Flathead intake manifold recomendations

Ol' Ron said:
HB32, why would you use Ross racing pistons in a street engine? Granted, their probably the best racing piston available. However they require excessive piston to wall clearance. Egge, makes a light weight piston that can be fir tight and has a modern ring stack. Back to alittle more research.
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Hi Ron, egge makes them with "metric"ring set?
That is new for me?
 
hb32 said:
Since I started this thread, I researched the death out of the 39-41 Merc and have switched blocks to a C69A 46 Ford. It will be opened up to 3 5/16 with a 4" Merc crank. Pistons will be Ross 3 ring and Manley stainless valves. Cam will be the L-100 which I have read lots of good reviews about. Rotating assembly will be balanced as well. A long way off my original intent which I have digressed from. I appreciate the help to date and still looking for thoughts on a manifold for the change in engine.
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I'm interested in why you changed from a 39-41 (99A) block to a C69A? What research lead to this choice?
Martin.
 
Martin, I'll jump in here; the C69A block has massively thick cylinder walls, and is a safer bet for the bigger bores.
 
I got a set of pistons from them last year thathad rings from a Volvo truck. Not sure if all of there 3 ring pistons have them.
 
Brian said:
Martin, I'll jump in here; the C69A block has massively thick cylinder walls, and is a safer bet for the bigger bores.
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The 99A engines I have stupid thick cylinder walls, these are Canadian war issue blocks. I haven't sonic measured them but they both look like they'd comfortably take a 3 3/8" bore and then some. The walls come almost right out to the trapizoid hole in the bottom middle.
Sure I'd been told the 99A was the one to have for silly big bores? Saying that, I've definitely been told the French ones were the best as they all go 3 3/8" as they don't ever have core shift! And we know that is completely wrong, they seem to suffer much worse than the old Ford cast blocks.
Thanks,
Martin.
 
Brian said:
Martin, I'm not gonna argue, but have you ever seen a C69A block?
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Yes, a long time ago though. I'm not arguing either mate, just saying what I'd been told, and related it to the 99A blocks I've got.
If the C69A block is thicker than the 99A blocks, I'd say they'd go 3 3/8" no problem, and if I had one I'd consider this to be my first over size.
When I said about the frog blocks not being what we're told, I was not questioning your conclusion on the C69A blocks, I was questioning the "99A is the best block for Big bores"
Martin.
 
Yes mate, a C69A block has thicker walls than the 99A/wartime military blocks. Accordingly is my first choice for building big bore engines. However, it is my opinion that the pre 59A series blocks are cast of a better cast iron, dunno, maybe more nickel or something, but the later blocks are definitely cast of a different grade cast iron.
 
Tim
When I recieved the pistons (3 5/16+.020") I was curious as to what the rings fit. So I looked up the number on the ring box and it fit the 4cyl Volvo truck engine amoung others. Egge also makes a .030" over piston as well.
 
Brian said:
Yes mate, a C69A block has thicker walls than the 99A/wartime military blocks. Accordingly is my first choice for building big bore engines. However, it is my opinion that the pre 59A series blocks are cast of a better cast iron, dunno, maybe more nickel or something, but the later blocks are definitely cast of a different grade cast iron.
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Thanks for the education and exactly what the supplier/builder of my engine has told me as well. He said that his machinist does not look forward to them. I went with the Ross Pistons on several reccomendations from posters on the Barn. A little digretion from my original post but I am enjoying the banter
 
Ol' Ron said:
Tim
When I recieved the pistons (3 5/16+.020") I was curious as to what the rings fit. So I looked up the number on the ring box and it fit the 4cyl Volvo truck engine amoung others. Egge also makes a .030" over piston as well.
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Interesting, thanks. So I'm assuming they were "modern" thin-style metric-type rings.
 
Ross pistons web site shows they have about 4 different flathead combo,s with the "Metric " ring pack .
Very good to know .
 
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