Moparts

Need to repair one broken piston - cheaply.

Posted By: Fab64

Need to repair one broken piston - cheaply. - 08/08/14 08:02 PM

Hi all,

I am trying to revive an old 383 that came from a salvage yard, and has been sitting for several years in my project '66 Coronet. I've finally decided to sell this car, but in the meantime I need to be able to get it out of the garage (I've bought another Mopar), and move it from side-to-side in the driveway (I live in an HOA). The condition of the motor was unknown to me. According to the PO, it came out of a '65 Chrysler, and had around 65k miles on it. A few of the intake ports were quite rusty, so I removed the heads to look inside. The good news: no evidence of water inside. The bad news: I discovered a chunk missing from one of the pistons:



As you can see, the top part of the piston is missing, and a portion of the top ring is visible. The cylinder wall doesn't appear to be scratched. Since I'm not keeping this car, I don't want to spend the money to completely rebuild the motor. But I also don't want to do a hack job, either. I'd like to buy one piston & rings, pull this one out, being very careful to be clean with everything, and replace it. Does anyone see any problems with that plan? Could I get by with using the same rod bearings on this one connecting rod, or should those also be replaced? I'd appreciate any advice, thanks.

Roger
Posted By: JohnRR

Re: Need to repair one broken piston - cheaply. - 08/08/14 08:07 PM

Changing the rings will require honing the cylinder , the bearings could be reused , the IMPORTANT thing is the piston is the same compression height and weighs basically the same ... oh and the correct bore size ....
Posted By: NachoRT74

Re: Need to repair one broken piston - cheaply. - 08/08/14 08:17 PM

I think the answer by John is pretty obvious... better replace the piston... which being stock, could be cheap to replace ( $30-40 ??? ) and even not hard to find.

A refill and machine job will be way more I think
Posted By: GTX MATT

Re: Need to repair one broken piston - cheaply. - 08/08/14 08:40 PM

I don't see anything wrong with it, as said if you change the rings you need to hone it though. So change all rings or change none.

A friend of mine bought a RoadRunner with a 383 missing the ringlands on #1 years ago. He swapped the pistons out and did rings and bearings. Well over 100K miles later (I'm not kidding) and that thing still moves good, doesn't smoke, burn oil, etc.
Posted By: HemiRick

Re: Need to repair one broken piston - cheaply. - 08/08/14 09:03 PM

Yea your plan is good reuse the rings on the new piston, this eliminates the need to hone and if the bearings look good reuse them.
Posted By: dogdays

Re: Need to repair one broken piston - cheaply. - 08/08/14 09:22 PM

Pistons either stock or replacement will be the same weight within factlry tolerances. No need to worry about that. (I assume you are not buying one lightweight custom forging!)

You can put new rings on whatever piston you end up with, just lightly run a ball hone through the cylinder. Actually, I have replaced rings with NO disturbing of the surface and they seated right up.

Compression height problems? Forget it. I know guys who circle track raced engines with three different compression ratio pistons, from three previous engines. The car ran good, no indication that everything wasn't kosher.

Heck, you could pull that piston, take off the rings, put a new set on except put the top ring in the second groove, put oil ring where it belongs, and run it that way! There are two-ring pistons running on racetracks. Three is not a magic number. Just like four was not a magic number back in the day.

You're not doing a restoration, you're trying to get a car to move under its own power long enough to be sold. Be honest, tell the buyer the truth, "the engine will need to be rebuilt." You don't need too go into specifics why. If you're telling him it needs to be rebuilt that covers whatever is wrong inside.

Good luck with that HOA! I bought my house specifically because it didn't have one.

R.
Posted By: Twostick

Re: Need to repair one broken piston - cheaply. - 08/08/14 09:37 PM

If you know someone with a blew up 383 or who just rebuilt one, a used piston would be more than adequate for that job. Rod and all if you can will make it an easy swap. A new set of cast iron rings and a quick hone to break the glaze and you're good.

