8ba engine

Grease348

Grease348

Junior Member
I’m rebuilding my first flathead. I have a block with a stock bore, no major cracks. Will be boring out .030 .060 stock 3.75 stoke. Who ‘s pistons should I be looking at?


Sent from my iPhone using Tapatalk
 
Mine (C59A) originally was rebuilt with a 40 thou bore, and it needed a 20 thou over to clean things up. So, 60 thou over with stk 3.75” crank and stk heads Went with Eggy domed pistons, but there is another thread here about using these pistons with aluminum heads as there could interference.
 
I’ve read that thread. Good information. I’m planning on using iron heads.


Sent from my iPhone using Tapatalk
 
Grease348 said:
I’ve read that thread. Good information. I’m planning on using iron heads.


Sent from my iPhone using Tapatalk
Click to expand...

Most of the stock iron heads are designed for the tri-radius piston crowns - so you should be okay. BUT - take a cheap profile gauge and check how the pistons compare to the chambers - you can learn a lot for a few bucks!
 
I’m still looking for recommendations. Egge, sealed power, ect. Help me out.


Sent from my iPhone using Tapatalk
 
I know what you are saying! There are so many choices it is confusing! The last 276 flathead I built I used Ross, a great piston. I'm building a .030 over Mercury 255 with NOS EAB heads, 77B cam, with crab distributor now and I'm also looking at the choices, 3 ring or 4 ring and leave the 4th one out, coated or uncoated, cheap Offenhauser or? Sorry I wasn't much help but offering moral support
 
On my last build, I bought a set of 4 ring pistons from Speedway; I think they're Offenhauser. I paid a bit more than $100 on their "Garage Sale" section for pistons, rings, and pins. I dropped them off at my machinist and after some close inspection and a few measurements, he said they looked as good as any. After a bunch of introspection and discussion on "The Boards", we installed them without the fourth (bottom) ring. The assembly was balanced that way. No road miles yet, but everything looks good so far. It is my understanding that forged pistons are unnecessary for a street engine, contributing only a bit of noise when cold. Leaving the fourth ring out seems to have been the correct decision, and the engines starts easily and runs well. I just thought I'd add my input to the above.

I'd have liked to have had "metric" rings and such, but since this engine will probably see less than 20K miles in the next 50 years, it's really not mandatory
 
Auuto-Thermac OR "steel strut" arre the best pistons for a stock rebuild. They can be installed with very little clearance .001/.002. I found a set of NoName pistons like this for my 3/8x3/9 296 engine that I built for Ron H. (NOt me). , Now has 15years and many miles on it. I don't like Ross pistons for street, great racing piston, must be installed with .004/.005 clearance. works fine for 15/20K miles known to burn oil in a cool engine.I do like the Egge 3 ring pistons, never had any problems with them
 
Ron,
I agree that the Autothermic pistons are great for a stock rebuild. But as far as I know, they are not currently manufactured for flatheads. I'd like to be proven wrong on that.
 
You must log in or register to reply here.
Back
Top