question about old pistons

[Guest rampagefan84]

I know modern pistons in reciprocating engines are non-circular and non-cylindrical when at low temperatures. Does that stand true for pistons in the 20's and 30's? Or are they circular? Would an antique motor benefit from modern style pistons? Thanks in advance for the replies.

[Rusty_OToole]

Many early cars used iron pistons. They expand less than aluminum, at about the same rate as the iron cylinders so they do not have the same clearance and piston slap problems.

Aluminum pistons began to be used in the twenties but Chevrolet stuck with iron until the early 50s.

Cam ground, oval, and other efforts to deal with expansion go back to the teens at least. They also offset the wrist pin to minimize piston slap, starting in 1913 if not earlier.

The one place new pistons have the advantage is in material. The best aluminum alloys of today are far better than anything they had in the 30s. A few years ago I saw a story in an English magazine about the restoration of a prewar Auto Union race car. They had to recreate the cylinder head as the old one was completely unusable. They consulted with the experts at a leading aluminum company (Reynolds if memory serves). Their chief metallurgist analyzed the head and told them "this is the kind of material we make lawn chairs and lamp posts out of". But in 1937 it was at the cutting edge of German technology.

Having said that, if the cylinders are not tapered and the pistons not worn or broken, it probably would not benefit from new pistons.

If it needs a rebuild, or you want to hop it up and run it at speeds it was never meant to go, that is another matter.

One more thing. You usually can't get an exact match for your old piston. The new replacements are more or less generic castings machined to fit. They may be heavier than your old pistons which will throw your motor out of balance.

[Guest rampagefan84]

Many early cars used iron pistons. They expand less than aluminum, at about the same rate as the iron cylinders so they do not have the same clearance and piston slap problems.

Aluminum pistons began to be used in the twenties but Chevrolet stuck with iron until the early 50s.

Cam ground, oval, and other efforts to deal with expansion go back to the teens at least. They also offset the wrist pin to minimize piston slap, starting in 1913 if not earlier.

The one place new pistons have the advantage is in material. The best aluminum alloys of today are far better than anything they had in the 30s. A few years ago I saw a story in an English magazine about the restoration of a prewar Auto Union race car. They had to recreate the cylinder head as the old one was completely unusable. They consulted with the experts at a leading aluminum company (Reynolds if memory serves). Their chief metallurgist analyzed the head and told them "this is the kind of material we make lawn chairs and lamp posts out of". But in 1937 it was at the cutting edge of German technology.

Having said that, if the cylinders are not tapered and the pistons not worn or broken, it probably would not benefit from new pistons.

If it needs a rebuild, or you want to hop it up and run it at speeds it was never meant to go, that is another matter.

One more thing. You usually can't get an exact match for your old piston. The new replacements are more or less generic castings machined to fit. They may be heavier than your old pistons which will throw your motor out of balance.

Thank you for the insightful post.

[GLong]

Hi rampage fan, there are several piston makers that can make just about anything you need or want.

There is one for sure right in the Detroit area, but the name of the company escapes me right now.

Depending on the engine, I think reducing the reciprocating weight would be an advantage towards getting

a bit more performance, due to less energy being used to accelerate the pistons back and forth in the cylinders.

Modern pistons with the smaller, shorter skirt will work in place of the longer full-cylindrical piston in older engines.

As long as the piston/cylinder wall clearances are correct.

What year and type of engine are you referring to? or is this just a general question ??

I know that Pierce Arrow's S80 engine used steel connecting rods and iron pistons for '25,'26,'27.

Then for '28, the S81 engines were fitted with aluminum connecting rods and pistons, the crankshaft

was changed to have a larger main bearing, but the vibration dampener was eliminated.

The bore and stroke were identical. Reduced reciprocating weight was mentioned in some advertising for '28

All later Pierce engines used aluminum pistons and steel connecting rods.

GregL

Edited January 13, 2014 by GLong (see edit history)

[Rusty_OToole]

Egge is the standard for old car pistons, they will make them to fit anything. Have heard quality can be questionable. OK for a show car that gets driven 5 miles a year on and off a trailer.

Ross will make custom pistons for race cars and possibly will make them to order for an old car if they have a suitable blank.

[Restorer32]

Actually there are some sizes that Egge cannot make. We had Ross make us a set of forged pistons for a '27 Kissel. No alternative since Egge did not have foundry patterns for that particular size blank. Forged pistons in a '27 Kissel is way overkill but we had no choice.

