CB500T Turbo Punsun Hardtail Bobber

[andrewaust]

Nice job Dieselfly, kind of keen to build something like that myself, awesome mate


A

[Sphere]

Yep, looks wonderful. Interested to learn how that turbo pans out.

[DieselFly]

We made up two couplers for the turbo outlet to intake manifold plumbing. I am using 1 1/2" tubing to add about 900cc to the intake volume.

[DieselFly]

The new intake has been tig welded togeather as well as all the couplers and tubes to go from the turbo outlet on the left side to the intake on the right.

old style intake

new intake

intake crossover

[XLerate]

You and your fine young crew have done one excellent job of it! Congratulations to all. Good things are worth waiting for and worth working for. Thanks for sharing.

[DieselFly]

Fired it up for the first time today. I had a tube full of oil gravity feed the turbo and the feed line for the turbo in a can. Start and yes indeed there is oil flow into the can and the turbo might have used a couple of drops. So after 10 seconds I shut it down and hooked the feed line back to the turbo. I put the tee fitting for the oil feed in the engine oil pressure port. We ran it for 20 minutes and checked the turbo compressor oulet for oil and it was dry. I need to reset the timing which I was playing with sound and vibration as a guide. I will see where the timing is now I know I had avanced it. I'm going to set 19 degrees then adjust it for least vibration by advancing the cylinder with the largest rpm drop when the decompression vavles are pulled one at a time. I also want to realign my CVT which is just shy of 4000miles and still going strong on the first belt. I will get some more pictures up this weekend

[DieselFly]

I still have some loose wiring to tie up but its done. I had it out and ran it around the parking lot at work. It seems to pull harder than without the turbo but the real test starts tomorrow when I pay for this years licence sticker. It started to pour rain mixed with wet snow just as I put the bike away but it is forcast to clear tomorrow stay tuned I will update with more info.

[DieselFly]

Well after riding my turbo conversion and chasing it with the car I'm pleased so for. Still lets out a black puff till the turbo spools enough and off it goes. The overall noise signature has been reduced both riding and following. and my first peak in the tank after 30 miles of running the piss out of it shows about 1 litre used. Right now my main focus will be on cleaning up from the oil down. Fixing my tailights as the cheap LED's are not very durable and sevaral segments are out again. There is a bike show coming up on the 28th that I want to put the bike in see if I can steal another prize from the over chromed gas (petrol, Benzine) burners.

Sean

[Kristof]

Is this where you got your engine from?
http://www.vtwinengine.com/
There is a 25hp version as well.

Have you had any issues with the engine so far?

Where can you get a part (like an oil filter) from?

How much hp has the turbo added? What is it off of from.

Is the ride comfortable?

[DieselFly]

Yes that is the company. They also have a Ebay store. I don't think they build engines. Mine was built by King Poo its cast right in the block. On top of that they sold it as a 20hp its not check the specs on King Poo's site its 15hp. You can look at the power graph for the 22hp and it will should a max peak of 22hp. If you look at the 1hr rating you get 20hp and if you want a continous rating it 18hp and that will be at 3000rpm not 3600. My bike was not really built for comfort but its okay. Parts for the guts are a hit and miss thing but you need to buy factory direct nobody on this side of the pond sells them. I use a NAPA gold oil filter had Fram on it with the right thread size and it blew off oiling down the rear wheel won't buy another one. The engine has been reliable so far but they are very poorly timed from the factory. I have no idea how much power the turbo has added. I bought the turbo through mbe motorsports but there are cheaper places on Ebay. Just google vz21 turbo. They can blow enough air for 80hp.

