engine got tight

[The Shmunk]

Hi All! Just got a G back together after having some crankshaft work and block bored with new pistons in it. We were cranking it over and it just doesnt seem to turn over very freely by hand with the plugs out, When putting it back together we used plenty of assembly lube on the journals and piston/cylinders. I know on this tractor It has a leaky needle and seat and when cranking it over it did seem we may have flooded it, could it be that the gas washed away all the assembly lube and cause it to get a little tight? I know the crankshaft spun freely and i popped both rod caps off after it started to get tight and the bearings look to be fine with no scoring or anything like that and the cylinder walls still look nice and crosshatched with no scoring. any ideas or suggestions?

 

[Anonymous-0]

More likely you have one or more bearings too tight but lots of things could go a just little bit wrong. Did you pre-lube the engine with motor oil? Did you use plasti-gage or something like it to make sure the rod and main bearing clearances are correct? Did you have the end gap correct on the rings? How about the heads? Do you have proper valve lash and valve stem clearance?

 

[rick deere]

what about the main bearings they will get tight as well usually first

 

[ET]

Pull the plugs out and shoot some oil in the cylinders. You washed the lub off the cylinder walls by flooding it.

 

[hojon]

How "tight" did you put the flywheel on?

You should be able to take a dial indicator and measure I think 8-10 thou play when pushing and pulling on the flywheel.

Maybe someone out there can verify this but it's a number stuck in my head.

 

[Greenday]

What year of G? Insert bearings or Babbit?

 

[The Shmunk]

The crank will spin freely ive isolated the problem to be with the pistons. They machined the rods for insert bearings so there arnt any shims anymore, the oil clearances were checked using plastiguage. The only thing done to the head was valves were ground and it was resurfaced. Im leaning more twards we washed the assembly lube off and it may have just gotton a little tight. Yes i used actual assembly lube and not motor oil. Think i need to take pistons out and clean the bores and relube everything? or could a guy get around that by squirting a bunch of oil in there and spinning it over?

 

[ET]

Just squirt the motor oil in the spark plug holes and roll it over, you will be amazed at the diffrents. I had a 36AO that did the same thing.

 

[t boy 2]

I always belt mine for a while with the plugs out and make sure oil pressure and everything else is ok and then if it is I put the gas and fire to it.

 

[Jake Winn]

Did you bore it and install new pistons/rings? It will take a bit for them to seat in and it may turn somewhat hard. If you put in aluminum pistons, did you get the correct clearance for the piston to cylinder wall? If the machine shop went off of stock specs, that is for cast pistons. Usually you need to add about .002 more clearance if using aluminum pistons.

 

[great dain]

Sounds like ya need to find some one in your area thats good at measuring clearance's. Ha ha

 

[jd b puller]

(quoted from post at 01:28:55 02/23/12) Hi All! Just got a G back together after having some crankshaft work and block bored with new pistons in it. We were cranking it over and it just doesnt seem to turn over very freely by hand with the plugs out, When putting it back together we used plenty of assembly lube on the journals and piston/cylinders. I know on this tractor It has a leaky needle and seat and when cranking it over it did seem we may have flooded it, could it be that the gas washed away all the assembly lube and cause it to get a little tight? I know the crankshaft spun freely and i popped both rod caps off after it started to get tight and the bearings look to be fine with no scoring or anything like that and the cylinder walls still look nice and crosshatched with no scoring. any ideas or suggestions?

What's the verdict?
What did you have done to the crank?

 

[The Shmunk]

Gas washed cylinder walls of its assembly lube, liberally applied oil to bottom of cylinder while pistons were at tdc and it was fine, got some cam timing and ignition timing bugs worked out only to find the starter isnt really happy with all this new compression.

 

[jd b puller]

(quoted from post at 12:57:21 02/26/12) Gas washed cylinder walls of its assembly lube, liberally applied oil to bottom of cylinder while pistons were at tdc and it was fine, got some cam timing and ignition timing bugs worked out only to find the starter isnt really happy with all this new compression.

What all did you do to it? Stock starter will still start with pretty good compression.

 

[The Shmunk]

All I did was an overbore with m&w's, resurfaced head and deck. The old bore was worn well out of round and the end gaps on the old rings were about a quarter inch. Like they always say, with every action there is an equal and opposite reaction. I did manage to get it started and i am very pleased with the way it runs, It will be a good plow day tractor! It does have the all fuel manifold on it yet, would a cold gas manifold help squeeeeeeeeeeeeeeze an extra horsepower or two out of it?

 

[The Shmunk]

I took the starter off and bench tested it and it turned over kinda slow and made growling sounds so im guessing it was okay with turning the old worn out engine over but not okay with the new bore and pistons.