- Thread starter
- #81
Read This: The 200rwkw engine has travelled 400,000km!!!!!!!!!!!!!!!!!!
12H-T performance Build (1 Viewer)
- Thread starter gbentink
- Start date
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The Nissan TD42 seems to be the only idi diesel which can take decent boost and still hold together. Most others crack heads without the addition of a turbo.
News just in on the 4BTswaps forum, standard Isuzu inline A pump measured at 140cc/1000 shots.
Injection timing has a huge effect on peak pressures too. The Powerstroke guys in the US retard their timing to keep their engines together at higher boost. Efficiency drops but it's still more efficient than a broken engine.
Baines book was $US95 plus postage. Last time I looked they didn't show any stock, this time they showed one copy.
My current flywheel is 16kg, cummins run about double that on their 4BT which is the same displacement and same configuration. How much I can add depends on how much I can move the clutch backwards (thicken the flywheel). Otherwise I need to mod engine or gearbox mounts and make a spacer between the gearbox and bellhousing.
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- #83
The other exception being the Mercedes diesels, which were all IDI until the CDI models. 1HZ's do not share the same reputation....
Anyway, for me it is as much about efficiency as it is power, and that rules out IDI.
I checked out the book today, had a bit of a read. Very theoretical and comprehensive. One note was that was that in theory fro 2:1 ratio, the turbine exducer cross sectuional area for the big turbo should be twice that of a small, but then it said tests showed that in practice, there was little difference when using ratios of 1.4-1.7:1..... The CT26 exducer measures at 52mm (I need to check that, some sites say 50.8mm) and the GT25 measures at 48mm but a better design. So there may be a mismatch on my turbine choice for the big one - but I kind of thought that already.
I plan to get the book out shortly, it is less than a 10 min walk from where I work though.
140cc from std pump.... thats huge.
By the way, can you tell me if there is a relationship between Cummins and Isuzu?? I get confused when I read about the 4BT and 6BT Cummins and then the 4BT Isuzu...... What are the differences, if any?
Anyway, for me it is as much about efficiency as it is power, and that rules out IDI.
I checked out the book today, had a bit of a read. Very theoretical and comprehensive. One note was that was that in theory fro 2:1 ratio, the turbine exducer cross sectuional area for the big turbo should be twice that of a small, but then it said tests showed that in practice, there was little difference when using ratios of 1.4-1.7:1..... The CT26 exducer measures at 52mm (I need to check that, some sites say 50.8mm) and the GT25 measures at 48mm but a better design. So there may be a mismatch on my turbine choice for the big one - but I kind of thought that already.
I plan to get the book out shortly, it is less than a 10 min walk from where I work though.
140cc from std pump.... thats huge.
By the way, can you tell me if there is a relationship between Cummins and Isuzu?? I get confused when I read about the 4BT and 6BT Cummins and then the 4BT Isuzu...... What are the differences, if any?
Yes the silly Fins are pushing up to 5 bar into a merc, but lifespan isn't great and no-one who writes english knows what dies in them.
There are a lot of bad experiences with turbo'd 1HZ's around the net, even rumours that some companies stopped selling turbo kits for them due to head problems.
So Waton-Janota has series turbocharging well covered? My book is going to take about three weeks to arrive.
The Isuzu is the 4BD1T, that model series started with a 2.8 litre 4BA1 and ended with the 4BG1TCX marine engine which is still in production.
It's got nothing in common with the cummins other than similar layout and capacity. Intake and exhaust on them are on opposite sides, fuel pumps and timing gear is different etc.
Is it done yet? Is it done yet? Is it done yet? 
Tapage
Club 4X4 Panamá
To be honest I didn't feel any big diference when I was at 20PSI or now than I'm running 14 PSI .. the only real diference that I can catch are the lower EGT ( that it's good, coz you can add more fuel as I do )
So my question is .. which it's the safe line with the CT26 ( stock ) in the 1HD-T ?
So my question is .. which it's the safe line with the CT26 ( stock ) in the 1HD-T ?