Sean

[DieselFly]

All fixed. Pull the rocker covers. Tapped the holes in the cylinder heads leading to the intake manifold 1/4x20 fit without drilling. Wound two grub screws with sealent into the holes. Drille the plugs out on the top of the rocker covers and tapped to 1/8"npt. installed two 5/16" barbed fittings tie together with a tee. I tie wrapped the hose overboard for the test run all that came out was a little water. I then drilled a hole into the air filter mount and stuck the hose on it. Rode the bike around close to work for 20km or so. After dinner I came back to work and rode it 30km home. Traded seats half way with a friend of mine as the roads were wet we both got soked pants . It easely pulls to 70mph. and yes the Yanclones have the PVC in the rocker cover. There is a video on Youtube showing this http://www.youtube.com/watch?v=aE_ftgNpOV4. I will update my build thread with pictures and get around to another video soon

[DieselFly]

Well I though it was all fixed . I'm still venting what would amount to a small amout of vapour. This seems to happen around 70mph which is well above normal cruise speed. I have now drilled the hole in the PVC valves located in the rocker covers. If my calculations are right I have increased the area by 120% for the vent holes. I will give this a try and see what happens. I'm thinking part of the problem could be the turbo return is to close to the centre vent and is picking up the vapour. Worst case it will mean making a small cyclonic separator to catch the oil. The weather here has been crap for the most part so testing keeps getting delayed. I want to enter the bike in a show next weekend and really want to keep the cleaning to a minimum. Not having a front fender makes a real mess in the wet

Sean

[Kristof]

Wow, how did you find that video? It helps explain what to do to counteract the problem caused by the turbo. I wonder why they built that in there in the first place, maybe this engine was ment to be turboed?

Oh and I couldnt find their ebay store.

[DieselFly]

I doubt very much that these engines were ever ment to be turbocharged. It would make for a very interesting roto-tiller though. Most of the small diesels are ment for industrial use and the turbo pushes them past their design limits. As I have stated before I am not looking for increased speed but more efficency a highway speeds of 50-60mph and some passing power. The odd short burst for 10 seconds or so should not hurt the workings. One needs to keep in mind the stress on the bottom end as well has higher cylinder pressures and EGT's

Wow, how did you find that video? It helps explain what to do to counteract the problem caused by the turbo. I wonder why they built that in there in the first place, maybe this engine was ment to be turboed?

Oh and I couldnt find their ebay store.

[DieselFly]

I was still blowing oil out the vent and past the o rings on the compression release shafts. I have built a air/oil separator. (very common in aviation). I mounted the separator under the seat and ran a clear 1/2"ID tube to it. I rode to work and could see a small amount of oil going through the tube. When I arrived at work there was oil around the rocker covers again an indication of to much crankcase pressure. The next logicall thing to do was pull all of the guts out of the centre PVC valve. Well I blew through it there was alot of back pressure caused by the screen material being jambed in to tight. Just for good measure I broke the flapper vavle out and drilled two more large holes in it and pulled the stuffing out. On the trip home I looked down and was alarmed at the amount of oil being blown throught the tube. I though I would be making a U turn back to work. I stopped and checked the air filter in the separator not a drop it was all going back into the engine through the oil return line. I have now put 100 miles on the bike I'm still finding a slight amount of oil being pushed by a few gaskets. I think with the amount of blow by that its trying to tell me something. The turbo is working the bike is much better at speed the smoke is gone. The power is up and I can now pass the odd car that is driving below the posted limit. I'm using less throttle to maintain the same speeds as before. There is a definite increase in power how much I don't know. I have had the bike up to 75mph as it has gone that fast before. No cloud of black smoke and it still has more in it but I don't want to blow it up. Next I need to open up the vent hole in the block under the centre PVC valve. Or open up the ones in the rockers more which will need another collector can. This has been a fun project as I really like the head scratching part. I am planning on a turbo 10hp yanclone for my daughter for 16th birthday (got a couple of years for that one) so this is good practice. I will up date the pictures soon

Sean

[toyotaracer9]

This is a really nice build , it has come a long way since the last time I was on here. I have the same turbo and my IAT were 160F so I put an intercooler, but one issue I have is oil blowing through the turbo seal and into the compressor side .

