Need gasket material - OS 35FP
#27
My Feedback: (11)
Actually, with almost all two-stroke glow engines, you'll see swirl marks on the rear cover even when a proper gasket is installed. That's because the connecting rod floats on the crankpin. It will always tend to rub slightly, but the rear cover's not eroded much because of the oil film that's there. One reason why our fuel needs so high an oil content. You don't want to see strong cut marks from the rod rubbing the rear cover.
#29
My Feedback: (3)
Actually, with almost all two-stroke glow engines, you'll see swirl marks on the rear cover even when a proper gasket is installed. That's because the connecting rod floats on the crankpin. It will always tend to rub slightly, but the rear cover's not eroded much because of the oil film that's there. One reason why our fuel needs so high an oil content. You don't want to see strong cut marks from the rod rubbing the rear cover.
Dennis
#30
The thickness of the paper gasket is so negligible, I doubt there would be any problems if one didn't use one. Typical model engine gasket paper is roughly .010" and the amount of fore/aft crankshaft movement can exceed that figure by double. Using a thicker thrust washer can take up some of that slack if it's alarming. The crankshaft will only be able to move fore/aft when starting and low throttle settings. Once at rpm, the thrust of the prop pulls the crank forward away from the backplate. I think this is not as big a deal as some make it out to be.
And the high oil content is really intended for controlling ignition timing, lubing the rod bushings, and lubing the crankshaft. I've found using 25% castor in bushing crankshaft engines to be cleaner and better running than 20% castor, or even the synth/castor mixes that are common in commercially made fuels.
And the high oil content is really intended for controlling ignition timing, lubing the rod bushings, and lubing the crankshaft. I've found using 25% castor in bushing crankshaft engines to be cleaner and better running than 20% castor, or even the synth/castor mixes that are common in commercially made fuels.
#31
My Feedback: (3)
The thickness of the paper gasket is so negligible, I doubt there would be any problems if one didn't use one. Typical model engine gasket paper is roughly .010" and the amount of fore/aft crankshaft movement can exceed that figure by double. Using a thicker thrust washer can take up some of that slack if it's alarming. The crankshaft will only be able to move fore/aft when starting and low throttle settings. Once at rpm, the thrust of the prop pulls the crank forward away from the backplate. I think this is not as big a deal as some make it out to be.
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Dennis
Last edited by Propworn; 08-01-2015 at 08:59 AM.
#32
if you chose not to use the gasket it is prudent to check how much its rubbing. Too much and the aluminium shavings can make short work of the bearings. On an old Brat .28 with the gasket removed the motor would not even turn over. Put one back in and it ran fine. Like Sport said once its running everything gets pulled forward if you hand start your engines its less of a worry but if your using an electric starter and forcing back on the crank the rubbing may be excessive.
Dennis
Dennis
#33
My Feedback: (3)
Dennis
#34
You would assume as much but sometimes when someone says something like the thickness of a .010 gasket would not make any difference some of the less experienced may just leave the gasket out and assume because one of the experienced guys said not to worry about it might not bother to check. I work in a world where we try to make everything monkey proof and just when we think we have it they come up with a better monkey.
Dennis
Dennis
#35
My Feedback: (3)
Yeah, well like I said... Part of this hobby requires a little common sense. Not everyone is as capable. If you're less experienced, maybe you should be using OEM parts of finding someone more capable to work on the engine. If you work on your engine and don't know what you're doing and wreck it, that's on you. Again, common sense and using your head.
Dennis
#36
Lot of great suggestions on making gaskets. Would anyone know of a place where small gasket punches can be found?
I tried using a small piece of brass tubing of the right dia. hole needed slightly tapered as a punch .. but I know there has to be
someone some where producing small gasket punches for this purpose. Any recommendations ?
Thanx - Ken
I tried using a small piece of brass tubing of the right dia. hole needed slightly tapered as a punch .. but I know there has to be
someone some where producing small gasket punches for this purpose. Any recommendations ?
Thanx - Ken
#38
Propworn: All I'm saying is if someone thinks what works on one engine works on them all may be wrong and they should do their due diligence to ensure what they're doing is correct or will work. One cannot teach someone everything. People have to learn some things on their own too. If someone is avid enough to make their own gaskets, I'd bet they know what they're doing. Raw assumption? Sure is.
In this hobby, there's about a hundred ways to skin a cat. I certainly would not tell someone to do something a certain way if I knew for fact it was wrong or wouldn't work.
Anyway, I can agree with some and disagree with others... We can all still be friends though, right?
Last edited by 1QwkSport2.5r; 08-01-2015 at 01:38 PM.
#39
My Feedback: (3)
Lot of great suggestions on making gaskets. Would anyone know of a place where small gasket punches can be found?
I tried using a small piece of brass tubing of the right dia. hole needed slightly tapered as a punch .. but I know there has to be
someone some where producing small gasket punches for this purpose. Any recommendations ?
