Home | Gallery | Forum | Ads YESTERDAYSTRUCK.COM 
The Classic Truck Resource Page
Vintage Truck Headquarters

Featured Photo

Classified Ads
Photo Ads

Discussion Forum
Forum Archives

Misc Truck Photos
Ford Truck Photos
Picture List

Research & Info
Model Profiles
Ford F-Series
Truck Links

Contact Us

Related Sites
Antique Tractors
Kountry Life
Tractor Parts
Tractor Manuals

Classic Truck Discussion Forum


Welcome [Log out]
Author  [Modern View]
Phil H

06-22-2015 12:40:28

Report to Moderator

I was wondering, when you set the height of the injector spring, are you setting the amount of fuel getting to the cylinders when the injector rack is moved in for full throttle and back for idle. My understanding of the injectors, is the rack, opens and closes the injector. So, does setting the height of the spring increase or decrease the amount of fuel. I am setting the injectors at 1.484, so if I set them at 1.600, is this putting more or less fuel in the cylinder.

[Reply]   [No Email]
Jon Hagen

06-26-2015 09:26:56

Report to Moderator
 Re: 671 DETROIT INJECTOR TIMING in reply to Phil H, 06-22-2015 12:40:28  
Adjusting injector height does not change fuel delivery, but it does change the injection timing.

which is the correct gauge to use is determined by injector type and number, plus if the camshaft is being run advanced or straight up timing.
It's in the DD shop or tune up manual.

[Reply]  [No Email]
Phil H

07-01-2015 15:47:37

Report to Moderator
 Re: 671 DETROIT INJECTOR TIMING in reply to Jon Hagen, 06-26-2015 09:26:56  
Thanks for the feedback, I wasn"t sure this was the form to get answers, so I posted on tractor pulling and there were a lot of people there. That"s why I am late replying to your feedback. I now have the correct timing tool(1.484). From setting cams on motor cycles I understand how this makes a motor pull hard by retarding the cam and by advancing the cam gives the motor a lot of top end. But I have never worked on a diesel. I just want my 72 IH 10 wheeler to run good and pull like it did before I had to change a stuck injector. I goofed up and turned the screws on the rack, and un knowingly changed the injectors ability to inject the same quantity of fuel into the cylinders. Now I know!!!! I will set things per the book and hope all turns out ok. Again, thanks for your time and comments....Phil

[Reply]  [No Email]
Jon Hagen

07-02-2015 11:32:14

Report to Moderator
 Re: 671 DETROIT INJECTOR TIMING in reply to Phil H, 07-01-2015 15:47:37  
Injector adjustment is critical for easy cold starting and power.
The rack lever adjustment is a learned art, more difficult with the old 2 screw levers, much easier with the newer 1 screw levers. Your reward for a careful rack lever adjustment is an old 2 cycle DD engine that idles smooth as an electric motor.

I still have one old DD 8V92 TI set at 440 hp that I crank up once in a while just to hear that sound.
Great old motors.

[Reply]  [No Email]
Phil H

07-03-2015 06:56:47

Report to Moderator
 Re: 671 DETROIT INJECTOR TIMING in reply to Jon Hagen, 07-02-2015 11:32:14  
Wow, 8v92, 440hp. That is a lot more than my 238hp. I have the 2 screw rack adjustment, on my engine, with 4 exhaust valves. I have watched a few videos on some ways to adjust the 2 screw rack, and can see that it is a matter of feel. Like setting 3-2barrel carbs. If I can get everything right I will be happy. Have a lot of work for this old girl. Seems like everything I have now is old, guess that follows right alone with me. My wife says we"re just getting to be old doggies now. Thanks for the comments Jon.....

[Reply]  [No Email]
Jon Hagen

07-05-2015 17:29:07

Report to Moderator
 Re: 671 DETROIT INJECTOR TIMING in reply to Phil H, 07-03-2015 06:56:47  
I repowered a little Versatile 125 4X4 with a 6-71 / 238 many years ago. Made a good tractor out of it. About 40% more HP than stock. Had to dual it to get enough traction.

[Reply]  [No Email]
Phil H

07-07-2015 17:54:30

Report to Moderator
 Re: 671 DETROIT INJECTOR TIMING in reply to Jon Hagen, 07-05-2015 17:29:07  
Hi, thanks for the reply, I"ll bet you had enough power!!!! That"s what I have, a 238hp. I just set the rack and now I"m going to haul some gravel out of the creek. The engine ran real sick last time I hauled 10 yards. So... kind of apprehensive.... but I did every thing the way the book said, and all those who have been good enough to help out with comments......so here goes. I will post my results for those who made comments and tried to help out, many thanks!!!!! Phil H

[Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Add a Reply]

Hop to:


Copyright © 2002-2013 YesterdaysTruck.com
Antique Truck Headquarters