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Thanks for asking. I live in upstate SC and travel into the mountains of NC fairly often, so I'm just looking to be able to maintain at least the minimum legal speed of 45MPH up some of the steeper main highways. Right now I can manage about 39MPH in 4th gear (it's a 5 speed tranny). Of course on the flat and up "normal" highway hills it can maintain 55-60MPH with no problem. The steeper sections I am referring to are ones where 90% of the fully loaded semis are able to do better than 45MPH, so I'm hoping to find a way that I can too.

The 4BT in my full-size Bronco is a 105hp model with VE pump, and was stock until last week when I had my mechanic install DDP Stage 1 injectors, which definitely made an improvement, but not enough. And I noticed the improved injectors made no difference to peak boost on the H1C.

The boost ramp-up on the H1C is very linear with RPM, which I spose is to be expected when there is no wastegate? My failed attempt to switch out the H1C for the HX30W this week held the hope that the improved turbo design of the HX30W together with the wastegate would lead to higher boost in the 2000-2500RPM range, and would continue to increase boost up to my self-imposed max of 3000RPM. But as I mentioned in my prior post, the HX30W couldn't be made to fit in the engine bay.

Other things that might be of interest:
  • Several months ago I installed a fuel pressure gauge and it always shows a steady 6lbs at all RPM and all throttle settings until/unless I go above 3000RPMs, which I did once to 3200RPM just to see what would happen. On that occasion, the fuel pressure dropped below 6 but I dunno how far below (I had it set to alarm below 6, and it did, but I was watching the tach, not the pressure gauge).
  • There is no smoke unless it sits without being run for a couple days. In that case it blows some white smoke for about 30 seconds or so after it starts. The longer it sits, the greater the volume of smoke it blows when started. Let it sit 2 weeks and it looks like a white fogger for the first 20 seconds after it starts. But no smoke at all if it's driven every day.
  • I've never messed with the smoke screw nor idle screw and can't say I understand those anyway. I have read that DDP's modified fuel pin may give me the slight power increase I'm looking for, so I'm thinking I may try that.
  • There is an hour meter on the motor. Dunno if it's accurate, but it reads about 1100 hours. Just grasping at straws thinking that might be about the life of an H1C. That, and reading so many other posts that speak of getting >10lbs boost.

Many thanks for any advice!
 

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This is hijacking the OP's post, start your own thread and we can continue to help out.
Cheers Steve
 

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Thanks for asking. I live in upstate SC and travel into the mountains of NC fairly often, so I'm just looking to be able to maintain at least the minimum legal speed of 45MPH up some of the steeper main highways. Right now I can manage about 39MPH in 4th gear (it's a 5 speed tranny). Of course on the flat and up "normal" highway hills it can maintain 55-60MPH with no problem. The steeper sections I am referring to are ones where 90% of the fully loaded semis are able to do better than 45MPH, so I'm hoping to find a way that I can too.

The 4BT in my full-size Bronco is a 105hp model with VE pump, and was stock until last week when I had my mechanic install DDP Stage 1 injectors, which definitely made an improvement, but not enough. And I noticed the improved injectors made no difference to peak boost on the H1C.

The boost ramp-up on the H1C is very linear with RPM, which I spose is to be expected when there is no wastegate? My failed attempt to switch out the H1C for the HX30W this week held the hope that the improved turbo design of the HX30W together with the wastegate would lead to higher boost in the 2000-2500RPM range, and would continue to increase boost up to my self-imposed max of 3000RPM. But as I mentioned in my prior post, the HX30W couldn't be made to fit in the engine bay.

Other things that might be of interest:
  • Several months ago I installed a fuel pressure gauge and it always shows a steady 6lbs at all RPM and all throttle settings until/unless I go above 3000RPMs, which I did once to 3200RPM just to see what would happen. On that occasion, the fuel pressure dropped below 6 but I dunno how far below (I had it set to alarm below 6, and it did, but I was watching the tach, not the pressure gauge).
  • There is no smoke unless it sits without being run for a couple days. In that case it blows some white smoke for about 30 seconds or so after it starts. The longer it sits, the greater the volume of smoke it blows when started. Let it sit 2 weeks and it looks like a white fogger for the first 20 seconds after it starts. But no smoke at all if it's driven every day.
  • I've never messed with the smoke screw nor idle screw and can't say I understand those anyway. I have read that DDP's modified fuel pin may give me the slight power increase I'm looking for, so I'm thinking I may try that.
  • There is an hour meter on the motor. Dunno if it's accurate, but it reads about 1100 hours. Just grasping at straws thinking that might be about the life of an H1C. That, and reading so many other posts that speak of getting >10lbs boost.

Many thanks for any advice!
Want to sell the super 30 to me ?
 

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OK, you have a problem that is hard to correct as an absolute bolt on. The old H1C is an obsolete unit and there are no bolt on parts to make it much better. Yes, the turbine housing for the HX30W is about 1.5" longer due to the wastegate. No getting around that. The solution is generally changing the exhaust manifold. Either use the top center mount manifold 3901635 (see first photo) if you have adequate hood clearance or the one that places the turbo all the way up front shown in the second photo. A third option is a cut down 6bt manifold shown in the third photo. The other thing you need to plan for if you don't have it is an intercooler. All the 4bt's above 105 HP had either a water/air aftercooler or and air/air intercooler. Hot air makes poor power. The 2 turbos we most commonly see used are the 44mm HX30W and the 46mm Super HX30W. The 44mm will have the same 3" air intake and oil line fittings as the H1C. The Super model has quite a few differences. Don't go looking for a better H1C because there isn't one. You can't go larger than the 46mm inducer because the 4bt just can't spool it properly. The only other turbo that would work is the HE221W and it may require other mods to fit.
 

