1971 deuce uneven power performance

[rustystud]

Like I said , if your careful drilling and taping you'll have no problems. When the engine is running there is enough force blowing out that small hole to push out any material. Wear Goggles ! Ask me how I know !!!

 

[Mud Hugger]

Like I said , if your careful drilling and taping you'll have no problems. When the engine is running there is enough force blowing out that small hole to push out any material. Wear Goggles ! Ask me how I know !!!

You bet did it last nigt. Went smooth. Thanks!!

 

[Mud Hugger]

I drilled and taped the pyro pre turbo on rear manifold set, Its functional. I wanted to see what she does before I mess with fuel screw or FDC to much. Normal acceleration and shifting it goes up to 950 degrees and would peak around 1040ish when id hold my foot in it for awhile. I then Went to a decent hill I travel offen and held my foot on throttle for a good 7min from bottom untill I regained my 50 mph starting speed on the flat past the climb. Max while on Jill was 1080 but peaked past the hill at 1105 degrees. And fell right down to 600 when I let off. How much is bypassing the FDC going to up the heat? I do go for joy rides occasionally but usually use it for hauling firewood from farm to my house 15miles one way. Not sure if I want to bypass or not. Is there a turbo upgrade I could do to help lower temp? Also I have not installed boost guage yet. I will soon and see how it's doing boost wise. I do understand That the large 395s make the truck work harder and the muffler could add a little extra restriction causing more heat. As well as the hoist and wet kit adding a few hundred pounds to truck. But these added ffeatures are not getting romoved to up so I can up the fuel. I'm happy the the way it is and if that's all I can get out of it I'll live with it.

 

[welldigger]

If you bypass the fdc and it sustains temps over 1200°F then you can back the fuel screw down. More than likely you won't need to.

 

[Mud Hugger]

I gues I can always hook it back up if I can't keep heat down. So if you think I can make it work I may have to try. I will however get boost guage in first and see how she does
then bypass and compare vitals. Thanks

 

[welldigger]

No need to re hook up the fdc. Just turn the fuel down a hair. That's the reason many people have increased power when they bypass the fdc. It retards the fuel. That's its function. But your fuel screw sets the max rate the fuel can be delivered. If it runs hot just back it down. Same thing hooking the fdc back up. Except you eliminated a leak prone part of the ip.

 

[gimpyrobb]

EGTs can be lowered by getting more air in the motor. Make sure your air filter is clean. If it is a stock military filter, it can be washed.

 

[Mud Hugger]

I know with my little cummins motors that a different turbo can play a role in EGT temps. We swaped turbos on our "500"hp E9 Mack at work and it alone dropped Egts and water temp as well as gaining boost with out changing any fuel rate. Didn't know if a turbo from a later model multifuel has better output numbers or not. You convinced me that bypassing FDC is a no brainer. Thanks and I'll post my reaults

 

[welldigger]

There aren't exactly many turbo choices for the mf. The "d" turbo produces the most cfm. Though it is possible to put an lds turbo on an ldt. It produces more cfm than the "d" but I'm not really sure what the results of the swap would be.

 

[gimpyrobb]

There aren't exactly many turbo choices for the mf. The "d" turbo produces the most cfm. Though it is possible to put an lds turbo on an ldt. It produces more cfm than the "d" but I'm not really sure what the results of the swap would be.

George had an lds427 turbo on his LDT and reported mid 20 lbs of boost. Thats the one turbo I haven't gotten to try out yet. I do have an LDS turbo with the bolw off valve, but I haven't installed it yet.

 

[welldigger]

George had an lds427 turbo on his LDT and reported mid 20 lbs of boost. Thats the one turbo I haven't gotten to try out yet. I do have an LDS turbo with the bolw off valve, but I haven't installed it yet.

If you ever get around to installing it do post the results. I know that waste gate turbo produces the most cfm but whether it justifies the cost of one is another question.

 

[gimpyrobb]

I will do my best. I'll have to get a boost gauge! Right now I only run a pyro.

 

[JasonS]

I get about 13 psi on my 4LE354 wastegate turbo; maybe more if I spin the motor to 2400 rpm. I don't have any numbers for CFM but I can trigger the filter minder with a new air filter. It never did that with the C or D turbo. I have the larger compressor and housing from the LDS465-2 turbo to install when I get some time.

 

[welldigger]

I get about 13 psi on my 4LE354 wastegate turbo; maybe more if I spin the motor to 2400 rpm. I don't have any numbers for CFM but I can trigger the filter minder with a new air filter. It never did that with the C or D turbo. I have the larger compressor and housing from the LDS465-2 turbo to install when I get some time.

Any noticeable power difference when driving? Just curious.

 

[gimpyrobb]

Also, is that a stock deuce filter? I plan on putting a 5ton filter on my deuce.

 

[rustystud]

Also, is that a stock deuce filter? I plan on putting a 5ton filter on my deuce.

I want to put a 5 ton filter on mine also, but where can you buy one for a reasonable price ?

 

[welldigger]

I was thinking of using a cummins optiair. It can flow 200-1200 or so cfm depending on model. It also uses off the shelf filters.

 

[gimpyrobb]

They aren't easy to find really. If you have any yards with international trucks, the dt466 motors use a housing/filter really close to that of a 5ton. I have both here, but have been busy recently. I'll try to get pics of them together if I can.

 

[rustystud]

They aren't easy to find really. If you have any yards with international trucks, the dt466 motors use a housing/filter really close to that of a 5ton. I have both here, but have been busy recently. I'll try to get pics of them together if I can.

Thanks Chris.

 

[Mud Hugger]

Bypassed FDC

Well I finally did it, drove it, watched EGTs. I must say what a difference, it's a totally different truck. It gets up and goes now. I will however say I deffinatly have to keep my eyes on the exhaust temp though. I can easily get it over 1200 degrees with ease. I turned the fuel down a couple flats and and going to take it for a road trip tomorrow we will see how she does. Real test will be when I heap it with firewood or dirt. But I would comfortably say I would drive her all the time now with the way it cruises now.