Piston Markings -What's Going On Here?

[Jocko_51_B3B]

 

I'm considering buying this 218 engine out of a '53 Plymouth but I'm wondering what these piston markings mean. Three of the pistons have no markings at all. The other three have a TD and an NG stamped on them. Since the pistons aren't marked with an oversize number (like .030) does it mean the pistons are necessarily standard size? Also the fact that the pistons don't all have the same markings has me scratching my head. The different piston markings tells me the engine must have been taken apart before, but why all six pistons weren't changed out together makes me wonder what's going on. Do any of you more experienced engine builders have any educated guesses before I spend my hard-earned money? The owner says the engine turns over just fine. I just don't like having unanswered questions - especially when cash is on the line.

 

 

 

[Dodgeb4ya]

Cylinder looks rusty..

Generally pistons will be stamped with the oversize on the tops.

Looks like the cylinders were some what rusty and honed and or wire wheeled clean ?

[Plymouthy Adams]

I agree Bob, looks like some short cuts taken....I would consider this as only a candidate for tear down.  

[kencombs]

18 minutes ago, Dodgeb4ya said:

Cylinder looks rusty..

Generally pistons will be stamped with the oversize on the tops.

Looks like the cylinders were some what rusty and honed and or wire wheeled clean ?

Yep, traces of rust left in the bore and take a look at the pitting on the intake valves.  Surely had water in it at some time, for a fairly long time I'd guess.

 

But, doesn't mean it's not a viable core, if the price right.

As to the piston markings, I've seen a lot of overhauls done and done some myself where the cylinders were OK, but a piston or two had broken or worn ring lands .  In my 230 that just got put back together it had 2 #3 rods on a set of .060 pistons.  Old rebuild with a bad rod so they used one from another engine.  Common in the rebuilder world.  Just wish they had remarked it.  Fortunately I have a habit of punch marking them anyway.

[DJ194950]

Many swear that +0.070 is fine. A few have said +80 after a check of cylinder wall thickness.

 

A friend has a 50's Mopar flat 6 at +70 with no problems after 20 years, and that is in central Calif. where 110 degrees F and normal in summer time. No overheating problems.

 

Time to take to a machine shop for tear down and inspection- then you can make educated decisions.

 

DJ

[Dodgeb4ya]

I'd keep looking..

[Plymouthy Adams]

Geico Pinocchio...when I look at this I see all kinds of potential.... 

[JBNeal]

I've had a few flatheads with odd markings that I couldn't explain because they measured as standard...but I agree, this engine may be salvageable but I wouldn't qualify it as an easy rebuild, the block etc definitely need teardown and thorough inspection...

[Jocko_51_B3B]

 

When I first contacted the seller, he sent me the pictures below. I messaged him again and asked him to check the top of the pistons for oversize markings. Instead he used something to scour off the top of the pistons and sent me the pictures I posted at the beginning of this thread (so I could see the piston tops for myself). I don't think he scoured the cylinder walls, just the piston tops. So, my main question is this; with no oversize markings on the pistons, is it possible this engine has never been bored oversize? That would seem too good to be true. 

 

I any case I would absolutely tear the engine down and rebuild it. I'm just trying to determine if I this block has never been bored out based on the lack of piston markings.

 

 

 

Edited February 20, 2020 by Jocko_51_B3B

[Plymouthy Adams]

that could be just an assumption...there could be many reason for the replaced pistons, busted top ring lands come to mind...should they have been replaced at random without regard to the cast weight consideration of the others...no but again not unheard of.  Many people have different ideas when it comes to repairs and to what depth and direction to proceed.  Unless the man would go measure the bore and sent that data...it is all speculation.  Is this block you entertaining within a reasonable drive to look and make a few observation/measurements for yourself.  That is about the only way I can advise one to proceed on an unknown and pictures only transaction.  Not sure many here could say more for you.  Maybe a member is closer to the block and would do a courtesy inspection.  That cylinder head has been off for some time, dobbers have built nests in the head bolt holes...the intake studs, couple of them look like they are not going to be an easy replacement either as there is no meat left on the bone...

