440 pistons.

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Cope

Cope

Fusing with fire
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http://m.summitracing.com/parts/uem-ic9953-030

What do you folks think of these for my.440 build? (open chamber 906 heads, 2.22int, 1.84ext.)
comp 23-702-9 mechanical roller.
.576 .582
@.50, .248int .254ext.
Harland 1.6 rockers.

victor intake with 950 profuel carb.


Thanks again for all the time and advice.
 
I have used the ICON piston in 2 different builds and are a nice piston for the money. A flat top at zero deck with a 79.5 cc chamber will be right at 11:1, so plan accordingly.

As far as the combo, it depends on your goals. For a pump gas street car, CR will be too high, but the cam duration should be good. Having a typical 906 chamber of 84-88 cc will actually make it worse as a tighter quench helps minimize detonation. A would not decking the block and leaving pistons ______- deck height.

If a race only deal, max effort (and rarely street driven) I'd get the cam up around the 260* area.
 
Shoot. I guess its time for me to CC the heads.
Im kinda stuck with the cam as its already in my pile o parts...

I guess 11-1 is to much for pump gas even with cam overlap?

Thanks again.
 
906 heads are around 88 cc, will give U around 9.5:1, fine on pump gas with that big cam
 
Just got a set of Icons like those with 0.990 pins for my 490. My machine shop says they are plenty good and still lighter than the stock units. They are very pretty!
 
Humm..

Doug says 11-1 and Marco says 9.5-1...

Thats a big difference...

I was gonna have the rods bushed so maybe I should look for the smaller wrist pin set?

Thanks again for all the time and advice.
 
This is the set I have. They are for the 4.15 (493) but I'm using the 4.125 crank so I lost 3 CID. I was wanting a set for the bigger pins but alas these were priced to the point I could afford the H beam rods....
http://www.summitracing.com/parts/uem-ic826-030
uem-ic826-030_w.jpg
 
Whats the advantage of the large wrist pins VS the small wrist pin?

I was thinking a bushed rod would be better suited to the small pin?
 
The ICON line is meant to be good value. They deliver. IMO, if this is a race only effort, better pistons can be had. But ICONs are good value, and decent units.
On the pin size - always go smaller. You will never break the pins. You might pull the pin out of the piston. So smaller pin = lighter, and smaller pin = more material around the pins on any given piston. Stock 440s are all pressed pin. If you're going full floating, the .990 pin keeps the rod as thick as possible as you bush the hole smaller, rather than making the hole bigger to bush for the stock size pin.
In terms of compression - you have to have your actual chamber size, deck height, and the gasket you're going to use to really "know". But I think you'll be fine with a flat top and 906s not drastically milled. Being an iron open chamber - IMO you want to stay under 10:1 for pump fuel. More can be done, but it takes a lot more in terms of engineering the build and care in tuning and parts matching.
 
I CCed the heads and got 87cc's with a R45TS plug installed. (shortest plug i could find in the shop.)

The guy I got the block from says it has not been decked but thats yet to be checked.

head gasket undecided.
so with a compression heigth of 2.067 and a stock stroke what SCR am i looking at?

Im building this as a strip first and street second build but I will drive on the street...

if you care to show me the math that would be great so I dont have to keep asking..

Thanks again for all your time and advice.
 
Easiest deal is just use the online calculators. I like KB-Silvolite.com but any of them will work.
 
Marcohotrod said:
906 heads are around 88 cc, will give U around 9.5:1, fine on pump gas with that big cam
Click to expand...

standard block is 10.720"-2.067"-6.766"-3.75/2=.012" deck, 87cc head, 5.6cc dish, .039" gasket, 4.41 gasket bore, 4.35" cylinder bore X 3.75" stroke = 9.6:1:)
 
Thanks Marco!!!

the calculator gave me 9.5:1

i figure then i should look for a thinner head gasket to get me 10:1

or should I just stay where im at and not worry about pump gas?
 
I would install a piston to check actual deck height. maybe go thin head gasket. depends on vehicle weight, rear gear etc.
 
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