More of a motorcycle engine look

#1
What do you all call the metal that covers the cooling fins? I know the part where the pull rope is is the shroud. I was wondering if a engine like a predator for instance could be run without all the other pieces that cover the fins and assist in channeling the air through the shroud where the flywheel and its fan blades are. I’m interested in removing some of the covers to make the engine look more like a motorcycle engine. I’m also considering taking one of my predator engines and turning it around so the head points to the front of the bike. I know the engine will be turning in the wrong direction but I’ve seen ways to correct that issue with some gears and chain. Also, could a flathead be done the same way to expose more of the fins for a more motorcycle engine look?
 
#2
The shroud (wraps around the cylinder and head) is part of the cooling system, it directs airflow from the fan/blower around the cylinder and head (it's basically a cooling duct). These engines were meant for stationary use, I would expect the engine to run a good bit hotter while stationary with the shroud removed. I don't know what the effect would be while moving but I think it would be less. If you look at it, you can see that the blower housing directs the airflow to the shroud and the shroud directs it around the cylinder and head. You would need, at minimum, a pyrometer to know what effect removing the shroud would have. I think your intended use would be a factor, whether you are going to putt around at low speed or be going fast (race bike), long rides or short blasts (drag bike)...

The shroud is kinda ugly but I leave them on.
 
#3
The shroud (wraps around the cylinder and head) is part of the cooling system, it directs airflow from the fan/blower around the cylinder and head (it's basically a cooling duct). These engines were meant for stationary use, I would expect the engine to run a good bit hotter while stationary with the shroud removed. I don't know what the effect would be while moving but I think it would be less. If you look at it, you can see that the blower housing directs the airflow to the shroud and the shroud directs it around the cylinder and head. You would need, at minimum, a pyrometer to know what effect removing the shroud would have. I think your intended use would be a factor, whether you are going to putt around at low speed or be going fast (race bike), long rides or short blasts (drag bike)...

The shroud is kinda ugly but I leave them on.
Hmmm, I think I may now have the excuse to build a drag bike. That would be a good reason to build it, run it and do some testing. I’m a HVAC tech of 38 years and I have quite a bit of test equipment that might come in handy for finding if a engine could stand functioning with the fins showing. I definitely wouldn’t try it on a trail bike or something in a stop and go situation. In the refrigeration trade (yep I do that too) there were instances back in the early days of my career (80’s) when the cast iron compressors that had fins for air over cooling were wrapped with copper tubing in the fins for water cooling. Water was circulated through the tubes and fed through a radiator or cooling tower. The fins on the compressor were a spiral so the tubing didn’t have to be bent over a fin to go to the next row. Obviously the rows of fins on a air cooled engine are individual and would require some manipulation to wrap them with tubing. I may look into this tomorrow to see if it’s possible. A water cooled mini bike would be neat.
Everybody at work calls me the mad scientist so now y’all see how I earned that badge of honor!
 
#4
If you want a motorcycle look, why not use a motorcycle engine? Right now, prices are kinda high due to low supply (new Chinese engines), but I have seen Lifan 125cc engines (multiplate clutch, 4-speed transmission, 11.6 HP @ 9,500 rpm) for around $350 not too long ago, complete with carburetor, wiring harness, etc., everything except air filter and exhaust. There is a Zongshen 212cc (multiplate clutch, 5-speed transmission, 18 HP @ 9,500 rpm), it ain't cheap at around $1,000 but it would make a beast of a minibike. Then there are a lot of small Japanese motorcycles... imagine a minibike with an old (but healthy) Yamaha RD250 engine, 247cc 2-stroke twin, 6-speed, 30 HP! o_O

https://tboltusa.com/store/engines-all-horizontal-pit-bike-engines-c-114_1034.html?sort=4a

https://pitsterpro.com/index.php?route=product/category&path=10&sort=p.price&order=ASC&limit=50

https://www.ebay.com/sch/i.html?_fr...eDesc=0&_odkw=predator+engine+212cc&_osacat=0
 
#5
I’m also considering taking one of my predator engines and turning it around so the head points to the front of the bike. I know the engine will be turning in the wrong direction but I’ve seen ways to correct that issue with some gears and chain.
If you were to do that, I imagine the engine would run cooler. I've seen pics of few minibikes with the engine turned around, the engine does look much better but the drivetrain becomes rather complicated. I've seen a couple with too many (IMO) sprockets and chains...

Then there's this five year old YouTube video...
 
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