- Thread starter
- #87
When I boosted my 1HD-T with stock turbo, installed the 3" exhaust and big fon mount intercooler, when set for 14psi, it would be down to 10psi by 3000rpm because, in my estimation, the turbo was running into choke flow.
Fitting a bigger compressor wheel allowed me over 22psi @ 3500rpm, so I felt my assessment of the cause was correct.
The standard wheel is good for 18psi, but only until 2200rpm, then it dies.
If you want to run this way, set your aneroid to control fueling in the 10psi to 18psi range. It wont feel powerful up top, but it shouldnt blow smoke either.
To be honest, while these motors are built to rev, they perform best in the 1400-2400rpm range, so the stock turbo would be fine in this range up to ~ 18psi.
Now, about power - your aneroid will REMOVE fuel above about 14psi unless you adjust the aneroid appropriately - I did this as recently as yesterday on a friends HDJ81V who is also running LPG. You can do it yourself. For ful adjustment of all external settings on the 1HD-T you need a 12m long socket, 10 and 17mm open ended spanner, 3 and 5mm allen key, small flat head screwdriver, a logical think about how it all works, adjust accordingly.
My job was to dial out the smoke but keep most of the power; we mostly achieved that.
I just realised that it probably isnt an issue for you regarding removal of fuel with higher boost since you have the stock turbo......
Fitting a bigger compressor wheel allowed me over 22psi @ 3500rpm, so I felt my assessment of the cause was correct.
The standard wheel is good for 18psi, but only until 2200rpm, then it dies.
If you want to run this way, set your aneroid to control fueling in the 10psi to 18psi range. It wont feel powerful up top, but it shouldnt blow smoke either.
To be honest, while these motors are built to rev, they perform best in the 1400-2400rpm range, so the stock turbo would be fine in this range up to ~ 18psi.
Now, about power - your aneroid will REMOVE fuel above about 14psi unless you adjust the aneroid appropriately - I did this as recently as yesterday on a friends HDJ81V who is also running LPG. You can do it yourself. For ful adjustment of all external settings on the 1HD-T you need a 12m long socket, 10 and 17mm open ended spanner, 3 and 5mm allen key, small flat head screwdriver, a logical think about how it all works, adjust accordingly.
My job was to dial out the smoke but keep most of the power; we mostly achieved that.
I just realised that it probably isnt an issue for you regarding removal of fuel with higher boost since you have the stock turbo......
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- #88
BACK TO THREAD
Head being collected today for head work
Camshaft being collected today for a regrind
After these items are completed, just need to assemble
I have ALOT of work to do to get the compound setup going.......
Head being collected today for head work
Camshaft being collected today for a regrind
After these items are completed, just need to assemble
I have ALOT of work to do to get the compound setup going.......
In your quest for improved efficiency, have you considered thermal coatings on the head, piston crown and ports?
Is the 12HT a parent material block? I wonder if gains could be made in cylinder insulation by using a seperate liner or different liner if it already has liners.
Is the 12HT a parent material block? I wonder if gains could be made in cylinder insulation by using a seperate liner or different liner if it already has liners.
- Thread starter
- #90
I was considering it, but this engine is my budget build because there are areas of experimentation. I figured that with a cast iron head an block, it is of less value than for alloy. With this project I am looking at cost to benefit ratio.
As an example, once I have maxed out the stock injector pump, I will likely use LPG for additional power. In this way I have a degree of control (electronic) that my pump doesnt offer.
If the std pump can delivere 500-600nm and I have extra 30% from LPG, I am in very happy territory.
yesterday I was playing with a friends 1HD-T that has intercooler, high flow turbo, 3" exhaust (basically an exact copy of my previous ride) andit is interesting. When I "only just" tuned the smoke out, it was clear the smoke increased when the LPG came on. This is what you would expect, however the internet is full of false info.....
As an example, once I have maxed out the stock injector pump, I will likely use LPG for additional power. In this way I have a degree of control (electronic) that my pump doesnt offer.
