Bigger Exhuast

[wadereg]

if someone would feel the urge to turn up the injection pump on a multi-fuel in an m109 and was worried about EGTs, would you guys think adding a little dia. to the exhuast would help tame the EGTs. I am not thinking about going crazy with increasing fuel...just a little with the help of a pyro. because i dont like the idea of a melt down. im also not looking for a extreme hp gain and i dont want to blacken the sky...just a little extra PEP.

i tried a search but could not find anything w/ or about exhaust dia. and temp. I just figured it would work becuase it did on the 5.9 cummins.

any help would be greatful. oh yea, whos selling shop manuals? i will be needing them asap the paper stuff or on CD for cpu don't care aint picky got money!

 

[CCATLETT1984]

larger exhaust would help some, but before you touch that fuel screw, GET A PYROMETER and install it. if you have a turbo, put it PRE-turbo.

 

[comdiver]

Wade, the manuals can be downloaded from this site. Free

 

[FreightTrain]

Ok,buy 2 pyros,Pull turbo,Drill tap both front and rear bank area at the manifold turn down(Turbo mounting flange about an inch up),install Pyro probes,reinstall turbo,Wire Pyros and mount,Hit the road for base line.Crank on the fuel screw(or you could just make shims out of washer like I do and slide behind the nuts on the fuel screw.

 

[army_greywolf]

pyrometer thermocouple should be located 4-10" before the collector ((turbo itself)) you only need one, two is a waste of time, if you have problems with one bank being higher than another you've got entirely different issues requiring a diesel tech to look at it.

couple things you need to do prior to baselines of a truck as old as yours. First you need to work on the fuel system, including running a can of seafoam/diesel mix through the fuel filters. The tolerances of the injection pump are quite forgiving when compared to modern pumps however years of abuse and military grade fuel ((anyone in the know would agree thats NOT a good thing)).

Maybe I should explain why it's important... well first of all, if your injectors do NOT have an even pattern, they will create hotspots that will simply cook and warp your heads, melt your pistons, burn exhaust valves, all while posting respectable EGTs. SOOOO Moral is, leave well enough alone unless you know everything is in good order. Or simply make sure your prepared for the worst.

Things that will make the motor happier with more power, well simply put bigger exhaust, SNOW performance water/methanol injection, matched injectors, adjusting the pump timing slightly advanced. Probably more important than any of that to get more power is changing out your turbo to match the fuel. Or changing governor springs to raise the top end is a good way to ensure EGTs will not be too high.

Most of the performance mods that apply to light trucks with diesels also apply to a military truck.

Other considerations about adding more fuel would be need for more cooling capacity. But meh... I am so bad at tangents...

Bigger exhaust will work fine for a slight fuel increase.

 

[SasquatchSanta]

FreightTrain wrote:

Ok,buy 2 pyros,Pull turbo,Drill tap both front and rear bank area at the manifold turn down(Turbo mounting flange about an inch up),install Pyro probes,reinstall turbo,Wire Pyros and mount,Hit the road for base line.Crank on the fuel screw(or you could just make shims out of washer like I do and slide behind the nuts on the fuel screw.

I agree with your probe placement (see attached picture) but question why two pyros? As you can see from the picture, I tapped my manifold both front and rear with the intent of installing two probes with a selector toggle switch so I could singularly read both probes with the same pyro. My motive was to be able to easily diagnose possible injector or cylinder problems by switching back and forth to compare front and rear EGTs. I didn't see it through because I felt it was a little over the top. IMHO I don't see why you would need two pyros to monitor EGTs

army greywolf wrote:

Things that will make the motor happier with more power, well simply put bigger exhaust, SNOW performance water/methanol injection, matched injectors, adjusting the pump timing slightly advanced. Probably more important than any of that to get more power is changing out your turbo to match the fuel. Or changing governor springs to raise the top end is a good way to ensure EGTs will not be too high.

You've covered a lot of ground here in a relatively short paragraph greywolf. Not all of us are expereienced diesel mechanics. Please elaborate on "changing out your turbo to match the fuel". I don't recall ever seeing anything on the forum discussing water methanol injection --- perhaps I'm wrong. It sounds like a mellon that would be interesting to open up --- in more detail. I'm all for lowering EGTs and getting more power but with 22:1 compression ratios on the multi I'm always concerned about head gasket failure.

PS: Keep Your Head Down Over There greywolf.