If the bearing is still grey, I'd use it over. If there is a bunch of copper showing, a new bearing won't break the bank.

Kevin
Posted By: floridian

Re: Need to repair one broken piston - cheaply. - 08/08/14 09:44 PM

Quote:



Good luck with that HOA! I bought my house specifically because it didn't have one.

R.



I am with you on that.. Looked a many homes ( here in Florida) with bankrupted HOA developments with NOTHING being done for the HOA fees, still a Lawyer is collecting the money..

One of my employees stopped paying his.. Almost lost his home.. Seems as if the Legal Firm was foreclosing in his home without telling him.. VERY SCARY......
Posted By: Fab64

Re: Need to repair one broken piston - cheaply. - 08/09/14 12:03 AM

Thanks very much for all the replies, guys. Yes, my main concern is that I'll need to make sure of the correct size for a replacement piston. Aren't over-sized pistons usually stamped on the top with the size? If nothing else, I'll take the bad piston to a shop, and have them measure it.


Quote:

Heck, you could pull that piston, take off the rings, put a new set on except put the top ring in the second groove, put oil ring where it belongs, and run it that way! There are two-ring pistons running on racetracks. Three is not a magic number. Just like four was not a magic number back in the day.



Unfortunately, after removing the pan, I can actually see daylight through the hole so re-using this piston is not an option.

Thanks again. I'm sure I'll have more questions before I'm finished!

Roger
Posted By: dogdays

Re: Need to repair one broken piston - cheaply. - 08/09/14 01:09 AM

Yes, oversized pistons are usually marked by stamping on the top of the piston.

At 64K miles your old piston should be 4.25 standard size measured close to the bottom of the piston.

R.
Posted By: Fab64

Re: Need to repair one broken piston - cheaply. - 08/09/14 02:13 AM

Thank you, dogdays. I've removed the piston and I'm taking it to my local, independent parts house for them to measure. The owner is an old-hand guy who knows everything. I'll have him order me a new piston, and install it on the connecting rod.

Also, I have no way of knowing if that 65k mile figure is accurate. For all I know, it could be 165k. From the looks of this piston, this engine may have more miles on it. Here are some more pictures. As you can see by the hole, this cylinder had no compression:





This doesn't look good at all:





The top ring is broken:




I'll keep you posted, thanks!

Roger
Posted By: RUNCHARGER

Re: Need to repair one broken piston - cheaply. - 08/09/14 02:27 AM

Anything special about this engine? I'm just thinking it might be cheaper to find a decent 383 in a JY and swap it out.

Sheldon
Posted By: Fab64

Re: Need to repair one broken piston - cheaply. - 08/09/14 03:13 AM

No, nothing special. I'm just trying to get this motor running at the lowest cost, since I will be selling the car. I've already got more in the car than I'll probably get when I sell it.

Roger
Posted By: JohnRR

Re: Need to repair one broken piston - cheaply. - 08/09/14 03:34 AM

Throw it back in and pull that plug wire off ... doesn't get cheaper than that ...

What does the cylinder wall look like ?

People complain that they can't give 383's away , you should be able to find something that runs for about what it's going to cost you to make that thing run on all 8 .
Posted By: Fab64

Re: Need to repair one broken piston - cheaply. - 08/09/14 03:58 AM

Quote:

Throw it back in and pull that plug wire off ... doesn't get cheaper than that ...



If only!!


Quote:

What does the cylinder wall look like ?



From what I can see and feel, it doesn't seem bad at all. I'm surprised, considering the condition of the top ring in the picture I posted earlier.


Quote:

People complain that they can't give 383's away , you should be able to find something that runs for about what it's going to cost you to make that thing run on all 8 .



