Kymco ZX50 w/Peugot Speedfight L/C kit Build.Port Map/Specs

[gsx600racer]

I took a step back from this project to do some reading from the Graham Bell & Gordon Jennings 2 stroke tuning guides and picked up few things. I wish they made a dummies version. LOL

My biggest problem is getting accurate degree #'s. My vision is not what it use to be. Trying to judge opening and closings especially when looking "down" at a angle into the cylinder I feel I am not getting correct/accurate numbers.

So I got a piece of 1/8"(.125) aluminum welding rod and set up a dial indicator on the piston. I had enough travel to measure the tops of all port openings. I stuck the rod thru the exhaust port and rotated the piston up till it hit. I zero'd the dial indicator and to a degree measurement. Then I removed the welding rod and rotated the engine piston up 1/8"(.125") and took another degree measurement. Seems the 1/8" rod made 10 degrees difference. I repeated this several times and got the same result. So basically you subtract 10 degrees before BDC(down stroke) and add 10 degrees after BDC(up stroke) when using the 1/8" aluminum rod. I used aluminum vs steel so I wouldn't damage the piston or cylinder.



So here is where I am at.

Exhaust:
Open 87°
Closed 270°
Duration 183°

Transfer:
Open 115°
Closed 241°
Duration 126°

Boost:
Open 120°
Closed 237°
Duration 117°

.008" Base gasket/shim(from Polini Corsa kit)
.039" Head shim(custom)
.030" Squish
143 psi Compression

Here are head shim options I made up.



Shim installed.





Next is the exhaust fitment. I noted before that the exhaust flange protruded further out than the original configuration. 



Not sure what I am choosing for an exhaust option yet.

[oldgeek]

Nice approach, way to make things work!

[190mech]

I think the crank/rod angle will change your 10 degree/1/8" welding rod measurement between the exhaust and transfers..Have seen the use of a feeler gauge on some European sites,but they were quite thin..Will research it and report back...

[190mech]

This is all I could find;
www.torqsoft.net/piston-position.html

I know there is a better example elsewhere,just cant find it in the internet haystack!!

[ThaiGyro]

Hey all...keep up the great work on this thread! My little Gyro will benefit someday from this, if I decide to go big.

[gsx600racer]

Feb 12, 2018 4:27:13 GMT -5 190mech said:

This is all I could find;
www.torqsoft.net/piston-position.html

I know there is a better example elsewhere,just cant find it in the internet haystack!!

Thanks 190mech.

I did not think of that but it makes sense checking out the link. Good info to know.

My major concerns were port openings/closing and durations, squish, compression, and BDC port to top of piston step.(cooling)

I could not make everything perfect, I thought about trying a different piston but finding a 47.54mm and the pin to dome measurement is a PITA. I found few but were leary of trying them. I know re-machining the head was mentioned, but thats another story.

[gsx600racer]

Well I picked up a few goodies from Treatland and took advantage of their recent moving sale.

I never would of thought I'd be installing this style temp gauge. I was just going to buy the sensor, but for 8 bucks more you get the whole thing, plus its the newer style with the button on the front.



Iv been procrastinating on a water pump. There were several options and I am still unsure. There is the electric option, Prius upper inverter water pump that draws 1.7a @12v.(test vid link) New or used they can be had for mid 30's and up to new for around mid 40's to over 100 bucks. I like the low current draw but with a 4 amp battery and a anemic charging system I wanted to keep this as "if all else fails" plan.



Then there is Peugeot Speedfight water pump that "fits" for $100, which has been verified here on a AF16 engine. My issuse with this option is I have to source it from RP with the 4-6 week wait. Plus when and if it fails, it can't be rebuilt. I also still will need to come up with the flywheel pump drive pins which would have to come from overseas as well. Have not had much luck sourcing Peugeot OE parts where the site needed to be translated. Plus a lot of sites(UK based) wont ship to the USA.



I ended up ordering this from Treatland as well. Malossi belt(o-ring)driven pump, and Polini drive flywheel nut and a belt/o-ring. I was a bit disappointed with the inlet/outlet port size.(smaller than expected.







