Cummins 4BT & Diesel Conversions Forums banner

1 - 5 of 5 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter · #1 ·
I am looking at a 1986 Isuzu box truck that says the 3.9L diesel engine is the Pre-NPR engine.
Are these good engines?
It did not say if it was a turbo charged engine or not.

Thanks
 

·
Premium Member
Joined
·
1,660 Posts
I wished I remembered the years but I seem to recall '86 has a 4BD in it. Prior to the 4BD-T's there were naturally aspirated 4BD's.. It is very possible you have one, it should have it cast in the engine somewhere...
 

·
Registered
Joined
·
6 Posts
Discussion Starter · #3 ·
I wished I remembered the years but I seem to recall '86 has a 4BD in it. Prior to the 4BD-T's there were naturally aspirated 4BD's.. It is very possible you have one, it should have it cast in the engine somewhere...
How hard it it to convert a 4bd to a turbo?
Can you just change the exhaust manifold and add a oil line to the turbo??

Thanks
 

·
Premium Member
Joined
·
1,660 Posts
yes but it is not designed for a turbo. So it might not work as well. Usually a factory turbo is far superior. I would check once you come across it.. Andre
 

·
Super Moderator
Joined
·
8,864 Posts
The NPR model series started in 1985.
Before then the models here were called KT26, they had a 3.9L engine which may or may not have been a 4BD1.
There was an earlier engine the 4BB1, but I can't find any information on it. We have a hitachi excavator here with a 6BB1 though.

My 4BD1T is from a 1986 NPR, truck model NPR59. Engine model number are cast into the block (beside the starter) and also in the head.

The non turbo 4BD1 has different pistons (approx 6mm taller), no oil squirters to cool the pistons and no aneroid on the back of the fuel pump.
The block has no oil drain hole on the exhaust side and no oil cooler on the intake side.
I have also heard that only the turbo models have nitrided cranks, but I can't confirm this.

Yes you can turbo a 4BD1 easily. But don't expect it to be as bullet proof as the 4BD1T.
 
1 - 5 of 5 Posts
Top