Any chance of working?

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Striikar

Striikar

Needs aTherapist 👨‍⚕️
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Ok so I bought this 29cc engine awhile ago. It was damaged by rocks in flywheel & who knows what else cause the case had broken off pieces. So I bought a cy case + piston/ring and flywheel.
The engine had very good compression. So I open it up to change case and see this damage. I not sure whether it's worth a chance to throw it back together with new parts?.
The main reason I'm thinking about is this is it's a ported head, I don't know who did it but it's a beautiful job whoever did it.
I heard it was an amazing engine previously.
Now I'm thinking maybe use it as a guide to port my own head.
You can feel the grooves with a finger nail but with a finger feels smooth. The plating is "mostly" still there in parts.? I bought a brake cylinder hone,thinking of trying it.
So do I cut losses or go for putting it together and run it?.
I'm thinking the worse is it spontaneously combust.
What to do - go for it or just get a new head or new stock one and attempt to port it myself?.
What would you do?.
 

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I think I'll throw it together and see how it goes.
I plan to start porting anyway,so I can use it as a template but the level this is done to would be time consuming.
It had to have been cnc'ed first.
I had been researching porting but there's so many ideas and ways people go about it varies drasticly. I've ported a few car heads decades ago,getting the right tools is one of the keys. Anybody have any examples or photos of their work?.
What was your approach to porting- which areas and the why?, If you know what I mean.
Thanks?
 
Go look at my dbxl thread. I think I covered some basic porting there. Intake, and exhaust port mods are about the easiest. You'll need a dremel pen, or foredom tool($$$) burrs, sanding drums, blah blah blah. Port timing can be messed with. Can make pop up pistons, cut the squish band, and base to get your compression up. Our new guy 21bb is sending his engine to has a pile of pics too.
 
I would not try and hone it. You might do more damage than good. Cylinder does not have a lot of support for the shoes and if it catches on a bridge might do more damage and break fins if it goes flying out of vise and hits floor.
 
voo2doo said:
A quick fix is an off-set woodruff key on the crank.Not porting but will increase power a bit by advancing timing.
J
Click to expand...
In the saws I port i just toss the key and degree them for timing. Bit of retaining compound on the crank and tighten the nut down with a bit of blue loctite. (Once you've figured out where you want the timing) have yet to have an issue with the flywheel slipping. Works a treat and no need for the added expense of machine work or offset keys.
 
Thought I'd toss these on here for your amusement. Not me, but this is how I clean cylinders.
This guy is considered a master with 2 strokes in saw world. Has a ton of vids about porting and what not.
 
Thanks all that replied.?
I'm considering a " EBay $40. Head to try porting on. That's a lot less then a Zen head.
I think stock Zen head copies are pretty much the same universal design.
Any difference between Zen and CY (4bolt) engines/heads in general?. Do they require any different or specific model mods.
I have a brand new FG CY 4bolt V260 and thought about modding that for more usable upper rpm then a 290.
I've been advised 26cc is the best size for higher rpm and usable power-(over 23cc), besides gearing of course.
I've always wanted to build a speed run/race engine/car.
The problem with FG is their limited gearing. I was wondering if another gearset could be swapped from say a baja. I see gearing ads that say they fit fg + baja )+1.5?
I also was considering getting a G320 to use in a fg.
I found a quick release FG engine mount already made to fit that engine. I'd have to order it from germany.
Yeah I know 2wd ,blah to much blah power blah.??
It's never stopped anyone before.?

(I severely edited this as it had become a novel.)?
 
I would be afraid of getting it out his way. Slip in the bore or grind to deep with that paper and ruined bore. We use muriactic acid to get aluminum out of both steel and chrome bores. Just be warned. Do NOT let the acid get on the aluminum port area and let it sit. It will start bubble on the aluminum and eat it. Which is what you want it to do to remove the transferred aluminum on the bore just not in the ports. If it looks like it is getting less action going on.. Just brush a little more on it. The area being attacked by the acid will be a dark color. Like black. Keep going until this is gone. One gone. Rinse off in water and inspect. If still some remains. Keep going until gone. Than use some scrotch brite pad green or brown works fine. Scuff area and if still looks good and no other signs of other damage have been done? Assemble and go. Just be careful around steel areas and benches with this stuff. It will rust them if not careful.
 
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Yeah no acid here. If theres any inconsistencies with the plating, a pin hole, a small scratch you just screwd the cylinder. Obviously the method mentioned above requires some finesse, but I've saved many cylinders using it. Some of the folks I've lost contact with, but I'll say near 95% of the people I've done work with are running engines with no issues. I'm not saying it's for everyone, but for me it works great, and theres one less hazardous chemical I have to keep around.
I'll also mention, the guy in the vid (randy) ports professionally. I've had the good fortune to run a few of his saws, and they rip. So I take his advice seriously.
But the great thing about here is we can all share our different methods. ?
 
Seandonato73 said:
In the saws I port i just toss the key and degree them for timing. Bit of retaining compound on the crank and tighten the nut down with a bit of blue loctite. (Once you've figured out where you want the timing) have yet to have an issue with the flywheel slipping. Works a treat and no need for the added expense of machine work or offset keys.
Click to expand...


Yep, that'll work too. But for $5 would you be arsed?
http://www.davesmotors.com/Rockit-Timing-Advance-Key-gprk.html

J
 
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