CB350 tranny + Yanmar L100 + Turbo

[mazdog355]

by Sphere » Thu Jun 18, 2009 1:11 am

Just get cracking with that turbo

Received my RHB31 Turbo monday afternoon, so , at 4:30 this morning, I decided nothing was getting done laying in bed, so i started the fabrication... I must have took about 100 pictures during the process, so i won't be doing much explaining, I'll just let the pictures do the talking.


Hmmm... Which one should I use



Removed "original" exhaust



Just seeing how things measure up



Where to put the turbo... This was about an hour long process.



Modification of the "original" exhaust.






Oil supply.



I don't work at the shop where i originally built the bike, so limited tools and resources call for some interesting fabrication techniques...





Rotating the bearing housing.









If only I had an Oxy-Acetylene torch handy.



Believe it or not, that's what it looks like when i'm done.












Finally got the exhaust where i want it...low.



All in a days work. That oil spill keeps following me around...






Oil bath air filter from an old VW van that i'll be using.


Hope you like it, I'll keep you posted.

[BoxerOtto]

that,s awsome man!!! I have mine on order,but coming to canada it will probably be stuck at custom's for at least another week. can't wait to see how it all turns out for you.

cool!!!
cheers otto.

[coachgeo]

real nice fab. work!!

[Sphere]

You're living it, the 1-cylinder diesel turbo dream

[Diesel Dave]

Remember you need a decent sized plenum chamber to hold the charge after the compressor ready for when the inlet valve opens.

Anecdotal evidence from a mad Dutchman who was drag racing a turbo'd Jawa single on nitromethanol suggests it should be at least 3x cylinder volume and not be able to trap water inside that would reduce volume.

Now if I could only think of a way to 2 stroke the cylinder too.......

Dave

[mazdog355]

Ok, for the inlet plenum i was planning on sealing off the engines original air filter box, removing the air filter, and running a pipe straight off the compressor into the back of it...that should work

[mazdog355]

I just made a video and posted it on youtube... i wanted to check oil line flow, so i pre-oiled the bearings and fired it up.

http://www.youtube.com/watch?v=RH3-QBU-gY8

I love how you can hear it spool up a little when i give it some fuel. And did you notice the turbine rotated a little the first attempt to start...

[mazdog355]

Progress was slow today, and i got a late start... but here it is.






A little aluminum foil makes a good gasket



oil inlet nipple. It's hard to see, but there's a little opening to allow just a trickle of oil.



I needed a tight bend for the intake piping and was feeling lazy...



Where's a holesaw when you need it. I really need to invest in some tools.






Getting there.



Safety first









Hey Dave, about that intake plenum chamber, I did some rough measurements of the inside of the airbox: 15cm. x 11cm. x 7.5 cm.
Comes out to about 1237cc. Which is approx. 3.04 times the engine displacement...Perfect. Do you think water collecting will be a problem?
That would be awesome to make a 2 stroke version of the engine, That'd be a real screamin' demon.

[Diesel Dave]

Water collecting can be quite a problem unless you drain it regularly.

Ever had a truck with air brakes? One of the daily maintenance tasks was to drain the water from the bottles.

Dave

[andrewaust]

Good stuff mazdog355 , now that has got to turn heads - it will also be interesting just how much more power you can get with a little boost.

Just keep an eye on temperatures if you can .




A

[vijaycool]

Super small TC. What is the cost of the turbo

[andrewaust]

I just picked the turbo up on ebay for 216 USD, couldn't say no at that price.

Hey Mazdog! How did you go with the oil outlet on the engine, I've been told it could be 1/8 BPT not NPT which most of the automotive stuff is.

I'm in the process of getting bits and pieces, then I'll get the pipe work welded up. Probably be a slow project for me.

PS: Be careful not to starve them journal bearings too.



Cheers


Andrew

[Diesel Dave]

Andy,

Watch your oil pressure!!!

Without a restrictor AFTER the turbo the oil pressure could drop dangerously low and all the flow go through the turbo rather than the crank feed.

I'd put a 1mm diameter restriction on the line after the turbo.

Just my 2p worth.

