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Question about custom pistons

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andrewb:
Now that I have the crankshaft and rods I need to start looking into having custom pistons made for a supercharged nitro engine.  For a manufacturer, I’m leaning towards Ross due to their familiarity with Ford Flathead engines. Anyone feel there is a better mfg for pistons out there?

IMO the most critical aspect of these pistons is making sure the piston dome matches that of the heads. Do I just need to send in a mold of the dome? I guess I could just call them but thought I’d ask.

I've done a great job at throwing money into this build so what “Optional Features” should I also consider? Gas ports, skirt/dome coatings, etc.

Oh, one more thing. The machinist always asks for a piston before boring, but if I make a piston mold it will be pre-bore.  What should be done in this case?


Thanks,

Andrew

dreracecar:
I have a fondness for ARIAS pistons, Of coarse I have lunch with Big Nick everyday.

forged pistons are all pretty much all the same when dealing with Nitro, The cost and how soon they can be in your hands is the determining factor in most cases.
No on the gas porting, and the fuel coating(anodizing) doesnt hurt but adds to the cost
I would think that a Nitro piston for a FH would be a flat dome or even dished to get the comp down to a workable CR for nitro so a mold of the head chamber is not required.I would ask the piston maker
For me I would have the bores done and all equal then order 16 pistons and let the experts at the piston maker do there job at designing what will work for you. The days of hand fitting pistons to the bores are over due to the quality of machining nowadays. This is a NITRO motor and not a swiss watch, tollarences are generally on the loose side. The pins for the pistons for me would be the important feature to discuss, dont want a liteweight or too small pin causing problems when sorting out a nitro fuel system.

Talked to Nick--- they have a thick wall forging that will work perfect

denverflatheader:
As usual (i.e. very commendable), dreracecar writes helpful timely information.  Same as Arias fh pistons, Ross makes excellent forged pistons for the fh.  For a third price comparison, I’d look at Diamond billet pistons.
 
http://www.diamondracing.net/pdf/Custom-Billet-Pistons.pdf

I had spoken to Ian at Ross a few years ago for a set of coated racing pistons.  If he’s still there, he will advise you should order the pistons from one of their distributors, back then it cost “much” less than ordering directly from Ross.  I ordered mine through Mike at H&H Flatheads.  Mike and their family business 1st Class.  I’d go with coating for supercharged nitro-methane protection, back then it added about $100 to the cost for set of 8.  I’ve seen coating kits on the internet for sale for do it yourselfers.  Here’s info on different type coatings:

http://www.jepistons.com/TechCorner/PistonCoatings.aspx

On piston design for fh pop-up heads, no help here.  Never seen one and no experience to share.  Might check to see if there’s compression ratio chart available for the Hanson heads with different bore/stroke combos already done.  Save you time mocking it up with scrap piston and grinding on to cc verify.  For me, I’d have to know the final compression ratio before I’d advance any further…

jeff/21:
i sprayed the head and cylinder with pam installed the head turned the block up-side down then filled the head and about one to two inches in the cylinder with bondo let it cure then it just fell out leaving a perfect sample. how much nitro you will be running will determine the compression  as stated above flat piston will probably work the best.

denverflatheader:
Jeff - neat solution, like it!.  Alan

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