Packard Forum Index » V-8 (1955-56)

Thankyou all very much. I went to look at the car today, and it requires a huge amount of work, more than I can afford time and money wise. Just as well. But I like Packards. A very good friend who may post here has a fantastic '37 Business Coup, a mild street rod. I will keep looking.

Regarding Egge pistons. In the arena I am most familiar with, Ford Y-blocks, they are well regarded. The clearance issue may be little more than the cam grind they put on the skirts.

At one time I had in possession a new set of Jahns racing popups for a Y. They called for .007 to .008 clearance!

The problem with ALL of the aftermarket Ford Y pistons, except Egge, is they decreased the compression height of the pin to piston top, dropping compression.

Appologies for cluttering up your fine Packard forum with Ford crap. Hopefully I will be back with Packard questions.

Mike

The Packard V8 OEM pistons have steel struts cast into the side of the pin bosses to insure even circumferential expansion. Thus, the Shop Manual instructs they be fitted at .0005"-.0015" piston-to-cylinder-wall clearance.

Egge Machine pistons are simple permanent-mold slugs of cast aluminum. They do not have the expansion control feature, thus need to be fitted at .003"-.0035" or they will scuff, overheat and otherwise give a bad account of themselves. Some of the sets I received in the past have been substantially heavier than the OEM pistons, thus necessitating rebalancing the engine.

thnx, jack vines

why does this have to be so damn difficult. why can't someone just make the damn things the right way. geesh.

i don't want to have to take this motor apart again, especially when i have the car all done an put together. i will be SO pissed!

To answer Mr. Yblock's question. The 320 used by Nash was the smallest displacement version of the Packard engine. Furthermore, I believe they installed extra thick head gaskets to reduce the compression. This was because they wanted a lower horsepower engine than Packard.

This means the Nash engine should be the least stressed,longest living Packard V8.

You should be able to raise the compression just by using Packard gaskets.

On the subject of piston expansion and piston fit.

It used to be common practice to hone cylinders and then knurl the pistons to expand them slightly. They could then be reused without any slapping or fit problems. This was considered a standard overhaul procedure.

There was a very interesting comment in a late 50s hot rod magazine about piston knurling. The editor had a hopped up 283 in his Corvette, that he equipped with solid skirt forged racing pistons. These pistons had to be fitted with a lot of clearance, 12 thou I believe, and normally they would slap like the dickens until the engine warmed up.

In his engine, he fitted them to the correct clearance then knurled them. He found the pistons worked well this way, with no piston slap. At the time of writing he had 30,000 or 40,000 hard miles on the engine with no problems.

So, it might be an idea to reuse your old pistons after knurling them, or if you use new pistons with a lot of clearance, knurling could reduce or eliminate piston slap.

Personally I would be VERY pleased to have a stock Nash or Hudson with the 320 cu in engine.

According to all contemporary reports they had plenty of power, and they should run fine on today's regular gas.

Remember the Nash was 1000 pounds lighter than a big Packard 400! And not much heavier than a Studebaker Hawk.

Would suggest, Mr Yblock that if you get the car you should try it out first. I expect you will be pleased with the engine in stock condition and that it does not need to be hopped up. But if you decide to go for more power it should be possible to pick up an extra 30 or 40 HP with a few simple mods like thinner head gaskets, a 4 barrel carb and dual exhausts.

The 320 Hash engines had lower compression because they used 352 Packard heads on them.

I am always learning something. If only it could all be remembered.

Yes 320 cubes would have been fine for me, if CR was up around 9. But the car was a disassembled hulk that would have required at least 2 years and many K dollars. Too old for that now.