Dave

[TedV]

doesn't the oil feed line to the turbo get the restrictor before the turbo bearings, if you need a restrictor? Thought there should be no restrictions on the oil return from turbo or the oil will shoot out the turbo shaft seals? Every turbo I've worked on has had zero restrictions in the oil flow after the turbo. 1/2" to 5/8" return lines. If the oil squirts out the compresor seal you can experience a run away engine as the motor oil then becomes the fuel. I have worked on some with coked up returns, oil was coming out the shaft seals and turbo's were getting rebuilt/replaced.

I've seen the oil supply line restrictors for sale at various turbo sales shops. Don't know if they work, I've never had to use one.

[Crazymanneil]

Not sure how relevant it is but the turbo on the smart engine does not have a restrictor in the return pipe either, though I do think the feed is at engine oil pressure so I am guessing the restriction comes from the turbo itself. I'd say screw it together and stick an oil pressure gauge on to see what it says - don't know if some turbos need a restriction..

n

[andrewaust]

Thank you for the comments guy's

All very good points, much appreciated and well taken .

Yes restrictors are used in the oil feed line for some applications, that is also correct regarding turbos, block the return line and oil will enter the compressor or turbine, the compressor side can be more dangerous. as mentioned the engine will most likely run away. Coked up turbo chargers can do the same, always important to run good oil etc.

I will be connecting up a pressure gauge when the engine is hot, Scott the Yanmar specialist said the L100's he has tested were getting the oil pressure to rise further then 100kpa when cold as it has no relief valve, so my 100 kpa gauge will just handle it. Must say it will be interesting to see if the engine will handle the turbo, if not then a restrictor in the main supply line will be in order. One must also watch this with journal bearings thought as imminent failure will result if no pressure can be obtained. These little brass bearings work the same as any other engine journal, the pressured oil keeps parts from contacting each other. Ball bearing races in turbo's are another thing, restrictors are strictly recommended.

This will be a slow project with much testing. I'm going to test the turbo and see if it is capable of maintaining pressure with small volumes of oil, one thing I really cannot risk is oil starvation to the front engine bearing and big end journal.

Fingers crossed all this will give good results.




A

[Diesel Dave]

Can't wait for the new air/foil bearings to become mainstream in turbo's - require no oil feed at all.

Andrew best of luck and keep that pleanum chamber big and water free.

Dave

[mazdog355]

Sorry i haven't been on for a while... i just had a Baby on the 15th and have been very busy...

The turbo project is near finished, just need to find some time to tweak and tune. It builds boost easily, and low to mid range torque has improved, but like any project, there are bugs.

Later,

[coachgeo]

wow..... you can build bikes with tinker tools, toy with turbo's.... and have babies too. Damn your good

If it's a boy name it Turbo!

Congratulations

[andrewaust]

Hey mazdog!


Congratulations on the birth of your little one.

Yep, can understand you now being very busy mate, don't worry there's always tomorrow for the bike, enjoy your little bub .



A

[bubby-joe]

Congrats to both you and the mom on the new one, bet that will cost you some sleepless nights, now to business, when you were doing the early part of your CB350 build did you take any pictures of the transmission modification. That would be of great interest to many including myself. No bike yet but 2 free Yanmar genset engines and a Yamaha 2 stroke 6 speed tranny/engine combination to work with, right place at the right time what can I say, I'm frugal not cheap and free is always good. A welder and lots of tools, I'm semi-retired, only work when I want to, way more time than money. Rode legal since 66 that's 19 not 18 way to many makes and models to count but never a diesel (YET). I'm not to OLD to embrace a different technology, my father however is remote challenged go figure.

[mamboman]

Regarding oil line restrictions, I came across this webapge which recommends :

Keep in mind that turbos do not need 3 gallons per minute feed, so to prevent overworking the pump motor the oil must be by-passed back to the feed side of the pump or to the oil reservoir. Typically this is done in a "Tee" fitting after the pump discharge with an AN4 feed to the turbo and an AN6 bypass line tom the oil reservoir. Tyical orifice restricts to turbo for Garrett GT Ball Bearing series is .109" to turbo and .1875" on bypass to oil supply.

The quote comes from a comprehensive guide to different electric oil pumps:

http://www.rbracing-rsr.com/oilsystems.htm

There are some interesting stuff there..

Waiting with baited breath to read if your turbo is a success...

