boatguy94

I have a 540 Merlin, edelbrock alum heads, 871 BDS, dual 850 Holleys. What hydrallic roller cam and lifters would you recomend? The machine shop said to use Crane 168741. Any help or recomendations would be appreciated.

KAAMA

iTrader: (1)

A good person to ask is "RMBuilder"/Bob Madara of Marine Kinetics in N.Y. (585) 654-8583. He will design a cam profile specifically for your engine and application. He has done cams for a lot of guys here on OSO over the years.

Chris Sunkin

I'm going thru this same exercise right now. The 741 isn't enough cam. Neither are the Edelbrock heads. They'll work, but you'll leave 100+ hp on the table.

Contact RMBUILDER.

boatguy94

Momma says I have to stay with the Edelbrock heads, but will contact "RM Builder", any other ideas are greatly appreciated thanks, BG

Chris Sunkin

Maybe find a few bucks in the budget for some porting mods to the heads. Make sure the valves you have in the exhaust side are Inconel. That's an absolute must.

boatguy94

Heads have been worked, replaced all the valves to Inconel, I think they will work ok. Not sure if they did any porting, how can I tell? Thanks, BG

Rebel_Heart

I changed to 540s a couple of years ago, I have the Dart Pro Ones. Made a big difference when I had them ported. Did a before and afer on the dyno. I used the 741 cam and it seems to work out ok.

Chris Sunkin

The Edelbrocks will have a "cast" finish to the ports- The texture of fine sand. If they're ported, they'll have either the marks of the tool or they'll be polished smooth. The tool marks will either be the "chattered" finish of a carbide burr or the linear sanding marks jeft from a sandpaper bob. Your biggest concern should be with the exhaust. The blower sort of compensates for intake port shortcomings- it will flow the same but there's more fuel and air per cc of volume in the intake charge because the charge is compressed. The exhaust still has to get rid of the spent gases the old-fashioned way. One way to kill a normally-aspirated head's performance is to have too high of an intake/exhaust flow relationship so some are deliberately more restrictive on the exhaust. One issue I've heard of several times about the very popular AFR 315 head is that its exhaust has too high a flow for N/A applications and some builders use a lesser-flowing valve to get the flow ratios more in line. Some bowl work would probably yield some nice performance gains at not too big a cost.