12H-T performance Build (1 Viewer)

[gbentink]

I rechecked the manual and the stock setting is actually the range of 255-267cc for 6cyl at 1000 shots.

So that is ~ 200gm-209gm/kwh

Which is where I would have thought, amongst the most efficient std fitment diesel of the era.

I am confused as the stock other values I gave you and will check some more.

Std boost range is 5.5-7.5psi

 

[gbentink]

Ignore last post, expect boost levels - that is std per manual and what I have seen.

The values I gave were for the 2H engine with no boost that makes around 210nm and the rpms are 2200, so not at the most efficienct revs - most efficient should be ~ 1700rpm (for a diesel).

Anyway, 345-363cc for 6cyl and 1100 pump rotations, 312nm, 5.5-7.5psi boost, 085 diesel density, efficiency, calc is as follows:

kw @ 312nm @ 2000rpm: 312*PI*2000/30000 = 65.3kW

Fuel usage @ 2000rpm @ 1hr = 345*0.85*60/1.1 = 15995mL

BSFC = 15995/65.3 = 245gm/kwh

OK, so this is pretty bad hey?

But, this is full load and not necesarily peak effciiency - smoke laws didnt change until 1995 so I am guessing this is a slightly overfueled condition.... maybe....??

 

[Dougal]

Ignore last post, expect boost levels - that is std per manual and what I have seen.

The values I gave were for the 2H engine with no boost that makes around 210nm and the rpms are 2200, so not at the most efficienct revs - most efficient should be ~ 1700rpm (for a diesel).

Anyway, 345-363cc for 6cyl and 1100 pump rotations, 312nm, 5.5-7.5psi boost, 085 diesel density, efficiency, calc is as follows:

kw @ 312nm @ 2000rpm: 312*PI*2000/30000 = 65.3kW

Fuel usage @ 2000rpm @ 1hr = 345*0.85*60/1.1 = 15995mL

BSFC = 15995/65.3 = 245gm/kwh

OK, so this is pretty bad hey?

But, this is full load and not necesarily peak effciiency - smoke laws didnt change until 1995 so I am guessing this is a slightly overfueled condition.... maybe....??

Sorry those numbers aren't making any sense.
365-363cc /1000 is an injection volume for a truck engine of maybe 25 litres.
What happened to the factory calibration of 11.3cc for 200 shots?

The maximum fuel injected and the maximum torque will give you the engines efficiency. You can't calculate it from fuel economy, you need to strap the engine to a dyno or use factory calibration figures.

I still get 265 g/kwH.

 

[roscoFJ73]

The highest power 12H-T that I could find anywhere on the net was 190HP and 462nm @ Flywheel. And I only found that with alot of searching and there was no dyno graph.

This is nice power, but not enough for me.

If anyone has a dyno of theres please post it, they are few and far between.

Even a serious intercooled 2H?? Anyone??

Surely someone out there has fitted a good turbo, intercooler and exhaust and maxed out the injector pump!!

Ask Frank Gerocovich at Diesel Fuel Injection in Osborne Park. He knows heaps about these and has his own dyno.

 

[gbentink]

I apologise for the tardy correspondence; I am trying to quickly rattle off this stuff while estimating earthworks in the Pilbra......

Quote

"Anyway, 345-363cc for 6cyl and 1100 pump rotations, 312nm, 5.5-7.5psi boost, 085 diesel density, efficiency, calc is as follows:

kw @ 312nm @ 2000rpm: 312*PI*2000/30000 = 65.3kW

Fuel usage @ 2000rpm @ 1hr = 345*0.85*60/1.1 = 15995mL

BSFC = 15995/65.3 = 245gm/kwh"


The error above is where I said "1100 pump rotations" I meant, 1100 pump rpm (2200 engine rpm) and 1000 shots, for ALL 6 cyl, so divide the 345cc by 6 = 57.5cc

So I stand by my 245, providing the equations listed are accurate, thats why I showed the calcs in case you thought there was an error there.

As for back calculating; if you look at fuel usage for 1 hour at a specific rpm, look at the torque value at a given rpm and work out the power produced;

(gm's Fuel used at x rpm for an hour)/ (kw @ x rpm) gives you the BSFC.......ie grams per kW running for an hour........

of course, you are spot on for 345cc being for 25 litre engine; 25/6 = .......

 

[gbentink]

Thanks Rosco, I will give him a call tomorrow. Actually, Dougal asked for the pump part numbers - I will check now.....

OK, the numbers listed on the pumps are:

AUTOMATIC:

17
ND-PES6A90B312RND147
093000-1471
7H0101

MANUAL:

20
ND-PES6A90B312RND190
093000-1900
6F0002


Dougal; I hope that helps. Surely Hino or someone else used these in an 8 liter 6 or a big 4 or something..? they are seriously overbuilt.

 

[Dougal]

I apologise for the tardy correspondence; I am trying to quickly rattle off this stuff while estimating earthworks in the Pilbra......

