Any suggestions on how to manually rotate a flywheel-forward 283?

Hello, I'm new to the forum and have little experience with Chris Craft motors (although plenty of experience with engines in general) so please forgive any dumb questions! I have a 1957 30' Constellation with twin 283s. Unfortunately the boat has been sitting for the last year or so with no batteries or fuel tanks as I have been making slow progress on cockpit deck repairs (long story involving pulling the tanks to get at the shaft logs to stop severe leaking due to corroded bolts...).

I had been turning the motors over with the starter every few weeks but since I pulled the batteries last year they have been just sitting and are now frozen. While at some point I do want to strip them down and rebuild I'm hoping that for now I can free them up without pulling them out of the boat. To that end I have sprayed penetrating lubricant (PB Blaster) into the combustion chambers and am letting them pickle for a few days.

Once the lubricant has had some time to work I will try to turn the motors over by hand but I am not sure how to do that as there is no bolt on the end of the crankshaft and as far as I can tell the hole in the end of the crankshaft is not threaded. There is a pulley bolted to the crankshaft via 4 bolts and I had thought of making a tool that would bolt to the same location but am looking for alternate suggestions. Anyone? Any opinions on my chances of success are also welcome...

Thanks,

Chris

Thanks for the advice. I've already tried a small strap wrench (I have the same one as in the eBay link) with no luck but maybe something larger would do it: <http://www.amazon.com/Ridgid-31365-...f=sr_1_19?s=hi&ie=UTF8&qid=1328493116&sr=1-19>

Chris

A stuck engine is not a fun job. I would use the pulley as a pattern and weld up a long stout breaker bar. It will take bit of time, but it sounds like you'll need to do this twice.
Once it does budge, you are almost home free...well sort of. :rolleyes:

Yeah - either a strap wrench or a custom tool. That's what I figured. Thanks for the input! I may try the one and then the other if that doesn't work. Fingers crossed...

Chris

clstevens said:

Yeah - either a strap wrench or a custom tool. That's what I figured. Thanks for the input! I may try the one and then the other if that doesn't work. Fingers crossed...

Chris

Click to expand...

And watch your knuckles, you'll need to save them for later!

Chris with a Chris Craft, when you say "flywheels forward", are these engines driving the transmissions from the front crankshaft end?
I ask because Chris Craft did a goofy front crankshaft drive years ago.

If not, then there should be a bolt in the front end of the crankshaft that secures the harmonic balancer.
However, I'm glad that no one suggested using this bolt to turn the engines over.
DO NOT use this bolt to turn these over!

Instead, make yourself a three fingered tool that will reach into the three spokes of the harmonic balancer.
Build it so that a breaker bar will rotate it.
This could also be a round plate drilled to fit the three bolt pattern.
(the 3 finger tool would be quicker to insert and use)
Any pulleys would need to be removed first.


If these are driving from the front crankshafts, then the flywheels sould be accessible.... yes/no?


Turning these engines in either direction is not an issue, as there will be no slack in the timing chain that could possibly cause a tooth to skip.
If this could occur, you'd have a larger issue.

Perhaps some more information and a few photos would be helpful.


.

Rick, thanks for the very detailed reply. Yes - the drive is from what would be the front of the crankshaft in an automobile installation. The flywheel is at the forward end however it is not very accessible because of a large cast front cover that includes the motor mounts. Here is a photo of a similar motor that should clarify the setup: <http://www.chelseacoachworks.com/images/dow/dow_283_134_r.png>. Drive is from the other end not shown in the photo. The alternator and raw water pump are driven from a pulley mounted to the four holes you can see in the crankshaft end. The more I look at it the more I think a custom tool that bolts to those holes is the right solution.

Chris

Chris,

If the engine in the photo is the same thing, I think I'd make a four hole breaker bar, maybe out of the same thickness bar stock as the engine stand in the picture.

In similar situations I've had luck using a big prybar or crowbar under the edge of the motormount/flywheel cover and catching a tooth on the ring gear. If you are careful and don't let the end of the prybar slip out of hte teeth you can litterally pick the engine up that way. This will give more leverage than either the starter or a close spaced bolt pattern with a breaker bar. I've not damaged a tooth and have gotten a number of engines freed this way. I would have a hard time believing that careful pressure with a prybar is harder on the teeth than than the starter Bendix drive slamming into it. - Though you might not have space in your boat to get a prybar where you need to.

The reason that the starter motor pinion gear teeth do not damage the ring gear is due to full width contact.
A pry bar may place this force onto only a portion of the tooth, and it may be too small for the load and break it.
You do not want to break a ring gear tooth unless the plan involves pulling this engine.

Here's a suggestion since you are in quite a predicament.
Find an old starter motor core that fits your engine.
Cut the rear end plate open and expose the armature shaft.
Or cut part way into this leaving a portion of the bushing.
Weld a large hex nut to the armature shaft.
Lock the starter drive pinion fully forward.... be creative... you find out how!
Install the starter motor.
Use a large breaker bar and socket on the now "flywheel turning tool" that you just built from scrap parts.
Now you have full width ring gear tooth contact and lots of leverage against the ring gear, and so on.

NOTE: the starter drive unit will have a sprague clutch in it, and will rotate the ring gear in one direction only.
You may want to weld the pinion and sprague clutch together so that you can rock the flywheel in either direction.

Here is a picture of a device that can be used to force penetrating oil into the combustion chamber. The basic part is a compression gauge hose with the schraeder valve removed and the gauge itself disconnected. The gauge is replaced by a standard air compressor hose which can deliver 100 PSI to the frozen cylinder. It is shown here on an outboard but will work on any engine. If the cylinder you are pressurizing is not on the compression stroke you would have to remove the valve covers and loosen the rocker arms until the valves are closed. Use this method on all cylinders before you attempt to manually rotate the motor.

Bob, with any V cylinder engine, the oil will have a tendancy to pool at the low point of each ring landing.
He'd probably want to fill the cylinders high enough to approach the highest side of the ring landings.
Don't get me wrong..... I like the idea.... just don't think it's the answer for a V-8 unless he was add quite a bit of oil.

well it might not sound to safe but on mine i used a crow bar
between the teeth of the flywheel and the front case.

A starter motor pinion gear contacts the entire width of each ring gear tooth.
A bar being used on a pin point area of a ring gear tooth, may fracture or break the tooth.
His engine is stuck/locked up/frozen.
I'd not suggest doing this.

Rick: I really like your idea of 'modifying' an old starter motor, very good! I completely agree with you about possibly damaging a ring gear tooth by using a prybar (I probably shouldn't have mentioned it, but I did and I have done that and I have been lucky so far). Your method is MUCH better.

If you do modify an old starter motor, perhaps figure out a way to lock the pinion gear to the armature shaft.
As it is now...., the sprague clutch will allow for one direction of rotation only..... and with a locked up engine, you'll want to be able to rock it in both directions.

.