Thanx - Ken
I tried using a small piece of brass tubing of the right dia. hole needed slightly tapered as a punch .. but I know there has to be
someone some where producing small gasket punches for this purpose. Any recommendations ?
Thanx - Ken
#40
My Feedback: (3)
I don't like the vinegar smell either.
Propworn: All I'm saying is if someone thinks what works on one engine works on them all may be wrong and they should do their due diligence to ensure what they're doing is correct or will work. One cannot teach someone everything. People have to learn some things on their own too. If someone is avid enough to make their own gaskets, I'd bet they know what they're doing. Raw assumption? Sure is.
In this hobby, there's about a hundred ways to skin a cat. I certainly would not tell someone to do something a certain way if I knew for fact it was wrong or wouldn't work.
Anyway, I can agree with some and disagree with others... We can all still be friends though, right?
Propworn: All I'm saying is if someone thinks what works on one engine works on them all may be wrong and they should do their due diligence to ensure what they're doing is correct or will work. One cannot teach someone everything. People have to learn some things on their own too. If someone is avid enough to make their own gaskets, I'd bet they know what they're doing. Raw assumption? Sure is.
In this hobby, there's about a hundred ways to skin a cat. I certainly would not tell someone to do something a certain way if I knew for fact it was wrong or wouldn't work.
Anyway, I can agree with some and disagree with others... We can all still be friends though, right?
Dennis
#41
#43
Thanks prop... but I already looked in Harbor. Looking for a set that will
do like 4-40, 6-32, 8-32, 10-32 etc. Only punches available in Harbor are for
making auto gaskets... too big. They start off at 1/4" go up to like 5/8" Have a set
of those out in the box. Looking for a small set. Only other place I can think of would be
Napa. - Blue Point tools. But I don't see anything that small.
do like 4-40, 6-32, 8-32, 10-32 etc. Only punches available in Harbor are for
making auto gaskets... too big. They start off at 1/4" go up to like 5/8" Have a set
of those out in the box. Looking for a small set. Only other place I can think of would be
Napa. - Blue Point tools. But I don't see anything that small.
#44
I know the office supply chain stores carry different size hole punches - or at least they used to. Small tiny circle punches, star, square, etc... Might be worth a look.
#45
My Feedback: (3)
Thanks prop... but I already looked in Harbor. Looking for a set that will
do like 4-40, 6-32, 8-32, 10-32 etc. Only punches available in Harbor are for
making auto gaskets... too big. They start off at 1/4" go up to like 5/8" Have a set
of those out in the box. Looking for a small set. Only other place I can think of would be
Napa. - Blue Point tools. But I don't see anything that small.
do like 4-40, 6-32, 8-32, 10-32 etc. Only punches available in Harbor are for
making auto gaskets... too big. They start off at 1/4" go up to like 5/8" Have a set
of those out in the box. Looking for a small set. Only other place I can think of would be
Napa. - Blue Point tools. But I don't see anything that small.
http://www.princessauto.com/en/detai...et/A-p8548059e
Amazon has all kinds look under hollow punch set.
http://www.amazon.com/Co-link-10pcs-...llow+punch+set
Last edited by Propworn; 08-02-2015 at 10:26 AM.
#46
What I have used for years is a paper punch from an office supply store in a 1/8 inch size. You can find all kinds of 1/4 inch ones and when you are lucky, you will also find the smaller ones that work for 4-40 bolts and a tight fit on 6-32 bolts and of course similar metric sizes also.
#47
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Sets of hollow point punch tools are available from most tool suppliers. They are not expensive. Propworn has a good link above. Well worth it if you work on model engines as part of your hobby.
Last edited by fiery; 08-03-2015 at 06:12 PM.
#50
Lot of great suggestions on making gaskets. Would anyone know of a place where small gasket punches can be found?
I tried using a small piece of brass tubing of the right dia. hole needed slightly tapered as a punch .. but I know there has to be
someone some where producing small gasket punches for this purpose. Any recommendations ?
Thanx - Ken
I tried using a small piece of brass tubing of the right dia. hole needed slightly tapered as a punch .. but I know there has to be
someone some where producing small gasket punches for this purpose. Any recommendations ?
Thanx - Ken
I use a drill bit..... Cut the hole to fit over the back plate and set the gasket over the back plate with the back plate on the bench, gasket up.. Use an appropriate sized bit and push it (the part that goes in the drill chuck) through the bolt hole. I usually grind the the end of the drill flat so the edges are nice and sharp. DO NOT use the fluted end of the drill bit. That technique fails miserably. Don't ask how I know Doing it this way the back plate becomes the "die" and the drill bit is the "punch". Now bolt up the back plate and gasket to the engine. Use an Exacto to trim off the excess gasket material.
Ken