[andrewaust]

Regarding oil line restrictions, I came across this webapge which recommends :

Keep in mind that turbos do not need 3 gallons per minute feed, so to prevent overworking the pump motor the oil must be by-passed back to the feed side of the pump or to the oil reservoir. Typically this is done in a "Tee" fitting after the pump discharge with an AN4 feed to the turbo and an AN6 bypass line tom the oil reservoir. Tyical orifice restricts to turbo for Garrett GT Ball Bearing series is .109" to turbo and .1875" on bypass to oil supply.

The quote comes from a comprehensive guide to different electric oil pumps:

http://www.rbracing-rsr.com/oilsystems.htm

There are some interesting stuff there..

Waiting with baited breath to read if your turbo is a success...

Yes! Ball bearing turbos can have restriction, journal bearing turbos not a good idea, it's like restricting the oil supply to your big end and main bearings in an engine. Journal bearings require pressured oil to keep the bearing away from the turbine shaft.

There are now turbo chargers that require no external oil supply, the lubrication is self contained http://www.aerocharger.com/index.php


A

[franky996]

i have a question about the fuel supply and the turbo. I'm interested in building a bike like yours myself, but don't really know much about these engines. I know that with the turbo and the added air, you need more fuel. So how does the fuel system on these engines work? I have some experience with a 5.9l cummins engine in a dodge truck, but have no clue how the yanmar gets it's fuel. Carburated? The how do you pressurize the carb, or does the air go through the carb first, then through the turbo? And did you need bigger jets?

Thanks for any help

Frank

[mazdog355]

The Yanmar is a direct injected diesel . Basically the diesel fuel is squirted directly into the cylinder slightly before top dead center on the compression stroke. There is no carburetor or throttle body that regulates an air flow mixture. I know that on my engine there is a spring assembly that you can adjust to "tweak" the governor system to get more fuel to the engine. When it's turned up, without boost , I twist the throttle all the way, and a huge cloud of black smoke billows out the exhaust, even a little white smoke, which is raw unburnt fuel. This means that the fuel pump is capable of injecting waaay more fuel than the engine will burn naturally aspirated...(That's where boost comes in ) There is an internal governor that meters the amount of fuel injected.

I found this link very helpful... This guy does very high quality work and there is a paragraph that explains the governor system very well.

http://www.altmann.haan.de/riding_on_salad_oil/

[Sphere]

Hrm, I don't understand something. Every stroke requires the same amount of fuel, you just require more fuel over time if your revs go up. So how do you persuade an engine to rev at 3600 instead of 2200? Wouldn't it be easier to control the fuel pump instead of the governor?

My Hatz manual says it's not really possible to pick a specific number of rpm.

[DieselCrazy1]

I been reading this conversation and curious to know what the end result is ?
Turbo Successful or Unsuccessful?

[albertaphil]

Sphere,

Engine rpm/ power output at a given rpm are regulated by the amount of fuel injected per stroke. That is to say, the same amount of fuel is not injected for every stroke. So what a speed governor does is add more fuel per stroke to maintain the rpm setting of the "throttle" which of course does not throttle anything on a diesel...it is actually a fuel control lever.

And I'm also curious as to how Kaiser has been doing with the turbo. Haven't heard from Mazdog in a while...hope everything is okay.

Cheers,
Phil

[mazdog355]

Hello All!

Haven't been on here in a while as i have moved and no longer have easy access to the 'net. But anyway, I actually removed the turbo from Kaiser, sadly. The turbo bearings failed after about 100 miles of riding and the compressor wheel rubbed against the turbo intake housing. Oh well, really not sure what caused it...I know there was plenty of oil flow to the bearings.
But the engine is fine and I have returned it to N/A.





But, Last month I was bitten by the Project bug again....I bought a used Kubota D905E and I'm going to build a hydrostatic bike. I've been messing around with autocad a little and here's what i got so far...









I'll be back...

[toyotaracer9]

WOW !! that really sucks about the turbo , I have the same turbo with around 150 miles on it rightnow . I guess I need to take my filter off and check for play . did the engine try to "run away" ? I think that would be the scariest part of this project . How were you able to check oil pressure going into your turbo ? do those air cooled engines have an oil pump ?