Thread: Isuzu into D1/RRC

john - bush65
the bolt pattern on that manifold looks different to the one on my 4bd1.

On my manifold the top bolt on each port is offset to the right and bottom bolt is offset to the left, rather than both placed in line with each port as in the photo.

are there variations in the 4bd1?

Originally Posted by rar110

john - bush65
the bolt pattern on that manifold looks different to the one on my 4bd1.

On my manifold the top bolt on each port is offset to the right and bottom bolt is offset to the left, rather than both placed in line with each port as in the photo.

are there variations in the 4bd1?

THe pic of the manifold john posted is for a 4bt cummins and id say he posted it to show how easy it was made i wonder if a stainless one would work beta and maby to be flash set it up with a water jacket to help cool the sucker

Originally Posted by wovenrovings

According to my manual the 4bd1 weighs in at 321kg.

A mate of mine in Bundy has a Range rover with a 3.6L turbo isuzu. And had to do a 2" body lift to clear the rocker cover. Goes well. He chose it because it is a little more refined than the 4BD1 (well it is a range rover).

What box is he running- LT95? Auto?

Originally Posted by lokka

THe pic of the manifold john posted is for a 4bt cummins and id say he posted it to show how easy it was made i wonder if a stainless one would work beta and maby to be flash set it up with a water jacket to help cool the sucker

Yes that manifold is for a 4BT Cummins. It is an example of reasonably simple construction that gave measurable improvements in boost pressure and exhaust gas temperatures.

For performance, a 4 into 1 manifold would be better, but more difficult with small turbo inlets. Or with a split inlet turbo, a 1 to 4 and 2 to 3 configuration would be better with the 4BD1 firing order (1-3-4-2).

Stainless is stronger at higher temps than mild steel and much better for corrosion resistance.

It is desirable to retain as much heat in the exhaust as possible, before the turbo. The turbine converts the heat energy to mechanical energy (driving the compressor). Here again, stainless is better at retaining heat, than mild steel.

Also thin wall tubing is better for retaining heat, than thick wall.

One disadvantage of stainless is the higher rate of thermal expansion, but attention to details can overcome the problems.

Other disadvantages are more expensive for materials, and welding is more specialised.

Mild steel however is very suitable, but corrosion resistance is a problem, and would demand greater wall thickness tubing.

Originally Posted by Bush65

Yes that manifold is for a 4BT Cummins. It is an example of reasonably simple construction that gave measurable improvements in boost pressure and exhaust gas temperatures.

For performance, a 4 into 1 manifold would be better, but more difficult with small turbo inlets. Or with a split inlet turbo, a 1 to 4 and 2 to 3 configuration would be better with the 4BD1 firing order (1-3-4-2).

Stainless is stronger at higher temps than mild steel and much better for corrosion resistance.

It is desirable to retain as much heat in the exhaust as possible, before the turbo. The turbine converts the heat energy to mechanical energy (driving the compressor). Here again, stainless is better at retaining heat, than mild steel.

Also thin wall tubing is better for retaining heat, than thick wall.

One disadvantage of stainless is the higher rate of thermal expansion, but attention to details can overcome the problems.

Other disadvantages are more expensive for materials, and welding is more specialised.

Mild steel however is very suitable, but corrosion resistance is a problem, and would demand greater wall thickness tubing.

Mate sounds like you know your stuff there as for stainless manifolds i cant see why it would be a drama as i have all the gear to fab and weld here at home and i have good contacts in the right places to get the material needed at the right price and lazer cut flanges would be doable to as i have contacts in that area as well

I was under the impression that diesel soot eats stainless steel, thats why non of the aftermarket exhaust kits are made of this.

And to add to the conversion conversation. the R380 WILL hold up to the Isuzu, but as bushie stated it's the low rpm torque pulses that kill gearboxes. I know guys that have done nearly 200k km on the R380 and it's still holding up without symptons of giving up.
The only set back would be finding the bellhousing for KLR to do the conversion to. And it's worth doing, mine drives like a dream now.
The LT-85 just dosn't quite match up to the R380.........

Cheers

Originally Posted by Larns

I was under the impression that diesel soot eats stainless steel, thats why non of the aftermarket exhaust kits are made of this.

And to add to the conversion conversation. the R380 WILL hold up to the Isuzu, but as bushie stated it's the low rpm torque pulses that kill gearboxes. I know guys that have done nearly 200k km on the R380 and it's still holding up without symptons of giving up.
The only set back would be finding the bellhousing for KLR to do the conversion to. And it's worth doing, mine drives like a dream now.
The LT-85 just dosn't quite match up to the R380.........

Cheers

As for deso gass and soot eating stainless id doubt that as i use to make scrubber boxs for undergtound equip and the scrubber is a larg s/s box with multipull chambers full of water the deso feums go in pass the water 3 times in seperate chambers and out the end as steam mainly the chambers full of water scrub out the soot and particle and noxious fumes tho the water turns to a sulfuric acid inside and has to be changed and they dont rot from the soot or gass the vibrations kill em or the hard knocks they get

IMHO, the best grade of staino to use would be 321 - ASTM A213-TP321 seamless tube or A249-TP321 welded tube. But 304 or 304L (low carbon) would be ok - ASTM A213-TP304 seamless tube or A249-TP304 welded tube (add an L for low carbon).

Duplex staino (SAF) would have the advantage of lower thermal expansion.

Here is a pic that shows a fabricated 4 into 1 manifold that should perform a bit better than the 1-2 3-4 manifold and simpler to make than other 4 into 1's that I have seen. This is not for an Isuzu, just shows the configuration.