Cat D2 5U Starting

Just acquired a pretty nice old D2 that has the pony motor removed and converted to electric start . My question is why would it need a huff of starting fluid to start even in warm weather ? It has a very big 12v battery though I’m not sure of the charge condition . The engine runs like a top with no smoke or blowby and seems to have very good compression , it just needs the starter fluid to get going . Btw I think it’s been a while since the fuel filters were changed .

Those Precompust Cats if they dont have glow plugs, first start you have to use ether , the pony was kinda like a glow plug it heated up the coolant in the head and also the exhaust of pony ran thru the intake manifold to warm up the air . usaully after the first start you can start them without untill its totaly cooled down, unless you add glow plugs that is the way they are .

No idea how you would add glow plugs to this engine ? How about an air cleaner heater ? Or maybe a circulating block heater ?

I have a D2 similar to yours, that was converted to 24V electric start. It has glow plugs and the necessary heavy duty switches on the dash. Whoever did the work did professional job. The glow plugs fit into the precups. Others on here more knowledgeable can fill you in on the details of what is involved with that. You're already half way there with the electric start. Anyway, with the glow plugs, I usually pre-heat for maybe 30 sec, spin over (it is always on compression), pre-heat again, then when I spin it with a little throttle, it fires right up, even in cold weather. So the glow plugs really do their job. Without the glow plugs, the ether works the same as always. Nothing wrong with that. I got rid of the ether can with my machine, since ether with glow plugs is a no no. I sure don't miss the rope starts on the older machines!

I’m not really afraid of using the ether but don’t want to put unnecessary wear on the rings and pistons . I do use ether with added lubricant .I don’t think I’d be interested in any major alterations to cylinder head etc. to install glow plugs . I may try one of the alterations I mentioned to see if starting is easier .

Finding a head with glow plugs isn’t very easy. Add a second battery to your machine; the extra cranking capacity helps. Several of my machines retain a working pony in addition to an add on starter . My preferred method is spin for 15 seconds without compression to get some oil pressure built up, then close compression , crank a few more seconds and open up the throttle. The majority of mine will start without the use of starting fluid.

the original pilot engine acted like a glow plug as the pilot's exhuast ran through the intake manifold.

they also shared coolant.

and it allowed you to wind the main over to get oil and fuel pressure up before you fired it.with decomp on.

what many do is wind it over on compression with fuel shutoff (after building oil pressure)for a few turns to build some heat in the cylinders then add fuel and it will fire.

try that. yes you need decent batteries with big reserve and cranking capacity. you get extra capacity by paralleling two batteries.

you could also do as im planning to do and get a manifold heater plug and mount that in the air intake pipe just near the manifold.

Hopefully one of the real experts will jump in and correct any mistakes I make. I am very familiar with the D318 used in the D6. I think the D315 and D311 used in the D4, and D2 used the same design. It would not surprise me if the pre combustion chambers are the same for all, but I don't know. In the 318 there are 2 different part numbers, that are not interchangeable. The threads are the same but upper part is bigger around. So you need the correct head for the larger chamber. The latter, larger chambers could be bought with hole that the glow plug fits in. To get them clocked correctly to not interfere with fuel lines the washer/seal comes in different thickness. So you needed extra washers to see which was correct for each cylinder.

By the end of the run of U series tractors the D2, D4, and D6 could be ordered from the factory with direct electric start and the glow plugs installed.

Yeah the heater plug is a good idea but I’m not too crazy about drilling and tapping the intake tube to mount it .

Check out how PNWH did his D4. You might like how he did his. I don't know what your single battery is at the moment, but you might find it easier to start with the added cranking capacity. A pair of group 24s seem to work well here. JM