Packard Forum Index » V-8 (1955-56)

Has anyone looked at a Chrysler 413 piston? the original bore was the same (for a '56 374 cu. in.), 4.125"
the only problem is that original invar-strut Chrysler 413 pistons are as rare as Packard pistons.

JV answered that question yesterday:

He wrote:

"6. The 413" Mopar pistons are NOTa recommended interchange. The compression height is .052" less than the Packard, which will lower the compression substantially and eliminate the quench/squish band, which causes the engine to ping under load, as well as reduces the power output. Additionally, the piston pin bore is larger and the pin boss is narrower, requiring substantial machine work on the rods. Just because they can be made to fit the hole doesn't mean they are good science. ...

thnx, jack vines"

Posted on: Yesterday 11:26:17

Edited to include additional detail:

6. The 4.188" bore diameter 413" Mopar pistons are NOTa recommended interchange for the 374" Packard pistons. The compression height is .047" less than the Packard, which will eliminate the quench/squish band, which causes the engine to ping under load. The only currently available pistons are dished tops for trucks and motor homes, which lower the compression substantially and further reduces the power output. Additionally, the 1.094" piston pin bore is larger and the pin boss is narrower, requiring substantial machine work on the rods. Just because they can be made to fit the hole doesn't mean they are good science.

thnx, jack vines

OK, I knew that there is a lot more to it than just bore size, I just wondered how far out of range the 413 was, and it's pretty far from ideal.

My '55 Pat 352 was rebuilt with Egge pistons (properly installed) 6000 miles ago, runs regularly up and down the Florida Turnpike between Orlando and all points south (put 517 miles on it a week ago, Tuesday) at sustained speeds WELL over 65 mph. As several people have said, if properly installed, they'll do for everyday, average driving.

LS wrote: " Egge pistons (properly installed)...)"

Yeah. ok. THE QUESTION IS WHAT is properly installed supposed to mean????

Thus far only JV has blessed us with definate and reasonable criteria for installation. I'll follow his lead.

BUT NO ONE ELSE has yet to set forth SPECIFIC installation instructions for the EGGE pistons. Not Kanter, Not Egge, Not Parts Wizard, whoever he is.

The only other recommendation was to perform an oven heat expansion test prior to installation.
SO, just EXACTLY AND SPECIFICALY what is "proper installation" for Egge pistons????

C'mon Parts Wizard who ever u are. U came in here hawking the Egge pistons for the V8. U now know what our problem is so tell us WHAT IS "proper installation" ???

Hey Guys,

I am rebuilding my 1930 Std 8 to get a set of Egge pistons out of it. I pulled the engine down because it was knocking and found that one of the pistons was scuffing on the front and back which is somewhat distressing. I pulled that piston and had had it measured by a machinist with the right tools... The wrist pin hole was not bored parallel with the axis of the crank, it's off .006" (up and down) over it's short length. This engine was rebuilt in the late 1980's and has only 9,000 miles on the rebuild. I will be looking at another brand of pistons.

Scott

Are u sure they are Egge pistons????? Do Egge pistons carry any kind of identification marks???? I really don't know.

V8,

I posted the pictures here and were told they were, no they aren't marked.

Scott

Scott, that is distressing news about your experience with the 20 year old version of the Egge pistons. Mine looked good, and so far are working well. These are such unique pistons, I can't imagine they will be easy to have made else where. I can only assume they have drastically improved the current pistons. Keep us posted.

PackardV8, I am not sure what anyone else means by ?properly installed?, but what I mean is following the piston fitment instructions that come with the pistons. Pistons manufactured with different materials, design, cam grind, and taper all require different piston to cylinder clearance. This is true with any aftermarket piston for any engine. I think it will be easier to get V-8 pistons made by another vender. There is probably more demand, and they are much more conventional in design. As for Mr. Part's wizard, it's to bad he did not reply. I saw him logged in the other morning, but never bothered to reply. I do think Egge does the old car community a service, but am a little unclear as to Mr. Wizard's motives.