Tuning a 3B (1 Viewer)

[vegas]

Is there a comprehensive guide on tuning a 3B for maximum performance? I’ve been reading these forums for years and read about turbos and intercoolers and such. It seems like most people just swap up to 15bt’s instead of trying to tune a 3B. I understand that but for someone like me that has a couple of 3B’s and an H55, what can I do to get the most out of the 3B?

My winter project this year is a 3B rebuild and tune project. Was planning on a turbo and intercooler, higher flow injectors maybe but I’m not sure if that’s a thing with mechanical injector pumps. Any pointers on 3B rebuild and tuning info would be helpful. I already have the 3B manual from Toyota and several other 3B maintenance books.

What is the most HP and torque anybody has seen out of a 3B? I’ve seen 1HD’s putting out more than double the factory HP and torque.

 

[vegas]

BTW, this is an ‘81 North American BJ42 w/power steering, front disc brakes, H55F out of a 60. I still have the original 4 speed.

 

[roma042987]

Are you trying to get the most power or most life out of it? That will be a fine balance. Will it be used for trails only or interstate highways? The reason most people replace with 15bft these days is because it is money better spent, a rebuild will likely cost as much as a much better engine.
For some reason many rebuilds also turn out to be mixed bags because of incompetent builders. If that's the cade it is even more money wasted.

A 15bft is direct injected, factory turbo, nearly a liter more displacement, and a bolt in upgrade, it was a no brainer for me.

I was never entirely happy with my turbo 3b for my needs. Sure you can get some power with more fuel and boost but it will never stay cool enough under the conditions I travel in. The solution was less fuel and boost and then you lack for power. Starting in cold weather was often a sore subject as well.

 

[roma042987]

It all ultimately comes down to requirements. I don't hate the 3b, it's a great engine for what it is, it just never met my requirements. If I had a trail only rig I would have left the fuel turned up where it made phenomenal power for very short jaunts.

 

[roma042987]

High flow injectors for a 3b aren't really a thing in my opinion because your factory ones will flow more than enough to destroy your engine.

 

[vegas]

Interesting. Where's the best source for 15b-fte motors?

 

[vegas]

Interesting. Where's the best source for 15bt-fte motors?

Actually, I think I'd opt for a 15b-ft to get mechanical injection.

 

[vegas]

Or do people prefer the 15b-fte so they can chip tune it?