Packard Forum Index » V-8 (1955-56)

Hi, Hank,

1. Your OEM piston was made with a notch on the edge to indicate that side goes to the front. The Shop Manual allows .005" taper in the cylinder before requiring re-boring. Pistons can be cleaned by soda blasting or bead blasting. New rings are then fitted and the cylinder walls are freshened with a brush hone.

FWIW, I had to clean, sort through and micrometer measure four 374" engines to get two sets of pistons to re-use. For whatever reason, some of the pistons were tapered in at the bottom of the skirts. Even though they are Packard pistons, years, miles and time have used up many of them.

2. Don't even think about re-using old head gaskets. The risk isn't worth it. I agree, I haven't had to use any composite head gaskets, as I have been gathering up the steel shim gaskets. The intake manifold gaskets have a much easier life as well as being easier to replace. If they look good, if the area around the exhaust crossover isn't rusty, clean them with thinner and re-use them.

3. I'm going to be ordering several sets of custom forged pistons and am negotiating for a better price. Let me know what your needs are and I'll see what I can do for you. The first set is the most expensive.

thnx, jack vines

Jack. inquire with Detroit Piston Service in Pontiac Michigan. That's the CITY of Pontiac not the car company.

It mite have even been called Pontiac piston service i just can't remeber now.

I'm not sure why they would have to be forged except for SEVERE racing conditions. Just a good piston equal in quality or a little better than OEM should work just fine for everything up to mild street racing.

You are correct that a modern hypereutectic cast piston would be the perfect replacement for 99% of Packard needs. Thanks for the suggestion on a supplier, but I can't find anything on either Detroit Piston Service or Pontiac Piston Service. Must be a hundred places who want to sell you Detroit Pistons basketball tickets, though.

FWIW, The number of piston makers in the US is dropping rapidly toward zero. Brazil is making a lot of what we get nowadays. I've talked with John Erb, formerly chief engineer of United Engine and Machine, makers of Silvolite and Keith Black Pistons, as well as a couple of others about the possibility of a Packard V8 replacement cast piston. They say it isn't going to happen here in the US. No smaller manufacturers left and just not enough demand to interest the big guys.

thnx, jack vines

That somewhat begs the question then: Why doesn't Egge et-al manufacture the Hyperuetectic cast pistons ??

Hank, I'd really recommend getting a new engine block if it's at all possible. You don't want to spend all this money on this engine just to have it fail down the road because of the little welding job on the side of the block.

Has anyopne tried to retrofit a 350 SBC rod and piston???? Packard V8 352 has the same bore as 350 SBC and a stroke that is either 1/64 or maybe it's 1/32 longer than the 350 SBC. SBC suppliers can probably easily supply a piston that mush taller and all that would be left is to figure out how to make up for larger SBC journal.

I'm currently playing with a Jag V12 rod and cap but it doesn't look real promising. The Jag journal is .050 larger than the Packard V8. I havn't tried the UPDATE a Packard rod cap yet.

turbopacman...i appreciate the concern and i agree with you if it wasn't for the fact that the block is numbers matching and is water tight as it has been sitting for 20 years with antifreeze in the jacket and it was still full. the guy i bought it from said he ran it after it was fixed until it was parked and didn't have any problems. i guess since it is just the outside of the water jack i am not too concerned as this car is a show car and i probably wont be treating it abusive as far as the motor. my dad looked at it, having worked for chrysler for 22 years, and he said it looked fine, that whoever did it did a pretty good job considering. it feels very solid and looks very solid, just kinda a sloppy weld, but noone will see it anyways.

i guess my sentimental values can get the best of me as i really want the numbers to match the car. i wouldn't feel good if it didn't and i wouldn't like the car that much anymore. i know....it is weird....but it is just how i am i guess. if it goes, then it goes, but at least it is just the water jacket and i will notice pretty quick if it does. i think if i do it right and take my time it will be just as strong as the rest.

besides, the machine shop should beable to tell me if they think it will be okay once they get the gunk out of the water jacket and see what the repair looks like from the inside. personally i am more worried about pistons jacking up my motor than the repair that was done to it previously.

i just want a good reliable motor, nothing badass, just stock and reliable and if Egge can't do that i want something else, like Arias or ??? and if i have to search up and down for metal head gaskets then so be it.....i want them too. ;0)

so, i agree with you that i probably should get another block, but......i just....can't....do it...(note: unless i absolutely had too)..;0)

1. The SBC isn't even a random possibility of an interchange. The Packard V8 is a .590" taller piston. Lots of 4" and 4.125" diameter pistons in the book, but that is only one of four dimensions which must be compatible. Try and find one with a 2.070" compression height - it doesn't exist.

2. The Egge pistons are certainly suitable for a "just stock and reliable" engine build. I don't use them in the engines I intend to run hard, but put them in with the proper clearance and they'll be OK for normal driving.

thnx, jack vines

Custom pistons based on SBC forgings may be possible, but I guarantee you that you'll never find an SBC rod that will even come close to the length of the Packard rod, then you have rod bearing width to deal with. The closest rod I found length wise to Packard was 460 Ford, and even then, the bearing width wasn't close.

Short of custom aluminum rods and custom forged pistons, you're pretty much stuck with stock.

I can help you on the steel head gaskets Hank, as I have an extra set if you need them, NOS. They come up from time to time on eBay too.