Turbo's

[Diesel Dave]

Chaps, Tiny Turbo finally arrived,Thats a 6" ruler included to provide scale, I now need to work out wastegate control, oil feeds and orientation and then hand over to the exhaust pipe man to knock up some pipes.

Any and all input will be welcome as this is my first turbo installation.

,,,

[Stuart]

Best of luck with that Dave. I remember Ernie Dorsett telling me a turbo wouldn't work on a single but I'm no expert there. Did have a try at something similar but the gases wouldn't turn it

[oilburner]

I have a very good book on turbocharging by Hugh McInnis, the 1984 edition. He describes the problem with small engines in the motorcycle section. The problem with small engines is compressor surge (pulsing). He recommends a plenum chamber on or incorporated into the intake manifold. He states the pipes from the compressor to the cylinder head(s) should have twice the volume of a single cylinder. A plenum three times as large as a single cylinder is even better. Another problem in small engines is oil pressure. The turbo uses one half gallon a minute which he says can lower the pressure to the rest of the engine. Also, the turbo transfers a lot of heat to the oil.

Most turbochargers are available with a selection of turbine housings to suit different applications. There's a picture in the book of the Warner-Ishi RHB3, a small turbo that it says can be used on engines from 500cc to 1300cc.

FYI

Avery

[Rick]

Oh man... That thing is CUTE! Even with the ruler next to it, it's hard to grasp how small it is...

[Byrdman]

Make sure the turbo is above the oil pan, oil drainage is very important.
Especially with a diesel!!!

[Anorak_ian]

A nice bit of kit, but low compression pistons are the nature of a turbo and just fitting low comp pistons and a turbo will not do the job un less you re align the injectors (else it becomes indirect and lack power?). Saying you do that, well fine but wont ya need a glow plug now?
I have thought of turbos and superchargers, and the way ahead for me is using the fan that is on the engine, just channel its air flow to the air in take and use a leaver to adjust the pressure. Sounds nuts I know but it will only need the extra power going up hills etc. I guess the trick is not to get to greedy with the engines revs.


What was the price tag with this turbo? I have to ask I'm always skint.

Ian

[Anorak_ian]

He recommends a plenum chamber on or incorporated into the intake manifold. He states the pipes from the compressor to the cylinder head(s) should have twice the volume of a single cylinder. A plenum three times as large as a single cylinder is even better. Avery

As a once dedicated scuba diver for many years (no longer as I have a family), I understand this, I have come to the same conclusion when I used to strip down diving regulators, I wondered how I could make the initial breathing resistance better for the diver with old regulators.
The answer I came up with was an air chamber in between the two regulators (tank reg and mouth reg). The way the regulators worked, was a lot of pressure but no real volume of air.
Basically in this case, a Plenum chamber gives an aria in which to mass compressed air (volume).

"Also, the turbo transfers a lot of heat to the oil". Maybe the engines fan can be used here?

Woops 2.15am time for bed zzzzZZ

[Byrdman]

A nice bit of kit, but low compression pistons are
I have thought of turbos and superchargers, and the way ahead for me is using the fan that is on the engine, just channel its air flow to the air in take and use a leaver to adjust the pressure. Ian

Ian, I wouldn't count on too much pressure being being gerated by the engines' cooling fan. Maybe 0.5 to 1.0 PSI MAX.

They really don't have positive displacement like a turbo / supercharger does.

[Anorak_ian]

Thats right, it will be a low pressure job, but with the normal compression thats all I want. Any more and it could go pop.

[andrewaust]

That's a neat little Turbo Dave - will be interesting to see how it goes.

I thought about doing something similar to what Ian has said, just supplying positive pressure to the intake through the air from the flywheel fan. That's about all it will be too - positive pressure, don't think you could measure it, but at least it will by theory, help fill the cylinder with a complete charge of air.

Suppose what I'm aiming for is something that is already there I can tap into and won't need to add much more weight to the bike, thinking all I need is a boot from the cowling and to redesign the air-box a little.

It will sure be great to see how you go Dave and Ian with the projects.


