davewallace

My Feedback: (29)

Captain,
As you can see from the pictures, there is a lot of space between the crankpin and the backcover. You can grind down the crankpin, about 1/16" and still have 0.020" exposed. You will need to tape the portion that you want to remain untouched. Dip in water often to retain hardness. You want to keep it very cool. Remove rough edges. You can fill in the space between the crankpin and rear cover by adding an aluminum disk or cutting down the rear of the case, or both. The disk is held in place with two screws through the rear cover tapped into the disk. Allow about 0.20" crankpin clearance. Remember that this must be vacuum tight. I thought that the crankpin mounting boss was square, but I was wrong. The piston has two webs below the wrist pin. These can be removed, since they contact very little cylinder wall and aren't needed to seal anything. This will lighten the piston and increase the cross section area of the transfer passages. The timing of a stock 25cc is: exhust=150 degrees duration, transfer=116 degrees duration, intake 120 degrees duration. These are actually typical of the more powerful chain saws and most glow engines. Of course the glow engines have rotary valves which open earlier providing greater duration. The last photo os of a Husqavarna saw piston with the webs of the Homey.

Dave

captinjohn

I could weigh the piston in grams or ounces to see what it weighs. How does one figure what it should weigh for good balance? I got another 25cc Homelite engine with stock flywheel. I think I will run that with exact conditions to see how much it vibrates. I got 2 more engines I got to run also. It may be some time before I try to balance the 25cc I have been running. Dave.... Thanks for all the Ideas. Capt,n

davewallace

My Feedback: (29)

Captain,
The thoughts in my last post mainly improve performance, not balance. The vibration may be a glow ignition related issue with the Homey. I havn't heard of this with EI conversion. After you run it with gas/glow mix and a Walbro carb you will know more. If it doesn't happen, you will know that it is glow ignition related.

Dave

captinjohn

Dave: I will try the gas/glow mix soon. As of now it is very hot and humid here. Not to good for running engine tests. It is going to cool down after 1 more hot day. Can,t wait! Capt,n

cochinito77

so let me get this straight, you took the flywheel, ignition, sparkplug and istalled the glow plug adaptor and plug gassed er up and ran it?

captinjohn

That is correct. The only thing the head was re-done to use a 1/4x32 glow plug. This was done about 7 years ago. After reading the Gas/Glow fuel mix and use of a hot 4 cycle pug....I decided to see how the 25cc Homelight would run. On regular 10 percent Glow fuel It starts so easy its amazing. Just a light backwards bump of the prop and its running! With just a few min of running the compression is getting high enough so the electric starter will not turn it over anymore. I kinda like this engine....except for the bad viabration it has at about 1/4-1/3 throttle. P.S. It is realy simple to convert to glow now. You can order a glow plug adapter and its plug and play! Thanks Capt,n

cochinito77

Cap'n
how bad of a vibration is it? like "sputter-sputterr" or "bail out we've been hit!" vibration?

captinjohn

Well I mixed up 8 oz of Gow fuel to 16oz of 93 octane gas. BP Brand. It started and ran quite well. One click on Supertiger needle would put it from slightly rich to nice screaming 2 cycle. 2 clicks to the lean slowed it down but she kept running. Only did that for a couple of seconds. The viabration is about the same. I grabbed the prop shaft and could flex the peg board more than I like. Net test....replace that pegboard with 5/16 ply to simulate fire-wall. You do have to let the engine warm up real good for throttle response. I wonder if this fuel mixture is going to work below air temps of 50 degrees? There may be a problem with that. Onboard glow would take care of that....I think. More tests to come. Capt,n P.S. No Sputter was noticed...also real good Idle Super easy starts!

captinjohn

I ran the 25cc Homelite again. I found a bad spot in fuel line in tank. Replaced with neopreme type. It was not so humid today. I adjusted the carb better. Idle was super slow, you could just about see the prop stop! My friend brought his tack over. Set top end at 8130 RPM. Time to try a pumper carb! Smooth Landings Capt,n

aero nut

So Captin!!!! what kind of prop are you using with the Homey???
did you like the Gas/Glow mix???? and what do you mean by a pumper carb????

captinjohn

aero nut: I am using a APC propeller. I do like the Gas/glo mix. Tne carb I was using has no pump. Not even muffler pressure. I am going to put a Walbro carb on it. It has a pump that pumps fuel from tank to engine. I can buy menthanol for $2.85 per gal. Gas is $3.25 or more for 97 octane. Seems like just forget the gas and get strait menthanol to cut the glow fuel. Have you tried that. I am going to! Capt,n

davewallace

My Feedback: (29)

Captain,
If you don't use gas in the mix, your fuel consumption will go up and you may not be able to use a stock Walbro without passage modifications. Streight glow is also harder on the diaphram.

Dave

emtpmike

captjohn,
what kind of adapter are u using to mount the supertigre carb to your homey?

aero nut

yes Captin I have tried the methanol/gas mix but didn't like it there is no punch to it and you'll need to keep the plug hot with battery at all times. the nitro helps quite a bit with the smoother running of the engine and kkeping the plug hot, no oil to purchase and it's only one step mixing.

captinjohn

emtpmike: I just used the stock manifold that comes on a Homelite engine. I then put a dremal sanding drum andd placed it in a drill press. Then plunge sanded the hole in manifold big enough for a tight fit. Was pretty easy to do. A little sealer of any type may be needed. Capt,n

captinjohn

Aero nut: I ment to ask ...did you try Glow fuel with 10 % nitro and 10%oil and then mix the mentahnol (in place of gas) with it. Nitro would be same in both mixes. Thanks Capt.n

av8tor1977

My Feedback: (6)

Captain... another point is that an engine needs nearly twice as much methanol as gasoline to run. So you really aren't going to save any money until gasoline is twice the price of methanol. (Just wait, it will happen...) Also, there is a chance that, depending on the carb you use, that the carb won't flow enough methanol without internal modifications. These reasons and others not so obvious are why we all came up with the Gas/Glow mix after a lot of experimentation.

Have fun!
AV8TOR

captinjohn

av8tor1977: You are right about the cost. I was just wondered about the running on strait menthanol. I guess I won,t even try it. Next experiment is Walbro or Zama carb. Capt,n

tkg

My Feedback: (1)

CaptinJ
Your set up so try the alky at 5%oil 0 nitro

captinjohn

tkg....OK... I will Capt,n

Walter D

My Feedback: (16)

captinjohn we're waiting for your test results with the pumped carburator, there's a Hurricane coming, hurry!

captinjohn

Walt... I may do the Walbro carb tomorrow afternoon. I had to show a guy the Homelite glow set-up first. I built a prop adapter for his Mitsibitisi engine. He loved both. Did all the work on his engine free. He has a plane I want to see him fly with his first little gasser! Capt,n

oldtimer2

My Feedback: (19)

Hi capt. Are you going to make any prop adapters for the echo 2400 engines? If so I would like to get one set up for gas/Glow and one for use with the flywheel, even though I don't have one as yet. Reading your posts it seems that you are a very busy man.

Later George

captinjohn

You mean if I working on too many engines...your very right. My wife has lots of plans also. thats plans ...not planes!!!!! Capt,n

mred33

Greetings one and all;
I am new to this gas/glow fuel thing and am very interested in trying a few things. I was wondering if this gas/glow fuel will work with a normal glow eingine. I have a couple of larger glow engines and would like to try them on this gas/glow, but after being out of the hobby for awhile, I am having to relearn quite a bit about everything. I can't believe how much this hobby has changed since I came back. Any information you could give me would be a big help. Thanks.

Mr Ed