Refresh or Rebuild?

[Bryan]

On 9/2/2022 at 1:27 PM, Bob Riding said:

Before I take it to the machine shop for magnfluxing and hot-tanking, I want to do any work that will create debris that the machine shop cleaning will remove.

To port/polish (or gasket match) or not, is the next question. I measured both the block and intake /exhaust openings  and they all measure out at about the same diameter- 1.3".

Does it make any sense to spend the effort to match them if they are already the same diameter, even though the gasket diameter is larger? 

I'm going with Langdon's split exhaust, which also measure at 1.3" dia.

I wouldn't try to match the ports to the gaskets. Don't know how thick the ports are with the water jacket behind it.  I bought the same exhaust manifolds.  I did my ports just to remove what ridges I could without removing too much metal, also rough spots and bumps. Under the edges of the valve seats need to be careful. Mine had recesses in some places so deep I couldn't grind it flush, or I'd undermine the seats.  Used a dremel.

 

Look at my posts.  I deburred sharp edges in the block, and cleaned out the oil galleries.  

 

Edited September 3, 2022 by Bryan

[Bob Riding]

2 hours ago, Bryan said:

I wouldn't try to match the ports to the gaskets. Don't know how thick the ports are with the water jacket behind it.  I bought the same exhaust manifolds.  I did my ports just to remove what ridges I could without removing too much metal, also rough spots and bumps. Under the edges of the valve seats need to be careful. Mine had recesses in some places so deep I couldn't grind it flush, or I'd undermine the seats.  Used a dremel.

 

Look at my posts.  I deburred sharp edges in the block, and cleaned out the oil galleries.  

 

Great thread, thanks! I agree-I don't think trying to port match is worth the effort. I will clean it up a bit and take it to the machine shop for magnafluxing and hot-tanking.

[Bryan]

1 hour ago, Bob Riding said:

Great thread, thanks! I agree-I don't think trying to port match is worth the effort. I will clean it up a bit and take it to the machine shop for magnafluxing and hot-tanking.

Hope you could find where I intended. Crazy link I thought would go to the correct page. It was on p14.

[Sniper]

If you click on the three small squares in the upper right corner of the post you want to link and click share it'll give you teh direct link to teh post to copy and paste

[Bob Riding]

I've been having fun disassembling the engine,  and I'm about ready to take it into the machine shop. Thanks to @keithb7for his great videos- it makes it easier to have the courage to dive in knowing someone else has been there and back and it's been recorded.  In looking over the parts, nothing jumps out at me (looking for something to cause the tapping noise that we discussed earlier) as the bearings seem good, all the wrist pins and C clips seem fine, and I can't see anything obviously wrong with the rods or pistons themselves as mentioned by @kencombs and @Sam Buchanan

 

I was planning to have the shop shave the head, but I'm not sure if someone has already done that. I mic'd the head and got 1.8 inches, + or -

I wasn't able to find any reference to stock head thickness - based on my understanding of the casting info, I have a Plymouth head made on June 24th, 1955, at 2pm. Stock compression ratio is 7.6 to 1. How much can be milled before I get into trouble? Is there a formula to determine compression ratio increase for every thousands shaved off?

[keithb7]

Looks good Bob. Nice work. Consider laying out your bearings. Wear side up. All con rods first, in a long time. Uppers on top. Lowers on lines up bottom. 1 thru 6. Take a photo and share with us. Then do the same for the mains.  We can study bearing wear. 
 

I see a top ridge on cylinders. No? Did you measure piston ring end-gap in their respective cylinders. This is a good indicator or ring to wall wear. 
 

Take head to machine shop. Ask them to measure deflection. If you are concerned tell them to only take off enough to make to flat again. I don’t have a spare head to measure for you. Did you see my oil fill teast video? 100cc vs 85cc of oil to fill combustion chamber. Maybe a similar test will give you some clues.  I took 0.030 off a stock head. No issues. 
 

 

 

[keithb7]

Tappets. Look for wear where rides on cam and where contacts valve. Did you measure tappet clearances before engine disassembly?

[Bob Riding]

@keithb7Here are pics of the bearings, tappets, valves and journals. I used a ridge reamer, then honed the cylinders -didn't get the cross-hatch pattern, but you can't feel any ridge now. Attached are the cylinder measurements I made with my dial bore gauge...seems in spec for taper.

 

I lapped the valves. The tops look kind of gnarly, but underneath seem clean.  You can see the different types of wear patterns on the tappets. An immediate concern is in the rough edge on the rear main bearing- I took a separate shot of both halves for detail.

Have at it! 

Scan Sep 27, 2022 at 1.28 PM.pdf

[keithb7]

This pic looks bad. The rear main thrust bearings by chance?  By chance did you pre-measure crank thrust before disassembly? 
 

