combo
 

hi, i need some help with my combo. I have 2 572ci engines short blocks with good parts, but i am having a problem selecting cam, cylinder heads, intake annd carb. i would like to make 700hp, but i prefer using iron heads instead of aluminum. I have flat top pistons and would like my comp to be 9:1. Can anyone help me please. THANKS

I would try a new title for this topic. Just a idea why you have not seen any reply's yet. Maybe "Best heads and Cam for a 572"

Jon

damn Audio you are truly a post whore no wonder you have so many replies you check EVERY thread!!!!

I'd contact dart or merlin on the heads,they have combos that will bolt right on,find out which heads and then contact your cam company give them the comp ratio,rpm range,ci,and theyll be able to reccomend the cam specs,make sure you inform the of the lenght of exh your running

Thanks offshore addiction. please help me anyone have any ideas.

The Merlin VR marine iron heads are very good stuff. Whatever heads you buy, make sure you get Inconel exhaust valves- automotive 'street' valves will fail big-time in a high performance marine engine. The Merlin VR marine is built with these considerations in mind. They are made by World Products- and can supply you with a real nice marine intake manifold that has a brass insert for the water passages.

You will need to determine carb- You will probably be happy with Holley 1050 or 1150 dominators. Make sure the carbs are marine, too. The bowl vents will be J shaped to dump fuel into the engine if a float sticks.

You will have to decide on what type of cam to use- Hydraulic or solid, flat tappet or roller. The solid roller lets you run more spring tension for higher RPM's and max power, but you will need to replace lifters every 50-100 hours.

The next step down is to the Hydraulic rollers, which are very reliable and will work well with reasonable spring tension. These are very popular and require little maintenance.

The issue then will be cam lift and lobe separation. Automobiles can get away with 108 degrees of separation, but on a marine engine 112-114 is better. there is less overlap, which will help maintain positive pressure in the exhaust system, and reduce the chance of water hitting the exhaust valves. There are many posts on the board- you can use the search utility to find previous discussions on specific cams, etc.

I would like to point out that the cam, lifters, springs, pushrods, and retainers all have to be correctly matched or you will have problems. Ther are a million bad combinations due to lifter height, spring tension, etc. Make sure the builder checks spring tensions, etc. against cam spec's, or buy from one manufacturer.

You should see 600-700 HP out of a tall deck 572 without going wild on cam, compression,etc.

Good Luck!!!
Bulldog

thanks for the info bulldog. I amgoing to give world products a call. A friend of mine told me to use a cam with 262/272 dur at 50 and 110 lobe .714/.714 lift, solid roller. Do you think that cam will work. THANKS