Can I run a cylinder upside down?

Lets say I take an E50, and case match the transfers so they will match up with an upside down cylinder. I put the piston on upside down. Then I put the cylinder on upside down, with the exhaust port facing up and the intake port down. I could then put a header intake out to the side from the bottom and mount my carb right side up. If I tweak a header on a pipe to stick out sideways from the exhaust port (which is on top) I could run my exhaust up top. Is there any reason this would not run?

Re: Can I run a cylinder upside down?

I don't know anything about E50 or potential problems with the case matching (is there enough meat?), but if everything is hooked up properly I don't see why it wouldn't work. I wouldn't want my carb down low and unprotected though. Why do this? So you can rout the exhaust a certain way?

Re: Can I run a cylinder upside down?

What is the point of this? I'm pretty sure this would cause fuel to pour into your carb...

Re: Can I run a cylinder upside down?

hilarious.

on a batavus m48 the carb is located underneath the engine and it still works fine (i mean...its still a batavus), but then again, those are case inducted. soooooo..

Re: Can I run a cylinder upside down?

🇮🇹💦 Of the Loin /

you would have to make the crankshaft spin in the opposide direction, otherwise it would still be trying to suck in fuel from the upper port.

i guess you could run your timing 180 degrees offset and disconnect your pedals though. That would make it work.

Re: Can I run a cylinder upside down?

🇮🇹💦 Of the Loin /

wait what the fuck did i just say?

Re: Can I run a cylinder upside down?

You're on crack Maitland

Re: Can I run a cylinder upside down?

@ Chris The float will still function like normal in the carb, and once the fuel has passed through the venturi, it's a gas anyway, it might as well get sucked up into the engine instead of sucked down.

@ Maitland Since the piston is upside down, the case doesn't know the difference, I don't think I'd have to reverse the crank.There might be a spark problem, but I think the rotation would stay clockwise like a stock E50, but would it cause the engine to run backwards?

Re: Can I run a cylinder upside down?

🇮🇹💦 Of the Loin /

im still waking up. ignore me probably for the best

Re: Can I run a cylinder upside down?

you would have to change the timing to make it run backwards. I can push start my Puch backwards, but the engine still kicks forward once it catches.

Re: Can I run a cylinder upside down?

I don't think it would run backwards. From the crank case perspective the connecting rod just moves in and out. Your timing isn't going to change. TDC is still TDC BDC is still BDC. All your ports will open and close at the same time. Just the exhaust will face up and the intake will face down.

Re: Can I run a cylinder upside down?

You would only have to make it run backwards if you mounted the crankcase upside down as well. If you rotate the cylinder, match the ports, and leave the crankcase right side up I'm pretty sure you wouldn't have to time it to run backwards.

Re: Can I run a cylinder upside down?

im surprised this hasnt been asked yet... _why_ exactly are you doing this? haha i want pics whatever it is.

Re: Can I run a cylinder upside down?

I would be more concerned with the heat transfer from the header. If it's going on a Maxi, would you really want that pipe so close to the gas tank? what, if any , metal stress in the frame might occur from heating up like that?

Also, clearance becomes a point of awareness. If I bounce off, like say, a big curb, would I rather risk hitting the header and be able to ride away with a dent in the pipe, or hitting the carb and be stuck on the side of the road with a broken carb?

Re: Can I run a cylinder upside down?

assuming, of course, the studs don't snap in either case.

Re: Can I run a cylinder upside down?

First off, Why? That i still really don't get. second off, i don't see why it wouldn't work. i guess it depends on where the case's ports match with the cylinder, but if it is completely the same, i don't see why not. engines don't use gravity, they use differences in pressure. That was a lot of Don'ts Haha

Re: Can I run a cylinder upside down?

haha use logic peoples!!!!

Re: Can I run a cylinder upside down?

First off, Why? That i still really don

Re: Can I run a cylinder upside down?

I bet he case matched wrong and is trying to remedy it...

Re: Can I run a cylinder upside down?

hehe . that might be the case, craig. no pun intended lol

Re: Can I run a cylinder upside down?

"you would have to change the timing to make it run backwards. I can push start my Puch backwards, but the engine still kicks forward once it catches."

AAAAAH! Oh my oh my. Isaac, you don't happen to have a video of this, do you?

Do you ever just find a hill, ride halfway up, kill switch, start rolling back down, release the kill switch, bang! start back up, ride up the hill, kill switch, roll back down, etc?

This is like a super-complicated track stand.

Re: Can I run a cylinder upside down?

I think it should work. You shouldn't have to mess with the timing or porting or any of that, just flip the cylinder and piston. I don't think the engine can tell the difference. You'll probably want to weld up the case transfers and re-grind them otherwise they might be a bit funky. On some older racing bikes they did this. Then the exhaust could run straight out the back with no bend in the header. Of course they had upright cylinders. This is common on racing solex also. They don't have any room behind the engine for a real exhaust so people turn the cylinder around so they can make a header and run it down the front of the engine. As mentioned it isn't exactly idea with a horizontal cylinder because your intake and carb will be exposed to more dirt/water/damage than it would neatly tucked on the top of the engine.

Re: Can I run a cylinder upside down?

Matt Scout The Scouting Dcon /

LOL, fess up Phil, did you really 180 the port match? :-)

Re: Can I run a cylinder upside down?

It would work. that dumb engine wouldn't know the difference

Re: Can I run a cylinder upside down?

I was just guessing. Seems like it would be easy to try it out and see if it works...

Re: Can I run a cylinder upside down?

Dude, there should be no problem other than the mechanical arrangement difficulties you described. Vespa smallframe scooters' engines are "upside down" . Go for it. Do it. Underseat Exhaust? Hawt!

Re: Can I run a cylinder upside down?

I wanted to do this too! but i was thinking of putting it on an a35, and running the exhaust up under the seat on a custom frame.

if the ports are matched right it would work. 100%

Re: Can I run a cylinder upside down?

I think this will work, AND be hilarious. It's a win-win, folks.

Re: Can I run a cylinder upside down?

yeah phil, it will work. you'll have to make sure the piston is flipped too, but you already knew that.

Re: Can I run a cylinder upside down?

I saw an Express engine for sale on Ebay, the picture showed the Jug mounted with the Exhaust on the Upside.

I thought it migth be cool to mount it 90 degrees and have the exhaust exiting the side

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