[DieselFly]

This is a really nice build , it has come a long way since the last time I was on here. I have the same turbo and my IAT were 160F so I put an intercooler, but one issue I have is oil blowing through the turbo seal and into the compressor side .

Do you have a restrictor fitting in the oil inlet? If not you need a 1.5mm or .060" restrictor

[toyotaracer9]

Yes I have a restrictor , It may be the engine is still so tight as I do not have an oil pressure gauge . Have you checked your IAT ? If its as high as mine you may be able to add a little timing and make more power with an intercooler.

[Kristof]

Any news on mileage? mpg?

They have 30hp engine now. ----> http://www.vtwinengine.com/list/65.html

[DieselFly]

The good the bad the and the ugly. My engine has been making more noise then normal since last fall before the turbo was installed. when warm the oil light(5psi) would come on at idle 1050rpm. It developed and oil leak at the front of the crankcase cover which was caused by the case halves fretting from vibration. The aluminum gasket was worn enough to spit a chunk out. I glued it shut rode the 30k to work and upon arriving the noise the engine was making said don't run it anymore. I pulled it apart to find the pto side main bearing was worn as well as one rod bearing was pretty bad. The crank looks okay though. My department head who had bought one of the three engine which we imported and not used yet. Long story short he offered it to me for less than half the original cost. SOLD! So I have brand new engine with the turbo installed on it. Only took five hours to swap it over. I had to retime the engine after the first test ride as it would only run on one cylinder with light throttle. I had also mentioned before that our engines were badged as Kingpoo not Punsun who I bought them from. Two of the engines had Kingpoo cast in the crankcase end. Well low and behold when I opened the crankcase the same part had Punsun cast on the inside. Anyways I will send Roger at Punsun a list of parts and fix the old on as a spare. School is winding down so I will update the photos and get some new video before I break it again

Sean

[alexanderfoti]

Ah that's a shame, how many miles where on the engine?

What sort of boost were your runing?

[DieselFly]

I think it may have been partly my fault for putting thin oil in it last fall. I could not get the oil past 60C when fully warmed up. I was concerned about oil flow when starting at +3C and riding away. The one rod cap that was in the worst shape looks like something floated into it and was pounded into its face. I'm sure the addition of the turbo did not help what was already damaged. So now I'm starting with a zero time engine with the turbo and we will see how it goes. I know for sure that I was running lower oil pressure to start with that was no fault of the turbo. My hour meter showed about 350hours of run time when I pulled the engine

[alexanderfoti]

ah right, so the engine was turboed after the damage. What oil did you put in it? Im running 10w30 but we dont see any temps below around 8dec in the summer. Good job getting a new replacement for so little though!

[Kristof]

How much did the original engine cost?

So the damage may have been caused by thin oil, otherwise it would have been fine?

[DieselFly]

I put 10w30 in it. I was running 15w40 normally and 5w40 synthetic with the turbo. I have now switch up to 20w50 as we are having 30C weather right now and I will go back to 5w40 when it cools off. I have put a few miles on the bike and will ride it back home (30km) tonight. If all is good I plan on going on a litle 100k ride tonight with a friend that we build a street tracker for. 10w30 just did not have enought viscosity to protect the bearings even in low temps. The turbo increased the oil temp which did not help with sloppy bearings. My oil temp seems to be right around 175-180F which is perfect

Sean

[res0wc18]

any updates to this?

Ever get it back together and on the road?

[DieselFly]

Yes it was back on the road two weeks after it broke. I was able to buy a new engine from a friend of mine. I just put it back on the road after winter storage and needing on valve seat cleaned up. Bike is running well. Now if it would just stop raining!!

any updates to this?

Ever get it back together and on the road?

[sbrumby]

Just a couple of questions from this thred, You talk about a PVC valve and a PCV valve. Are these the same thing and what are they for?

[alexanderfoti]

PVC is https://en.wikipedia.org/wiki/Polyvinyl_chloride

[focodiesel]

When I click on those vtwinengine hyperlinks I get some Chinese site with no engines, any suggestions?