[Jocko_51_B3B]

Thanks Plymouthy. He wants $400 for the engine, but I'm pretty sure I can get him down to $350. Unfortunately, the seller lives about 575 miles away near Knoxville Tennessee and he says it's too much trouble to ship it to Illinois. If I lived closer to the seller I'd take a dial bore gauge there myself. I don't like buying anything without a personal inspection, but neither do I want to make an 1150 mile round trip to look at a bad engine so I really appreciate getting as many opinions as possible - especially from this forum. In the meantime I'm keeping my eyes open for something closer to home.

Edited February 20, 2020 by Jocko_51_B3B

[Plymouthy Adams]

Was in Knoxville just a couple days ago.....rain made for a poor trip, roads, always pot hole all around Knoxville.  I would not want to venture back there until some very nice weather moves into the area.  I think there would be more engines closer to home....just got to shake a few bushes...check with any local car club or back shop ratrodder hangouts....they always swapping in the small bent engines and usually have or know if there are any of these engines in your area.  If you do not know these folks or where they gather in your area, ask your local over the counter big box parts retailer...they have a fair handle on who is doing what and where in the local area.  Good luck...this one is really on the outer limits for inspection I agree.  Get a lead on these guys hangout, show up with some beer, they usually respond similar to Pavlov's dog....

Edited February 20, 2020 by Plymouthy Adams

[CO54]

My 2 cents.  My truck got parked in '73 in an Arizona field and barn, until it was moved to a barn in Wyoming in 2008.  When I tore mine down this year, I found the T-stat housing had rusted out and all the coolant passages where full of rust and grime.  I've flushed the head a few times, and the block a few times to get as much as possible out.  The machine shop will be doing an acid dip to kill it all internally.  I will say though that when I pulled my head off for the 1st time,  all my pistons, cylinder walls, and valves looked better than pictured above.  The pistons have some carbon build up, the intake valves had a little too, and the exhaust where all stained white from leaded fuel.  If I was in a pinch for a replacement engine to rebuild, I would probably pull the trigger on this one.  Even with the drive, call it a weekend getaway. 

[Jocko_51_B3B]

I'm not trying to drag this out forever, but here are two more pictures of this same engine that I think might shed some more light on its overall condition. The first picture shows the end of the water distribution tube which doesn't look like it's corroded badly at all. The same photo also gives me a peek into the water jacket at the #1 cylinder wall which also looks pretty good to me. But the best indication for me is the second picture below which shows the female threads for the coolant drain valve. The engine block I have in my truck right now only has two good threads left. This one has ten. That tells me that the water jacket should be in pretty good shape. I asked the seller specifically for a picture of those threads. I realize that nothing beats a personal inspection followed by a total teardown.

 

 

 

 

[bkahler]

Based on the pictures I wouldn't have any hesitation in buying that engine block.  I would be surprised if it has been bored oversize.  I would venture to say someone has definitely been in the engine and done a few things but I don't see anything that would scare me away.  

 

The only information you don't have is condition of crank and there's no way to see that without pulling the pan.

 

 

[Dodgeb4ya]

If you are doing a complete rebuild yes it's probably ok....but might need all new valve seats..$$$...valves look rust pitted

Hopefully all the rods are original..they might have swapped a rod and piston...requiring balancing...sme shops make it worse ..seen that before

Crankshaft wear could be a big issue too.

Too bad it's not close.

[Mike36]

Sent you a PM. Let me know if interested.

[Young Ed]

What is your goal here? Are you trying to find a good block with a matching engine code for your truck? Or just a good block? A good block should be available closer to home but it this one is good and also a matching engine code I'd say hit the road. I think I'd probably offer $200 and see what they say. The resale market for these as cores isn't strong. 

[Fernando Mendes]

Std

[Jocko_51_B3B]

It would be great if I could find a nice block with a T306 engine code, but Plymouths seem to be the most common. I'd go with a Plymouth block if I had to. Being a purist is nice, but you gotta do what you gotta do.

[bkahler]

1 minute ago, Jocko_51_B3B said:

It would be great if I could find a nice block with a T306 engine code, but Plymouths seem to be the most common. I'd go with a Plymouth block if I had to. Being a purist is nice, but you gotta do what you gotta do.

 

I got lucky.  About the time I was ready to take my Plymouth engine to the machine shop I found a T306 block in the junk yard.  $50 later the T306 block was on it's way to the builder