870 turbo pump timing

[J-J]

I have added a turbo to my 870. The turbo is for a 190 allis. I am wonder what I should do with the pump timing and how much more fuel I should add? It sound so smooth running now.
Thanks for the help

 

[Dieseltech]

Use the stock timing setting. Use a PTO dyno to set the max fuel screw, don't guess at it.

 

[jon f mn]

Case generally advances the timing on turbo engines a bit I believe. Rod just did a 770 and hopefully hewill respond as you won't find anyone more knowledgeable. But since an 870 is a 1370 with 2 less cylinders I would find the 1370 spec and set it there. A half a turn on the pump shouldn't hurt anything either. You just want smoke, buy thin enough to see through when at max load. Did you add a pyrometer?

 

[Dieseltech]

Books I have show 770, 870, and 970 29 degrees BTDC. The 1070, 1170, 1175, 1270, and 1370 30 degrees BTDC. The 1570 is 25 degrees BTDC. While engine MIGHT sound better with an earlier timing setting, the PTO power usually falls off some as the peek cylinder pressure is too early to take advantage pf the rod/crank angle. There are some Cummins engines that are 12 to 16 degrees BTDC now instead of the 25-30 most engines used for years. Timing depends a lot on the full load RPM engine is to be run too.

 

[J-J]

We have not added a pyrometer yet. Just starting to get it running. Thought we might run it to the county fair tractor pull and see what it did. Have a 504 running in the lower 30s but hopefully around 700 horse. I am not expecting anything close to that just wanted a starting point. Thanks for the help

 

[1370rod]

I have installed a turbo on a 770 and only recommend using the factory timing specs. You will be very happy with the tractors performance even without additional fuel but if you do and lug the engine install a pyro to keep an eye on things. And remember only pull things faster , not larger. Rod.

 

[jon f mn]

Do you have the specs for a 780 or W14 with high altitude kit? Those are 336 turbo engines and the specs should be right.

 

[jon f mn]

The industrial versions of that run around 140hp. A good 504 will rum 300 hp easy, so I would think 200 would be easy with stock parts. We had a local guy who had a 301 in an 830 that pulled competitively against 700 hp tractors, but I would guess he was closer to 500 hp but got some advantages from the com. The 336 would be capable of more than that if you want to spend the money.

 

[Dieseltech]

I should have the Bosch pump/governor specs, not sure about the timing spec pump to engine.

 

[J-J]

Thank you, I checked the timing and according to the balancer its 29 or 30 so I will leave it alone. I did turn the fuel up a little and made a word of difference in the throttle response. This tractor has a NOS ,I believe 9.5mm pump purchased from eBay about 10 years ago. A pyrometer will be used in the future if we start using it much. Thanks again

 

[J-J]

Rod, what did you use for the exhaust elbow on your turbo and where did you get it? I have the elbow from a 190 but I think I need a spacer as I am a little short of the factory exhaust hole in the hood. Thanks

 

[1370rod]

You are exactly right, you need a spacer. I used the 190 exhaust elbow also, then seen I needed a spacer. Went to my large pile of assorted bearings and races. Found one with the
correct ID and long enough. Got 4 longer bolts to secure the elbow and spacer to the turbo and it worked great. The exhaust going out nicely through the hood now with no other mods needed. To make a spacer from the correct size pipe would be no big deal if one can not be found, Rod.