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Discussion Starter · #1 ·
I live in a mountainous area with some very challenging grades. The downhill runs are complicated by my NV4500 ratios. 3rd gear tops out around 30-35 mph, and 4th gear is a long stretch away. A gear assisted descent results in a 25 mph limit in 3rd, and 4th is too high for any compression braking benefit as I'm going too fast to handle the tight curves. Answer: exhaust brake. Problem: the usual, $$$$$!

I'm going to build my own exhaust brake and have the mechanics of it laid out but a thought struck me. Certain models of exhaust brake call for an upgrade to 60 lbs exhaust valve springs, and stockers are around 30 lbs pressure, so does that mean that my exhaust brake would only require about 30 lbs apply pressure on the butterfly to slow the vehicle by compression? For some reason I was thinking 100's of lbs pressure but now I'm wondering if a relatively light pressure would slow the vehicle? Can't see why I would have to exceed the exhaust valve spring pressure to have compression braking. Thoughts?
 

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JimmieD why take a risk with the 60# springs they are cheap and easy to change, you don't need to take the head off as long as the piston is at TDC for the cyl you are working on and then rotate the crank to get TDC for the next one. Sounds like an interesting project to make your own exhaust brake though you will have to post pics of it though.

Gaza
 

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I might be totally off on this but aren't valve spring ratings still being measured by the amount of foot lbs of torque they generate at an specified height by using a height scale jig and a torque wrench for calibration? The calibration jig looks like a small modified arbor press.
So in other words a 30 pound spring has 30 pounds of compressed loading resistance at a specified height?
 

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exhuast brake

why mess with the valves at all, get a brake setup for late model diesel pickup. these exhaust brakes close the exhaust after the turbo to create back pressure. seems if you were making it yourself this would be an easier setup than going through your valve train
 

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why mess with the valves at all, get a brake setup for late model diesel pickup. these exhaust brakes close the exhaust after the turbo to create back pressure. seems if you were making it yourself this would be an easier setup than going through your valve train
Gus, he is trying to go the exhaust brake route(by making his own), but if the valves wont hold the back pressure, then he will need to bump up to a higher rate valve spring. Most, if not all the newer style motors have higher rater springs stock 4bts.
 

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Discussion Starter · #6 ·
JimmieD why take a risk with the 60# springs they are cheap and easy to change, you don't need to take the head off as long as the piston is at TDC for the cyl you are working on and then rotate the crank to get TDC for the next one. Sounds like an interesting project to make your own exhaust brake though you will have to post pics of it though.

Gaza
Well yeah, you're right about the 60 lbs springs Gaza, but I won't need them. By drilling the right sized orifice hole in the butterfly the backpressure never exceeds the valve spring seat pressure. What I was wondering is if my thinking is right: that the max pressure needed on butterfly is 30 lbs or a little less, maybe 25-30. Previously I was thinking it would take 100's of lbs pressure on butterfly linkage to give sufficient backpressure without butterfly blowing open, but now I'm thinking the max would be 25-30. Speculation, not sure....

With the proper sized bypass orifice, and controls that cause the e-brake to open instantly at any positive throttle application the valves/pistons are safe.
 

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You'll also want a release switch on the clutch pedal.

The ones in light trucks that I've used don't have enough restriction to kill the engine at idle, just pull it down by 50-100rpm.
 

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Well yeah, you're right about the 60 lbs springs Gaza, but I won't need them. By drilling the right sized orifice hole in the butterfly the backpressure never exceeds the valve spring seat pressure. What I was wondering is if my thinking is right: that the max pressure needed on butterfly is 30 lbs or a little less, maybe 25-30. Previously I was thinking it would take 100's of lbs pressure on butterfly linkage to give sufficient backpressure without butterfly blowing open, but now I'm thinking the max would be 25-30. Speculation, not sure....

With the proper sized bypass orifice, and controls that cause the e-brake to open instantly at any positive throttle application the valves/pistons are safe.