[Guest rampagefan84]

GLong,

This was a general question that spawned from my thoughts of making a dodge brothers speedster. So to answer your question, the engine in question would be a chrysler flat head straight 8.

As to the idea of custom pistons, that sounds pricey. What would a guy have to pay for 8 custom pistons from "ross" or other such places? Are they billet, cast, or forged?

Thanks in advance.

[DavidMc]

I can recommend Arias pistons, superb quality . I had no problem getting a set for my 1912 Maxwell. They were slightly cheaper than Egge.

http://www.ariaspistons.com/

[Rusty_OToole]

I would be leery of the Chrysler straight eight. Some parts are getting impossible to find. If they are anything like the six cylinder cars, the pistons are prone to breaking. This might be what you had in mind with your piston question. I think I started a thread on this same question some time ago.

Packard 1951 - 54 is a better straight eight for performance and parts easier to come by.

Not saying the Chrysler isn't a good engine, it is one of the best. But Packard would be better for this purpose. For one thing they were available with a manual trans, while the Chrysler was only made with Fluid Drive from 1939 on. They never came with a modern automatic either. So any other trans would have to be adapted.

Edited January 13, 2014 by Rusty_OToole (see edit history)

[DavidAU]

There is also a piston manufacturer in Australia who has a good reputation and they may be able to supply what you are looking for at a reasonable price.

I recently bought a custom made set of pistons for a vintage car from them and thought the price very good.

http://www.jp.com.au/JPPistons.html

[Owen_Dyneto]

I have great respect for Rusty and his experience and advice, yet I'd dispute that Egge pistons are only suitable for trailer queens. There are MANY collectible cars happily driving the length and breath of the country on tours with Egge pistons, including my own 34 Packard. They did have a quality problem, but that was about 8-10 years back. Unless you're going for a very modified, high-output performance engine, I'd have no reservations about Egge pistons for a older car to be driven in pretty much the same manner that it was originally intended for.

[Restorer32]

Re the Kissel pistons I mentioned above. We first contacted Egge, they said their foundry pattern for that particular size piston blank was destroyed in a fire so we contacted Aries. Amazingly Aries said their foundry pattern for that piston blank was also destroyed in a fire. Coincidence? I second Owen's opinion of Egge pistons. A set of 6 Ross forged pistons with rings cost us almost $1000 for the Kissel.

[Guest rampagefan84]

Re the Kissel pistons I mentioned above. We first contacted Egge, they said their foundry pattern for that particular size piston blank was destroyed in a fire so we contacted Aries. Amazingly Aries said their foundry pattern for that piston blank was also destroyed in a fire. Coincidence? I second Owen's opinion of Egge pistons. A set of 6 Ross forged pistons with rings cost us almost $1000 for the Kissel.

Forged aluminum right?

[Guest rampagefan84]

I have great respect for Rusty and his experience and advice, yet I'd dispute that Egge pistons are only suitable for trailer queens. There are MANY collectible cars happily driving the length and breath of the country on tours with Egge pistons, including my own 34 Packard. They did have a quality problem, but that was about 8-10 years back. Unless you're going for a very modified, high-output performance engine, I'd have no reservations about Egge pistons for a older car to be driven in pretty much the same manner that it was originally intended for.

I am leaning more towards high performance.

[Rusty_OToole]

I have great respect for Rusty and his experience and advice, yet I'd dispute that Egge pistons are only suitable for trailer queens. There are MANY collectible cars happily driving the length and breath of the country on tours with Egge pistons, including my own 34 Packard. They did have a quality problem, but that was about 8-10 years back. Unless you're going for a very modified, high-output performance engine, I'd have no reservations about Egge pistons for a older car to be driven in pretty much the same manner that it was originally intended for.

My remarks were based on comments by Egge customers on this and other boards. If they have improved their quality control, good for them. The last Egge pistons I used were in a 52 Chrysler hemi about 15 years ago, they seemed fine but I lost track of the car years ago.

[GLong]

Most Egge pistons are cast, and many do not have an expansion 'strut' cast into the piston. Many years ago, the aluminum alloy was about one step up from pot-metal. I've seen Egge pistons with most of the piston crown gone, down to the top of the compression ring.

The newer Egge pistons do have Invar struts cast in them, and the alloy seems to be much better.

But I use forged pistons whenever I can, I don't like cast pistons. Especially for any high rpm application.

Greg L.

