alky Briggs and Stratton

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DJ

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Jan 12, 2004
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I thought about putting this in the small engine section but thought the alky part made it fit over here better.
My brother runs an alky dirt track gokart with a small B&S on alky he runs some 0weight gokart oil and has been thinking of trying one called Kramac(sp?), they change it frequently like after every night or maybe during the night depending on how much use it sees. What really suprized me is he said they only get like 20 runs out of a motor. I know alky is nasty stuff but was wondering if something like some 132 might add a little moly to the mix and help out on that front. My reading on the gokart oils is they are nearly additive free. Anyone have any experiance or thoughts to share?
 
Has anyone tried adding some pure glycol to the alcohol fuel so it would lubricate better? You'd have to readjust the mixture for the increased fuel viscosity.
 
To pass tech you can't run anything other than 100% methanol. Cramac is a good product and will give your brother good service. I have used it in the past but moved on the other products that were easier to purchase. FHS and Cool Power are good oils as well. The reason the engines are rebuilt so often is alky is very dry and the top ring gap opens up. It is also necessary to have nearly 100% valve seal to make max power.
 
Redline makes a alcohol fuel lubricant. Says its not detectable by normal fuel tests.
 
I also assume that it likely isn't using the stock rod or piston. I've seen some stroker, big bore , w/ longer rods that have the cases all but whittled to nothing and pushin compression that would scare the majority of all. and 20 races, or 20 nights. big difference actually. 20 nights...??thats actually too long, by a bunch. 20 races..? that would be like 6 to 8 nights, thats a lot more realistic. Thats life and the nature of the beast, you want it to live, don't race it , lower compression, etc... thats not an option, so you change the parts out before they self destruct. Welcome to reality... I know of one that they were gettin like 43 HP out of a 5HP briggs originally... the thing literally made the ground shake , but the changeout rates on it were a bit more frequent than what you are talkin, like it came apart every other time it raced.....inspected and rebuilt basically every race night. horsepower costs.......how fast can you afford to go..???
44H winged 360 dirt sprint driver/owner
michael harris
 
43 hp out of a 5 Briggs? Not likely my friend. Using the WKA max cubic inch rule that would be 3 horsepower/cubic inch. Not possible with a flathead on alky. Hot fuel maybe, but alky no.

[ July 04, 2005, 08:25 PM: Message edited by: Slick17601 ]
 
this most likely wasn't within any kart rules, this was for an indoor winter series here in s.w. idaho. I'm almost positive those were the numbers. Its been a few years and all but I havent taken that many hard hits to the head. or to my head either.
44H
 
Yeah I know alky is dry and that is the source of the problem. That is why I was wondering if something with moly could plate the cylinder a little and help it last a little longer as I know the top ring will see little oil and the alky will get rid of the little it does see.
 
Is the oil up to full temperature before he runs the engine hard?

What temperature does the oil run at?

Does the oil have a cooler?

What does the UOA indicate?
 
Slick pretty well nailed it. It does get warmed up before the run but how warm is anyones guess we are talking a splash oil system here not an automotive type circulating filtered system. They do restrict air flow if they need to run warmer and they do watch head temps to help monitor that as well as the AFR. The oil is 0weight so it flows well at any temp and I am totally unsure how warm it needs to be. I know as an alky motor it will be high maintenance just thought I might be able to help him find a way to get a little more life out of it and save a buck. He is out in PA so I can not be right there to help so I try to help with research.
 
The problem is that the alcohol cools the cylinder walls to below the boiling point, and you get liquid fuel washing all the oil off the cylinder walls. I destroyed a lawn mower motor in two hours this way, by running it on 90:10 ethanol/water mix (moonshine). I ran it really rich to keep it running smooth, and after cutting the grass like this three times, it had almost no compression. The carburetor was really cold when running this fuel.

The solution is to keep the cylinder and piston hot, but that would reduce the charge density, and reduce the power output. Maybe a bit of glycerin in the fuel would pass the fuel test. What's the octane rating of glycerin?
 
I am unsure of the exact procedure for post race as I went with him one night and left to come back home to the midwest the next day and I know he planned to work on the kart after I left. I do know that they are picky about making sure it is on the compression stroke every time after it is shut off and things like that. Stop air circulation and hopefully inhibit corrosion. Guess that is the nice thing about one cylinder you can do things like that. I wonder about overoiling the air filter to get some lube in there, guess it wouldn't last long though and would not combat the temp drop part of things.
 
That is a heck of a good idea I will have to pass along. Probably tame enough to get him to go for too. I was barely able to get him to try some FP/Neutra 'brew in his mid-90s Ford so he is not as adventurous as I on this front.
 
the methanol/ cold walls/ hot piston/ cylinder washing is a problem since long before I was thought of. It is what it is. there are issues and they likely will never go away and likely will never get fully cured. I would run some sort of upper lube if you can swing it. if not purge it out w/ a standard gas/oil mix at the end of the night. helps everything involved, thats what we did on our 250 micros and it kept everything from drying out , etc..
44H
 
We changed our oil after every heat and race per our engine builder (Todd Miller). I can't remember what the oil was now but it was a blend of two oils, sorry got CRS. I will try to look it up as it has been several years.

Jim
 
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