VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 Piston problems.... What alternatives? Egge?

The engine on my 34 Master has just been rebuilt, but....

We have now found out that the JAHNS alu pistons that was installed, expand to much, so the engine stops when it gets hot (the pistons get stuck in the cylinders.....).
The bore is correct (+ 0,030) and the pistons are "correct" (+ 0,030), but they expand more than they should.
After searching on internet, I see that I am not the only one who have experienced this after installing alu pistons in an old engine.

My two alternatives are then to hone the cylinders more and reuse the same pistons, or get another set of pistons that hopefully do not expand as much.
Of the two alternatives, I would prefer to get another set of pistons, then I would not have to take the engine out of the car again (the pistons can be changed with the engine block still installed in the car).

Fillingstation sells Egge alu pistons. I think that is what Kanter sells too (can anyone confirm that?).
Is there any other alternatives than "Egge alu" and "Jahns alu" pistons out there?

Do anyone here have good/bad experience with Egge alu pistons?

Thanks.

I never had a problem with aluminum pistons but understand that can happen if fit too tight.
I would bet, from what I have seen, that all brands of aluminum pistons are of the same T slot design and will react the same.
I wonder if the T slot was installed on the wrong side of the bore.
Would it be possible to remove the pistons and have them re-sized smaller by .002" or .003".

I purchased a rebuild kit from Kanter for my 32 several years ago and it had EGGE pistons. I did have a problem but it was because the builder did not properly fit the piston pins. The engine was rebuilt a second time after 5000 miles and the pistons were re-used this time with oversize pins and so far after 7000 miles have had no problem. It's my opinion that the Jahns pistons have a better reputation than EGGE. If it were mine I would use the Jahns pistons again. What was the piston clearance when the pistons were installed?

"because the rebuilder did not properly fit the pins"???
New pistons should come with the pins fitted.
Also with aluminum pistons the pin fittment gets looser as the aluminum heats up and the pistons ecpand.

I think that the engine builder did not allow proper clearance in the cylinder bore. Not sure what the factory clearance is supposed to be, but I would bet money that the cylinder bore is way too tight .

I believe it needs 3--5 thousands clearance between piston size and bore.???

owner needs to micrometer the pistons and the bore to know where he stands and problem is.

mike

Stay away from Egge Pistons. I would stay with the JAHNS pistons and have the clearance corrected between the pistons and the cylinder bore. If you want to change pistons I would go with cast iron pistons like what was used originally. Cast iron pistons work great, especially if you have your engine balanced.

Yes Gene the new pins came with the pistons however the ones removed were oversize so the new standard pins did not fit tightly in the rod. There were no lock rings to retain the pins, only the lock bolt and even though tightened did not hold securely.

You could be right about the design (T-slot design). But maybe different brands use different tolerances for heat expansion? And maybe different brands use different alloys, so the heat expansion could be different?
My pistons are marked with "front" on top, they were installed the correct way.
Maybe it would be possible to re-size my Jahns pistons (I have no idea if it is), I will see what I find out about that.
Ok. So you mean you would disassemble the engine and have it honed again (bigger bore)? That is a lot more work than to just change the pistons (but it might be worth it?).When you buy a piston set that is 0,030", it means you should bore the cylinders 0,030" more than standard and the pistons will fit perfectly (it does not mean that the piston is excactly 0,030 bigger than a standard piston), the builder should not have to think about getting the correct clearance (this was calculated when the pistons were produced).
The cylinders were bored 0,030" more than standard, they are now excatly 3,3425". The pistons are 3,3405" when cold. We have now tried to heat a piston up to about 195 fahrenheit in water, and the diameter is then 3,3440 (bigger than cylinder bore).
So you are right, the cylinder-piston clearance is not correct. But this is not the engine builders fault (he bored the cylinders correctly + 0,030), it is the pistons that expand more than they should. When it says 0,030" on a piston, it means it should fit in a cylinder which is standard + 0,030". It does not...Ok. So you have bad experience with Egge too? I do not know where I can find the correct 0,030 cast iron pistons, but I guess maybe on ebay. One good thing about aluminium pistons, is that I have heard that the engine will be "more comfortable" driving at higher speeds (50+ mph) with the lighter moving parts. I do not know how big the difference is?

I sent an email to Egge, asking if they have experienced "heat expansion problems" like the ones I have now. They answered that I will have no such problems with their 0,030 pistons in my +0,030 bored cylinders (it will be a perfect fit). But since some of you write that I should not go with Egge, i guess I should think a bit more about what to do...

