Zeda Engines - Differences

[gary55]

Yep. Or I could just pawn it off on someone else and just get this same frame again but get it in the proper 135mm drop out and redo my build lol.

In the end I am trying not to worry too much on the finish for now. I am currently looking on this engine I ordered it already from Zeta Motorsports and I am just wondering if I should really invest in the $200 sleeved cylinder and piston to upgrade this engine.

Bro you have a very nice looking build. We all approach these things from different angles. I love the idea of the sleaved cyl. just jumped in a different direction. If your comfortable in your finances than use what's left for what you like.

 

[Rusty_S85]

Well work is just screwed up for some reason this year. I am commission so this build here has been mostly funded by my tax refund which is just about gone now. I'm not in a financial hard spot yet but I can take my time on this as I am close to it being mobile under its own power. Not only that but I guess I could run the engine as is now and then upgrade it when I have the funds to spend on the sleeved cylinder. I just haven't seen much on here or online about if flaking chrome will wipe out the bottom end.

For me I don't mind having to run 93 octane fuel so I have no problem pushing the compression up to that level for extra power. I just hate to damage the bottom end in the mean time till I get to upgrade to the sleeved cylinder.

I also need to get my 410 HD chain I think it is out of the box and see if I can use that size chain for my drive chain from chain ring to freewheel cassette. I will have two chains and if I can use it I need to do that. I also need to invest in a chain breaker so I can get the chain the right length.

For me my main goal is to have it built in a way that I can take it down to some local car shows and show it off so that's why I don't want it to look rigged up too much. Why I also don't want the finish to get too bad either.

 

[gary55]

If that's the mission than do that. Your concerns with increased compression aren't clear to me because I don't know the dimensions of their sleaved cyl.. Put the bike together, achieve the short term goal, and get a kick out of accumulating the knowledge for the next build. This is just the beginning. Remember that half of us are full of bulls**t, and in the end only you will be able to tell which of us it is. PS the zeda engine has a wide drive gear so be ready for 415.

 

[Rusty_S85]

If that's the mission than do that. Your concerns with increased compression aren't clear to me because I don't know the dimensions of their sleaved cyl.. Put the bike together, achieve the short term goal, and get a kick out of accumulating the knowledge for the next build. This is just the beginning. Remember that half of us are full of bulls**t, and in the end only you will be able to tell which of us it is. PS the zeda engine has a wide drive gear so be ready for 415.

From what I am reading the steel sleeved cylinder comes with a 50mm piston supposedly its a flat top piston to increase compression. Only way to fully figure in compression would be to figure up the clearances and do some math to formulate a compression ratio itself.

But up side is I got confirmation about 20 minutues ago that my engine has shipped. so that's good

 

[gary55]

From what I am reading the steel sleeved cylinder comes with a 50mm piston supposedly its a flat top piston to increase compression. Only way to fully figure in compression would be to figure up the clearances and do some math to formulate a compression ratio itself.

But up side is I got confirmation about 20 minutues ago that my engine has shipped. so that's good

Cool, can't wait to see your finished product. You'll love it. A flat top piston won't increase compression. It will decrease it. Think about how you would get more comp. out of your hot rod by installing pop up pistons in the engine to decrease the volume in the head chamber.

 

[Rusty_S85]

Cool, can't wait to see your finished product. You'll love it. A flat top piston won't increase compression. It will decrease it. Think about how you would get more comp. out of your hot rod by installing pop up pistons in the engine to decrease the volume in the head chamber.

That's what I was thinking but Zeda swears up and down the flat top piston with the larger 50mm piston will actually increase compression over the smaller cylinder with the slight dome.

 

[gary55]

The reason for the flat top piston I believe is with the increased diameter of the piston a domed piston would hit the head without modifying the diameter of the heads chamber to begin it's ascent nearer the cylinders edge.

 

[gary55]

That's what I was thinking but Zeda swears up and down the flat top piston with the larger 50mm piston will actually increase compression over the smaller cylinder with the slight dome.

It may have more compression but it isn't because the piston is flat. The piston is flat out of necessity of the geometry of the heads chamber. The increased compression would be caused by the increased volume of the larger cyl. being compressed into the unchanged volume of the heads chamber.
With the 50 mm cyl. you are now compressing 78.5cc's into the same head that was getting 69.4.cc's. Since most of the heads are form 6 to 8cc's a gain of 9cc's from the cyl. would have higher com. even with a flat top so they are right about the boost, just wrong about the cause. The dome of the piston I would not imagine displaces more than 2 to 3 cc's so the comp on the sleaved cyl. is probably much higher.

 

[Rusty_S85]

The reason for the flat top piston I believe is with the increased diameter of the piston a domed piston would hit the head without modifying the diameter of the heads chamber to begin it's ascent nearer the cylinders edge.

makes sense. Also going with a 50mm piston that is wider that means it can pull in more air/fuel like boring an engine out. Use of a flattop piston if you are compressing it to the same deck clearance as you were before boring it would increase compression ratio in that sense. But without having valves I don't know if it would make as much of a increase as it would on a 4 stroke.

 

[gary55]

The more I think about this the more I believe you would need the larger volume 8cc head to stay below unmodified case damaging compression.