Cruising speed???

I have just finished restoring a 1960 CJ6 with the Hurricane F4 engine. I have it going into the garage for a tune up and service Wednesday. I am very disappointed with the road speed of the old Jeep. Top speed with full throttle is 70Klm/hr or for my American friends 45 miles/hr. The engine is in brand new restored condition, electronic ign. although not yet fully tested the timing with a timing light. My question is what cruising speed should I expect? Can anyone give me an idea of that? A CJ5 with the Hurricane F4 engine should be the same.

My 1965 CJ-5 with the 4-134 F engine runs about 45 to 50 mph tops. I'm not really sure what the hurricane should run.

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Originally Posted by Stumpy steve

I have just finished restoring a 1960 CJ6 with the Hurricane F4 engine. I have it going into the garage for a tune up and service Wednesday. I am very disappointed with the road speed of the old Jeep. Top speed with full throttle is 70Klm/hr or for my American friends 45 miles/hr. The engine is in brand new restored condition, electronic ign. although not yet fully tested the timing with a timing light. My question is what cruising speed should I expect? Can anyone give me an idea of that? A CJ5 with the Hurricane F4 engine should be the same.

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Most Jeeps in that time frame came with 5:38 gear ratio for a recommended 45 mph and with a 4:27 gear ratio option expect 50 mph tops.

That's about right for the cruising speed,Even with an over drive unit you are not going to get much more top end.

I have a 1960 cj5 with the 4 banger and 5.38 gears. it runs at about 55 tops but thats with 33" tires. Im going to order the over drive unit just for the extra gearing on the hwy.

Good news I did not know there was and overdrive unit available. Any leads on where?

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Originally Posted by Stumpy steve

Good news I did not know there was and overdrive unit available. Any leads on where?

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look on Ebay, but they aren't cheap. expect to pay from $200.00 upwards to over $600.00 As dave44 said in his reply ,it will not get you much more speed. A friend had one in a 1971 CJ-5 V-6 with I believe 4:10 gears and I didn't see the cost of the unit for what little difference in road speed he got. I found out if you do 45 mph you will get to the same place as others doing 60 mph in about 10 minutes later ( say a 1 hr. drive. )

I believe that Kaiser Willys sells the overdrive units in their catalog...If you have really steep gears (5.38s), this OD unit probably won't give you the highway speed that you are looking for...For what an OD unit costs, you can swap your ring and pinion gears at both ends to get the speeds you want, say 4.27s or 4.10s with money left over...New ODs cost around $1300.00 !! Remember, the Willys four bangers, L134, and the F134 are LONG stroke engines...They are built for low speed "grunt", not high rpms like modern fours...Keep rpms down so that your engine lives to a ripe old age...Remember too that a short wheelbase jeep gets "squirrelly" at highway speeds over 60mph...And you only have 9" drums...panic stops at speed can be very interesting !...Just keep the old girl in the slow lane...Been there..done that.

Gear ratio calculator.

http://www.grimmjeeper.com/gears.html

So I have a STOCK 1959 Truck and I know it has the 6-226 Super Hurricane motor and a Dana 53 rear axle, the Dana 18 transfer case, the T-90 3 speed transmission. I do not know the official front axle it has, nor the gear ratio of the front or rear axles. However I was hoping that even with that limited information someone could still give me the rough speed and rpm that it would like to run at on the freeway/ highway? Everything else is stock as far as the wheels and the rest of the drive train is concerned. Thanks, much regards TGB59.

Hopefully you can locate the ratio tag on the rear axle. There may still be the original tag indicating the ratio in place. It could be a 5.38 or a 4.88. The tag was located under one of the rear cover bolts on the axle housing. It was usually the lower right corner but it could be under any one of them. If all else fails just jack it up and put it in neutral. Rotate the driveshaft and count the rotations to make the tire turn one complete revolution.

Here is a good calculator from the tech library on this site:

https://willysjeepforum.kaiserwillys...e-speed-at-RPM

I have a 1961 cj5 134 Hurricane engine. Max speed 59 MPH.
When timing , I had a carburetor rebuilder sent me a paper on how to time them with out a light. He said back in the 60's gas octane was a lot lower then it is now and the timing marks were set for that.
He said warm the engine up, go to the exhaust pipe and put your hand up to it. It should be smooth exhaust flow, if you feel pops advance the timing until it is a smooth flow.
Believe me it works! The 134 has a long stroke piston and you get the complete burn of fuel this way.

Beef, I have seen and heard a lot of "ways" to time an engine. The method you have described is not one I would recommend however. There are a few issues with doing it that way and none of them are good. If you are looking for better performance you can achieve a very slight increase by running a few more degrees of timing. For the most part you are not going to get much more. The inherent low compression of the Willys and the increase in today's octane levels will allow a lot more timing without detonation. This does not correlate to more power or a better running engine however. The only place to really see power increases by advancing the timing would be best done on a chassis or engine dynamometer. You could do some serious damage if you increase the timing to far at idle and cause the total timing to be too much. The best total timing is a function of peak power at peak loads at a given RPM.