Quote

"Anyway, 345-363cc for 6cyl and 1100 pump rotations, 312nm, 5.5-7.5psi boost, 085 diesel density, efficiency, calc is as follows:

kw @ 312nm @ 2000rpm: 312*PI*2000/30000 = 65.3kW

Fuel usage @ 2000rpm @ 1hr = 345*0.85*60/1.1 = 15995mL

BSFC = 15995/65.3 = 245gm/kwh"


The error above is where I said "1100 pump rotations" I meant, 1100 pump rpm (2200 engine rpm) and 1000 shots, for ALL 6 cyl, so divide the 345cc by 6 = 57.5cc

So I stand by my 245, providing the equations listed are accurate, thats why I showed the calcs in case you thought there was an error there.

As for back calculating; if you look at fuel usage for 1 hour at a specific rpm, look at the torque value at a given rpm and work out the power produced;

(gm's Fuel used at x rpm for an hour)/ (kw @ x rpm) gives you the BSFC.......ie grams per kW running for an hour........

of course, you are spot on for 345cc being for 25 litre engine; 25/6 = .......

245 does sound about right. But I'm still getting a different answer.

Agreed on the torque and power figures at 2000rpm (312 & 63.5).

56.5cc/1000 shots, 3 shots per rev, 2000 rpm, 60 min per hour, 0.85g/cc
Gives me 56.5/1000*3*2000*60 = 20,340 cc/hour
20,340 cc/hour * 0.85 g/cc= 17289 g/hour


17,289g/65.3 = 265 g/kwh.

Why are you dividing by 1.1? It is reducing the fuel quantity in your equation by ~10% while the fuel injected per stroke isn't changing.

Any pics of the injector pump also?

 

[Tapage]

Tapage - regarding the 2H, given there are no oil squirters or intercooling

I know ..

I would expect low compression/cracked precoms being a problem after a while.

Not in my case .. or at least not yet .. I'm still pushing 14 - 15 PSI now from 2 years ago more less .. and still runing nice ..

So your 1HD-T easily has more fuel supply potential?? Mine could supply way more fuel than I could get air into it. I sold it before changing the turbo again.

In my case yes .. I can easy blow my Pyro gauge in a hard mile run .. it take much more time in my 2H setup to do the same ..

 

[gbentink]

My Bad, I divided by 1.1 because I confused myself with regards to pump rotations (1100 vs 1000), anyway, it just seems really bad economy.

What mileage in km/L (is that an oxymoron) do you get with your Isuzu, and how much does it weigh?

Economy was one of the reasons why I attempted this.................

 

[gbentink]

Dougal, I will take some pics tomorrow night.

I am a bit bummed out regarding the theoretical economy!

 

[Dougal]

My Bad, I divided by 1.1 because I confused myself with regards to pump rotations (1100 vs 1000), anyway, it just seems really bad economy.

What mileage in km/L (is that an oxymoron) do you get with your Isuzu, and how much does it weigh?

Economy was one of the reasons why I attempted this.................

I'm getting a steady 10km/l with my Isuzu, it's in a rangerover which is 2.3T empty and fulltime 4wd.
Best it does is 10.6 (which is 30mpg), towing half a ton it does around 9 km/l.
It's geared to do 2000rpm at 100km/h.

The reasons I'd expect a 6 do not do so well are the smaller cylinders (more exposed wall for the volume), more cylinders (more internal friction) and maybe even air supply to #1 and #6.

 

[gbentink]

Yeah, I considered the combustion chamber area vs capacity - my thinking was that if I can lower the combustions temps and increase torque and run at lower gearing (0.718 final drive, 3.7 diff, 35" tyres…) then I might be in front economy wise. I would like to use 50-75% of max torque when crusing to maximize efficiency. Hence, as much boost as I want could in theory be available very early (like less than 1400rpm).
I posted pics, but to the wrong thread. What a noob! Anyway, here some are to see the VNT and some porting shots.
Hope they spark some interest and see if people can see why I decided to port the heads……..

 

[gbentink]

more pics

 

[gbentink]

some more pics

 

[R2HKS]

Great project! There should be more of this for diesels with exact mods tested on the dyno.

Be watching this with interest. Let me know when you go nuts with a 3B.

 

[gbentink]

The two conrods by the way are for the 12H-T (the long one) and the 1HD-T (FT/FTE)

 

[gbentink]

Annd the big turbo is for the next project - I always plan ahead........., it surely is bigger than the ol CT26.........

 

[Dougal]

Looking good soo far.

Increasing your gearing will certainly help economy, but running cooler temps actually works against it, Carnot has all the reasons why but basically the higher peak temp in the cycle the more efficient you can be.
Basically hotter air maximises the work you get from each cylinder full.
But there is also a tradeoff between higher peak temperatures (which raise efficiency) and higher dynamic compression ratio (more boost, which also raises efficiency).
These two are working against each other and finding the best point between the two would take either some time or some luck.

One other interesting Isuzu feature is the square combustion bowls in the pistons, every other DI diesel I've seen inside has round.

 

[rideglobally]

intercooler

great thread, i will be following it, i am especially waiting on how you do your intercooler........thanks .

 

[Dougal]

Is that HD-T conrod bent or just a trick of the camera?