100 lbs, 30 lbs, 5000lbs, it's torque that you are looking at. Since the buterfly rotates, your moment arm will decide the required force necessary to acctuate the valve. you should be looking for a ft-lb rating for the valve. 1 pound of force applied at one foot from the rotating center is one ft-lb. at 6" it would be .5 ft-lbs.

I would try and find out what actuator comes with the setups for dodge rams, etc, they are pneumatic i'm pretty sure and find out what it is rated for and go from there.

You may need to install an aircompressor, one inline with your power steering pump or a v-belt pump like a York.
 

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Discussion Starter · #9 ·
You'll also want a release switch on the clutch pedal.

The ones in light trucks that I've used don't have enough restriction to kill the engine at idle, just pull it down by 50-100rpm.
Thanks, Dougal, I hadn't really decided where to put the release but that's the best thought, similar to a brakelight switch, but at clutch linkage. Probably a microwsitch with a flexible reed that trips switch at any movement, but then allows clutch linkage to then pass by reed for normal operation. Thanks, good idea!
 

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Discussion Starter · #10 ·
Thanks, Durango, that's right where I was stumbling. I have very poor mathematical skills and don't even know standard formulas. There are at least 5 types of actuators: pneumatic, vacuum, hydraulic, electric solenoid and pull cable. I see what you mean about lever arms and ft. lbs. relationships and that helps.

Your anwers helped, guys, and I now have the solution to the problem. I'll let y'all know how it turns out, hopefully pretty soon?
 

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Thanks, Durango, that's right where I was stumbling. I have very poor mathematical skills and don't even know standard formulas. There are at least 5 types of actuators: pneumatic, vacuum, hydraulic, electric solenoid and pull cable. I see what you mean about lever arms and ft. lbs. relationships and that helps.

Your anwers helped, guys, and I now have the solution to the problem. I'll let y'all know how it turns out, hopefully pretty soon?

glad to help. i can't wait to see what you come up with and how it works...
 

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Jim;

I have a 2003 Ram CTD with Exhaust Brake. The Jake is wired thru the Throttle position sensor and then to the Engine Control Module. There is a switch on the Shift lever to arm or dis-arm the Jake. In an armed conditon, when your foot is removed from the Throttle Pedal, in 2 seconds the Jake is actuated. The 2 second delay is so you can shift without the Jake coming on. Push on the throttle and the Jake is released. In the dis-armed mode, no jake is operational. I leave my Jake armed all the time.

I was planning on putting a Jake Exhaust brake on my M37. BUt I just dont have the real estate to mount it.

However, I was going to put a Normally Open Micro Switch on the throttle linkage somewhere so that when the pedal returned to idle ( foot off pedal) , the switch would activate and go closed. This would start a 555 IC Timer to count down 2 seconds and then fire a single shot to latching relay driver. The relay could control a Air or vacuum electric valve or possible even a big womping solenoid ?? When you stepped on the throttle and the Micro switch went back to Normally open, the relay would unlatch and the system would revert to no Jake. It would be a poor mans copy of the Jake/Dodge System.

Back in the 80's when I was into electronics this would have been easy with a 555 timer and 7400 series IC's. I have been out of electronics so long I dont have a clue what is available now days to do this job. But you can bet your shirt that Digi Key has the components on shelf, and cheap !!!. I no longer do anything in electronics nor do I want to. Those days are long over. However, you need to find a Amateur Radio guy who likes to build things. He could whip one out for you quicker than............well quick and cheap. I would have to do the same. Ask on some of the forums you visit if there is a Ham who could give you a little help, you may be surprised how quick help is available. Ham's love to design and build. By the way, the system woudl operate on/off in an instanbt just like the Dodge/Jake system and may even be more reliable since its dedicated and uses less systems.

Paul ( Unstable Gyro
 

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Discussion Starter · #13 ·
Most excellent, kind sir, and all data filed! From that it is a simple thing to assemble. I have a machine controls background so no problem fabbing it all up, thanks!!! Again.....
 

