Builds Moonshine - A Build Thread (18 Viewers)

[boots4]

Also sounds like your idle is set pretty low ...

After listening to the latest video with some real speakers I definitely agree that your idle is way too low. I think it's below or barely at 700rpm. It should be spinning at least in the 800 range. Bump that up to a nice little purr.

 

[Dirtgypsy]

I would wait to reserve the thought of lag till you drive it and get a load on it. Fuel and misc adjustments are easily mitigated after you have a running driving truck.

I would agree on the idle. Turning it up will smooth it out some.

Congrats! Well earned

Clint

 

[bluehawk]

I wanted to see this thing run sooooo bad, I drove 350 miles just to see it in person and hear it run. Oh yeah and buy a H55. Man Moonshine sounds like a beast in person, just awesome. Outstanding job Johnny

 

[GLTHFJ60]

Mine is also immediate. Wonder if it's that governor spring? It doesn't make since that it would be that though because that spring is stiffer to allow more rpm before defueling so it would seem like it could potentially help response.

That washer (assuming it's what I think it is) would only limit the end travel of the fuel pin and not the beginning. I'd be curious about your smoke screw on top of the AFC housing. I wonder if it's backed out all the way which means the fuel rod will start on the shallowest part of the fuel pin. Wonder if you could screw the smoke screw down (clockwise) in increments to see if response improves. The balance is how smokey it will be at idle and slight throttle but with your faster spooling turbo you may be able to get away with it. Also as Dave says maybe the fuel pin is turned to the mildest setting. Turning that and adjusting the smoke screw can accomplish similar results at idle and minor throttle input.

The other thing could be the throttle arm itself if there is a decent amount of play in that spring and pin/stopper thing on it. My spring and pin have been warn over the years so I flipped the spring so that it would ride on a different part of the pin/stopper to close down the gap caused from wear.

I'd drive it first before making any adjustments so you can get a baseline for performance and real readings from your gauges; boost and egt. Once you have some gauge results that can help tell us what's going on.

Fantastic information Mike. I haven't played with the smoke screw, so that'll have to be something to check into. It could be that the governor spring is limiting throttle response simply because it's longer than the factory spring, I'm just not sure.

When I put the injection pump in the pump guy suggested bumping the timing a bit, so the IP is clocked about 1/16" towards the head. Would this affect throttle response at all?

Different settings on the same injection pump can make a difference in sound so there would definitely be a sound difference between different pumps. Yes, the turbo also plays into that.

Right, now that you mention it, I remember you posting in your thread that you can tune it to change the sound of the motor. I'll have to read into that more.

X2 ^^^^^^^^

but I didn't see the big smile on your face .. !

It's right here

Honestly though, while awesome, getting it started was a bit anti-climatic. I like doing work right the first time, so the fact that my work had to be re-done pisses me off. Oh well, live and learn, right?

I'm just running an H1c with a 12cm2 housing.

Gotcha. How are boost and pyro readings with that turbo? Laggy?

Also sounds like your idle is set pretty low which may account for the throttle lag. Do you have a tach hooked up? A Tiny Tach is cheap and easy to install.

I agree, idle speed does sound low. I just called the IP shop and asked about whether or not idle speed was set at the shop. He told me that they can't use diesel fluid on the IP and injector test stands, that they use what's called 'calibrating fluid'. Due to this and other fuel system differences between the test stand and the motor's system, idle speed needs to be set on the motor. However, I need to get a tach hooked up to do this properly.

I've done a bunch of reading on the Tiny Tach. Where do you mount the sensor on a 4BT? Do you have to drill a hole in the flywheel housing to mount it or is it mounted somewhere else?

X2 on turning the smoke screw in first which should pickup idle. Drive and record differences, then try turning the full power screw a little...which will also increase idle speed

Will do man, thanks for the input!

That thing sounds BAD ASS! Congrats.

Thank you sir! Saying I'm happy about how it turned out would be an understatement

After listening to the latest video with some real speakers I definitely agree that your idle is way too low. I think it's below or barely at 700rpm. It should be spinning at least in the 800 range. Bump that up to a nice little purr.