Does rod bearing #1 have pitting? Did you squeeze your oil filter in a vice. As per my video. Possibly metal filings from thrust beatings present in filter?

 

I think we see some pitting in valve seal surfaces? Hard to tell. Valves are cheap. I put all new in my engine. 
 

 

[Sniper]

1 hour ago, keithb7 said:

Valves are cheap

 

Valves were cheap, good luck finding them anymore.  Maybe your local machine shop can redo the ones you have.

[keithb7]

The surface area of the crankshaft where the main thrust bearing contacts. How does yours look?

 

[Bob Riding]

15 hours ago, keithb7 said:

The surface area of the crankshaft where the main thrust bearing contacts. How does yours look?

 

No pitting or scratches you can feel. I didn't squeeze the filter, because it didn't have one. 

[Bob Riding]

16 hours ago, Sniper said:

 

Valves were cheap, good luck finding them anymore.  Maybe your local machine shop can redo the ones you have.

I checked with the usual suspects- AB, VPW, Robert's and Kanter, and they all carry them for $14-$15 each. Are you saying they aren't very good? Chinese repros, etc?

 

[Bob Riding]

18 hours ago, keithb7 said:

This pic looks bad. The rear main thrust bearings by chance?  By chance did you pre-measure crank thrust before disassembly? 
 

Does rod bearing #1 have pitting? Did you squeeze your oil filter in a vice. As per my video. Possibly metal filings from thrust beatings present in filter?

 

I think we see some pitting in valve seal surfaces? Hard to tell. Valves are cheap. I put all new in my engine. 
 

 

Both #6 and #1 have slight (I guess you'd call it pitting - can't really feel it with your fingernail) on 1/3 of each surface. None of the other rod bearings show any pitting, only a scratch here or there. #6 and #1 below:

[keithb7]

Imagine the car parked for years. The engine not started. #1 and #6 at or near TDC. The con-rod bearing not submerged in the oil in the pan. At least not the top half of the con-rod bearing. The top bearing has the oil hole right?  Consider that bearing corroding from humidity. Maybe on a hot day gasses flash off the sump oil and travel up the dry upper bearing. At night things cool down. Humidity condenses on the metal parts. Water drip down into the oil pan. Maybe some drips down an ends up in the con rod bearing too. Next summer it gets hot again. The water partially vaporizes maybe. Vapor travels into the dry upper bearing again. This happens year after year. Seasonally.  The upper bearing surface corrodes as witnessed here. 
 

The pitting you are seeing here on these bearings is not friction wear.

 

At sone point some type of dirt or other foreign object did enter the bearing area via the oil feed hole. You can see the wear score mark lines up right to the oil hole.  These are called witness marks. The bearing did its job and absorbed the force of the object as it rotated around the crank. 
 

 

Edited September 28, 2022 by keithb7

[Bob Riding]

52 minutes ago, keithb7 said:

Imagine the car parked for years. The engine not started. #1 and #6 at or near TDC. The con-rod bearing not submerged in the oil in the pan. At least not the top half of the con-rod bearing. The top bearing has the oil hole right?  Consider that bearing corroding from humidity. Maybe on a hot day gasses flash off the sump oil and travel up the dry upper bearing. At night things cool down. Humidity condenses on the metal parts. Water drip down into the oil pan. Maybe some drips down an ends up in the con rod bearing too. Next summer it gets hot again. The water partially vaporizes maybe. Vapor travels into the dry upper bearing again. This happens year after year. Seasonally.  The upper bearing surface corrodes as witnessed here. 
 

The pitting you are seeing here on these bearings is not friction wear.

 

At sone point some type of dirt or other foreign object did enter the bearing area via the oil feed hole. You can see the wear score mark lines up right to the oil hole.  These are called witness marks. The bearing did its job and absorbed the force of the object as it rotated around the crank. 
 

 

 

53 minutes ago, keithb7 said:

Imagine the car parked for years. The engine not started. #1 and #6 at or near TDC. The con-rod bearing not submerged in the oil in the pan. At least not the top half of the con-rod bearing. The top bearing has the oil hole right?  Consider that bearing corroding from humidity. Maybe on a hot day gasses flash off the sump oil and travel up the dry upper bearing. At night things cool down. Humidity condenses on the metal parts. Water drip down into the oil pan. Maybe some drips down an ends up in the con rod bearing too. Next summer it gets hot again. The water partially vaporizes maybe. Vapor travels into the dry upper bearing again. This happens year after year. Seasonally.  The upper bearing surface corrodes as witnessed here. 
 

The pitting you are seeing here on these bearings is not friction wear.

 

At sone point some type of dirt or other foreign object did enter the bearing area via the oil feed hole. You can see the wear score mark lines up right to the oil hole.  These are called witness marks. The bearing did its job and absorbed the force of the object as it rotated around the crank. 
 