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Most excellent, kind sir, and all data filed! From that it is a simple thing to assemble. I have a machine controls background so no problem fabbing it all up, thanks!!! Again.....
Hey Jim; I was thinking while dining tonight, yes, My dog and I dine ha ha. This is 2007, I bet sitting on the shelf at some electronic control company is a little black box to take open/closed switch contacts and have a NO/NC relay contacts come out the other connector.

Paul
 

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you could probably pickup a dodge exhaust brake for a 89-93 for $200-300 and install it right off the hx30 exhaust housing i cant remember if the band clamp is the same, or upgrade to a hx35 and run the 94-98 12cm housing.
 

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you could probably pickup a dodge exhaust brake for a 89-93 for $200-300 and install it right off the hx30 exhaust housing i cant remember if the band clamp is the same, or upgrade to a hx35 and run the 94-98 12cm housing.
Dusty;
Would a 89-93 E Brake be 3" ? Is 89-93 Dodge Down Pipe 3"

Paul
 

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yes they were a 3" down pipe off the back of those years and they were non WG and used a band clamp i think the same as the HX30 uses

the wh1c and h1e's had 18 cm and 21.5 cm Non WG housings but the 12cm 14cm and 16cm non WG housings can be had throguh cummins
 

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Discussion Starter · #18 ·
Thanks, Paul and Dusty! Dang, that almost sounds like a Country Western band....

Okay, the deal is the same deal as always: terminal no-bucksness. That means I have to fab my own and go as simple as possible. I don't have either a vacuum pump or compressor installed, just a P/S pump, but I removed that because I'm manual steering. I've got the raw materials to build an E-brake and it would be much cheaper than even buying used with all the required correct pieces. Plus the challenge is interesting and I'm a nut for DIY!

If this thread wanders off into a general discussion about E-brakes that's sure fine with me, so have at it ha hah! Not many other threads on this forum regarding them so maybe a good place to run it out?

Thanks for the help, guys, it helped me to find the solution.
 

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Did you ever finish your E-Brake? I would be interested to see pics of constuction and performance info.
 

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If this thread wanders off into a general discussion about E-brakes that's sure fine with me, so have at it ha hah! Not many other threads on this forum regarding them so maybe a good place to run it out?
Okay, you asked for it. LOL. Here's the skinny on the whole 30# versus 60# spring thing. Yes you can run an exhaust brake with 30# springs. The only catch is you can only generate 30# of back pressure before you run the risk of floating the valves and allowing them a very intimate encounter with the pistons. With the 60# springs, you can generate twice the back pressure, and yes, you can definitely feel the difference.

Here's the problem with the bypass orifice, yes it works, but it is not very consistent. Let's say you engage the brake at 3000rpm and have 30# of back-pressure (assuming you don't change the springs to save cash), when the engine slows to say 2100rpm, you may only be generating about 22#, and by 1500 only around 7-10# . This was a problem I saw allot when I installed Pacbrakes on motor-homes and duallies. They worked great as long as the revs were up. Then I started installing the US Gear version. They were much better at keeping a stable restriction. They use two butterflies, one large and one small. The large one would close the pipe, and the small one was the bypass. There was a little arm hooked to it, almost identical to a waste-gate. This was calibrated to open at either 30# or 60#, and would open at high rpm to keep the pressure at a safe level, then start to close as the rpm's dropped off to keep the pressure up. Quite the slick idea.

My biggest issue with any of the aftermarket toys is that they are just too damn expensive for what you get! So I applaud you for making your own!

Check out US Gear's website and look at the D-cellerator. That's the one I'm speaking of. Another cool feature it has is that every time the truck starts, it cycles itself twice to keep the soot gremlins at bay.

As far as the clutch pedal release, that would certainly work, although most of the aftermarket ones don't do it that way, and most of the old road tractors didn't either. It does make it very easy to change gears quickly because the engine returns to idle much faster, although this isn't as much of an issue with a synchronized light truck tranny.

Good luck with your project, and post some pics when you get it done so we can all steal your idea! LOL:rasta:

Later,
SS
 
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