I'm going to hook up a tachometer before I set the idle speed. I agree though, it's currently idling too low. I may screw it in a bit just to get rid of the huge shakes.

I would wait to reserve the thought of lag till you drive it and get a load on it. Fuel and misc adjustments are easily mitigated after you have a running driving truck.

I would agree on the idle. Turning it up will smooth it out some.

Congrats! Well earned

Clint

Agreed, getting it driving comes before messing with the fuel settings. Too many unaccounted variables with it just sitting in the driveway.

Thank you Clint!

I wanted to see this thing run sooooo bad, I drove 350 miles just to see it in person and hear it run. Oh yeah and buy a H55. Man Moonshine sounds like a beast in person, just awesome. Outstanding job Johnny

Thank you Ryan! She's gonna be a fun truck. I hope to get out to wheel with you TN guys this coming year!

 

[GLTHFJ60]

Speaking of getting this up and running, I picked up my driveshaft yesterday and tried to put it on, but found that they made it too long, by 3" or so. WTF???

Brought it down to find out that the guy to whom I described my order took it down as 41 5/8" CJ to CJ ( center joint to center joint ), whereas it should have been CJ to Flange. The Toyota end needs to be measured to the flange because it does not couple up to a yolk. As a result, it's too long. Brought it back today and it should be done tomorrow.

Looked pretty good too:

 

[boots4]

When I put the injection pump in the pump guy suggested bumping the timing a bit, so the IP is clocked about 1/16" towards the head. Would this affect throttle response at all?


I've done a bunch of reading on the Tiny Tach. Where do you mount the sensor on a 4BT? Do you have to drill a hole in the flywheel housing to mount it or is it mounted somewhere else?

I have played with timing on my engine from stock to about 1/4 of timing. In my experimenting it seems like 1/16 is about a degree in timing. That is really just a rough guess but it's somewhere to start. Right now I'm at 1/8" of bump which gives me around 15 degrees. In all the playing throttle response didn't change much, meaning it was always immediate.


The tiny tach (diesel version is what I have) is very easy to hook up. The pick-up mounts on one of the injection lines to read the pulses. Then it gets switched power and you're done. I had always planned to get the factory tach working but the tiny tach has been a great permanently temporary solution.

 

[krzyabncanuck]

Speaking of getting this up and running, I picked up my driveshaft yesterday and tried to put it on, but found that they made it too long, by 3" or so. WTF???

Brought it down to find out that the guy to whom I described my order took it down as 41 5/8" CJ to CJ ( center joint to center joint ), whereas it should have been CJ to Flange. The Toyota end needs to be measured to the flange because it does not couple up to a yolk. As a result, it's too long. Brought it back today and it should be done tomorrow.

Looked pretty good too:

Good thing about that to fix is they just cut the amount it is over out and reweld and true up again. Add paint and drive.

 

[GLTHFJ60]

I have played with timing on my engine from stock to about 1/4 of timing. In my experimenting it seems like 1/16 is about a degree in timing. That is really just a rough guess but it's somewhere to start. Right now I'm at 1/8" of bump which gives me around 15 degrees. In all the playing throttle response didn't change much, meaning it was always immediate.


The tiny tach (diesel version is what I have) is very easy to hook up. The pick-up mounts on one of the injection lines to read the pulses. Then it gets switched power and you're done. I had always planned to get the factory tach working but the tiny tach has been a great permanently temporary solution.

Good info Mike, duly noted. Advancing the timing increases top end power, right?

Which transducer size did you use for the tiny tach? I think ill pick one of those up!

Good thing about that to fix is they just cut the amount it is over out and reweld and true up again. Add paint and drive.

Very true. It'll be done tomorrow.

 

[GLTHFJ60]

Which transducer size did you use for the tiny tach? I think ill pick one of those up.

