Including me. The eye is always the biggest liar for dimensions
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Telescoping Gage Expectations
- Thread starter heli_av8tor
- Start date
- Joined
- Jan 2, 2019
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- 6,542
I used to run a small engine/powersports business, before that I built racing go kart engines. Did most of this work with pretty basic tools and sold lots of high end modified engines to happy customers around the country. Honestly, I used a cheap set of telescoping gauges and a HF digital caliper for most cylinder measurements. Never touched a micrometer or needed all the fancy kit I have now.
If you're just doing rebuilds for garden equipment most of what you're asking about is overkill. If the cylinder is far enough out to need reboring you'll be better off replacing the whole engine. Of course what you want to do, and what's required might be two different things. I'm just saying, in my kart engine business the lathe was mostly used for cleaning up valves and I didn't even have a mill.
John
Like they say in life is it better to know or to have? I don’t have the first in quantity so compensating on second. But I hope I repair what I have that’s the first and main goal
- Joined
- Feb 27, 2014
- Messages
- 2,130
There are a bunch of great video channels for learning to machine.
BlondiHacks has some targeted to entry level/beginners
Mrpete222 is very prolific with lots of good info.
Many more but this is a good place to start
Thanks a lot man. I will check them and make a playlist to watch/do.
- Joined
- Jan 2, 2019
- Messages
- 6,542
Most small engine repair is carb rebuilds, if the rings are worn a new set and ball hone the cylinder will get you there. Start a new thread when you tear into the 420cc. I'll try to figure out how you can use these fancy tools to get it done....
John
BTW, our modified Briggs 305cc would put out ~34hp on the dyno with straight methanol. No more than 25% nitromethane for racing or you'd be sending it back in pieces....
Wow, thanks a lot man. I will for sure, I welcome all the help I can get. I have a few crazy ideas on where to put that engine too. But 34hp from 305cc that’s freaking crazy. How did you do it man.
- Joined
- Dec 18, 2019
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- 6,464
Using telescoping gauges takes a little bit of practice to get repeatable results. Ideally, one should have a couple of reference gauges, so you know what you should end up measuring. But you can get by without them. One needs to take the measurements with the idea to minimize the variation between measurements. Take 10 measurements of the same bore and see how far apart they are. If they are within a couple of tenths, you are doing well. If not, practice your technique of using both the device, and your micrometer. I find that if the ratchet engages on the mic, my measurements are not uniform. Instead I do it by the feel of first solid contact. This tends to give lower measurement variation. Having a micrometer stand lets you concentrate on that "first solid contact" rather than juggling everything. If you really need an accurate measurement, take a bunch of them and average them. Hope this helps.