VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc 28 piston

hello, have aluminum piston out of 28 it apears to have hole drilled with slot on skirt my question is is it possable for the slot to be a crack?
thanks jp49

It is possible that someone tried to stop a crack by drilling a hole at the end of the crack.

It is also not only possible but likely the hole was put into the piston skirt when originally made. The hole distributes the stress so a crack doesn't form from the end of the slot.

FYI, here is an image of a brand new piston for a 1928 Chevy engine. It shows the slot and hole in the skirt. The image comes from the online catalog of Egge Machine Company. I used their pistons in my 2017 engine rebuild.

Cheers, Dean

all posable, the engine was runing 20 yrs ago when set aside. is piston useable, guess i will compare other 3

The "T" slot in the skirt of the piston is there to allow for the expansion of the piston skirt when it heats up from normal use.

And faces the trust side.

Nope.
This has been discussed before
The slot ALWAYS goes to the NON thrust side of the engine, which is the side OPPOSITE the CAMSHAFT. The left side of the engine when facing the direction of travel.

The last thing you want is the thrust force on the piston trying the squeeze the slot closed... and thus making the piston smaller and the clearance between it and the bore bigger.

Thanks

Your welcome. :-)
Didn't want some one to make a mistake that will cost them down the road.

it all makes sense will do .
thanks jp49

is it possable to get rings for or have to change pistons

You can buy new rings and pistons from Egge. Here's their website: https://egge.com/

I used them when I rebuilt Lurch's engine. Very pleased with them.

Cheers, Dean

I put Egge pistons in my 38 a couple of years ago. The instructions were very specific and the slot went on the thrust side. The ring grooves were more narrow than the originals and only fit Egge rings.

Many people think the thrust side is the left side of the engine.
It is NOT.
The thrust side is RIGHT side of the engine when facing the direction of travel.
And every mechanic learns to put the slots to the LEFT side of the engine.

I stand corrected. The right side would be the thrust side because of the angle of the rod. Thanks for that correction.

You are very welcome.
I figured you actually knew which way to install the pistons... and that it was just a matter of terminology. :-)
That's why I worded the first sentence of my post the way I did.

egge out of stock for over a year with rings

Bummer! I suggest putting a post in the "Parts Wanted" forum for the rings that you want. Someone might have an extra set in their stash.

Here's a link: Parts Wanted forum

Cheers, Dean

You could also try Gary Wallace (www.earlychevyparts.com) or Kanter Auto Parts (www.kanter.com) for pistons and rings.

-Tyler

I have heard that 261 pistons can be used in '28 Chevy engines. Might be worth checking with a machine shop for piston specifications and compare to those for '28. Ray used Badger pistons from a local parts house in his "School is in session" rebuild.

Yes, but keep in mind that Ray bored out his cylinders to .060" over.

Cheers, Dean

thank you to gary wallace have plus 5 set on way.
jp49

Hi All
I just went through a similar situation a few weeks ago with a local machine shop that needed a set of .040 oversize pistons for a 1928 Chevy right away. Gary was out of commission at this time so had to get them from Egge Machine. Egge did not have ring sets but did have the pistons in stock so did some digging in the piston ring books plus talking to Caleb at Egge, I found out the piston rings from a 1956-57 Dodge V8 325 engine uses the same 3 11/16 piston with 5/64 compression and 3/16 oil rings which the Egge pistons take. Caleb informed me that since Grant Piston Ring moved to Mexico and that a foreign company purchased Hasting Pistons Ring, these piston rings in this size are getting hard to find. I guess Hastings will not be producing any piston ring older than 10 year applications from now on. Luckily I found a set of NOS Muskegon .040 oversize piston rings in perfect shape for 325 Dodge engine on eBay at a great price so I have enough for 2 sets of pistons.

I checked my piston catalogs to see what piston may work in the Chevy 4 engines and a Chevy 261 truck piston would work if you have to bore it to .060 oversize. The 261 truck piston is 3 3/4 bore compared to the Chevy 4 bore of 3 11/16 with a slightly longer compression distance (plus 3/32) and would work. The major drawback from using the 261 truck piston is the piston pin size. The Chevy 4 has a .850 pins size where as the 261 has a .927 pin size. The connecting rod would have to bored out or a bushing pinned to the piston. I had my local machine shop that needed the pistons check out if they wanted to use the standard set of 261 pistons that I have in stock but the labor to make them work would exceed the price of a regular set of piston plus the fact that they only had to bore the engine to .040 oversize and the I could find them a set of pistons and rings.