1/4" is the diameter of the 4BT injection lines:
http://www.4btswaps.com/forum/showthread.php?8121-The-new-and-improved-Tiny-Tach&highlight=tinytach

 

[bluehawk]

Hi Johnny, You get the drive shafts in yet? Would love to see Moonshine moving under her own power. Merry Christmas

 

[krzyabncanuck]

He is up north right now.

 

[GLTHFJ60]

Yes sir, I drove her for the first time Friday night. I'm back in upstate ny for the holidays. More updates when I return.

 

[bluehawk]

Awesome, Merry Christmas

 

[Elbert]

After you have had it running for a few months and worked out any gremlins be nice to post up some feedback on driving impressions, fuel use, torque impressions, off-road use , hwy cruising speed... likes / dislikes, pros / cons?

 

[GLTHFJ60]

Awesome, Merry Christmas

Merry Christmas and Happy New Year! I'm going to start looking for that shift knob in the next few days.

After you have had it running for a few months and worked out any gremlins be nice to post up some feedback on driving impressions, fuel use, torque impressions, off-road use , hwy cruising speed... likes / dislikes, pros / cons?

Will do! Look for that report early spring.

 

[GLTHFJ60]

Well guys, on December 21st, I drove Moonshine for the first time. Throttle lag is ridiculous which makes perception of power difficult. The truck was filled with all kinds of parts ( rattles ) and it was very cold, so it was a very "raw" experience. I loved every second of it

When I parked it, the front brake line blew out and the PS reservoir leaks like a sieve. She will sit till next weekend when I have more $ to buy the parts needed to push her into DD duties again.

As for the throttle lag, I believe that it's due to the increased length of the 3800 RPM spring. The throttle arm is indexed to fit the shorter, stock, 2500rpm spring and I suspect that I need to clock the throttle shaft a couple of hash marks counter-clockwise to restore proper throttle spring tension to allow proper throttle response. See this thread as a reference. Thoughts?
http://www.4btswaps.com/forum/showthread.php?16609-93-cummins-3800-gov-spring-and-no-start

Pic of stock spring and '374' ( 3800rpm ) spring as a comparison:

 

[boots4]

Yes, adjusting the index on the throttle lever is not hard, just a little time consuming because I'd suggest going in increments rather that a huge jump. Re-indexing will mess with your idle adjustment so expect tinkering with that too. I don't know anyone running the 374 spring so you'll have to do some experimenting to get it right which means you'll need to trust in your troubleshooting and results. Once you wake that thing up the grin will return.

 

[GLTHFJ60]

Yes, adjusting the index on the throttle lever is not hard, just a little time consuming because I'd suggest going in increments rather that a huge jump. Re-indexing will mess with your idle adjustment so expect tinkering with that too. I don't know anyone running the 374 spring so you'll have to do some experimenting to get it right which means you'll need to trust in your troubleshooting and results. Once you wake that thing up the grin will return.

Thanks for vetting my thoughts. I guess I'm venturing to undocumented territory with this mod.

I've seen a couple of posts online on Diesel Bombers and Diesel Truck Resource stating that the throttle plate needs to be re-indexed, and that the spring itself may need to be trimmed. Once I get a new battery I'll start playing with it. A Tiny Tach is coming down the line soon so that I can measure my RPMs.
http://www.dieselbombers.com/5-9l-rotary-performance/15277-gov-spring-numbers.html
http://www.dieseltruckresource.com/dev/archive/good-news-3800-rpm-spring-fitment-t79879.html

 

[GLTHFJ60]

Ordered my Tiny Tach.

I'm getting a bunch of advice to play with the smoke screw in my aneroid before messing with the throttle index, as it controls low boost fuel supply. Think I should install the stage 2 fuel pin before anything else, seeing as I intend to do that anyway? That way I'll be making final adjustments as opposed to getting it running right to start off with, only to readjust everything later.

Thanks again for the advice!

 

[TRAIL TAILOR]

Johnny,

Great to see your diesel come to life. Lots of good info in this thread. Keep it coming. I'm on the prowl for one too.

J