 

[wadereg]

thanks for the input, like i said im not looking to go crazy i just want a little more power for the beach. i already have ONE pyro ready for install...and have the heat gun ready to check manifold temps at each cylinder to check for proper balance and any dead cylinders or bad injectors. it has been thought through just wasnt sure how the high compression multi would react to a little tinkering...good point gray wolf on cond. of eng. due to multiple people beating the crap out of it, the point is well taken mainly because i didnt even think about that. thanks again for the feed back.

thank you for the advice on manuals too comdiver, less money spent = happy wife =happy life.

 

[saddamsnightmare]

January 27th, 2008.

The concept of water injection into the cylinders isn't new, it was used during WWII on US Fighters and bomber enginers to reach what was called"War Emergency Power", the theory was that it would flash over to steam and increase the power output for a very short time. When I had the M422A1 USMC Mighty Mite back in the late '70's, it was suggested that as the engine wasn't happy with the humidity levels in the Ohio Valley (too low), that a water injector be added to handle the high preheat of the intake air due to the lube oil cooler being around the carb and dumping its waste heat on the cylinder bodies, thus creating a death spiral on overheats. The theory there was that the water would cool the lube oil coolers and help remove excess heat from the cylinder cooling fins, as the Mighty Mite was only happy in Asia AND the Artic/Antaric areas (which is why you find aluminum cold weather enclosures for the Mite now and then (Mike Pop take note!).
It would probably boost the HP slightly on the multifuel, but if you're using it on the beach, you'll need to change tires first as NDT's are poor performers in loose sand or snow. The digging out might not be worth it- see Mike about his Mighty Mite, it's much better for that useage. Good luck and keep us informed so we can all learn something.
Regards,
Kyle F. McGrogan
1963 Mercedes Benz Unimog S404.114 (Swiss)(Beach Buggy par excellance!)
1971 Kaiser Jeep M35A2 Wo/W "Saddam's Nightmare" Kuwait DuneBuggy and "Nam mud buster veteran truck

 

[Jones]

Personally, I'm not real sure of a need to tell what the post-turbo EGTs going out the tailpipe are; by then they've done all the damage/good they're going to do.
Monitoring pre-turbo temps would be far more critical because that's where burned valves and valve seats, and burned turbine blade tips are going to occur. Excessive EGTs pre-turbo could also contribute to turbo bearing and seal failure if the circulating lube oil couldn't carry the heat away fast enough.

 

[wadereg]

even with War Emerg. Power you had and increase in eng. temp., my pops ran same set up in his crop duster for climb out power. my questiion is; isnt the water methonal inject. designed for gas. engs. never heard of it being used in diesel...not to comfortable with the idea of pushing it through my multi. if anything i would think about going to propane injection with a little nitro...pop. the heads right off that bad boy...but, i dont want to do that. i just want that little kick in the pants when i hit the sand.

NTD are being kicked to the curb for the 395s little brother the 365/85r20 michelins and maybe some diablo rims....

 

[devilman96]

Propane isnt going to pop heads, if installed right it will give you more power and lower EGT's...

 

[spicergear]

Yes, water injection can be used on diesels.

I have to wonder about the main topic about the exhaust size increase. I'd think this would be more needed if there was any kind of restriction or baffle/muffler...but there isn't. For the size engine, no restrictions, and only 2800rpm...me thinks it'll be okay for long time.

 

[wadereg]

I was talking about going crazy with propane, nitro and fuel...over exaggerating a little. I was trying to make a point that I want to add more fuel but manage EGTs and get a "LITTLE" more power. Mainly I like a fat exhaust and I wanted to have a logical reason for doing so. You guys are great but you all sometimes make it hard to make a decision. Once again I don't know what to do...anyone want to do a pros and cons list for me. I am taken back my statement that this was a well planned idea...

 

[wadereg]

I guess by the way my last post was worded it made me sound like an @$$ and may have given some the idea that i dont care about their input. Well, I was just trying to be funny and I am sorry for being so thoughtless. Everyones input is needed in my decision making when it comes to the m109 providing i have very little experience with these trucks thats why i am so adamant in getting everyones opinion. I have heard each and everyones statements and i am thankful for every post. i would now like to ask if there could be a vote (yes and no) from each who care on whether or not i should make the change. PLEASE!

