gb diesel roosa master conversion

Jesse Bergmann · Feb 16, 2014

I"m attempting a conversion from the bosch pump to a roosa master. I"ve already changed over the lines,drive and pump coupler. Can I still use the original fuel filter system and injectors. Also I have the original heads but a 504 bore. I"m sure the compression will be high. How many degrees btdc should I start my timing on. Please help.

Dieseltech · Feb 16, 2014

Would be best to post the DBGFCC # to see what pump you are using. PSB pumps were beginning of injection timed while the Roosa/Stanadyne are timed for end of injection.

mightymolinekid · Feb 17, 2014

If you have an IT manual like mine that has all the MM models in it, I would time it to whatever tractor you got the pump off of. Keep the injectors and heads you have on, you will benefit from the small gain in compression. The beauty of the Roosa-Master pump is the ease in changing the timing.

Jesse Bergmann · Feb 17, 2014

The Stanadyne pump # is DBGFCC637-2DH. The IT book says 11 degrees btdc for g705s etc...but I'm pretty sure this pump is 10% over and newer than those tractors' pumps. Plus with the increased compression I figured it should be timed differently.

Jesse Bergmann · Feb 17, 2014

So the increase in compression won't be a problem?? Have you done this conversion?

Dieseltech · Feb 18, 2014

The pump you have is for a G-1000. Pump has 4 degrees advance for 8 degrees at the crankshaft. I would use the G-1000 timing spec to start with, and don't advance it any. If the pump has been turned up it will be advanced some already, as this pump is constant end, variable begining type. Early MM Roosa pumps did not have speed advance, cam ring was fixed. What is max RPM you want to run will help decide with final timing, or better yet play with it on a dyno.

Jesse Bergmann · Feb 18, 2014

So put the flywheel on 8 degrees btdc and the pump at 4? Will the timing lines in the pump window be off a bit

Dieseltech · Feb 18, 2014

No, set it as if the tractor is a G-1000 with the pump timing lines together.

Jesse Bergmann · Feb 18, 2014

I set it around 6 degrees btdc and turned the pump to line up the timing lines...I'll try to start it this afternoon...hopefully everything works correctly. Thanks for all the gelp

mightymolinekid · Feb 18, 2014

I'll admit I haven't done this exact conversion, but I did go way beyond it. The increase in compression isn't all that much, so don't worry. It will actually be a benefit to you.

Dieseltech · Feb 18, 2014

Early G-1000 was timed at 6 BTDC while late models were 2 BTDC. Not sure if there was an early and late pump, will check wensday. If it starts hard you may need to try 2 BTDC, which makes more compression heat before the fuel is injected.

Dieseltech · Feb 19, 2014

Your pump is the early G-1000. The late models had DBGFCC 639-1DH, 2DH, or 1DW with the larger .390 plunger head and 6 degrees pump speed advance, 2 degrees BTDC is correct for these pumps since the advance curve is changed.

Jesse Bergmann · Feb 19, 2014

Alright...thanks

Jesse Bergmann · Feb 20, 2014

How did u go way beyond it...did you make an 800 diesel??

gb diesel roosa master conversion

Jesse Bergmann

Member

Dieseltech

Well-known Member

mightymolinekid

Member

Jesse Bergmann

Member

Jesse Bergmann

Member

Dieseltech

Well-known Member

Jesse Bergmann

Member

Dieseltech

Well-known Member

Jesse Bergmann

Member

mightymolinekid

Member

Dieseltech

Well-known Member

Dieseltech

Well-known Member

Jesse Bergmann

Member

Jesse Bergmann

Member

Similar threads