Cheers

Andrew

[Anorak_ian]

Looking at the specks for my engine the Volume of air needed for combustion is 1500 liters per min, the cooling fan knocks out 15,800 liters of air per min. This has got to be more than 1 psi?

Any way if this doesn’t work I'll put on a steam whistle lol

[Diesel Dave]

I don't think you will get much pressure, but you might remove any vacuum from the inlet manifold.

You might get a slightly better result from a purpose made centrifugal blower belt driven from the flywheel. What about an old vacuum cleaner?

Dave

[addicted]

What size turbo is that you have there?

I noticed a reply on this post about a turbo for 500cc to 1300cc turbo. I was doing some looking a few weeks back and about the smallest I could find was a Garrett GT12. Good for 400cc to I can't remmeber. Perfect to a tad big for the 406cc clone.

It would add weight but I think keeping the oil cool would be to easy with a very very very small oil cooler. This would allow you to add an extra 1/4-1/2 quart of oil as well. I look at the one on my Mercedes and it is overkill (as I've heard in europe some of the cars didn't come with them) and others here in cooler climates have never had a problem when they take of the damaged ones.

Has anyone measured the negative pressure at the intake? I agree that you would only need 1+ PSI to make huge difference considering you are probably running a couple PSI on the Neg right now. Would be very interesting to see the negative pressure on the intake.

On the other side of that you can add the air, but how easy is it on these to increase the other component of that....Fuel??? I see on the video's that on hard accell that they are producing quite a bit of smoke so the turbo would clean that up if you could get 1+PSI but you could do a lot more if you could get more fuel in there to the point you just start smoking again. Then again assuming you can attain enough boost in the first place to clean up that smoke.

I would not be surprised depending on the current negative inlet pressure if you could get 2-3 HP out of that engine given you could get above 1 PSI and turn up the fuel a bit.

Then this leads back to the problem of heat. I'm not sure how efficeint these air cooled engines are but if you are adding more fuel or at least burning that excess that is usually leaving as soot and unburned fuel you might need to worry about EGT's. I've heard they get a bit high as it is. Of course and Intercooler is absolutley out of the question so it would be very interesting to see the dynamics.

As for the heat I only see a couple options if it is a problem.

A small electic pump operated water jacket and radiator or for those really hard core people out there a wather/meth injection haha sorry I could help but put that in there.

Can't wait to see how this moves forward.

[Byrdman]

When I was with Yanmar, we had a turbocharged L-100 prototype.

The problem is that the pressure waves are spaced fairly far apart because it's a single cylinder. The damn thing only ran well under full load at full speed. Anything slower and the engine pulsed very bad.


The key is to smooth out the pressure pulses by using a fairly large pressure manifold. The large volume will help to dissipate the peaks and valleys.

[addicted]

Do you have any more detailed information on the turbo's l-100 experiment. Did you ever try a larger manifold?

Besides being annoying would the pulsing really hurt anything as if I could do something similar yet a tad better I would as I do mostly highway speed.

did it have any problems with the oil temps for the lubrication/cooling system?

[Byrdman]

Do you have any more detailed information on the turbo's l-100 experiment. Did you ever try a larger manifold?

Besides being annoying would the pulsing really hurt anything as if I could do something similar yet a tad better I would as I do mostly highway speed.

did it have any problems with the oil temps for the lubrication/cooling system?

I don't have any other info, it was just a fun afternoon experiment.

We didn't play with a larger manifold and only loaded it for a few minutes. It did make a bunch of horsepower though, I believe close to 18! I would also assume that the oil temperatures were extremely high, definitely not sustainable.

As far as reliability goes; at full speed the pulsing seemed fairly minor but I'm sure pressure in the system was bouncing all over the place. I would guess that if one could keep it cool enough, the engine might survive. Sadly, components downstream would get beat up pretty bad. Clutches and driveline parts would get hammered to death.

[addicted]

Wow. That is quite impressive. If you could get 18 HP out of that thing it would be a whole new beast.