 

[kaiser2help]

Grey Wolf and others. I am glad to have stumbled apon this topic. I am about to install a pyro on my LDS 465 1A and I have not done so yet because I am undecided of location. I am a diesel mech and I fully agree on pre turbo location. However, why is it that MAck, CAT, and Cummins all have a pyro post turbo. Do they perhaps run a different style pump. afterall we are just helping to clear the engine for the next cycle, and lower emissions, and even help the eddy currents of flow through the engine with our turbo. It appears grey wolf you have a good step up of knowledge on me. So I am calling on your help, and any others as well. Also, drilling and tapping cast creates a powder like particles .So I was thinking why not idle your engine, create a little back pressure, and drill the manifold slowly with the turbo intact. I am sure that there have been harder carbon particles that have gone by the turbo than the small powdery cast ones. Plus the positive pressure of the exhaust would assist. The same with tapping. Grease the flutes and just go easy. Real easy.

 

[spicergear]

OH...I got it now- Five inch with a slash cut top!

 

[SasquatchSanta]

Whether a larger exhaust system is needed or would appreciably help I can not say. When I installed the duals on my truck I also installed an LDS engine therefore there was no bace line comparison.

I've toyed with the propane concept and several months ago did quite a bit of reading and noodling on how to build a system. From what I remember propane doesn't cause as much heat as diesel fuel. If this is true one would think it would be a good "get me over a hill" short term boost remedy.

I've thought about using an electric two speed axle switch mounted to the transmission shifter lever to control a simple propane injection system. When you come to a hill simply hit the switch for boost.

I've got an old propane system out in my garage that I may play with next summer. I'm basically thinking about a constant flow orfice, manually controlled with the 2-speed switch and only engaged it at certain rpm rangse and probably only in 5th gear.

If you were to inject the propane pre-turbo it should increase the boots pressures but I don't know exactly how safe pre-turbo injection is ???

The one concern that I have is the question of exactly how much propane dries out an engine. I'd hate to use too much and end up scoring a liner.

I "think" it would be a good way to get a lot of short burst power while keeping EGTs in a safe range.

 

[kaiser2help]

Location for pyro

Can someone help elaborate on this topic. Perhaps I posted in the wrong discussion. Could sure use some insight though.Thanks.

 

[steelsoldiers]

RE: Location for pyro

There are a lot of diesel hot rod shops out there playing with all kinds of hop-ups. Some of the more common add-ons are methanol injection systems, propane and nitrous oxide.

Methanol serves as a "chemical inter-cooler." It lowers combustion temperatures so that more fuel can be safely added. Methanol also acts as a fuel for more power. One of the more common systems is Snow Performance.

Propane systems tout more power, better mileage and cleaner emissions with appreciable increase in EGT's. Propane is typically burned at a 1:4 ratio to diesel.

NO systems pack a super-dense charge of oxygen as an accelerant into the intake. These systems are typically used on demand in full throttle situations, which makes them used more frequently for racing, truck pulling, etc...

For a deuce used for play, the most economical way to go is to add a pyro gauge and tinker with the fuel delivery. The open exhaust systems of the turbo trucks should not limit performance. Don't forget to run a good diesel additive like Power Service to combat the low sulfur lubrication issues, boost cetane, and prevent gelling/algae.

The next step would be to add a boost gauge, more fuel, and a larger turbo. Personally, I don't think a LDT is a good candidate for big power increases. It is much happier and more reliable at the stock or close to stock settings. That said, I would love to see someone build a hot-rod LDT from the block up. You know, all the big hop-ups: blue-printed block, ARP studs, o-ringed heads, performance pistons, piston oiling, custom cam, custom IP, big turbo, valve-job, valve-springs, custom governor, etc.... I wonder how much time and money you could sink into it to make it match the power of a built 5.9L Cummins?

 

[FreightTrain]

RE: Location for pyro

Water is very dangerous on a diesel.If done right it is perfectly safe and gives a nice boost of power but there is a VERY fine line.Not enough and you don't get much umph.Too much and you have a 1800lb paperweight.Gotta think.More power means less engine life period.A candle that burns twice as bright burns half a long.Water methanol injection can cause cracked piston if you overdo it.I have a Ford V8 that has 8 star cracked pistons(looks like spiderwebs!) and one cylinder with a wrist pin pulling out of the piston.Propane is one of the best bangs for th bucks(with safety is taken into the mix).But Pane is really only good for near WOT or at WOT.If you ran it with any noticible power increase full time a grill tank would only last about 20 miles.