Spree Engine Swap: Honda Elite CH80 onto Spree

[Tyler VR]

Got the cylinder head off.

[paulpauly7]

I love this thread keep up with the pics .Great work

[Tyler VR]

Lots of carbon buildup on the piston and combustion chamber. A few light scrapes on the cylinder walls, I'm hoping to get away with a hone job and a new set of rings. This was a good running engine with around 6k on it but I might as well replace a few parts while I have it taken apart. Everything will need some clean up work for a closer inspection before I start porting.

[ped]

Very nice build. great photos.

[Tyler VR]

Cleaned up the cylinder head, everything looks good.

Before I open up the intake and exhaust ports I'm planning on having the combustion chamber "dead space" filled with weld. Just the area across from the spark plug, it's been done on ruckus engines and car cylinder heads. The stock compression of the ch80 is 9.3:1 according to the service manual. This mod should raise the compression and make the combustion chamber more efficient. I've also been looking into other combustion chamber mods like the Somender Singh grooves that could improve performance.

[Tyler VR]

My brother is doing the fill weld for me, he's a pretty good TIG welder. I bolted the old head gasket on and set the valves in place to protect the surfaces and valve seats. Heating it up first with a torch makes the weld penetrate easier and burns off any impurities.

[Tyler VR]

Midway through welding, a little issue with the TIG arc jumping to the valves. Looks like I'm going to need new valves but I'm glad the seats are fine.

[Tyler VR]

Welding is done, went just up to the dome ridge. I've seen people weld higher up to the gasket surface and then have the head resurfaced, but I'm not going that far.

[Tyler VR]

Did some grinding, it will need a bit more work. I'll probably do the somender singh grooves too.

[lacedgod]

im afraid of what my engine looks like, never had a filter since i couldnt get it go fast with one on, rode for 3-4 months straight backfiring everytime i let off the gas and somehow i was riding it with no oil. once i get a job im getting a rebuild kit and might try some of the things you posted or buy another ch80 and do it so i still have a running engine if it breaks

[Tyler VR]

im afraid of what my engine looks like, never had a filter since i couldnt get it go fast with one on, rode for 3-4 months straight backfiring everytime i let off the gas and somehow i was riding it with no oil. once i get a job im getting a rebuild kit and might try some of the things you posted or buy another ch80 and do it so i still have a running engine if it breaks

With no oil you're lucky it still runs, these ch80 engines must be bulletproof. You should be able to find a spare engine or parts bike, keep a eye out on craigslist.

[Tyler VR]

Here's the exhaust port before and after opening it up.

[lacedgod]

yea i know. up here its hard to find a elite 80 on craigslist. luckly i know a few people that are all about elite 80s but i think il have better luck finding a engine on ebay. i even went 10 miles without a fan since the fan and shroud exploded while i was doing 47 now im stuck using a fan off a 2 stroke and whats left of the shroud.

[Tyler VR]

yea i know. up here its hard to find a elite 80 on craigslist. luckly i know a few people that are all about elite 80s but i think il have better luck finding a engine on ebay. i even went 10 miles without a fan since the fan and shroud exploded while i was doing 47 now im stuck using a fan off a 2 stroke and whats left of the shroud.

If you could make the trip near Portland there's a guy with a bunch of ch80 parts at reasonable prices. I've bought one of my spare engines for $100, nearly complete too. He has a test stand made from a elite frame so he was able to show me it runs. He advertises on craigslist like once a week, here's the link:

http://portland.craigslist.org/mlt/mcy/4281785227.html

[Tyler VR]

Here's my cheap porting tools, I use a lot of different bits.