Turbocharging a Jinma 254 Build (Y385)

[ElectroTechnics]

It builds boost very nicely with a max of 10psi.
Turbo's require very little oil but it must be delivered after the filter. Too much oil slows the turbo rpm so I would install an orifice in the supply and verify the quantity by measuring the turbo drain output.
90cummins

I made an adjustable regulator and we are running a separate oil gauge just for the turbo so I will be able to set the oil pressure just over the minimum and well under the max. The engine's air consumption has the turbo at 80k rpm according to its map, so the turbo will not be seeing near the stress it did on the 2.3l volvo spinning the turbo to 180k rpm.

Did you have to lower your stock compression ratio down from 23:1 before running 10 PSI of boost or does the engine handle the 38:1 effective ratio fine?

 

[Bob Rooks]

I'm not certain that a calibration is required. We are not planning on getting anything calibrated. I have read that there should be a smoke (fuel) screw on the back of the pump that can be adjusted.
I think it restricts the fuel return line directing more to the injectors.

Please post a pic of that "smoke screw". If you're thinking of an aneroid valve, these pumps don't have them. The cam lift and the helix on the plunger is what regulates the fuel to the injectors. The return line isn't part of the equation. But I don't know anything.

 

[ElectroTechnics]

According to the manual there is a governor high speed and idle speed screw, to my knowledge that would set max and minimum speeds of the engine. The manual also states that there is a max fuel flow set screw for the governor. I am guessing that just allows the governor to "open" the pump more supplying more fuel. Once we get the turbo on and working I will experiment with that adjustment screw. Hopefully that should provide the effect I am looking for. That is probably the adjustment I read about, and not actually a "smoke screw".
But thanks for correcting me about the return line valve. I still have lots to learn about diesel injection pumps since this is the first diesel engine I have worked on.

 

[Bob Rooks]

All the governor does is control the rack in relation to engine speed vs. throttle setting. The rack rotates the plungers within the barrel which are lifted by the cam. Since there is no droop adjustment on these governors I'm a little confused. I have a TY395 engine and there is no such "screw". Sorry for butting in.

 

[ElectroTechnics]

I was assuming the max fuel adjustment that the manual mentions increases the rack travel so when under load the governor moves the rack more. Again I will have to do some trail and error and I will be sure to post my results.

 

[Bob Rooks]

Since you are only going to have minimal boost pressure, you will overcome and eliminate the parasitic natural aspiration draw, and that will give you a net gain of about 10 HP at rated engine speed, and still maintain a decent BMEP number. I'm anxious to see how this works out for you.

 

[ElectroTechnics]

Not much has been done so far, but lots of prep work. Nearly all the parts have showed up. My pictures of all that parts in a pile are too big to upload. So tomorrow I will compress them and post it up, probably along with the turbo mounted. I will update as the project progresses.

 

[D0TC0M]

Can't wait to hear how you make out.

 

[doxford jim]

You will realise a gain in output if the engine can breath better. Straight suck, squeeze, bang and blow is limited when naturally asphyxiated !
Providing you don't have too big a turbo and turn up the fuel too much, you should have an increased performance - albeit limited.
I too look forward to read of your progress on this project.
An added note, I turbo'ed the 1986 F250 with a designed after market tubo (CTS) and it made a huge difference when towing a 27' travel trailer in the mountains.

 

[Bob Rooks]

You will realise a gain in output if the engine can breath better. Straight suck, squeeze, bang and blow is limited when naturally asphyxiated !
Providing you don't have too big a turbo and turn up the fuel too much, you should have an increased performance - albeit limited.
I too look forward to read of your progress on this project.
An added note, I turbo'ed the 1986 F250 with a designed after market tubo (CTS) and it made a huge difference when towing a 27' travel trailer in the mountains.

Were you monitoring EGT's? Just curious if there was much of an increase.