 

After that detective work, I'm thinking you are the long lost-third brother of "Click and Clack"!  I am of course going to replace all the bearings. What do you think about the tappet wear, and although I haven't checked the ring-end gaps, I was going to get new rings.  

[kencombs]

On the subject of tappet wear, the adjustment screw surface is easy to either replace or regrind.  A lot of old valve refacing machines had the attachment to do that and/or rocker arm surfaces.  The other end is much more critical.  IMO, any wear on the surface that contacts the cam warrants a cam regrind, or replacement as well as new or reground lifters.  Your valves look usable to me.  Chucked in a valve lathe and check for even contact and adequate edge margin would prove or disprove quickly.  Have you checked the guide wear?  Quick and dirty method, just put the valve in with it about 1/2" off the seat and wiggle.  Wear will be obvious.  Mine only needed exhaust guides.  I suspect they were all done in a long ago rebuild as it had .040 pistons and an .020/.020 crank.

 

In my case, my cam for some reason would not turn smoothly in the block.  Seemed to be bent slightly.  Original cam, bearings that had been replaced when it was rebuilt years ago.  Had to change the cam with one I had on the shelf.  New bearings, used cam, all was smooth.  But, I didn't have a set of lifters that were matched to the used cam.  So, I had a set reground at an big engine rebuilder.  Cheap and they looked new when done.

Edited September 28, 2022 by kencombs

[Bob Riding]

36 minutes ago, kencombs said:

On the subject of tappet wear, the adjustment screw surface is easy to either replace or regrind.  A lot of old valve refacing machines had the attachment to do that and/or rocker arm surfaces.  The other end is much more critical.  IMO, any wear on the surface that contacts the cam warrants a cam regrind, or replacement as well as new or reground lifters.  Your valves look usable to me.  Chucked in a valve lathe and check for even contact and adequate edge margin would prove or disprove quickly.  Have you checked the guide wear?  Quick and dirty method, just put the valve in with it about 1/2" off the seat and wiggle.  Wear will be obvious.  Mine only needed exhaust guides.  I suspect they were all done in a long ago rebuild as it had .040 pistons and an .020/.020 crank.

 

In my case, my cam for some reason would not turn smoothly in the block.  Seemed to be bent slightly.  Original cam, bearings that had been replaced when it was rebuilt years ago.  Had to change the cam with one I had on the shelf.  New bearings, used cam, all was smooth.  But, I didn't have a set of lifters that were matched to the used cam.  So, I had a set reground at an big engine rebuilder.  Cheap and they looked new when done.

Great info! How will they grind the adjustment screw surface on the lifters to "match" the cam?

[Sniper]

5 hours ago, Bob Riding said:

I checked with the usual suspects- AB, VPW, Robert's and Kanter, and they all carry them for $14-$15 each. Are you saying they aren't very good? Chinese repros, etc?

 

 

Well, those sources aren't cheap valves, if they have them in stock.  I paid $112 for all 12 valves a couple of years ago.   At $15 a pop that's now $180.  Of course the usual sources you mention always have charged a premium.  I got my set from Ebay, but now I see it's $120 for 6 intakes or 6 exhausts ?

Edited September 28, 2022 by Sniper

[kencombs]

17 hours ago, Bob Riding said:

Great info! How will they grind the adjustment screw surface on the lifters to "match" the cam?

The adjustment screw surface can be reground on a valve machine.   The bottom, cam surface, requires special tooling to get the crown correct as most lifters are not flat, but slightly higher in the center.  Really slightly!  Those that aren't use a cam lobe offset from center or tapered cam lobe to assure that they rotate.  That's not a 'match' exactly, just a specific shape and finish.

[kencombs]

16 hours ago, Sniper said:

 

Well, those sources aren't cheap valves, if they have them in stock.  I paid $112 for all 12 valves a couple of years ago.   At $15 a pop that's now $180.  Of course the usual sources you mention always have charged a premium.  I got my set from Ebay, but now I see it's $120 for 6 intakes or 6 exhausts ?

I guess I'm cheap.  No, I know I'm cheap but have never replaced all the valves in one of my engines.  Only exhaust that are badly burnt, or valves that have hit the piston get changed.  Others get reground and discarded only if they become to thin.   Even then I usually find a used replacement in my stash.

 

To be fair, my Dad had a salvage for 30 years so my stash was much bigger than most!

 

I don't think I've ever encountered a stem that was worn beyond use.  Well, maybe on a Y-block Ford that suffered from the chronic lack of overhead oiling.

But never on a flathead where the opening thrust is directly in line with the stem, no side loading like OHV engines.

 

I doubt if my flathead will see 20k miles of use so having room for another regrind is not an issue for me.