Flathead Pistons and Rings Advice Please

3

31 coupe

Member
Hi folks,
I'm about to order pistons and rings for a 276" (3-5/16" x 4") street hot rod build with 2 x '94's, Edelbrock 1125's, L100 cam etc.
I'm leaning towards the 3 ring EGGE type but I've heard negative comments about the dome contour misfitting etc.
There are plain iron or moly rings options with them too so what is the best choice here please.
I'll welcome any input from the FORDBARN wealth of knowledge.
Thanks in advance, GB.
 
I've always used Egge. When considering the dome clearance, in most cases the head needs to be milled. However, in richards engine the clearance was so close to ideal we forgo that operation. He used the new 65cc edelbrock heads. Watch out for open threads in the spark plug area. There was no problem with valve clearance. Ross pistons are probably the best racing pistons you can buy today, and I put thenm in racinf engines.
 
You cannot go wrong with the Ross pistons for these Flatheads.

We use them in just about every decent build and normally have about a dozen sets on hand at all times! We use numerous sets of the 3.312" x 4.000" and 3.312" x 4.250". The longer stroke is more preferable.

We use the Scat rods and the Eagle cranks, no problems to date!

No issues with "dome-radius", come with the lightweight "metric" (1.5, 1.5, 3.0) ring pack and are basically "ready-to-install". The 4.000" stroke pieces weigh around 308 grms, the 4.250" ones around 320.

Thanks, Gary in N.Y.

P.S. If you're not using the stock rods, I would recommend using the Scat rods over the Eagle's, less "clearancing" with this brand due to the narrower beams! The Eagle shaft's are easier to balance and gets the job done!!
 
A huge thanks everyone, I sure got the most knowledge there.

You've convinced me to now go the ROSS route but which ring package is right for regular street rod use, the GRANT iron ring versions or the more expensive metric moly package, please include the reasons.
Is there also any advantages between GRANT or HASTINGS ring packs if the alternative is available.
Thanks again, looking forward to your replies. GB.
 
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You won't go wrong with a moly ring pac that is available from most good ring manufactures.The cast ring will perform there also but is not designed to do the same job as moly in most modern applications.The machine shop needs to know your choices as the cylinder bore finish is different for each application.Moly would be my first choice from the big ring company.Hastings have been doing it for 100 years.There are also different groove combinations available metric or fractional.You will have to pay attention to how clean the bores are if you are building the engine yourself as this is an area that if not done correctly will come back and bite you in the ***.The assembling should be thoroughly thought out and done in a clean environment.Hope this helps.

R
 
I am having trouble finding moly rings for my '53 flathead Ford V-8. Can anyone help with a vendor? I'm locating plain castiron rings only so far, but really want a fine set of molys. The Merc pistons are aluminum alloy with four rings at 0.060" over.

Please help? Thanks.
 
I picked up my completely rebuilt 258" 8BA from the machine shop Tuesday. This is the one I had built with 4 ring pistons with only the top 3 rings used. I should have this engine up and running in a week or two. I'll let everyone know how this works out.

I hear you guys about the moly ring packs and Ross pistons, but at my age and budget, I am more interested in saving a few bucks rather than the last couple of horsepower or the second 50,000 miles of engine life.
 
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The widths of the Moly rings is narrower [2 mm I think] than the standard rings [3/32"]. I think the original application for those rings was some Volvo truck engines.
 
Rings are produced by a size only,not really application.The problem becomes no moly produced for 3/32 width grooves.A good example is 4"bore all common to the big three in 5/64" width.That combo has plain cast chrome and moly.A small block ford and a gm 350 all take the same ring set.A standard bore 340 4.040" bore dodge has the same rings as a 350 .040" over.Or a 289 302 351w .040" over ford has same set.All done by size not application.

R
 
Back in the day it was common practice to repair worn top ring grooves with a hand lathe that cut the groove wider and then a shim was used to go back to standard ring thickness. Anybody know if these shims would reduce ring grooves to fit modern narrow rings? (just a backyard engineering possibility).
 
The use of Ross pistons in a street engine offers no advantage. The excessive piston clearance can lead to more oil constitution. However, IF you do plan on runnig Ross pistons use 180 stats. Running the engine at 190/200 degrees will tighen them up. The 294 is setup this way.
 
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