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OK, you have a problem that is hard to correct as an absolute bolt on. The old H1C is an obsolete unit and there are no bolt on parts to make it much better. Yes, the turbine housing for the HX30W is about 1.5" longer due to the wastegate. No getting around that. The solution is generally changing the exhaust manifold. Either use the top center mount manifold 3901635 (see first photo) if you have adequate hood clearance or the one that places the turbo all the way up front shown in the second photo. A third option is a cut down 6bt manifold shown in the third photo. The other thing you need to plan for if you don't have it is an intercooler. All the 4bt's above 105 HP had either a water/air aftercooler or and air/air intercooler. Hot air makes poor power. The 2 turbos we most commonly see used are the 44mm HX30W and the 46mm Super HX30W. The 44mm will have the same 3" air intake and oil line fittings as the H1C. The Super model has quite a few differences. Don't go looking for a better H1C because there isn't one. You can't go larger than the 46mm inducer because the 4bt just can't spool it properly. The only other turbo that would work is the HE221W and it may require other mods to fit.
Thanks again, from my pictures I can’t tell the difference between my manifold and your picture #1?
I was hoping to get that Super 30 . And I’ve seen the oil lines sold for them I believe.
Motor vehicle Green Cylinder Valve Gas
Motor vehicle Green Cylinder Gas Auto part
 

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Thanks again, from my pictures I can’t tell the difference between my manifold and your picture #1?
I was hoping to get that Super 30 . And I’ve seen the oil lines sold for them I believe. View attachment 131620 View attachment 131621
This is the plan for an air to air IC
You can see I already clocked my current turbo. Just don’t know it that link I posted is legitimate..
Tire Wheel Automotive tire Motor vehicle Automotive design
 

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Your exhaust manifold is the 3901635 in that 1st photo. That manifold was common on some the the 4bt's found in Ford E350 vans and many industrial applications. The Super HX30W should fit it just fine. The exhaust pipe connection will be the same, just about 1.5" farther back. Cummins actually made a vertical outlet elbow for those. Part # 3910992 shown below. Those were used on industrial equipment where you had a vertical muffler. You may need a stepped boot for your air filter. A 4" to 3" should be easy to find or change to a larger filter. One thing I see in your photo that you want to avoid is the oil line drain being tilted. It should point straight down for best draining. May need to modify or replace that drain pipe to correct that. I'll see if I can find the part # for the correct one. It may have been a flexible type. Diesel Tuff has the oil line kit for $89.
 

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Your exhaust manifold is the 3901635 in that 1st photo. That manifold was common on some the the 4bt's found in Ford E350 vans and many industrial applications. The Super HX30W should fit it just fine. The exhaust pipe connection will be the same, just about 1.5" farther back. Cummins actually made a vertical outlet elbow for those. Part # 3910092 shown below. Those were used on industrial equipment where you had a vertical muffler. You may need a stepped boot for your air filter. A 4" to 3" should be easy to find or change to a larger filter. One thing I see in your photo that you want to avoid is the oil line drain being tilted. It should point straight down for best draining. May need to modify or replace that drain pipe to correct that. I'll see if I can find the part # for the correct one. It may have been a flexible type. Diesel Tuff has the oil line kit for $89.https://www.benzforce.com/products/new-genuine-holset-hx30w-super-4051167-2835278By looking at this picture would you be able to indicate whether or not it’s a real or a fake? I was thinking about going this route for a replacement
 

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Anything with a wastegate is an improvement over the H1C. HX27w and HX32w are good turbos as well. I use the HE221s myself. I would run an HX25w over an H1C.
 

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Yes, it looks perfectly happy sitting up there. That about as good a turbo as you could want. Members who have those seem to be very pleased with them.
 

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If you use manifold 3901223, it will move forward 5"-6" plenty of room for exhaust down.
 

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Usually the diesel might smoke a bit when you first take off due to the fact the turbo hasn't come on yet. After that you should see very little if any smoke. Owners try to tune to avoid smoke as that is wasted fuel. Might put you a flapper cap on the exhaust pipe like a tractor or industrial engine. Don't want rain going down the pipe when you're not running. Might double check your state. Some would not allow that vertical pipe due to being a visual obstruction.
 

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Thanks, I appreciate it.
The end goal is a Rat Rod and I’m a *** so I like the stack.
Hope the Diesel will smoke a little! - Polski76

Always some smoke but coal rollers are ask holes and keep getting more and more regulations, restrictions and fines put on diesel owners. Then they usually bitch about the EPA. Too much smoke is a bad tune and visual inefficiency.

You running around Henderson a couple of days ago?
 
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Thanks, I appreciate it.
The end goal is a Rat Rod and I’m a *** so I like the stack.
Hope the Diesel will smoke a little! - Polski76

Always some smoke but coal rollers are ask holes and keep getting more and more regulations, restrictions and fines put on diesel owners. Then they usually bitch about the EPA. Too much smoke is a bad tune and visual inefficiency.

You running around Henderson a couple of days ago?
I appreciate your input, still working on it and have a few more months to go .
I wish I was on the road !
 

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What are the dimensions of your i’cooler? Model number and where got?

Thanks, Ed in CO
Ed it’s a Mishimoto S series.
it’s a universal fit.
measures 22 inches wide by 12 inches tall. I fabricated my own mounting plate/bracket for the bottom
 
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