Combines F2 4cyl motor in 880 cotton stipper cranking problems

[tbran]

When it does not crank, does it smoke while crankingIJ

 

[Cott]

Yes it sure does

 

[Cott]

Thought I might add, It produces noticable whiteish grey smoke, the whole time running. The motor does not burn any oil till after about 60-75 hours after oil change. Just a tip I picked up along the way, my allis dealer told me to start using Kendall 30w instead of the Delo 400 30w I was using and I have seen a dramatic improvement in oil pressure and it uses far less oil per day after 60-75 hours.

 

[tbran]

Ok you have a low compression by design. It is also highly turbocharged to the tune of about 25PSI. Thus the OEM compression ratio of about 14.1 to one. Another question is does it have AC or Bosh injectors. Only the latest 433I's had the higher compression ratio and bosh injectors. The tell tale sign is if it has TWO air heaters under the intake manifold. The later high compression engines also had smaller hole injectors and higher popping pressure. Now assuming you have the low compression engine, you can pop in the later pistons and injectors which I assume is not what anyone would do. You need to check the timing. Retarding the timing back to 16 degrees instead of 18 usually helps starting but might cost four or five hp. You said the pump was rebuilt - we have found some advancing at cranking speed as the engine starts turning over faster thus advancing the timing and causing hard starting. Also setting the intake valves at hot .017 (Ex sets .015 hot) has helped. Finally since this is a low compression engine a factory ether system WIll NOT hurt engine life IF the factory nozzel is used. We have some older 6080's that have 6000 plus hours on them (if they have a water conditioner installed) .

 

[Cott]

Thanks for the help Tbran, that really explains things. The stripper is a 1980 model so im assuming it is the low compression engine. Motor has always run great, just curious as to the cause.

 

[tbran]

Also to explain the theory behind this, At the time AC needed an efficient 70 to 115 hp power unit. They had a D262 6 cyl to work with. Harvey guys developed a direct injection head for this unit, I saw one, but the bottom end would not hold up at 100 hp for the engine life needed. The 6 Cyl 301 2900 would but was too big for powerunits at 70-90 hp as utility tractors were sized for 4 cyl size and also did not have the economy needed. Now enter a sidebar - tractor pulling was entering the multistage turbocharging and they found that unless they dropped the compresssion ration to about 12 to one that bad things happened at high boost to the insides . Therefore the engineers found that they lost no horsepower by lowering the comp ratio and in theory gained engine life. One substituted incoming boost pressure for compression pressure. The only problem was not enough heat at cranking speed to fire off the engine in cold weather. After introduction the feedback came loud and clear - make them crank. Thus the increase in comp ratio - now back to 16something to one and smaller hole inj tips and the dual air heaters and ether inj. Also there has been no decrease in eng life noted by all this as well. These engines were used in K2-F2 880's-6060 6070 6080 Barko log loaders- 706dForklifts 715D backhoes Gen sets, Water pumps, and probably a bunch more.

 

[NDDan]

Common mistake for the unfamiliar is to install Bosch built injectors 1_2 turn off. Be sure return line is next to rocker cover. Say Tbran have you ever installed high compression pistons in the 301s and do you think you have to monkey with injectorsIJ I would sure like to raise compression on some of the older Allis tractors that have been retired to loader work. Do you think a guy could weld a bead down around combustion chamber to take up some roomIJIJIJIJ

 

[tbran]

Yup, YEARS ago we had a 185 whose owner had a feed lot, he installed some aftermarket kit at 17:1 and what a diff it made. He also tied the 3gpm draft section into the power steering flow to get it to steer at low idle high load. An 1_8 " bead around the lip machined smooth would probably do the trick.

 

[NDDan]

Thanks Tim, It's been so nice since we got diesels that start so well. It's very rare to have to add ether assist anymore. Has anyone seen a high compression kit offered for 426CI enginesIJ If not I'll be visiting the welding shop. We used to plumb that oil from little traction boost pump to row finder on the beet harvesters years ago and lately we'll plumb into hydralic remote circuit. Thanks again and take care.

 

[tbran]

There was a dykes type ring for pistons on a kit from MandW. I don't know if anyone still makes it or not. I think it was just over 17 to 1. Amen to diesels that crank. I think I told this before but we had two 185's in the shop once as trade ins. One would crank like no AC I have ever seen. The other would not crank unles ethered. We set about finding why. We switched EVERYTHING from one engine to the other. Both had identical sound and HP. The one that would not crank had MORE compresion than the cranking one. We could not make the one crank nor keep the other one from cranking. The only thing we did not check was the cam timing. Some old hand once told us that if the cam was advanced with an offset key it would crank better. Don't know, never did, never will.