Yes, where are all these people?!?! Craigslist shows a 383 in Carlsbad for $200. But it has also been sitting for 10 years, which sounds pretty much like what I'm dealing with right now. I'm beginning to question the wisdom of trying to get this motor running.
Posted By: JohnRR

Re: Need to repair one broken piston - cheaply. - 08/09/14 05:12 AM

Quote:

I'm beginning to question the wisdom of trying to get this motor running.



Posted By: Twostick

Re: Need to repair one broken piston - cheaply. - 08/09/14 05:26 AM

Quote:

Thank you, dogdays. I've removed the piston and I'm taking it to my local, independent parts house for them to measure. The owner is an old-hand guy who knows everything. I'll have him order me a new piston, and install it on the connecting rod.

Also, I have no way of knowing if that 65k mile figure is accurate. For all I know, it could be 165k. From the looks of this piston, this engine may have more miles on it. Here are some more pictures. As you can see by the hole, this cylinder had no compression:





This doesn't look good at all:





The top ring is broken:




I'll keep you posted, thanks!

Roger






What do the rest of them look like? That is some pretty serious abuse there that might show up in more than 1 hole.

Kevin
Posted By: Jim_Lusk

Re: Need to repair one broken piston - cheaply. - 08/09/14 07:05 AM

Detonation will cause that. When I picked up my old 66 Barracuda it probably would have run (my buddy I bought it from suggested that), but I knew that it had been smoking pretty bad and I already had a good running rebuilt 273. When I pulled it apart I found that four pistons had broken top rings and the piston on the right was the one causing most of the smoke...

Attached picture 8234435-273pistons03.JPG
Posted By: Fab64

Re: Need to repair one broken piston - cheaply. - 08/09/14 07:21 AM

Quote:

What do the rest of them look like? That is some pretty serious abuse there that might show up in more than 1 hole.



The others all have some carbon buildup on the tops (as this one does), but none of them show any signs of being cracked or broken. I suspect some of the oil rings may also be bad. When I had the motor tilted on its side on the engine stand, oil was leaking down past a few of the pistons (or maybe that's just where the oil control ring gaps were in those cylinders?).

In any case, I've decided to hold off doing anything until I investigate other possibilities (namely, looking for another motor).
Posted By: JohnRR

Re: Need to repair one broken piston - cheaply. - 08/10/14 05:43 AM

Quote:

Quote:

What do the rest of them look like? That is some pretty serious abuse there that might show up in more than 1 hole.



The others all have some carbon buildup on the tops (as this one does), but none of them show any signs of being cracked or broken. I suspect some of the oil rings may also be bad. When I had the motor tilted on its side on the engine stand, oil was leaking down past a few of the pistons (or maybe that's just where the oil control ring gaps were in those cylinders?).

In any case, I've decided to hold off doing anything until I investigate other possibilities (namely, looking for another motor).



Rings have gaps so if you put oil against them the oil will eventually find it's way out ... gravity ...
Posted By: Fab64

Re: Need to repair one broken piston - cheaply. - 08/10/14 07:38 AM

Thanks, John. I'm no expert in this stuff - I know just enough to be dangerous - LOL!
Posted By: Fab64

Re: Need to repair one broken piston - cheaply. - 08/18/14 07:23 PM

UPDATE - After scraping the carbon off the piston tops and wire brushing them, I didn't find any stampings to indicate over-sized pistons. The number inside the skirt of the broken piston is 1858663, a Chrysler part number. According to my local machine shop, his sources say this is a "high performance" piston, and they want $125 for one. Can anyone verify this? Surely, I should be able to obtain a replacement piston for less than this? All suggestions appreciated, thanks!

Roger
Posted By: Challenger 1

Re: Need to repair one broken piston - cheaply. - 08/18/14 07:43 PM

Quote:

Quote:



Good luck with that HOA! I bought my house specifically because it didn't have one.

R.



I am with you on that.. Looked a many homes ( here in Florida) with bankrupted HOA developments with NOTHING being done for the HOA fees, still a Lawyer is collecting the money..

One of my employees stopped paying his.. Almost lost his home.. Seems as if the Legal Firm was foreclosing in his home without telling him.. VERY SCARY......