If the std pump can delivere 500-600nm and I have extra 30% from LPG, I am in very happy territory.
yesterday I was playing with a friends 1HD-T that has intercooler, high flow turbo, 3" exhaust (basically an exact copy of my previous ride) andit is interesting. When I "only just" tuned the smoke out, it was clear the smoke increased when the LPG came on. This is what you would expect, however the internet is full of false info.....
There is no end of outright BS on the net about lpg fumigation. Personally I'd never do it to an engine I liked.
For a start the LPG pre-ignites and does it violently enough to shake the engine on it's mounts. I don't think you'll acheive 30% power gain with it either. People with dyno measurements show next to nothing when it's set at a level with no audible detonation. That's audible over a diesel engine at full power. Others are showing internal engine damage of the types that don't happend with diesel unless you've got it seriously wrong.
Secondly it displaces your intake oxygen and your cooling nitrogen at a rate that's going to prevent you from reaching your power goals. Both by increasing EGT's and reducing the burn quality.
Stoich is about 15.6:1 by weight, by volume it's 24:1.
For each litre of lpg you bleed in, you need to provide an additional 24 litres of air.
You need to pump 5% more air to make up for just the dead volume. Then you need to pump more to keep the EGT's down. With LPG's limited range of flammability I don't see it giving 30%.
I was wondering what Brian had been up to!! Really must catch up over the weekend.
Tim
- Thread starter
- #93
Hi Tim, yes Brians is running quite well, but we just can't seem to get the turbo response I was getting in mine with the ceramic compressor wheel!!! I am starting to wonder if the compressor cover was not machined correctly when it was high flowed....
Hi Dougal,
With there is no question of an inordinat amount of BS on the net regarding LGP fumigation, I can now offer information based on experience - something I am always happy to have! By the way, in Australia there are sites that show dyno curves of the Nissan TD42T going from std 110hp @ wheels to over 160HP @ wheels. Some (minority) say the LPG lowers EGT - this of course is baloney.
Brian, as Tim mentioned, fitted a fumigation system that has a computer (thats what the manufacturer calls it, probably an exagerration) that provides LPG only after boost is 2psi and only after the engine has reached operating temp. The 1HDT in question has a CT26 (Mildly High Flowed), a good Safari Brand front mount intercooler and a 3" exhaust. Brian (and Tim) run their Landcruisers on Vege oil. Tim's has the 12H-T engine though and appears to run better than the 1HDT (I think injector pump and injector setting differences). Very smooth and very little smoke. A bit down on power though compared to Brians 1HD-T, but I can fix that (Tim......)
I adjusted the aneroid spring on the 1HDT VE pump to maximum height which introduces coil bind before the plunger can make a full movement. This stopped the fuel cut with high boost that was being experienced and is likely a temporary tuning measure. We then cut back the base fuel setting using the main screw adjustment. The strategy being only mild smoke when blipping the throttle briskly.
By tightening the aneroid preload, extra fuel is not put in until over 8psi boost
The LPG can be turned on and off in the cabin and the amount of LPG is metered according to the boost
OK, results:
With LPG on/off prior to 8psi, the difference is quite considerable. The vehicle in question is an auto and the drivability is much improved.
Smoke increased with the LPG in the very low end of the revs while boost was getting to an efficient level but once boost was up, and prior to 2200rpm, there was no smoke to be seen.
This vehicle has always been smokey, even after a recent full rebuild.
The end result is that the car is still exceptionally quiet and there is NO DETONATION. This engine is about the quietest Diesel I have heard (except the Landrover TDV6/TDV8). And when running on vegetable oil, is almost indistinguishable from a Petrol of the same vintage. My 1HDT was the same, very quiet.
In the end, the LPG has proved a winner and provides such useful power that it is a bit of a pain when cold being sluggish until the LPG turns on.
Of interest was the boost increase with LPG. When first turned on, the needle moves slightly (0.25-0.5psi) as you would expect (water injection did the same thing) as it takes up volume, however the boost then increased ~ 2-3psi and the power was noticably good.