I also picked up a Koso Oil Drain Plug Adapter(M14 x 1.25 x 15L PN/BG241412)that I had to machine the length down to fit to adapt the temp sensor to fit.





I put the engine back in the scooter. I was getting tired of seeing it on the bench and parts scattered all over the basement.



Then once I bolted the shock up I noticed this issue.



I need to order an new boot anyways, this one does not lock on the threads of the plug. Basically the rubber insulator holds the cap on. I going to try and heat the plastic and bend it up some and see if I can gain some extra clearance for the plug.


As for radiators, I have a few I like.

www.ebay.com/itm/ATV-Radiator-For-Yamaha-Fits-Banshee-YFZ350-Over-Sized-Tanks-A012HD-/272785044830

scootertuning.ca/en/cylinders-replacement-parts/17099-radiator-taida-with-cap-275cm-x-13mm.html?search_query=radiator&results=12

www.motorpartsmall.com/index.php?main_page=product_info&cPath=53_60&products_id=1373&zenid=63428873d1a400555fdbf950e0278c00

I really wanted to mount the radiator under the foot rest but had concerns of it get damaged I had to take a "short cut" over a curb. I really wanted to go for a stealth look. Unfortunately it will end up on the front and have it be obnoxious looking.



I also prefer not to have to cut holes in my front fairing, its in new condition.



So any thought on radiator options and source would be greatly appreciated.

[190mech]

How big does a radiator need to be?Does a 70cc need a 350cc rad?A properly ducted rad can be mounted in any location,the inlet duct can be quite small,outlet must be larger..I'll try to dig up some good tech reading on this subject...

[ryan_ott]

I have a Aprilia SR radiator that’s about 10” or 12” square or so I can put in the mail for you. I believe the connections are 1/2”. I can get you some measurements when I get home.

[gsx600racer]

Feb 21, 2018 6:51:17 GMT -5 190mech said:

How big does a radiator need to be?Does a 70cc need a 350cc rad?A properly ducted rad can be mounted in any location,the inlet duct can be quite small,outlet must be larger..I'll try to dig up some good tech reading on this subject...

I don't think the radiator has to be that big. I only chose those few because of filler neck and in/out port location.

Most of the radiators in/out ports are straight exiting and I did not want to drill holes in the front fairing. If the in/out ports were angled 90 degrees down and were both on the same side, id route the hoses under the bottom of the fairing and above the front fender and make up brackets to hold the hoses in place.

Ideally I would like to find something like this.(aprilia scarabeo light 125/200 )


 

[gsx600racer]

Feb 21, 2018 12:12:14 GMT -5 ryan_ott said:

I have a Aprilia SR radiator that’s about 10” or 12” square or so I can put in the mail for you. I believe the connections are 1/2”. I can get you some measurements when I get home.

Thanks ryan_ott

[190mech]

Some stuff to look at in regards to rad ducting,,

support.ansys.com/staticassets/ANSYS/staticassets/awc/optimizing-the-cooling-air-flow-of-formula-car.pdf


www.google.com/search?q=radiator+duct+design&sa=X&tbm=isch&tbo=u&source=univ&ved=0ahUKEwjZoIGqn7jZAhXI5YMKHURFBqoQsAQIKA&biw=1024&bih=620

In the rear wheel well with a proper duct would work I think...

[ryan_ott]

Feb 21, 2018 14:16:41 GMT -5 gsx600racer said:

Feb 21, 2018 12:12:14 GMT -5 ryan_ott said:

I have a Aprilia SR radiator that’s about 10” or 12” square or so I can put in the mail for you. I believe the connections are 1/2”. I can get you some measurements when I get home.

Thanks ryan_ott

It’s just over 8” square and uses an expansion tank as the fill point. If you want it just say so and I’ll get it out to you.

[gsx600racer]

Feb 21, 2018 22:05:03 GMT -5 ryan_ott said:

Feb 21, 2018 14:16:41 GMT -5 gsx600racer said:

Thanks ryan_ott

It’s just over 8” square and uses an expansion tank as the fill point. If you want it just say so and I’ll get it out to you.

PM sent

[gsx600racer]

I got a couple care packages from ryan_ott & oldgeek a couple days ago.





Thanks to you both. I made a pay it forwards donation to the site in your behalfs.