Thank you for all inputs!

Since you have a problem I think you should know that every book I have on engine rebuilding instructs fitting the new pistons to the bore, before installing, with the manufactures recommended clearances. Also the rings should be fit into the bore and gap confirmed. Same with pins to piston, & etc. a precision job requires precision work. I would not be afraid to use Jahns or Egge pistons. The pistons in my '36 are factory cast iron and run just fine also.

My reference book suggest .002 clearance at the ring lands and .001 at the skirt (full skirted pistons cast iron) per inch of piston diameter and the aluminum pistons are .001 greater for each. Published by the American Technical Society 1934. The above is a "rule of thumb" if the manufacturers specs are not available.

New old stock or new old replacement stock cast iron pistons are not that hard to find.

I agree on the ease of finding some replacements however the challenge will be to find ones that allow the proper clearance. Otherwise as has been stated the bore will need resizeing. Either the pistons he has are not properly manufactured or the block not machined correctly. The only conclusion I can make is that the machine shop did not "fit" the pistons properly.

While the machine shop was 100% accurate on their boring work it is always the responsibility of the final assembler to verify that the parts used are correct. Also since the block is machined to a "standard oversize" I think that replacing the pistons with ones of correct dimensions would be best. That way future servicing if needed would be with standard made parts rather than "custom" fitted pistons in a non standard dimension.

I would try to find a shop that would take .002" or .003" off the pistons. This would eleminate removing the engine. Or if you are brave, honeing that amount out of each cylinder.

Note the history. I believe he got this car in a un-assemleled mess and did not asemble the engine or employ the machine shop.

I don't believe 2-3 thousandths will be enough. With 3 it only allows 1.5 clearance when hot. As I noted above (unless it is not accurate) the rule of thumb quoted was for .002 for every inch of piston diameter and that equates to .0067 so I believe the math says .005 needs to be removed. I may be correct and may be incorrect, however the machine shop or person doing the job needs to be the one to determine the amount as they will be the one that has to stand behind the work. If the pistons are ground down then the ring lands and end gaps will also need to be rechecked for proper fit. With all the machining etc being done it is essential that the shop or person doing the work is willing to guarantee the outcome. That's not a good position to be in as you will then become responsible for repairing someone elses mistake. With new correctly sized pistons then normal assembly procedures can take place and that includes verifying that the pistons are correctly sized BEFORE installing them.

I was using that as an example. Often the ring area is slightly small than the skirt.

Thank you very much for all inputs and good information!

Can I ask why Egge does not seem have a good reputation?

I can only say your piston issue would not be an issue, if cast pistons were used.

Regarding Egge, I have used them for many years, without negative experiences. That has been MY experience.

Egge has been around for a long time. A long time operating business can add to both the positive and negative comments.

We see these positive and negatives in life, each day. If EGGE was a terrible company, it would not be still in business ..... in my opinion.

Just recently, the same "good" and "no good" debate went on and on, but this time it was Petronix ignition system.

Just be aware that the pistons need to be cam ground and not just have a few thousanths cut off on a lathe. The expansion is greater inline with the piston pin that the rest of the piston.

Unfortunately, there are numerous businesses in various fields with bad reputations that supply inferior products and/or services that are still in business and have been for years.

My opinion is that Egge has a poor return policy and attitude toward their customers. In addition their manufacturing process results in some inconsistent or defective parts that might not be apparent when shipped. I am told they use "standard" master parts that are machined to produce parts for a wide range of applications. They are located in So. Calif so their costs are higher than other places and therefore so are their prices. If they would just stand firmly behind their products and services and keep most customers happy all would be good. But they for some reason appear to distrust their customer's honesty and therefore irritate a bunch of folks. Or feel that they are the best available so "let the idiots go somewhere else". Since they don't have a lot of competition they still have "enough" business. Often they are the "only game in town".

I choose to not do business with them or their retailers if I know the parts are supplied by Egge. Others can do as they wish.

Same here...and I am speaking from experience.

[quote=Chipper]My opinion is that Egge has a poor return policy and attitude toward their customers.

In my experience with EGGE, I have not had the need to return items. Perhaps I've been lucky enough to miss out on their self inflicted negativity.

Good info to know.

The shop that did my engine only used them as a lost resort as when problems arose it was always the builders error and never their product.