Hi Dougal,
With there is no question of an inordinat amount of BS on the net regarding LGP fumigation, I can now offer information based on experience - something I am always happy to have! By the way, in Australia there are sites that show dyno curves of the Nissan TD42T going from std 110hp @ wheels to over 160HP @ wheels. Some (minority) say the LPG lowers EGT - this of course is baloney.
Brian, as Tim mentioned, fitted a fumigation system that has a computer (thats what the manufacturer calls it, probably an exagerration) that provides LPG only after boost is 2psi and only after the engine has reached operating temp. The 1HDT in question has a CT26 (Mildly High Flowed), a good Safari Brand front mount intercooler and a 3" exhaust. Brian (and Tim) run their Landcruisers on Vege oil. Tim's has the 12H-T engine though and appears to run better than the 1HDT (I think injector pump and injector setting differences). Very smooth and very little smoke. A bit down on power though compared to Brians 1HD-T, but I can fix that (Tim......)
I adjusted the aneroid spring on the 1HDT VE pump to maximum height which introduces coil bind before the plunger can make a full movement. This stopped the fuel cut with high boost that was being experienced and is likely a temporary tuning measure. We then cut back the base fuel setting using the main screw adjustment. The strategy being only mild smoke when blipping the throttle briskly.
By tightening the aneroid preload, extra fuel is not put in until over 8psi boost
The LPG can be turned on and off in the cabin and the amount of LPG is metered according to the boost
OK, results:
With LPG on/off prior to 8psi, the difference is quite considerable. The vehicle in question is an auto and the drivability is much improved.
Smoke increased with the LPG in the very low end of the revs while boost was getting to an efficient level but once boost was up, and prior to 2200rpm, there was no smoke to be seen.
This vehicle has always been smokey, even after a recent full rebuild.
The end result is that the car is still exceptionally quiet and there is NO DETONATION. This engine is about the quietest Diesel I have heard (except the Landrover TDV6/TDV8). And when running on vegetable oil, is almost indistinguishable from a Petrol of the same vintage. My 1HDT was the same, very quiet.
In the end, the LPG has proved a winner and provides such useful power that it is a bit of a pain when cold being sluggish until the LPG turns on.
Of interest was the boost increase with LPG. When first turned on, the needle moves slightly (0.25-0.5psi) as you would expect (water injection did the same thing) as it takes up volume, however the boost then increased ~ 2-3psi and the power was noticably good.
- Thread starter
- #94
I have done the same experiment that shakes the engine on it's mounts.
It is nothing more than the revs increasing and fuel is cut back by the idle feedback in the pump, so it starts to miss....simple.
When meterd in though, runs nicely and smoother than std.
I know what detonation is and sounds like too.
It is nothing more than the revs increasing and fuel is cut back by the idle feedback in the pump, so it starts to miss....simple.
When meterd in though, runs nicely and smoother than std.
I know what detonation is and sounds like too.
I shall try those experiments again sometime. May need to refill my bbq bottle first.
Interestingly Aussie has a supply of LPG with very low cost compared to the rest of the world. Here it's dearer than diesel which puts the economics of lpg injection straight out the window.
Interesting reading here: The second link has reference to burn problems above 15-20% fumigation but doesn't say if that's 15-20% more fuel energy, volume or what.
Engine & fuel engineering - Expert advise on diesel propane fumigation
http://www.eng-tips.com/viewthread.cfm?qid=7832
- Thread starter
- #96
And if the diesel is not under a level of load, the flame temp is not high enough to ignite the lpg completely. In the experiment I did a few years back, the lpg unburnt at idle was clearly evident in the exhaust smell.
So, the LPG is usefull over a certain load range, but not all. And if you are at max fuelling already and boost cannot be increased, then LPG will be counter productive.
However in my setup, boost will be limited by fuel, I am sure of it. As a result, I expect addid LPG will increase boost and keep mixtures in check.
the unknown is how the lpg combustion will be effected by very high combustion pressures.....
I hope to find out without experiencing a "BANG"
So, the LPG is usefull over a certain load range, but not all. And if you are at max fuelling already and boost cannot be increased, then LPG will be counter productive.
