumbers O-rings as the liner seals out combustion gas to the O-ring.


c0VTSt7.jpg

LpesbDw.jpg
 

Badhippie

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I can see your points . The nitro motors would get really hot and detonate then burn the piston and sometimes burn under the head gasket snd melt he block recking both block and head . I used bits of copper strands on my model killer motors just as you you said there was just enough crush to seal . I had a couple ducted fan motors blow th head right off stripping the bolts out. There was another nitro called tetra nitro that was good for finishing off a weak motor. It was pretty dangerous stuff actually . Kids don’t alwasys know what they are playing with. That stuff is very illegal in today’s drag racing. I don’t think you can even buy it s civilian now. Bo I don’t have any laying around. LOL

byron
You surly are not talking about
Tetranitromethane are you Lmao isn’t that an oxidizer for rocket fuel or some **** like that. I know it’s used to raise the cetane numbers in diesel fuel. But if I recall that’s not very stable is it.
 

Bentwings

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You surly are not talking about
Tetranitromethane are you Lmao isn’t that an oxidizer for rocket fuel or some **** like that. I know it’s used to raise the cetane numbers in diesel fuel. But if I recall that’s not very stable is it.
Yeah it was tetra. That was in the era of Sputnik’s and kids everywhere were shooting rockets uff. I got the stuff from the chem lab where I worked. They were rocket experimenter then . They had a number of fires and rocket explosions in the parking lot . It’s a wonder the whole place didn’t go up in a mushroom cloud. I made nozzles for some of their stuff as they didn’t know how to use the cool shop equipment they had. I was into real hot rod model planes back then . Shortly after that I went to work in the auto shop and ran the engine rebuilding part and did a lot of work on the shop top fuel dragster and funny car. So I had ready access to race nitromethane. I still do although he steam models are taking over now. It’s nice to have the shop machines now but my vision is hindering me. Fortunately my son and grand son are coming along nicely in doing machine work for me . Dad is still the engineer and family runs the shop production. I’d like to make a useful product to generat some income. It may come along. I don’t know. I’m still pretty weak on electronics but I spend hours every day reading as much as I can I’ve got two steam turbines coming I’ll hook them up in line and see what I can get out of them I’m working on a compound planetary gear reduction so I slow the output from 50k to more usable rpm the gear set is probably going to make more noise than the turbines. I may 3D print the gear sets as proof of design before I get into metal gears. The 3D primer guy says he can metal print nice gears so I may give him a try . He says they are really strong and has a variety of usable metals . I’ll have to get back in my cad program or just break down and get fusion like others are using it’s really not that expensive but does take a little time to learn .

byron
 

Brian Rupnow

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Okay--a report back. I did use a 1/16" cross sectional diameter Viton o-ring as a head gasket (they are actually 0.070" dia.). I milled an annular slot in the end of the cylinder 0.017" deep, and in the cylinder head 0.017" deep. When the head was bolted down "steel to steel" on the cylinder, this gave a 50% crush on the o-ring. It sealed just great and worked like a charm. I will use that method on future engines.---Brian
 

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