134 fresh rebuild vs old tired one

My little 134 is getting really tired, And since I don't have anything to compare it to. Will a fresh 134 have more get up and go than my tired one? I know it should but will it be very noticeable. Mine holds about 7 to 10 lb oil pressure when warm at idle, and smokes a good bit. my motor runs good and starts good but In mud it almost has to be in low range or I will stall out and looses it pretty fast on the hills.

So this winter is the time to do something, either rebuild or swap. What would you guys do if it was your JEEP? just getting ideas. I live in Ohio so I don't need the low gears of a truck tranny, and don't have the mountains like you guys out west.

 

:v6: !!!

 

What's the compression? The bearings condition won't change the power output, but low compression will.

Can we assume there's nothing else wrong, like a burnt valve or a worn camshaft? You can just replace the rings and maybe grind the valves and see how much improvement there is. This can be done with the engine in the car.

 

Tim I haven't checked the compression but since it smokes like it does I would guess it is low. It seems to run good and will do 45 to 50 all day long as long as you are on the flat...
I guess i should do a compression test first and see where it is at!

 

You may have stuck rings.
How is your oil consumption?
Does one of the plugs (or more) look black and sooty when you pull them?

Might seem dumb, but you could change to synthetic oil and run that for 6 months or so with regular oil changes. May free up your rings and get rid of the smoke.

 

Yeah the plugs are pretty black and sooty and it does burn a bit of oil, it leaks some too..... lol

This summer I had to put on a new head gasket, the cylinder walls looked pretty good, no scratches or marks, but they are very smooth!

 

Sooty is too rich. If you have a lot of oil leaking in, you'll get a black, tarry build up on the plug.

Oil can come in around the valve guides, as well as the rings. Worn rings will show up in your compression test, as uniformly low and uneven compression.

 

Even better at pinpointing a problem is a leak down test.

You use an air hose to pressurize the cylinder, and listen at the carb, exhaust pipe, and oil filler for any leakage.

You can also do a differential test, where you put in a measured amount of air pressure, and the test instrument will tell you how much you are leaking. This is how we do it with aircraft engines.

Here is a link to a differential tester. http://www.chiefaircraft.com/aircraft/tools/compression-testers.html

 

rebuild that puppy!

 

do a compression check. But to answer your question probrobly not much improvement. I rebuilt my flathead. The top two rings on every cylender were cracked in many places and the block was cracked. Rebuilt it all fresh as a daisy boored .060 over and really not a whole hellof a lotta difference in power. Some but not wow

 

:v6: !!! If your looking for more power, you'll be way happy! Fined a 66-71 cj5 with a v6 and swap it all over.

 

When I did my worn out F-Head the power difference was hardly noticeable. To be honest I could never tell if there was improvement or I just 'felt' improvement because I wanted it so bad. If you want a bunch more pep swap motors. What I will say is rebuilding my F-Head was cheap, dirt cheap so it does have that going for it.

Ken

 

Over on the 2A page Allen Boyd (RIP) rebuilt the engine in his farm jeep, the Mule. I rode in it before and after the rebuild. THis was a totally worn out but still running engine, and he did the rebuild entirely by the book. There was a noticeable perfomance increase as well as a top speed increase. I don't know the specifics of what all he did to it but he was a stickler for making stuff mechanically right. So, I would say, if a complete tune up to specs doesn't do it and you can't get the old girl to stop smoking, rebuild it this winter.

 

if it is smoking, it most likely needs a rebuild.

Mine used to burn a quart every 100 miles. At the end, it would start up, rev up, but had NO power on hills.

The rebuilt motor isn't a huge difference in get up & go, but it will hold speed on hills a whole lot better & accelerates much better/smoother, especially at speed. These are the benefits of good compression.

So to sum it up, it will not be like dropping a v-6 in there, but it will run better, have noticeably smoother acceleration, and noticeably more power on the hills.

A new cam & lifters helps, too.

I can now do 60 up (and down!) all but the steepest hills on the freeway.

See if your machine shop will save .010 or so off the head for you, too. The higher compression is always welcome!

 

To answer your original question of swap vs. rebuild, my answer is rebuild! You'll know exactly what you have afterward and you won't be replacing your problems with some other guy's. If you want to swap to a V6 then that's a different story, but swapping a used identical motor is not worth it.

 

You never know. I have had a 134 totally rebuilt, and a major screw up by the machine shop made it worthless - but not discovered until it was all installed.

On the other hand I have an original stock '57 that smoked and burned oil, and the more I have driven it, the less it burns.

I'd say drive some other F-heads first, see if yours is really underpowered, or if you are comparing to modern vehicles.