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Just bought a mystery 401! Need opinions?

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JolleyGreenSST View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JolleyGreenSST Quote  Post ReplyReply Direct Link To This Post Posted: Oct/31/2018 at 1:18pm
Originally posted by Trader Trader wrote:

Take it or leave it, but I would do the following with limited tooling:
- take off the piston rings
- clean and clean some more
- put each piston down the respective hole upside down, using feeler gauges, measure the skirt clearance at the mid and top of each hole and record.
- if all are under 0.006" and on a budget, clean everything and then clean again, re-ring, re-bearing, have the crank polished and re-assemble
- drive and enjoy for several years and determine if you want to budget for a performance rebuild some time in the future. 
Any recommendations on feeler gauges, three finger hone and what grit stones? Also what would that cost me compared to having a shop do it for me? because I would need a shop to polish the crank anyway right.
"God is good all the time and all the time God is good!"
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Trader View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Oct/31/2018 at 2:43pm
6" or 4" feeler gauge set will cost less the $10 and a three finger 220 grit cylinder hone 3" to 7" will be about $35.
A shop is going to cost you $90 an hour labor and then job cost on the block. Likely want to magniflux, hot tank, and measure. If out of spec they would likely not want to assemble. So $200 to $300 for the shop on the block and your not that much further ahead then spending the $45 and doing this part yourself - again, my opinion.
The web link in the previous post tells you how to do the honing. Not that hard, agree with White that a ball hone is not for a novice.

If you find the block is not within tolerance at this point then your going to have to spend money and do the shop anyhow. But you will have information for them and be able to get a good estimate of total cost, including, boring, new pistons and balancing. As with the others it does not look like you need this, but I'd do the cheap check before $$$, again - my opinion. 


Edited by Trader - Oct/31/2018 at 4:24pm
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JolleyGreenSST View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JolleyGreenSST Quote  Post ReplyReply Direct Link To This Post Posted: Nov/06/2018 at 3:27am
harbor freight has a hone for $23 with some pretty good reviews and they got a 4" feeler gauge set for $5 but either way I'm going to continue the disassembly before I make any final decisions.
I did some research and found out that "king bearings" makes a .0040 undersize bearing for the 401 which makes me feel way better knowing that I'll have an option if polishing the crank doesn't work.
I'm surprised nobody on here mentioned that the crank could still be ground down if needed.

"God is good all the time and all the time God is good!"
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Post Options Post Options   Thanks (0) Thanks(0)   Quote BassBoat Quote  Post ReplyReply Direct Link To This Post Posted: Dec/05/2018 at 10:47am
There are right ways to do things, and good enough ways to do things, and ways that may or may not be. 
A professional shop will measure the OD of the pistons with a micrometer, the ID of the cylinder with a calibrated dial bore gauge, and be able to look at the out of round and taper of each cylinder.
An amateur like me would use an inside micrometer and a lot of patience to evaluate the cylinder bore.  Someone on here mentioned snap gauges, and that is also accepted practice.  Calipers only tell you a rough answer, maybe enought to decide if a block was bored 030 or 040.  Pistons need to be measured with a micrometer.  
You will get a better result if you use a ball hone than a 3 finger hone assuming you have cylinders that are relatively good.  The cross hatch I see in your pictures is encouraging.  Maybe the block is fresh.  Then again, maybe someone took a hand hone to a sloppy tapered cylinder and scuffed it up.  
That imaginary professional shop will install the new bearings, torque eveything to spec and then use a dial bore gauge to measure the bearing ID.  Then use a micrometer to measure the journal diameter and determine the oil clearance.  Honestly, you can use plastigauge if that is all you have and get within a thou of what the clearance is, and that is probably good enough for a stock rebuild.
good luck
BB
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JolleyGreenSST View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JolleyGreenSST Quote  Post ReplyReply Direct Link To This Post Posted: Dec/07/2018 at 3:07am
Originally posted by BassBoat BassBoat wrote:

There are right ways to do things, and good enough ways to do things, and ways that may or may not be. 
A professional shop will measure the OD of the pistons with a micrometer, the ID of the cylinder with a calibrated dial bore gauge, and be able to look at the out of round and taper of each cylinder.
An amateur like me would use an inside micrometer and a lot of patience to evaluate the cylinder bore.  Someone on here mentioned snap gauges, and that is also accepted practice.  Calipers only tell you a rough answer, maybe enought to decide if a block was bored 030 or 040.  Pistons need to be measured with a micrometer.  
You will get a better result if you use a ball hone than a 3 finger hone assuming you have cylinders that are relatively good.  The cross hatch I see in your pictures is encouraging.  Maybe the block is fresh.  Then again, maybe someone took a hand hone to a sloppy tapered cylinder and scuffed it up.  
That imaginary professional shop will install the new bearings, torque eveything to spec and then use a dial bore gauge to measure the bearing ID.  Then use a micrometer to measure the journal diameter and determine the oil clearance.  Honestly, you can use plastigauge if that is all you have and get within a thou of what the clearance is, and that is probably good enough for a stock rebuild.
good luck
BB
The holidays have slowed my progress down, hopefully I will take it to a machine shop soon and I will post the results once I have it inspected.
"God is good all the time and all the time God is good!"
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69amx290 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 69amx290 Quote  Post ReplyReply Direct Link To This Post Posted: May/24/2022 at 1:23pm
I realize this is a very old post but thought I would give it a try.  I'm having trouble finding a carburetor spacer for a 1977 401 out of a Wagoneer.  It has the original 4 hole manifold for a Motorcraft 4350.  There is a picture in this discussion that looks like what I need.  If anyone can direct me to where I can get one that would be great.  If I can't find one I plan on making my own. It would be helpful to have the specs.  I have the OEM spacer to manifold gasket and the carb to spacer gasket.  The carb to spacer gasket is very thick with no bolt holes.  I'm not sure if that thick gasket fits into a recess into the spacer or if it is just compressed between the flat base of the carburetor and the spacer.  The picture shows a raised radius around the primary and secondary barrels.  Does this face the carburetor or the manifold?  Is the other side flat or raised or have a recess for the thick gasket?  Any help is appreciated.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Heavy 488 Quote  Post ReplyReply Direct Link To This Post Posted: May/24/2022 at 3:41pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 69amx290 Quote  Post ReplyReply Direct Link To This Post Posted: May/26/2022 at 9:51am
Thanks for the picclick link.  eBay is one place I go to for hard to find parts.  Plenty of gaskets and 4350 rebuild kits.  So far no luck on the spacer.
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