Valve seat width
 

Looking for recommendation on what should be run for valve seat width. I believe marine motors run a wider width for better heat transfer. I also imagine many of the people on the board wind up using street builders and might not get heads back set up for marine application. So now that you guessed that I need to use someone not normally in the marine market I want to be able to let him know what I need.

I have Merlin cast iorn heads 2.300int 1.880ext, hydraulic roller .632 lift new springs will have 150 @ 1.940

Any other info needed? What should my seat width be???


Russ

Re: Valve seat width
 

.060"-.080" intake....080"-.100" exhaust. The more heat, the wider the seat. Bad thing about iron heads is they don't dissipate the heat out of the valve seat as well as aluminum, therefore if it is high horsepower(900+) you will probably have leakage on the exhaust side after a short period of time.

Re: Valve seat width
 

Naturally aspirated motors 6000rpm or less. Less than 800 hp but I hope not by that much. Anybody else, is this standard for seat width or do you do diferent things between N.A. and blower motors?

Re: Valve seat width
 

I agree with RC572, except that I would run on the high end of his recommendation.
I would also recommend new valves, no matter what the old ones look like.

Re: Valve seat width
 

I also would check the valve stem to guide clearance also. I don't know what Dave recommends but open up the intakes another .0005" and the exhaust another .001".

Re: Valve seat width
 

Hey Dave,

How are you doing, Evey time I turn the corner somthing eles is stopping me from having finished motors :rolleyes: Yes new valves are going in as all EXT were bent and 2 INT were bent.

Also found a broken land on 1 piston ( no damage to cylinder)
so Aries is cutting me a couple of replacements. I should have all back by tuesday so I guess I will be in the bilge on the 4th.

Re: Valve seat width
 

.060-.080 Intake and .080-.100 Exahaust

These are good number to work with. AS was also said guide clearance is very important. I agree with .0005" extra on the Intake and .001 on the exhaust. I personally don't run stem seals on the exhaust to allow extra oil to get to the exhaust side. You may see a little puff of smoke when you start the engine but nothing obnoxious.