The Stovebolt Site Forums The Shop Area Engine Shop Turning engine with new rope seal

Was going to drop my newly built 261 in it' new home but thought I would see if the engine would turn under the power of the starter. While building it I left the rear main loose because with the rope seal tight it was very hard to turn. I know all the bearing cleatances are fine, it's the rope seal that put a bind on things which I hear is normal to some extent. However the starter will only try to turn the engine. It's a twelve volt starter and ring gear and I am considering using two batteries in series to zap it with 24 volts for short durations to get it started. Any one try this method, I have heard of draging them down the road to start new engnes, don't think I will be doing that.

Thanks

Grant, I'm not up too much on the 261, but my guess You have other problems. I'm sure someone much more knowlegable than myself will chime in.

Are you absolutly sure of your electical connections both positive and ground. Doesn't take much interference before starter won't turn properly

the rope seal willnot put that much drag on your crank look for something wrong..remove seal torque all mains and rods see what you have..if you cannot turn engine over with a 24 inch screwdriver in the flywheel end of the crank you have something wrong...doc

They have a rubber replacement seal for those now. I got mine from Carquest. It should turn free. Make shure all your rod & main caps are in there original position & faceing the same way they were. Make shure you did not pinch a piston ring & the rings have enough gap.

Something seems to be in a bind or too tight.I would take the advice of wrenchbender and doc.What about the position of the pistons on the rods?Check the valve adjustment.

Wrenchbender, do they have the rubber one for the 1954 261 i bought from john ? Is the rubber one better or just easier to install ?

Grant,a properly installed NOS type rope seal will have enough drag so the engine assembled with crank only will need a bar to rotate it.But the starter motor won't have a problem turning it over.
Did you install new mains,drop in the crank,torque it down,then try to rotate the crank? If all is well,the crank will rotate easily by grabbing the front snout with one hand.Then take out the crank and install the rope seal.

Thanks for all the replies. I use the rope seal because they are supposed to seal longer than the rubber seal. I assembled this engine myself so I know the pistons are not in wrong and I also know the bearing (cleatances) clearances are OK. The engine will spin as it should with a light drag until I sock down the rear main cap. I have also measured and plastigaged the rear main bearing as well as all other bearings. The shop that did the machine work says the rope seal will make it hard to turn and they do as Tony says, they build the engine and put in the rope seal last. Live and learn. I did try the sugestion to make sure everything was OK electrically and used real battery cables instead of the jumper cables. This got the motor to spin, though not very fast.

Thanks

I would think the rubber one would be best. I,ll call Carquest tomorrow & check the application & get the part #.

Here is some instructions on installing the rope seal.I thought this might help.I read it a few times ,so i will be familiar with it.Hope it helps.

OIL SEAL—REAR BEARING—UPPER
The upper half of the rear bearing cap oil seal, located in the cylinder block, can only be replaced with the crankshaft removed from the block.
See “Minor Service Operations, Oil Seal—Rear Bearing Cap” for replacing oil seal in bearing cap.
1. Remove old wick seal from groove in block and make sure groove is thoroughly cleaned.
2. Install new wick seal in groove with fingers.
3. Use a rounded tool and roll the seal into the groove starting at one end and roll it to the center. Then starting from the other end again roll to the center.
4. Cut the small portion of the seal that pro trudes from the groove off flush with surface of the bearing.
NOTE: A round block of wood the same diameter as the crankshaft flange should be used to hold the packing firmly in position in the groove while the ends are being cut off.

The same instructions apply to the seal in the rear cap.

Are the bolts installed in the cams thrust plate ?I don't know if that could move and bind the gears.Check the starter and starter switch,could possibly bad.

Grant,although your clearances may be spot on,there's always the possibility of a burr on a bearing insert,a piece of crap somewhere, or something like that.
If you have any doubts at all,no matter how slight,pull the crank back out,yeah ,I know it's a pain in the [censored] at this stage of assembly, but.........See the crank spins freely without the seal,then do the seal.Once a piston and rod is installed and torqued down,try and move the rod big end back and forth with your fingers.Should easily move the 12 or so thousands of side play.This will tell you all is ok cause the drag of the seal and rings can mask interference problems.
The rubber crank seals are available at any parts store in a day or two.It's also my experience,a properly installed rope seal will not leak.These engines have suspect machining from the factory in the seal area,a rope seal is more tolerant than a rubber seal in this situation.

Another possibility is that the starter is binding on the ring gear. You might loosen the starter and try to manually turn it. Take the plugs out would make it easier since you wouldn't be fighting the compression. Might try that too before loosening the starter just to be sure the issue isn't poor connections, weak starter, weak battery.

Thanks for the ideas and the offer for a part # for the rubber seal. I have rubber seals left over from the gasket kit, I chose to buy some rope seals. The crank spun fine if I loosened the rear cap, the one that holds the seal. I have had that cap off to check and plastigage more times than I can count, saw no problems and think the seal was just tight. After spinning it a few times with the starter today to set the valves it seems to turn OK.

Thanks

What did you do to get the starter to turn the engine ?

The part # for the rubber seal is Jv 737 from Carquest. It fits 53-62 235 &261.