Dumb ??? - what is safe cruising RPM? Am I really limited to 100kmh

[mpetersrx7]

I have a converted FJ60->BJ60 where they took the stock drive train out of a 82 BJ60 (3B w/4 speed) and transferred it over. So around town it is great (although I think it is running lean), but my highway speed I feel is limited.

Now I know that the gearing in the 4 speed is not meant for hiway driving but I don't feel comfortable driving any more than 2500RPM which comes out to be about 62MPH/100KMH from the GPS. Is it safe to drive at higher RPMs for long distances. I realize fuel economy will greatly suffer at higher RPMs.

I have already gone to 33" tires for the rubber overdrive.

Thanks,
Mark

[wesintl]

3k is no problem for some stretches. I'd put a pyro on it and watch the heat though....

Time for a turbo...

[Gold Boy]

take my 13bt upto 3000 rpm all the time for short periods, have to keep my eye on the pyro....

high revs, <3000 rpm for short periods of time is good for the a diesel engine?

[UpsideDown]

Go nuts, you can take it up much higher than that. There is a rev limiter built in to the pump, so you can't really rev it too high (though it limits out past the operational redline). Cruising at 3000 or a little more is okay.

[gbcruiser]

It's good to run an engine through its rev range once in a while...just don't overheat it and you'll be fine.

[amaurer]

Gee I wish I knew how fast my 3B was spinning! Gotta get a tach...

I find that all the engine noise makes me lose my nerve above 100kph. If thats only near 3000rpm then holy shit 3Bs make a lot of racket...

[mpetersrx7]

Thanks guys for all the responses. I usually run my shift points up to 3k all the time. I am putting together my turbo system right now so I guess I will know my egts better.

[eleblanc]

At about 110 kph my rig turns 2850-2900 rpm. running 34" with 4.88 and a 5 speed. It is high, but it runs fine. Ideal with my current setup is 105 kph.

Movie2.wmv

[lowenbrau]

Red line on a 3B is 4150. As Upside Down said, they have a rev limiter there. The mines run them like that all day for years and years. You won't hurt your engine driving it with your foot to the floor all the time. It'll run out of power on the highway long before you get to redline.

[amaurer]

seriously is mine just a piece of shit or something? it sounds like the world is ending at 100kph, i had it to 110 once and thought for sure that a firey death was moments away.

or do you just have to learn to ignore it?

[lynchmob]

I drive my bj75 ( 4 sp, 4:10 gears, 33" tires) up to 130 km/h on the hwy all the time - driven several 2000 mile trips at those speeds with no issues. I usually maintain 120.

[fe sus]

just took my btj60 cross country and back. with the pyro as a guide I stayed around 1k F, 63mph or 2500. it can do more than that but it does sound like... well bad.

[gbcruiser]

If it's that noisy, have you considered changing oils? Try Rotella T 15w40 for one change, with a Toyota filter. It's a fantastic detergent oil. Also, what kind of noises are you hearing? Valve adjustment in your recent past?

Of course the best way to eliminate diesel engine noise is to turn up the stereo and ignore it. Mind you, I wouldn't push the thing on the highways too much...it is a smaller, older engine after all.