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Can you pull 502 BBC crank w/o removing heads

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Can you pull 502 BBC crank w/o removing heads

Old 09-14-2019, 03:18 PM
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Default Can you pull 502 BBC crank w/o removing heads

Can the crankshaft be pulled to change rod and crank bearings WITHOUT having to pull the heads on a 1998 502 mpi - just work thru the pan?

I have recently done a valve job so it has new intake/head gaskets, so would save money and time not to have to pull anything off the top, including new manifolds, etc.
Just wanted to make sure there is enough clearance first of all with all the rods still in place.. Just never done it this way.
thanks for info.
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Old 09-14-2019, 03:28 PM
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Will you be able to check bearing clearances in the boat?

Easier to pull engine
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Old 09-14-2019, 03:30 PM
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Yes it can be done

and guess your not worried about other clearance issues?
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Old 09-14-2019, 03:39 PM
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Underpsi
i am pulling the motor. Brother has a lift and motor stand so we can turn it over to work on it.
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Old 09-14-2019, 03:49 PM
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All Dodge
Just considering everything i thought it would make it so much easier/quicker/cheaper. But always value opinions.

Motors had been completely rebuilt 6y ago when i bought the boat.
Compression was good last summer and a valve job and seals done again 2y ago.
Your right, a little risky but seems in good shape. If anything looks suspicious from underneath, will pull the heads.
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Old 09-14-2019, 04:11 PM
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As with all quick questions, most folks don't understand the background.

If we understood why the bearings need to be changed this might help. I'm just thinking, crank needs to be measured and determined if it needs work or just a good polishing. New bearing should be plastic gauged or oil clearance. Just not enough info, but I am assuming all this has been thought of prior to making the decision
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Old 09-14-2019, 04:17 PM
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This takes me back to my 20's when I didn't have much money and did an in-block overhaul in my drive way. Pulled heads but not the block. When installing the crank, under the car it was a bit windy. Didn't plastic gauge and think some dust got on the bearings. I didn't get 50 miles out of the motor before the rods started knocking
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Old 09-14-2019, 04:34 PM
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You think it needs rod and main bearings? But you think the cam bearings are ok?
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Old 09-14-2019, 06:21 PM
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I’ve done stuff like that, and got away with it. You know your engine better than we do. On the other hand winter is around the corner so you got time. Gaskets aren’t that much, spread out over the whole winter.
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Old 09-14-2019, 07:15 PM
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Yeah, more to consider I guess. Dodge i do suppose history would be good info for yall. As you can tell, im working my way thru this.

What happened was after a days outing, when starting it at dock to put on trailer, instantly heard a knock like same RPM as motor. Shut off immediately. Restarted it for no more than 5 seconds to get a look at oil pressure. Same knock. Oil pressure good, 30 at idle.

The other port motor did this same KNOCK thing a couple months after we bought it in 2014, even though both motors had had complete rebuilds by a shop in Texas.
I dont recall if it was the crank or rod journals, but they were machined so bad you could feel the machining grooves left in them and see them - on most of them.
It just held up for a couple months. Rebuilt most everything although about all it needed was the bearings and crank. No issues since.


I suspect crank or rod journal bearing is bad on this one also, that there may not be anything wrong elsewhere.
But I did see a few METAL FILINGS in the entering side of the oil filter. One thing im not sure of, is the path of the filtered oil. Isn't everything from the bottom of the valley and cam on up filtered oil ?????
If so, the filings should be just in the pan and oil pump and lines.

Also, if it is a rod bearing, not a crank, and we can't get to the rod caps to mic them after the crank is out, will have to pull the heads. Can the rods be mic'd in place?????
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