Air to Water intercooler on a diesel power unit?

[JFriesen]

Hoping some diesel buffs can help here. On our farm we have several diesel irrigation motors 75-125 hp load 466 john deeres, 5. 9 cum, iz. and cat. most are cooled through a cooling coil in the irrigation water. All are turbo'd but they aren't intercooled. With $2. 90 farm diesel we were just considering adding air to water intercoolers to the engines to save fuel. Would plumb in to the 56 degree water to run through the cooler, like the drag car ones I found on EBAY. Any experience with charge air temp versus fuel economy numbers? Approx 6 gph fuel usage on most of these engines. We don't need to run radiatiors to cool the engines so you can shave all those fan horsepower requirements. Just can't run a traditional aftercooler without a fan. Thanks

 

[DCreed]

125hp? dont think they're workin' hard enough for intercooling. Also cold air doesnt burn as well in diesel so may use MORE fuel.

 

[JFriesen]

125 hp continuous (for thousands of hours) at 1750 rpm is quite a bit different than a dyno run at 3200 rpm for a short time frame.

 

[rbattelle]

This is an interesting question. We know that increasing inlet temperature tends to reduce ignition delay and so does supercharging, so a non-intercooled turbocharged engine should run with less delay and a more favorable rate of pressure rise.

But then, why are many on-road engines intercooled? Presumably, the answer is charge density. By cooling the intake charge at constant pressure and volume (assuming the turbo compressor is keeping constant pressure), the mass of air in the charge will increase (thus increasing the density).

And so we find a tradeoff between high charge air density (improves power) and delay (improves smoothness and durability).

I can't say how much (if any) economy improvement you'll see. Maybe convert 1 engine, and see what happens.

Here's a thread where we discussed this awhile back.

Ryan

 

[JFriesen]

Pete Tomka in the new TDR mag claims "Every 10 degree F drop in intake air increases milage by 1%" This is dealing with air intake systems but the same should apply to air cooled after the turbo, not?



I would think it would be fairly easy to drop the temp by 50 degrees = 5% or . 3 gal/hr x 1200 hr/year = 360 gal x $2. 90 = $1044 per year savings per engine. Hence my enthusiasm for this idea.

 

[DCreed]

there has to be a practical limit though, or we would get BETTER milage in winter... but we dont.

 

[cojhl2]

there has to be a practical limit though, or we would get BETTER milage in winter... but we dont.

Thre are a lot more variables in milage than in these constant output power engines. I don't think there is a valid comparison.

 

[JLEONARD]

Per a diesel engine engineering book I have, intercoolong increases efficiency by about 5%.

Book was written inthe 80s

 

[tgordon]

there has to be a practical limit though, or we would get BETTER milage in winter... but we dont.

Main problem there is you have a change in fuel along with (I am guessing) more idle time to warm up.



Deere used liquid intercoolers on the 466's. Just brace yourself before you ask the price. Anyways, just the intake manifold I belive is in the neighborhood of 3-500. That does not include the cover, gaskets or the inter cooler itself. You will have a great source of cool water their sounds like a great idea, now just have to fund it:{ This was before they switched to the air to air. My guess is since they were using the engine coolant they could get it cooler with air to air.



Do you ever run into trouble with the coolant getting to cold going through the water like that?

 

[DCreed]

Do you ever run into trouble with the coolant getting to cold going through the water like that?

That IS essentially what I'm saying! the engine NEEDS heat to run efficiently ,just how much I dont know, but most engines are about 180*. If they are allready running "cold" then cooling the intake air further doesnt seem helpfull.

 

[tgordon]

Here they talk about it and referance some where in the 50-70 degree range is where the maximum efficiency is.



Intake air temp - Dodge Cummins Diesel Forum Which would be supported by



DCreed you might take a look at this article



http://www.everytime.cummins.com/every/pdf/MPG_Secrets_Whitepaper.pdf



As the air cools it increases the drag on a vehicle and hence I am not sure but what the drop in winter milage has to many variables for it to be placed in any one area.



JFriesen it sounds like you are in a perfect situation to teach us all here having a liquid source that falls into the "Ideal temp" range. Just make sure the cooler will flow enough CFM for the engine, a lot of the ones I say looked like they would be on a rather small engine. I am guessing 1000 hp in a little 4 banger is a little differant flow rate from what it would be in a diesel





I keep finding more interesting stuff onthis subject, this one talks aobu thow cetane value will effect the starting and running of th eengine.



Re: What are the benefits or detrements of adding a cetane booster in diesel

 

[JFriesen]

Do you ever run into trouble with the coolant getting to cold going through the water like that?

No they usually run 180-200 degrees depending the weather.

 

[cojhl2]

That IS essentially what I'm saying! the engine NEEDS heat to run efficiently ,just how much I dont know, but most engines are about 180*. If they are allready running "cold" then cooling the intake air further doesnt seem helpfull.

I bet there is a coolant to water heat exchanger complete with themostat. I can't believe they run the irrigation water (especially under 80lbs/in2 presssure thru the water jacket. .



JFriesen where are you??

 

[tgordon]

most are cooled through a cooling coil in the irrigation water.

It is one of those things where it depends upon the size of the coils etc as to how much it cools it.



This sort of stuff intrigues me and now I will sit and try to find the info. I found a lab in CA that has a N14 single cylinder set up with several windows in it to film diesel combustion and attempt to figure out emmisions formation.

 

[rbattelle]

Pete Tomka in the new TDR mag claims "Every 10 degree F drop in intake air increases milage by 1%" This is dealing with air intake systems but the same should apply to air cooled after the turbo, not?

No, not necessarily. Remember, you've got to consider the effect of colder air on the combustion process (specifically delay angle).



If it were me, I'd do 1 engine and see what happens.



Ryan

 

[DCreed]

If it were me, I'd do 1 engine and see what happens.



Ryan

I think THIS is the BEST advice . Then when you know the answer YOU could help US!

 

[JFriesen]

cojhl2- We're in SW Nebraska.



I think we might try one, if our engine salesmen have any insite it might help. I'll try and remember to post some fuel use numbers be the end of summer for those that will remember this good discussion till then. Thanks all.

 

[tgordon]

You'll have to let us know what the intake temps are also. From the data I found I don't think you could get it cold enough to actually hinder the combustion at all.

 

[HoleshotHolset]

I'm sort of helping a friend and fellow TDR member repower two tractors: Oliver 1650 (with a 4BT) and a White 2-135 (with a 160hp 6BTA).



He priced out a new aftercooler and it was darn near $700 from Cummins - so you may want to steer clear from buying a new aftercooler core unless you've got someone to give you a better price on one. Finding these in a used condition is a bit tough...



You'll also have to get new injection pump lines since they're routed around the aftercooler on the 4BTA's, 6BTA's and even the 8. 3L 6CTA's. The cheap eBay air/water intercoolers might be your best bet to do some experimenting. They look like they're pretty good quality for the money...



Good luck and please keep us updated - I'd be interested to hear the results.



Beers,



Matt

 

[CNeubauer]

If your gonna try a unit for a gas engine I'd make sure it will flow enough air for your diesel. Your engine's shouldn't be using huge amounts of air at those power levels but it's still going to be more than most gas engines.