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#1 |
Junior Member
Join Date: Jan 2012
Posts: 7
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Hi guys,
just wanna get the opinion of anyone running these mummert heads on the street and whether the price is justified in the performance. Ive heard varying increases from 50-75hp. I see Ted Eaton has tested them with a variety of carb set ups, has anyone tried them with a supercharger? Are they ready to run right out of the box ? Any insight is greatly appreciated. Regards Rob |
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#2 |
Senior Member
Join Date: May 2010
Location: St. Michael, Minnesota
Posts: 1,713
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If I had the money, I would have a pair.
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#3 |
Senior Member
Join Date: May 2010
Location: now Kuna, Idaho
Posts: 3,818
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At what RPM do they start to outperform stock heads? Do they need a hot cam to realize their potential? Will they do any good if you use the stock '57 4 bbl. intake?
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#4 |
Senior Member
Join Date: Mar 2013
Location: Kent, WA. Tucson, AZ
Posts: 1,626
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I've got a set on a 292 with a 312 crank, offset ground for 320 cid. Like any other engine parts, they've got to work together. The main thing I'd watch just changing the heads is the chamber volume/compression ratio. I pulled a set of Mummert ported iron heads IIRC, 471 castings, and put the aluminum ones on. The static ratio went from 9:1 to a bit over 10.5. That meant the 5# boost at 5000 rpm blower had to go. The flat top pistons, at 0.00 deck, didn't leave a very good quench area.
After a cam change to move the dynamic compression ratio down, and ceramic coating on the piston tops, we pretty much solved the quench problem. The motor has FPA headers. 2 1/2" exhaust, and an older Blue Thunder manifold. I didn't have an engine dyno available, but the car runs better than it did with the supercharger. The best info, as state above, can be gleaned from Ted's site. http://www.eatonbalancing.com/blog/category/y-block/ I'd do it again, in an instant, but best on a full rebuild where you could dial in the Pistons a little better. I just couldn't bring myself to toss a set of custom pistons from the stoker kit, and spend the money to replace and rebalance the whole lower assembly. |
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#5 |
Junior Member
Join Date: May 2014
Location: Melbourne
Posts: 2
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