To speed or not to speed...

Looking at a 65 cj5 with a four cylinder. Total stock .
My question is: at what speed can it be driven on the highway
without abusing it?
Also does anyone have experience with an add-on overdrive?
Thanks.

 

thats so crazy
it just might work!

 

just my honest opion, with 5.38 gears f134, no over drive 50mph is as fast as i want to push it, 45mph is a little bit more comfortable for me

 

Anything over 45 on a highway, and the only thing catching abuse will be the driver!

 

R) this is so true

 

no tach in my jeep, my ears tell me when enough is enough

 

i keep it at about 35-40.
if i am in a hurry i'll drive my truck.

 

my 66 w/ the v6 is wound pretty tight at 55 mph

 

the F head runs great at 4000 RPM.....for about 12 seconds, BOOM

 

I once did 70 in mine, but that was with the windshield down and a crazy teenager at the wheel.

No seatbelts either, but then it wouldn't have made any difference.

It was only for a very short distance -- I don't know what would have disintegrated first, gearboxes, engine, or my ears.

 

With 31" tires and 4.88 gears the v6 should be spinning 3000rpm at 57 mph. I drive mine with 3.73's at 70-75mph on the interstate. A good Dauntless should spin at 4 grand all day long. So yours isn't wound up as tight as you think.

 

the f 134 is a very durable engine, I will give you that. but if you are revving much over about 3000 rpm for long periods of time I highly doubt it would last very long. It has a very long stroke, not designed for high speed revving!

 

yes, we know what some opinons are on the subject...
here's my facts.

lasted 11 years for me...all highway and dune driving, 4000rpm no problem.
it only came out because I wanted the 225.
they aren't fragile, and they are very durable, long stroke included.
(this of course assumes that the F4 in question is mechanically sound.)

folks that believe the 3500 or less theories seem to not have much seat time driving .....but lots of reading time.

 

Just took a trip this yesterday in a CJ3A (L head, 5:38's, stock) 45-50 was fine I could push 60 if I wanted but 50 with no belts and fun steering is fine for me. My wife drove the 3b (V6 5:38's overdrive, 32" tires) It can do 70+ no problem but feels comfortable at around 55-65. The power or gearing isn't the limiting factor it's me. These Jeeps are sure fun to just tool along and enjoy the sites at a leisurely pace.

 

Wasn't there a stress test that someone posted a few years back where the military tested the orignal L head for somehting like 10 hours at 4000rpm before signing off on the design?