VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 1954 pistons

The pistons in my 54 engine are Nelson-Bohnalite, with no GM markings but they are std. size. There is some info on the internet but not a lot. I am curious if they are OEM pistons or replacements.

Chevrolet made their own pistons. Their will be a GM moulded into the inside of the skirt. 38359xx on the other side.
A notch on the top front if the edge of the piston designating front and the letter F on either side of the pn indicating front. The wrist pin is off set to one side (not in 1953).

Well Gene it has that and more. The number inside is 3835996 with GM on the opposite side. Also cast inside the skirt is Bohnalite and stamped on the two inner reinforcements (steel) is Nelson Bohnalite which is visible thru the skirt cut-away. I did not think to look inside the piston once I saw the name thru the cut-away. Thank you for todays lesson and I am sure I will be back with more questions.

OK, I looked inside of the piston with a flash light and found the Bohnalite name.

I have a new set of pistons that I thought I would install in my 1950 some day. (53-62 aluminum) I doubt if that will ever happen as it runs like a watch today.

If my pistons did not look so good I would buy them. I checked the clearance and there is .007 with the used pistons top and bottom and side to side and everything is standard. The pistons have very little wear on the skirt thrust sides so I will be re-using them. That being said my vendors are telling me to use the cast ring sets if not boring the cylinders. I know the chrome-moly would last longer but they advise without boring even after honing the C-M rings are harder to seat.

I agree. I would go with the cast ring sets.

Thanks Skip. That seems to be the general consensus. The last time I used C-M rings in a Chevy six was in 1965 and I had to dust the cylinders with Bon-Ami to get the rings to seat.

Oh ya......I have heard of the Bon-Ami trick quite often.

Ever since they were introduced in the mid '50's we used the GM Chromeflex piston rings for replacement and had no problems. The compression rings were cast with an expander behind the middle ring, also a steel wafer ring. The oil ring was a top and bottom chromed wafer ring with spacers in between that pushed the oil ring against the wall. They were made for GM by the Muskegon Piston ring company.
If you do used a non-chrome ring make sure expanders goin the oil ring groves behind the ring.
I will get back to you soon on the pistons THAT I WILL NEVER USE)