New Engine QA and Paul Shinn's Concerns

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That tight spot on that crankshaft would not be acceptable to me. I'd fix it and make it right. That's early bearing failure waiting to happen.
 
Big hammer said:
When I was watching the video and saw the tightness, I thought why not one at a time remove the bearings too find which bearing is tight, then proceed with an adjustment. We are loosing good machinist/mechanic every day, so many tips and tricks are being lost !
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Paul spent hours in my shop and we did exactly what you have suggested. You can't see everything in a one minute video.

The first time it was checked was with the "shipping studs" and nothing else, the first thing that happened when they were unloaded at my place was to pull all the caps, clean the blocks and caps then assemble and torque with the permanent studs. Then the main bore sizes were checked.

Next new bearings were removed from their boxes and all checked with a ball mic at the crown before being installed in the block. After the cranks were checked for run-out on a set of rollers supporting the end mains they were checked for size with a micrometer, not calipers. Then the crank was laid in the block with light oil on the lower bearings (block is upside down) then checked with platigauge at proper toque with permanent studs as the engine would be in final assembly. Then the crank was removed, plastigauge cleaned off and re-installed with light oil. Mains torqued to proper spec and the crank given a spin.

This all took hours of checking bearings for rub, tapping caps around to see how things might change and a myriad of other things that you don't see in one minute.

Both engines #111 and #123 are almost finished and will be run soon. #123 is going into a 1929 Fordor sedan for some hard driving and a lot of miles. We will see just how well it/they hold up. Should be a lot of fun. Remember, "Fun" is why we do this. :)
 
I would also like to add that Paul was nothing but nice and a genuine good guy with me, we had a good time that day. He was just looking for facts. I don't think picking on him and backing him into a corner will help anything. I believe he intends to make a statement to clear this all up but everyone coming at him isn't helping.
 
mctim64 said:
I would also like to add that Paul was nothing but nice and a genuine good guy with me, we had a good time that day. He was just looking for facts. I don't think picking on him and backing him into a corner will help anything. I believe he intends to make a statement to clear this all up but everyone coming at him isn't helping.
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Dragging his feet the whole way sure isn't helping matters one bit as you can see.

Regards
Bill
 
mctim64 said:
Paul spent hours in my shop and we did exactly what you have suggested. You can't see everything in a one minute video.

The first time it was checked was with the "shipping studs" and nothing else, the first thing that happened when they were unloaded at my place was to pull all the caps, clean the blocks and caps then assemble and torque with the permanent studs. Then the main bore sizes were checked.

Next new bearings were removed from their boxes and all checked with a ball mic at the crown before being installed in the block. After the cranks were checked for run-out on a set of rollers supporting the end mains they were checked for size with a micrometer, not calipers. Then the crank was laid in the block with light oil on the lower bearings (block is upside down) then checked with platigauge at proper toque with permanent studs as the engine would be in final assembly. Then the crank was removed, plastigauge cleaned off and re-installed with light oil. Mains torqued to proper spec and the crank given a spin.

This all took hours of checking bearings for rub, tapping caps around to see how things might change and a myriad of other things that you don't see in one minute.

Both engines #111 and #123 are almost finished and will be run soon. #123 is going into a 1929 Fordor sedan for some hard driving and a lot of miles. We will see just how well it/they hold up. Should be a lot of fun. Remember, "Fun" is why we do this. :)
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mctim64 said:
I would also like to add that Paul was nothing but nice and a genuine good guy with me, we had a good time that day. He was just looking for facts. I don't think picking on him and backing him into a corner will help anything. I believe he intends to make a statement to clear this all up but everyone coming at him isn't helping.
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Thanks for your input Tim.
 
There is a difference between rolling torque and break away torque. I've found this on both Timken bearings and babbit or removable shell type bearings. When they are set up to a close tolerance (journal bearings) or with a specific pre-load (Timken bearings), they can and will have a break away point when first attempting rotation. On multiple journal type bearings, there can be enough difference between journals to create a spot with more drag than the rest of the arc of rotation. If one has a tight spot in rotation then it should be marked between shaft and stationary block component with a felt marker to see if it is consistently more resistant to rotational torque in that same spot on each revolution. If it's not consistent, then it is just break away resistance. If it is consistent then it is a slight journal to crank pin offset on one or more journal bearing locations. The fact that it rotated through at all is a good sign. Once warmed up to operating temperature after the engine is complete and operational, everything grows and clearances change. There is no way of knowing if this would decrease the life of the crankshaft journal bearings or not but time will tell. A person can remove the pan at some point and recheck the clearances with plastigauge. With 5 main bearings, the crank definitely won't move around as much as a stock model A engine with only 3-mains. I'd venture a guess that it would have a long and healthy life once it's bedded in.

I've seen worse problems with V8 engines in the modern era from a cracked connecting rod to a mis-drilled lifter bore on brand new engines. These were domestic engines too. Warranty covers the expense but it doesn't cover the time wasted with such products.
 
Ruth said:
sez the guy who has been BANNED and signed up under another username.
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Even someone of your mental acuity should see the difference between a party using his megaphone to impugn an honest man..as opposed to getting kicked out of the Mickey Mouse club for hiding the denture cream..
 
I have built a few (very few) 60's-70's era V8's and have felt the crank as pretty draggy. I have never done this but could you put some fine valve lapping compound on the sticky insert and turn the crank several times to take the high spots off? Of course, you would have to clean everything before trying the crank hand spin test again. Would this be a reasonable approach?
 
jack backer said:
Even someone of your mental acuity should see the difference between a party using his megaphone to impugn an honest man..as opposed to getting kicked out of the Mickey Mouse club for hiding the denture cream..
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Do we need to separate you two?
Don't make me pull this car over!
 
GeneBob said:
Why? If you are willing to file the edges of the inserts, why not lap them in?
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Not the bearing surface, on the backside where the clearance is tight next to the stud. The procedure is in the online builders guide download at modelaengine.com
 
Another area that should be checked is the thrust surfaces of the crankshaft. A bad spot will show up on the thrust bearings.
 
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