Turbo Isuzu 6bg1 engine

[Wick]

Looking to turbo an Isuzu 6bg1 engine in a 4wd service truck I am setting up, anyone know if the naturally aspirated engine has piston cooling nozzles fitted as standard? I have made some calls with conflicting answers and the only info I can find on the net is that pretty much all specs are the same, except the pistons, anyone know?

 

[nickbowers]

Looking to turbo an Isuzu 6bg1 engine in a 4wd service truck I am setting up, anyone know if the naturally aspirated engine has piston cooling nozzles fitted as standard? I have made some calls with conflicting answers and the only info I can find on the net is that pretty much all specs are the same, except the pistons, anyone know?

didnt the 6bg1 come out in a 230hp turbo?

 

[OzDozer]

Wick - I've never had one apart, but all the Isuzu information, specs and drawing I can find, seems to indicate that the B series Isuzu has exceptional parts standardisation - and both the turbo and NA engines seem to have oil cooled pistons in the specs.
However, I'm with Nick on the same question. Why fool around with turbocharging an NA engine, when Isuzu build factory turbo engines?
There are many subtle differences in engine design and components, that are often not listed (for "commercial advantage" reasons) - and the camshaft is one typical item.
I have a brand new 6BGT-1 camshaft sitting in my shop, and I know that that camshaft is specific to the turbo engine. Therefore, the turboed engine obviously has different valve lift and timing to the NA engine.

 

[Wick]

didnt the 6bg1 come out in a 230hp turbo?

Yes this is my understanding Nick, I have been told the turbo intercooled version around 220 - 230 hp was used in the American market, and on the information I have the turbo version pretty much only came over here in small numbers fitted to busses.
I am trying to find out if the nat aspirated 6bg1 engine that is in this truck has piston cooling nozzles fitted, so I can have a bit of an idea after turbo and intercooler how much I can jar it up without turning it into a hand grenade. As seems to be common for a lot of vehicles built for our market the gutless naturally aspirated version was the standard. This is one thing that has always puzzled me why Jap imports to Aus have always been somewhat underpowered compared to what is built for the American market, they must think that Aus is dead flat, though I guess a lot of it is. For the terrain around here though you need a vehicle with some balls especially for a loaded truck of any sort.

 

[OzDozer]

Wick, 98% of Australia is pretty flat. The average elevation of Australia is 244 metres (800'). You just managed to live in the more mountainous parts!
The reason why we get the lesser powered engine versions from Japan is because Australian operating conditions are regarded as more severe operating conditions for engines, than the U.S operating conditions.
We have a lot of long steady grades, and exceptionally long distances without a break - coupled with high ambient temperatures - that are all engine killers.
A turbo engines problem is heat production. They produce a substantial increase in heat output over an NA engine - therefore the engine needs more oil capacity, increased coolant volume and cooling capacity, and shielding of the turbo and exhaust manifold.
Most NA engines don't have oil-cooled pistons, and they usually have to have oil jets installed when doing turbo conversions. The 6BG series engine is one of the few engines I have seen, that appears to have oil cooled pistons on both varieties.
I was surprised to see that the compression ratio is exactly the same on the 6BG-1 and the 6BGT-1. This seems to indicate that the amount of boost provided by the factory turbo is minimal.

 

[Wick]

Thanks oz for the info,
Yes I have found a used turbo engine for around 10 k and if I wasn't such a tight/a I could go down this track but by the time I got it here, put it in (there would no doubt be differences to sort out as it would have come out of a different model truck, the one I have is a twin cab) set up an intercooler etc and taking into account the age of the truck, the rough bush use it will get and as the engine I have has only 60,000 ks on it, I thought I would check out this option first.
BTW how did you come to have the cam, do you have a use for it? both engines have roller followers.
cheers

 

[OzDozer]

I acquired the camshaft in an auction deal, because I used to buy and sell a lot of machinery and parts and repair a lot of items. I don't do much of that now that I'm retired.
I'm happy to part with it, if you're interested. It's a genuine, unmarked, NOS factory Isuzu camshaft.
Send me a PM and we can discuss a deal.

Regards - Ron.

 

[Wick]

Thanks again oz
you just beat me with your reply, agree with all you said, this is where references like the cummins cpl book is handy.
The only other differences I have been able to find are the turbo version having a bigger fan (I would assume therefore a bigger radiator) and different pistons with .05mm reduced compression height (but the same c/r ?)
Gudgeon size the same, not sure about the crank or rods.

 

[nickbowers]

Yes this is my understanding Nick, I have been told the turbo intercooled version around 220 - 230 hp was used in the American market, and on the information I have the turbo version pretty much only came over here in small numbers fitted to busses.

Late reply but for future reference the 230hp Turbo was in quite a few trucks from frr550 upto fvr950