Used pistons, does anyone save them?

36coupe

36coupe

Well-known member
I have a friend that is looking for used mercury pistons. He is in his 80s and builds, freshens up old flatheads. Being north of the border it cost a small fortune to buy new ones. He has a few mercury cranks and no pistons. When he scraps old engines he will save valves and guides that are in good condition along with cams for future builds. He prefers original oil pumps.
He refers to the pistons as seasoned.
This way he keeps costs down and it reflects in pricing.
I’m sure this might be controversial to some people. Not everyone has 10 K to build a new engine with everything new.
He actually has an 8ba 239 new pistons cam and crank bearing for less than 4K usd. He is 5 minutes from Maine
 
To answer your question, I do. I save them for all the same reasons he does. I think there are several people here who prefer used real ford parts that pass inspection over today's offshore parts. I have a pretty good piston collection, but at 71 yrs old I may have a few builds left. I applaud your friend's way of thinking.
 
I think the issue is as time goes on and engine cores get less and less, getting the pistons out without damaging them is the trick. Most of the engines I've torn down have been stuck in one way or another and I've had to drive one or more of the pistons out.

I guess if you get them out without damage, why not? That said, I'm a believer in metric ring packs.

If you need to do a budget rebuild, certainly good used pistons could be an option.
 
In considering old pistons for rebuild/overhaul use I am always reminded of piston knurling.
Z


Z


Z


Z
 

Attachments

  • zzzzz.jpg
    zzzzz.jpg
    61.4 KB · Views: 82
I've always installed new pistons, mainly Egge. My thought was if I'm spending $4,000 for machine shop services, new bearings, rings, valves, springs, ect.... why chance the investment with a used piston? I do understand the budget build aspect though.
 
Wow all positive. Thanks. He has done a couple for me. One with stock pistons in a 239 and another with stock mercury pistons in a 81a block and mercury crank, bored 1/8”.
 
J Franklin said:
I always thought pistons were some of the less expensive parts for a rebuild.
Click to expand...

But if most everything else is used, brand new pistons would just add to the expense. Careful measuring tells what is ok to put back. A friend once gave me a completey rebuilt 51 merc engine that he and his dad overheated and cracked on their first test drive in a '46 cabover. That's an extreme example, but I have overhauled quite a few engines from trucks that sat in a field until the tires were rotted and brakes shot, but engine parts very good. Ford published an overhaul manual for it's dealers with full instructions of measuring parts, including pistons, bearings, valves, guides, etc for acceptable re-use in a ford authorised 'overhaul'. It has been my guide through perhaps six or eight overhauls. When these vehicles were daily drivers not everyone had the 400 bucks for a complete rebuild to 'as new'.
 
In thinking about this, wouldn't it be prudent to get used pistons magnafluxed at least before using? It would be real bummer if you ruined a new build because there was an undetected crack in one of the pistons.
 
I bought a blown up low mileage mercury engine. Never knew the story. The block was broken, crank tore up even the cam was broken in three pieces. Savalaged 5 pistons 15 valves and guides,16 adjustable lifters & a mellings oil pump. Everything new. Probably won’t use the pump and pistons I’m a fan of stock 8ba pumps. Everything else I’ll use.
 
Tim Ayers said:
In thinking about this, wouldn't it be prudent to get used pistons magnafluxed at least before using? It would be real bummer if you ruined a new build because there was an undetected crack in one of the pistons.
Click to expand...

Can you magaflux aluminum?
 
36coupe said:
I bought a blown up low mileage mercury engine. Never knew the story. The block was broken, crank tore up even the cam was broken in three pieces. Savalaged 5 pistons 15 valves and guides,16 adjustable lifters & a mellings oil pump. Everything new. Probably won’t use the pump and pistons I’m a fan of stock 8ba pumps. Everything else I’ll use.
Click to expand...

What size are the merc pistons? I'm in need of 2 @ .030+ , I have six with 5000 miles on them. As for magnaflux, I'm sure there is a suitable alternative for non ferrous stuff. Must be common in aviation. Something with ultra-violet dyes or some such.
 
GB SISSON said:
What size are the merc pistons? I'm in need of 2 @ .030+ , I have six with 5000 miles on them. As for magnaflux, I'm sure there is a suitable alternative for non ferrous stuff. Must be common in aviation. Something with ultra-violet dyes or some such.
Click to expand...

Has to be, right? Almost all modern small truck and passenger cars have aluminum engine blocks and heads. There must be a way to check aluminum products.
 
flatjack9 said:
If not worn and the ring lands are OK, I keep them.
Click to expand...

Most pistons collapse after decent use and are junk even if the ring glands are fine.

I'd consider used pistons in an engine just a refreshening, and not a rebuild. I personally wouldn't go to the effort of pulling and tearing down an engine to put used parts in them. But apparently there's a market.
 
Tim Ayers said:
Has to be, right? Almost all modern small truck and passenger cars have aluminum engine blocks and heads. There must be a way to check aluminum products.
Click to expand...


Yes, they can be dye checked. Usually though, a cracked piston can be seen visually since it's most always the skirt area that would crack. Rare in a flathead piston, most have worn ring lands or heavily worn skirts if they are rejects. Parts that measure and check good are reused at my shop.
 
cadillac512 said:
Yes, they can be dye checked. Usually though, a cracked piston can be seen visually since it's most always the skirt area that would crack. Rare in a flathead piston, most have worn ring lands or heavily worn skirts if they are rejects. Parts that measure and check good are reused at my shop.
Click to expand...

Makes sense
 
You must log in or register to reply here.
Back
Top