Another tip is to Not buy a house with a front facing garage because the community can tell you what your allowed to do in your drive/yard in front of your home. With a drive and garage in back anything goes...at least around here.
Posted By: Challenger 1

Re: Need to repair one broken piston - cheaply. - 08/18/14 07:45 PM

Quote:

UPDATE - After scraping the carbon off the piston tops and wire brushing them, I didn't find any stampings to indicate over-sized pistons. The number inside the skirt of the broken piston is 1858663, a Chrysler part number. According to my local machine shop, his sources say this is a "high performance" piston, and they want $125 for one. Can anyone verify this? Surely, I should be able to obtain a replacement piston for less than this? All suggestions appreciated, thanks!

Roger



Are 383s hi po motors?
Posted By: azmopar

Re: Need to repair one broken piston - cheaply. - 08/18/14 07:58 PM

Quote:

UPDATE - After scraping the carbon off the piston tops and wire brushing them, I didn't find any stampings to indicate over-sized pistons. The number inside the skirt of the broken piston is 1858663, a Chrysler part number. According to my local machine shop, his sources say this is a "high performance" piston, and they want $125 for one. Can anyone verify this? Surely, I should be able to obtain a replacement piston for less than this? All suggestions appreciated, thanks!

Roger



hers a set of 8

http://www.ebay.com/itm/MOPAR-383-SET-OF...7be&vxp=mtr
Posted By: JohnRR

Re: Need to repair one broken piston - cheaply. - 08/18/14 08:12 PM

Quote:

UPDATE - After scraping the carbon off the piston tops and wire brushing them, I didn't find any stampings to indicate over-sized pistons. The number inside the skirt of the broken piston is 1858663, a Chrysler part number. According to my local machine shop, his sources say this is a "high performance" piston, and they want $125 for one. Can anyone verify this? Surely, I should be able to obtain a replacement piston for less than this? All suggestions appreciated, thanks!

Roger



You should be able to find a 383 for $125 ... your local guy source is still watching reruns of circus d' sand from 2005 ...
Posted By: BSB67

Re: Need to repair one broken piston - cheaply. - 08/18/14 10:58 PM

Quote:

UPDATE - After scraping the carbon off the piston tops and wire brushing them, I didn't find any stampings to indicate over-sized pistons. The number inside the skirt of the broken piston is 1858663, a Chrysler part number. According to my local machine shop, his sources say this is a "high performance" piston, and they want $125 for one. Can anyone verify this? Surely, I should be able to obtain a replacement piston for less than this? All suggestions appreciated, thanks!

Roger



http://www.summitracing.com/parts/slp-w366np/overview/
Posted By: Fab64

Re: Need to repair one broken piston - cheaply. - 08/19/14 12:30 AM

Quote:

http://www.summitracing.com/parts/slp-w366np/overview/



Thanks for the link - Summit has this piston (W366NP) for $46 (it's $74 at Rockauto). Still more than I want to spend. I've just gotten a line on a used piston for $10.

JohnRR - I've been scouring the want ads, but have been unable to locate a running motor in the SoCal area for less than $400-500. I've found a few for less than that, but they are in pieces - which is basically what I'm dealing with right now. Unfortunately, I don't have the luxury of time to let one fall into my lap. I only have two months to get this car running, and vacate this space in my garage.
Posted By: dogdays

Re: Need to repair one broken piston - cheaply. - 08/19/14 12:41 AM

Don't mess around. You can buy one piston right now on Rockauto for $24.67 plus shipping, with a 5% discount if you're savvy enough to go to retailmenot.com and get the discount code. There's only two left at this price. Buy a ring set while you're at it. Then put the doggone engine back together and get on with the project.

ENOUGH trying to make this problem any more complicated than it is! Find a machine shop to press off the old slug and press on the new one. Won't cost more than a few $$$.

