Here are some pics of an engine I won on e-bay. The seller believes it is a Homelite. Was told it spun a 24x10 on the bench. I have a A&M Sachs 4.2 and it is bigger that a 4.2. Can anybody help me out ? Thanks.

*rcnats*

Check out this carb!

*rcnats*

Another angle (from the rear)

*rcnats*

Weighs about 5 lbs. Any info will be appreciated. Thanks.

*rcnats*

I might say its large, about 80-100cc? maybe a MAC? thats only because I was rummagine at a small engine repair shop yesterday and the shape looked familiar, I like the angled carb mount, just what I need on my ProMac 60cc.

Very old McCulloch or Homelite with the Tillotson HL carb on it. In the 60s sometime. Muffler leans toward Mac.They weren't worried about ear damage back then!!

I cant say for sure on the engine but the bench appears to be a whirlpool washer and dryer.. :idea:

Koltz:
Now with 20/10 vision like that I just know you can tell me something about this engine . I plan to have the flywheel taken off and put an electronic ignition system on it to take some weight off. Thanks for your input.


Flypaper:
Do you mean from the 1960's or in the 60cc range?

Anybody:
Will a Walbro carb mount where this one is? I have no experience with Tillotson carbs. Thanks.

*rcnats*

I will bet you when RCIGN sees this thread he can tell you exactly what this engine is and probably get you in line for an ignition swap..

Make ? nope, never saw one like it..
If it weighs only 5 lbs now it would be about 4 lbs without the flywheel and coil..Very good for a larger than 4.2 engine..The bolt pattern of the carb is wider than the later Walbro SDC and WG series used on the newer engines..Easy to make an adapter plate for a different carb...It might be a little narrower with the carb mounted right on the case instead of the angle mount....
Looks like an interesting project

Thanks RCIgn! Now I know what to do with some of my tax refund . The price is right too! Sent off the returns on Tuesday so give Uncle Sam to do his paper work . I will get back in touch with you. By the way, the weight of 5 lbs was a guess (ok, a llooonnggg guess). Any ideas on a mount? Thanks again.

*rcnats*

rcnats:
From the 1960s. Both Mac and Homelite had 6cu. in. or 100 cc motors back then. More popular HR carb kit will fit it. check saw shops. Same kind of parts in a Walbro, just rearanged parts a bit. As rcign says, may be easier to make a plate. Don't forget to put a pulse hole in it, if it has one on the intake flange.

Flypaper,

Is it safe to say that this is a 100cc engine ? If it is, Wow! I plan to put this in a biplane. At 100cc, the field is sort of small when it comes to selection. Anyway, you were right, "rcign" has a plan for it. Now all I have to do is wait for my refund! . Thanks again.

*rcnats*

Well, the only sure way to tell is to yank that cylinder off and break out the micrometer.

Jwv3,

Wish I could do just that. However, I don't have a micrometer and just what would I measure ? I 'm not trying to be funny, just confused. Thanks.

*rcnats*

Well, the one piece cylinder/head means it's not easy to get a measure of the top of the cylinder bore but measuring the top of the piston is close enough for gov't work. This is your bore.

Then you measure the stroke. It's easier on half crank engines were you can slide the con rod off the crank journal. I'm guessing your engine has a full crank with counterweights on both sides of the rod journal. This makes it a little tougher.
If the spark plug isn't angled too low, you might be able to use a small 'indicator' like a piece of wood or plastic. Squirt tubes from wd-40 works okay. Place the indicator down the cylider touching the top of the piston. Mark it at TDC then BDC and measure the difference. This is your stroke.

Multiply .7854 x bore x bore x stroke and this is your displacement.

That thing looks like a brick.

RCNATS
If you can, take off the micky mouse muffler, I'm sure you would want something quieter anyway,and with the piston at the bottom, measure across the cylinder as accurately as you can, in inches, then i'll see what tye book says. Maybe stick a piece of coathanger wire across it, mark it and measure with a ruler.
Let me know.

Okay Guys,

Here's what I think I have.

Bore: Stroke:
1.2" TDC: .5" (1/2")
BDC: 1.5"
Stroke: 1

.7854x1x1x1.2=.94248 or 94/95cc's. Is my math right? Now I am using what I have as far as measuring tools (a tie wrap, a measuring tape and a calculator). Let me know. Thanks.

Oops, forgot to tell you that the piston has 2 rings on it. This might help too

*rcnats*

RCNATS:
Can't figure out your numbers. What does it measure across the bore? 1.2" tdc Must be bigger bore then that. Where does .5 [1/2"] come from?

Okay, here's how I got the numbers.

Bore: I took of the "pig tail" muffler and used a tiw wrap to measure across the top of the piston. Length was 1.2" better yet 1-1/8".

Stroke: I removed the plug and with the piston at TDC I measured .5 or 1/2". I turned the flywheel until the piston was at BDC and measured 1.5 or 1-1/2". The difference is 1". Then I used the formula and got 95cc (0k .942). Hope this was right. Let me know. Thanks.

*rcnats*

Somehow our numbers got messed up. For instance a Quadra 35 is 1 7/6 in bore and 1.28 stroke and is only 2.1 cu in. or 35cc. My math leaves something to be desired. Forgot formula on how to do volume of a cylinder.

This may sound silly to you 2 cycle vets but when I used to do porting and polishing on small block chevies I had a plastic plate fitted over the valve chamber, filling it with liquid from a measured container it would tell me how many cc's of volumne was in the head. Could this work from a viewpoint of say a little modeling clay in the intake/exhaust ports, piston at BDC and pour say some Marvel oil into cylinder through spark plug hole? then before it runs past the rings pour it back into a cc measure container, would this work?

Daniel:
that's what you would do to figure out compression ratio. It would work on 2 or 4 stroke. Volume is diameter x length x another number, which I can't remember!!

You sure the measurements are correct? If I use your numbers: 1.2" for bore and 1" stroke, that gives you 1.13 cu. in. or about 19cc.

Must be larger than that, just looking at the pics. My little featherlite weedie engine has a 1.35" bore.