4JA1 and 4JB1 internals

[rtwelder]

Hi!

I would like ask if the 4JA1 and 4JB1 non turbo engines have similar internals to the turbo versions?

parts such as pistons, connecting rods, crankshafts.........


I am thinking of adding a small turbocharger to my non turbo engines but I am not sure if the engine can reliably handle the added power.

[isuzurob]

It will be fine with a turbo, air doesn't kill a diesel the more air the better the fueling side is where you wreak your engine

[rtwelder]

Yes but can the internals (such as crankshaft, connecting rods, pistons) handle the increase in power and still be reliable?

[isuzurob]

Yes it will be more than fine just don't go crazy on the fuel screw

[rtwelder]

just for the knowledge, are the internals in the turbo and the naturally aspirated engines the same?

4JA1 and 4JA1-T
4JB1 and 4JB1-T

[KarlssonOnTheRoof]

i have a 4ja1 N/A i ran 2 bars (29 psi) stock internals ran like a rocket still with the N/A pump it poured black smoke till it hit boost an ran clean it still drives fine after it and didnt really care starts fine and no blow by whats so ever, but for a daily 1.5 or even 1 bar is plenty enough

Sorry for my bad english im from sweden

[gtyler]

When I bought parts for my 4JA1 the dealer pulled out the 4JB1T and con rods pistons to show me. The Con rods were thicker, and gudeon pins bigger dia, but that was the non-turbo 2.5 tp the turbo 2.8, not sure about the turbo 2.5 and non-turbo 2.8. I now have a non-turbgo 4JA1 in my NKR motorhome, want to add a turbo. Does the diaphram that gets manifold pressure on top of the injector pump change cutoff time or delivery rate? what about the fuel screw? does that change cutoff ? how does it change the volume of fuel delivered?