[Buffalowed Bill]

Two years ago I called Egge to ask about pistons for my 1937 Studebaker President coupe. Even though they were shown in their catalog, I was told that I was only the second person to call for that piston in the last twelve months, so they weren't going to make any more. Then he told me that they would custom make a set for me. Now these are cast aluminum, so not real high tech stuff, for a little over two thousand dollars. This was in spite of the fact that their catalog listed them for eight hundred dollars. I bought a beautiful set of forged Aries pistons for the same price as they wanted for the Egge cast pistons. Expensive yes but no more so then anything else for that engine since parts are virtually impossible to find.-Bill

[ron hausmann]

All,

Like Restorer 32, we have rebuilt several Kissel engines. In most cases we have found matches in connecting rods and pistons from other year cars and tractors believe it or not. Our Kissel 1920's Model 6-45 engine happened to match the more modern Ford rods for example, which we used. We have used modern alloy connecting rods and domed pistons to get better performance out of these old original engines. However, some dimensions just cannot be matched. A Kissel Model 6-55 engine used from 1923 to 1927 or so, for example, has no close enough matches so we had to cast new internals. Very expensive, but no choice. One nice thing about using these new, lighter weight rods and pistons is that the overhauled engine, when done, will perform much smoother and crank much better - not slapping around all that iron! I would recommend to anyone restoring a teen or 20's iron original, to instead use modern rods and pistons.

Thanks, Ron Hausmann P.E.

[DavidMc]

Ron,

Do those Kissell engines have counter balance weights on the crankshaft and if so do you reduce the balance weights to match the lighter piston/con rod?

[nickelroadster]

If the Kissels are six cylinder then you should be ok. Fours or eights would be better with a rebalance.

[Restorer32]

Forged aluminum right?

Yes, forged aluminum.

[Ivan Saxton]

Forged aluminium alloy pistons have been used for many decades in aircraft engines. I showed a wartime new replacement piston for a Wright Whirlwind R975 radial engine to Bill Freame, who manufactured competition pistons for local "V8 Supercars", and many other purposes. His immediate response was that he would stake his professional reputation that it was a forged piston. It is a beautiful piece of work. All that we had were made under licence by Continental, because Wright did not have the capacity to make them in required numbers for Medium M3 tanks. Now there was no compromise variation from aircraft standards, despite the very short expectation of service life.

You could find that aluminium alloy composition for forging may differ from the range recommended for cast pistons. Cast pistons should be heat treated before machining to ensure against change of dimensions in service. I do not know if this is also required for forged pistons.

Pattern making used to be a highly skilled craft; but corebox and pattern sets can now be easily made with even a home-made computer-controlled 3 axis router.

[edinmass]

Egge pistons have been nothing but problems for years. I wont bother with a long post, they are junk, I had a piston failure from them on a 31 Caddy. They make lots of other parts, that we will not install due to quality issues. Again, I won't bother with a long post about them. We drive our cars, we use Ross or Aries pistons. If you use Egge parts be sure to test them for correct materials. They sold me sets of valves that were soft. That's why in our garage we make all our own parts, valves, guides, springs, bearing shells, cam bearings, it's not worth the effort to use junk parts and have an engine failure. I could write a book on junk parts being sold to the old car hobby. Buyer beware. And yes, there are some of us who drive our cars, and run them hard. A properly restored car is a reliable machine. The problem today is it's just so expensive to properly build an early engine most people try to take short cuts. Modern pistons and ring packages control oil burning and blow by much better. Recently a friend made his own patterns and cast a set of pistons for his pre 15 car. They are working fine. He used cast iron. Sure was an interesting process to follow. Always use the best parts available, in the long run they give the best value. I find that Ross and Aries are not much more money than Egge. Ron's advice is correct.

Edited January 26, 2014 by edinmass (see edit history)

[PONTIAC1953]

just to throw in my two cents worth, in the 1975 I had my Pontiac 268 straight eight professionally balance and blueprinted when rebuilt by the engler brothers machine shop in santa monica, ca. they chose egge to supply them with new 0.030 oversized pistons, the engine was tuned by Harold kennedy, a veteran Pontiac dealer mechanic of several decades. I drove the car for two years, only adding 15,000 miles to the odometer, then one day the 7th cylinder piston completely came apart at the oil ring groove. when I approach egge with the bad piston, the best they could do was to sell me another set, now 0.060 over, for half price. they were responsible for a $1,500.00 complete engine rebuild being ruined. so I will never advise anyone to buy products that egge makes, never. Charles Coker, 1953 Pontiac tech advisor.