Diesel Dave where you at

I think in the name of all home built diesel motorcyclists (of which I am not yet but hope to be) you need to let us now how it is going. I'm going to see today if I can find any more information on turbo's and trying to get rid of pulsing.

So on that experiment what size Turbo you using? Apperently the gasses had no problem spinning up the turbo.

Hmmmm I like where this post is going moohhwwwwhhaaaahahahaha

[andrewaust]

Supercharging a Diesel usually gives a 30% boost in power. My calculations you would get around 14hp max, unless you start injecting other goodies into the engine

A blower would work a lot better on a single then a turbo, especially if you can get the rpm's down to around the 2200 mark where all the torque is.

Yanmar Diesels don't fair well with too much boost - from what I read they tend to melt This came directly from Yanmar - so I guess the clone would be exactly the same.

I'd guess a 2 pound boost would be the max for most singles.



Cheers


Andrew

[SamM]

Diesel Dave,
Where did you buy your small turbocharger and what is the manufacturer and model number? If you don't mind! I've been looking for a small turbo to boost my 456cc Winsun with. Since I have to fab a complete intake and exhaust anyway. I may as well try pressurizing it.

Thanks!

SamM

[toyotaracer9]

Im not sure which make and model he has but you can look up IHI rhb-31 , I am pretty sure its the smallest turbo you can buy . I bought one on Ebay a few months ago , my 700cc engine spools it to 10-11psi around 2600rpm which is where the WG opens up . I ran it without the vac/pressure line hooked up and it made 18psi before i let off the throttle so I am sure 400cc engine should make some decent boost .

[SamM]

Thanks for the info toyotaracer9. I'll check it out. If anyone else has any info about small turbos please PM me.

Thanks!

SamM

[MrDizzo]

LOOKED INTO TURBO CHARGING MY CUSTOM BUILD MONKEY BIKE AND FOUND AN ELECTRIC ONE FROM TINY TURBOS THIS WILL FIT SMALL PIT BIKES AND THE LIKE WOULD PRESUME CAN BE ADAPTED TO A DIESEL FAIRLY EASY AND HAS SWITCH SO CAN BE USED WHEN NEEDED AND NOT ON CONSTANT THINK MPG SAVING ALL FOR THE PRICE OF £90

[Sphere]

Your CapsLock key is broken.

[gsfighter]

I've been led to believe that a air con pump would work as its belt driven and wouldn't matter if it was a single, but i've not ever tested this theory

Dave

[bernhard]

Sorry for the naive newcomer question but wouldn't it be worthwile to also look at root type compressors a simpler to realize boost alternative to the turbo?

Obviously a turbo is optimal as it does not suck engergy from the little there is but it seems to be a comlex and difficult task to make it work. If you are successful I will be the first one to follow. However, a boost via a belt driven roots compressor has several significant advantages: linear air delivery proportionally to the engine revs (no turbo hole, less pulsation), much less heat problems as it is not thermally connected to the exhaust (less or no need for an intercooler), just to be bolted onto the engine driven simply via a belt. Obviously it has also significant downsides: It would draw significant power in the range 1-3 kWs from the engine which comes at the cost of increased fuel consumtion, I guess about 10-30%.
Which roots compressor would fit the purpose?
For a 400cc Diesel bike like mine I calculated over the thump that a suitable compressor would need to shuffle approx 90m3/hour at an overpressor of 0.5-1 bar.
The first practical questioin is does a suitable roots compressor exists?
In deed there seems to be one around: There is (was) a Peugeot 125 scooter with a roots type compressor which is highly praised about pwerformance. It rivalled the 250cc version and had a real punch. Obviously this is no Diesel but the compressor could be of the right size as the Diesel turns half the revs at double the engine capacity.
The second practical question is are these compressors available?
When I was checking the net I found not the shred of a glimps of a used compressor, but may be someone is more lucky. As a last desperate resort I read that there there are new spares still available from Peudeot at around 1200 Euro .

Was such a project discussed earlier, does such a project make sense? Looking forward to your points of view.
Bernhard