I know all about getting stalled on a project, trying to make it perfect. Don't get caught in that trap!

R.

PS: It's not a high performance piston, it's just a garden-variety piston from a Newport of something.
Posted By: Supercuda

Re: Need to repair one broken piston - cheaply. - 08/19/14 01:27 AM

You realized that missing portion melted/burned away. Had that happen to a 43 that massively overheated. That smeared metal on the rings is melted aluminum.

Odds are very good more than just that piston has issues. I would put a smogger 400 in place of that 383 before I tried to cheaply fix it and only if I absolutely had to have it running to get rid of it.
Posted By: OzHemi

Re: Need to repair one broken piston - cheaply. - 08/19/14 01:51 AM

Quote:

I only have two months to get this car running, and vacate this space in my garage.



Posted By: Fab64

Re: Need to repair one broken piston - cheaply. - 08/19/14 09:05 AM

Thanks, Dogdays, for the virtual slap in the face - I needed that, LOL! You're absolutely right; I'm being penny wise and pound foolish. It's pointless to drive 40 miles to buy a used piston, just to save a few bucks. I'll order one from Rockauto and be time and money ahead.


Quote:

You realized that missing portion melted/burned away. Had that happen to a 43 that massively overheated. That smeared metal on the rings is melted aluminum.

Odds are very good more than just that piston has issues. I would put a smogger 400 in place of that 383 before I tried to cheaply fix it and only if I absolutely had to have it running to get rid of it.



Supercuda, I'm guessing there may have been an intake manifold leak at the #7 cylinder, which caused that one to run way hot. After cleaning off the other pistons, they really don't look bad at all. And, as noted above, I have been unable to locate a suitable replacement motor, so I'm proceeding with my plan to keep this one. There's not a huge demand for '66 Coronets, and I can't count on selling this car in the next two months. Hence, I need to get it running in the meantime.


Oz, I hear ya! I know I've got my work cut out for me, but I really think I can pull it off. For one thing, I'm not restoring anything to the standards that I would if I were keeping the car. I'm just doing some basic cleanup of parts, and doing the repairs. I also decided today that I can skip doing the power steering pump, brackets, hoses, etc. Same goes for the electrics (except for the ignition circuit). This car doesn't need to be completely road-worthy; I just need to be able to start it, and move it around in my driveway.
Posted By: OzHemi

Re: Need to repair one broken piston - cheaply. - 08/19/14 05:45 PM

I've got a couple power steering pumps and brackets out in the back shed...can't remember if they were small or big block if you did want to get it steering easy too

I've got room on my driveway.. not sure if I am in the mood for a project or not though off hand.
Posted By: dogdays

Re: Need to repair one broken piston - cheaply. - 08/19/14 06:02 PM

F64, I'm glad you took that the right way.

I SO recognized my own pattern, and realize the pattern is keeping me from finishing easy things that should have been done long ago. I probably never will completely get over this issue, but I'm working on it.
Good Luck!

R.
Posted By: Fab64

Re: Need to repair one broken piston - cheaply. - 08/19/14 06:54 PM

Quote:

F64, I'm glad you took that the right way.

I SO recognized my own pattern, and realize the pattern is keeping me from finishing easy things that should have been done long ago. I probably never will completely get over this issue, but I'm working on it.
Good Luck!

R.



Posted By: SomeCarGuy

Re: Need to repair one broken piston - cheaply. - 08/19/14 08:15 PM

I'd list it as a non-runner. You will solve this and then find 50 other little things that will bog you down. At that point you'd have been better off finding a whole drivetrain, etc so on and so on. These things just never seem to end.
Posted By: BSB67

Re: Need to repair one broken piston - cheaply. - 08/20/14 03:27 AM

Quote:


I'm guessing there may have been an intake manifold leak at the #7 cylinder, which caused that one to run way hot.




