Piecing a 741 comfort King together

Quazi245

New User
Hi folks, I am new here but have grown up around several 30 series Case tractors. I have a 741 gasoline that grandpa bought new in 1966. Sometime in the late 70 s, while planting corn, the engine gave out. They had a 841 LP parts tractor, so they put the 284 ci LP engine in the 730 and put another 1000 hours on while burning gasoline through an LP engine before it was parked for starter issues in 1999. I understand that the LP engine runs higher compressions so the fuel pre-ignites and the engine "pings." My primary question is, is the difference in compression between an LP and a gasoline 284 engine all in the heads? If so, do you see any issues with me finding heads from a 284 gasoline engine and using them on an engine that was built for burning LP?
 

Have you tried running a bit higher octane fuel or adding an octane booster. Depending on how much you use it that may be cheaper than finding heads and having them done over. We run higher compression ratios in our pulling engines without problems. But to answer your question , if you find gas heads for the same CID engine they can be installed. Do you have a preignition or a detonation problem, do you hear a distinct rap in the engine when it is pulling hard.
 
I have a 800 with the LP engine that I changed to a carb. and gasoline. Runs great on gas. Compression between LP and gasoline doesn't actually change that much....did you try retarding the timing to eliminate the "ping"? I'm sure the Case tractors used for serious pulling run at a much higher compression than your LP engine just fine after finding the correct timing.
 
CC, yes, we run as high as 12.5 :1 but use pretty high octane in them engines, I agree if it runs without knock let it alone.
 
Thank you everyone, this all makes a lot of sense. I have never heard this tractor run, as it has been parked since I was 7 years old. The report of the
?ping? is my Dad and uncle?s recollection of using the tractor. The engine was stuck when we brought it from my uncle?s farm a few weeks ago. I tried
PB blaster, let it sit for a week, still stuck. I tried ATF, let it sit for a week, still stuck. Yesterday, I mixed acetone and ATF, let it sit 5 minutes, and it broke
free. There is still a fair amount of fluid on top of the cylinders.
When I have a working starter, should I hit the key with the plugs out to get the sleeves cleared of my fluid mixture? Is there a better way?
 
First, if you haven't taken the valve covers off, do so, then take a brass hammer and tap each valve to see if they are free. If any are stuck keep soaking and tap tap tap. Don't drive the valve down, it a booger to get back up. It may take a month. I have a 63 730 that has the same problem and I've decided to pull the heads and see how bad things are. I found lots of rust on top and cleaned it up by blocking holes, scraping while vacuuming at the same time. Twenty years ago I put a gas head on a LP block on a gas 300 Case, I'm still using it to do the light work around the farm.If I ever figure out how to post a picture you will see it. It's still a looker!
 
Check if the distributor advance works properly, the (50 plus year old?) advance springs have not weakened over time and that the distributor shaft bearings are not worn. If the distributor is sticking or sloppy the timing could be way off or bounce around erratically, contributing to the pinging.
 

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