Torn between mtdi and 1.6/1.9 Frankenmotor

[theman53]

So it would be 3.14x 11mm vs 3.14x 9mm

[8v-of-fury]

Correct on the second measurement, but I do not have the information for the cam lift of the Rovers cam plate.. so I cannot say for sure.

Yes physically the plunger will move more fuel.. but as you know the fueling can be de tuned by turning the max fuel screw down. This decreases the amount of throw the internal throttle has on the control collar, opening up the spill ports at a sooner time and thus injecting less fuel per stroke. The plunger moves the same stroke for idle or WOT, but the position of the control collar is what meters fuel injected.

[theman53]

so does the arm on the splines. I don't see it as a good comparision unless both pumps were the same. Put your rover on the aaz and report back.

[8v-of-fury]

So does the arm on the splines.

No sir, that only compresses the governor springs which in turn pulls on the internal throttle and moves the control collar up the plunger to allow more fuel to be injected.

It is not a perfect comparison, but it is good enough. I ran my TDI on a fully turned up 9mm 1.6TD pump to begin with post swap and it still had more torque than the AAZ or 1.6TD. Ran out of top end fueling though.

[theman53]

That is kinda what I was going for on the spline comment

Slap the landy pump on the aaz and do a run. I say that as not only will the fueling be different but I am sure the advance curve is as well. It will be night and day I bet.

[8v-of-fury]

No can do, its got the big snout. Will not fit the pump bracket.

[8v-of-fury]

That is kinda what I was going for on the spline comment

Aye' but it still does not move the control lever any further in relation to the plunger or as far as a DI pump does. The IDI pumps under-fueled my DI engine big time in stock form. And even then again as a 10mm DI hybrid with modified long throw internal lever.

That is why I said in stock form, they are similar in displacement, turbo and fueling. 9mm and big injectors vs 10mm and small injectors.

With the same fueling the DI will always be more powerful, its in the engine design.

[theman53]

Aye' but it still does not move the control lever any further in relation to the plunger or as far as a DI pump does. The IDI pumps under-fueled my DI engine big time in stock form. And even then again as a 10mm DI hybrid with modified long throw internal lever.


EXACTLY my point dear Watson. The TDI is getting more fuel no matter how you want to cut the pie, it is getting a bigger piece. At least that is the way I percieve it.

[libbydiesel]

So it would be 3.14x 11mm vs 3.14x 9mm

Actually, you want to take the radius^2 x pi x camplate lift. 95.0mm^3 vs. 63.6mm^3.  

Maxed out, tho, the IDI can't burn as much fuel per rev and what it does burn, it burns less efficiently.  At the same EGTs and same RPMs, the TDI wins.  The IDIs have a greater RPM range, tho, so it evens out and all else equal, they will make the same power.  IDI will burn 10-15% more fuel for the same power, tho, and drop pre-chambers every so often...

[theman53]

I liked your comment Libby in my imaginary facebook world.

[8v-of-fury]

The IDIs have a greater RPM range, tho, so it evens out and all else equal, they will make the same power.

Do they though? Why would a 1Z/AHU/ALH not spin the same 6000 rpms that limits the Bosch VE pump?

IDI will burn 10-15% more fuel for the same power, tho, and drop pre-chambers every so often...

This is enough for me to wave good-bye and never look back haha.

[dieseljunkie69]

Mtdi all the way

YEAH BABY! TDI was the successor for a reason!

[libbydiesel]

The IDIs have a greater RPM range, tho, so it evens out and all else equal, they will make the same power.

Do they though? Why would a 1Z/AHU/ALH not spin the same 6000 rpms that limits the Bosch VE pump?

IDI will burn 10-15% more fuel for the same power, tho, and drop pre-chambers every so often...

This is enough for me to wave good-bye and never look back haha.

Yes, due to the different combustion properties of the IDI and TDI, the rpm range is expanded for the IDI at the expense of fuel economy.  That is WHY IDI engines were produced.  When the rabbit diesel came out, DI engines had a hard time making it past 2,000 rpms making them unsuitable for automotive use.  Changes in injection technology have massively increased the DI rpm range but it is still more limited than the IDIs.

The pre-chamber issue is a big deal to me as well.

[RabbitJockey]

The IDIs have a greater RPM range, tho, so it evens out and all else equal, they will make the same power.

Do they though? Why would a 1Z/AHU/ALH not spin the same 6000 rpms that limits the Bosch VE pump?

IDI will burn 10-15% more fuel for the same power, tho, and drop pre-chambers every so often...

This is enough for me to wave good-bye and never look back haha.

Yes, due to the different combustion properties of the IDI and TDI, the rpm range is expanded for the IDI at the expense of fuel economy.  That is WHY IDI engines were produced.  When the rabbit diesel came out, DI engines had a hard time making it past 2,000 rpms making them unsuitable for automotive use.  Changes in injection technology have massively increased the DI rpm range but it is still more limited than the IDIs.

The pre-chamber issue is a big deal to me as well.

diesel mekken has built an inline pump that went on to a tdi pulling tractor, he says it pulls to over 10,000 rpm.  i used to think the same thing but now i am not so sure.  a guy in hungary sent me a video of a buggy with a 1.6tdi built with tdi pistons and head with a 1.5 crank, he buillt the pump for it, he says it revs to 5500.

[carrizog60]

had a friend with a 1.9td,with a maxxed out 9mm pump.
he changed to a 10mm(not a 11mm!)  and he needed to make the fuel screw almost stick out to match the same power levels...
also,at high rpm a bigger plunger will benefit in eficiency in burn as it will inject more fuel in the same time.
a 9mm could inject the same fuel but most times out of time resulting in smoke but no power.

on a modded engine tdi will win in reliability,but on my head its just because IDI´s investigation stoped many years ago.
~with the right materials and developement i think those problems would be over.

but i think its like 2 stroke engines...
they are smokey,noisier and eat more fuel but damn!they are fun lol

some factors make 2 stroke engines research stop in favor of 4 stroke and i guess its very hard to invert that tendency,just like IDI engines...