However in my setup, boost will be limited by fuel, I am sure of it. As a result, I expect addid LPG will increase boost and keep mixtures in check.
the unknown is how the lpg combustion will be effected by very high combustion pressures.....
I hope to find out without experiencing a "BANG"
- Thread starter
- #97
LPG more expensive than Diesel.............I would forget about it then
In Australia it is cheaper AND the goverment pays you $3000 to fit it, which is quite incredibly
the cost to install......
Try the experiment when under >30% load, you will then notice smooth running, quieter and extra power.
the idea here is economy and engine cleanliness..... But I would not pay more for LPG since it's calrific value by liquid volume is much much lower.
12HT ENGINE BUILD
Good new from the head shop, my porting of the seats and ports has not neccesitated the fitment of new seat inserts. This is good news to my pocket........
I may get a revised cam timing reground on my cam with steeper lift and 250 degrees duration (inlet). I am wondering if necessary since I should have adeuate boost anyway, I knind of want to leave "good enough" alone....
Oh, for the 12HT owners out there, I fitted 43.5mm inlets and 36.5mm exhausts.
Std is 42/35 and std for the 1HDT (I measured it at Brians on Sunday) is 43/36 and the ports are no more impressive. The upshot for 1HD-T owners is that you should be able to fit 45/38mm valves, port it, good cam and get the marine 700nm torque.................
I have the dyno curves if anyone is interested in the Marine 1H series engines.... Big power (730nm, 315HP for the 4 valve by 3000rpm....)
In Australia it is cheaper AND the goverment pays you $3000 to fit it, which is quite incredibly
the cost to install......Try the experiment when under >30% load, you will then notice smooth running, quieter and extra power.
the idea here is economy and engine cleanliness..... But I would not pay more for LPG since it's calrific value by liquid volume is much much lower.
12HT ENGINE BUILD
Good new from the head shop, my porting of the seats and ports has not neccesitated the fitment of new seat inserts. This is good news to my pocket........
I may get a revised cam timing reground on my cam with steeper lift and 250 degrees duration (inlet). I am wondering if necessary since I should have adeuate boost anyway, I knind of want to leave "good enough" alone....
Oh, for the 12HT owners out there, I fitted 43.5mm inlets and 36.5mm exhausts.
Std is 42/35 and std for the 1HDT (I measured it at Brians on Sunday) is 43/36 and the ports are no more impressive. The upshot for 1HD-T owners is that you should be able to fit 45/38mm valves, port it, good cam and get the marine 700nm torque.................
I have the dyno curves if anyone is interested in the Marine 1H series engines.... Big power (730nm, 315HP for the 4 valve by 3000rpm....)
- Thread starter
- #98
I will try and read the links referenced today
- Thread starter
- #99
I also should mention that I propose to use water injection above about 15psi boost when and if propane is installed on my engine. This should reduce peak compression temps dependant on how much I use.
Eventually I plan to controll the lot with a Megasquirt ECU, custom programmed.
Eventually I plan to controll the lot with a Megasquirt ECU, custom programmed.
It's not the diesel flame that ignites the LPG, the heat from compression is enough to do it.
You'll notice that engines like the cummins-westport that run on LPG (spark ignition) have a compression ratio of only 9:1.
This is a whole point lower than the same engine running on CNG and about 9 points lower than the diesel engine it started life as (cummins B series).
Go above about 14:1 and LPG compression ignites.
Cummins Westport Inc. • B LPG PLUS.
Cummins Westport Inc. • B GAS PLUS.
What I'd like to do with the Yanmar marine engine is convert the fuel consumption curves back to BSFC in g/kwh.
You'll notice that engines like the cummins-westport that run on LPG (spark ignition) have a compression ratio of only 9:1.
This is a whole point lower than the same engine running on CNG and about 9 points lower than the diesel engine it started life as (cummins B series).
Go above about 14:1 and LPG compression ignites.
Cummins Westport Inc. • B LPG PLUS.
Cummins Westport Inc. • B GAS PLUS.
What I'd like to do with the Yanmar marine engine is convert the fuel consumption curves back to BSFC in g/kwh.