Have you tried to wrap any logic around that statement?
Posted By: Fab64

Re: Need to repair one broken piston - cheaply. - 08/21/14 05:11 PM

Quote:

Quote:

I'm guessing there may have been an intake manifold leak at the #7 cylinder, which caused that one to run way hot.




Have you tried to wrap any logic around that statement?



My bro-in-law, a retired mechanic, is the one who suggested this. He has seen instances of intake manifold leaks causing such things. A leak at the intake runner for #7, where the manifold meets the head, would allow outside air to be pulled into the cylinder, diluting the a/f mixture, thus leaning out that cylinder, and causing it to run hot. Since none of the other pistons show any obvious signs of either abuse or overheating, this sounded like a logical and reasonable explanation for what might have caused this issue. Does this not sound possible to you? He wasn't saying this is definitely the cause. If you ask five people on this board, you may get five different explanations.
Posted By: JohnRR

Re: Need to repair one broken piston - cheaply. - 08/21/14 05:20 PM

Quote:

Quote:

Quote:

I'm guessing there may have been an intake manifold leak at the #7 cylinder, which caused that one to run way hot.




Have you tried to wrap any logic around that statement?



My bro-in-law, a retired mechanic, is the one who suggested this. He has seen instances of intake manifold leaks causing such things. A leak at the intake runner for #7, where the manifold meets the head, would allow outside air to be pulled into the cylinder, diluting the a/f mixture, thus leaning out that cylinder, and causing it to run hot. Since none of the other pistons show any obvious signs of either abuse or overheating, this sounded like a logical and reasonable explanation for what might have caused this issue. Does this not sound possible to you? He wasn't saying this is definitely the cause. If you ask five people on this board, you may get five different explanations.



What did the gasket look like??

But does it really matter at this point , since you are selling it as a running core anyway ???
Posted By: HotRodDave

Re: Need to repair one broken piston - cheaply. - 08/21/14 06:30 PM

If you were close by I would give you a good 383 just to stick it to the HOA, they have NO BUISNESS telling other people what they can or can not do with property they did not pay for! If I had read this two days ago you would be receiving the motor today, a friend just went down there in his truck to get me an nice 02 Durango R/T with a blowed motor
Posted By: HotRodDave

Re: Need to repair one broken piston - cheaply. - 08/21/14 06:31 PM

Post your bore size and I will see if I have a spare piston.
Posted By: Fab64

Re: Need to repair one broken piston - cheaply. - 08/21/14 07:02 PM

Quote:

Post your bore size and I will see if I have a spare piston.



Thanks, Dave. I have not yet ordered a new piston from Rockauto. Unfortunately, they don't have any std-sized rings for a single-piston left, just complete sets (for all eight).

I need one standard-size piston with rings for a 1966, non-HiPo 383, bore size 4.25". This motor came out of a Chrysler, and the block does not appear to have been bored over-size. If you have a spare piston with rings on it, I would happily pay the shipping.
Posted By: cudaman1969

Re: Need to repair one broken piston - cheaply. - 08/21/14 11:03 PM

Just a thought, maybe it swallowed something that broke those ring lands that way?
Posted By: BSB67

Re: Need to repair one broken piston - cheaply. - 08/22/14 02:36 AM

Quote:

Quote:

Quote:

I'm guessing there may have been an intake manifold leak at the #7 cylinder, which caused that one to run way hot.




Have you tried to wrap any logic around that statement?



My bro-in-law, a retired mechanic, is the one who suggested this. He has seen instances of intake manifold leaks causing such things. A leak at the intake runner for #7, where the manifold meets the head, would allow outside air to be pulled into the cylinder, diluting the a/f mixture, thus leaning out that cylinder, and causing it to run hot. Since none of the other pistons show any obvious signs of either abuse or overheating, this sounded like a logical and reasonable explanation for what might have caused this issue. Does this not sound possible to you? He wasn't saying this is definitely the cause. If you ask five people on this board, you may get five different explanations.



And likely not that one, or at least I would hope not............ well maybe.
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