Full Force

iTrader: (5)

Trying to research what material EXACTLY is used in these brand heads.... not finding anything really looking around..intake and exhaust...

AFR?
DART?
EDELBROCK?

14 apache

iTrader: (1)

Ductile iron is a standard exhaust seat it's cheap and will work well with leaded fuel. Not good for unleaded fuel. Also might have a lot to do with inconel it might have a rough grain.

MILD THUNDER

iTrader: (3)

Darts automotive heads, get Ductile Iron. Darts "marine" heads, get powdered metal.

AFR uses Ductile Iron.

Brodix uses ductile iron, but will upgrade seats if you wish.

Engine Quest uses Powdered Metal.

Teague uses Tucker valve seats.

Heres a good read about valve seats here

http://www.dura-bondbearing.com/Port...tech-guide.pdf

MILD THUNDER

iTrader: (3)

Powder metal seats are very good at handling thermal stress as well as impact stress, and typically show minimal wear after tens of thousands of miles of use. The homogeneous consistency of apowder metal seat also improves heat transfer, which is good for thevalves, too. Powder metal seats also tend to experience less micro-.welding between the seat and valve even at high com-bustion temperatures, which helps extend the life ofboth components.Even so, some powder metal seats tend to be very hard (up to Rockwell 40 to 50) and can be difficult to machine. As long as you have equipment that can cuthard powder metal seats, remachining the seatsshould be no problem. But if you don’t have equipment that is designed for this kind of work,you may be better off replacing the seats with newones to restore the proper finish and seal.

A valve seat must do several things. It must support and seal the valve when the valve closes, it must cool the valve, and it must resist wear and recession. Consequently, a performance valve seat material should provide a certain amount of dampening to help cushion the valve when it closes at high rpm. Very hard materials, especially on the intake side, are not the best choice here because intake valves tend to be larger, heavier and close at faster rates than exhaust valves. The wilder the cam profile, the more pounding the valve and seat under-go at high rpm.

MILD THUNDER

iTrader: (3)

Many late model domestic and import engines have seats that are made of powder metal. These types of seats are very hard and durable, so they typically show little wear at high mileages.

The main reason why vehicle manufacturers have switched from cast alloy seats to powder metal seat inserts is to extend durability. Most late model engines have to be emissions-certified to 150,000 miles or higher depending on the application and model year. If the valve seats can’t go the distance during durability testing, the vehicle manufacturer can’t certify the engine.

MILD THUNDER

iTrader: (3)

Heres a teague engine. Look at the description, and you will see "AFR HEADS", and "TUCKER VALVE SEATS". Teague installs upgraded seats in their afr heads.

http://teaguecustommarine.com/em0011...ong-block.html

“Here are the facts,” said Kiekhaefer. “On the 565, we found a more durable valve seat material in long-term endurance testing. We gave new 565 owners the option of having us install our new seats now, or at a more convenient time of their choosing—as late as first rebuild. Nor-Tech and Formula chose now. Cigarette chose later.”

The 565 engines currently being constructed at Mercury Racing to fill orders that came out of the Miami show will have the new valve seat materials, as will all subsequent 565 units when the engine goes into full production next week.

Full Force

iTrader: (5)

i am gonna do some research the best I can to see if older AFR heads were the same I know a handful with no seat changes and no issues, not to say they can't have issues, but this nonstop spending on new heads has to stop... None of this stuff comes up until I'm already into this stuff it seems, might just go with it and roll the dice because I'm plain and simple fed up

14 apache

iTrader: (1)

Don't run a solid cam if you roll the dice.

MILD THUNDER

iTrader: (3)

Tim, something Dan and I were talking about last week, was maybe a leaded fuel additive? Not sure if there is one that works, but , might be something to consider if you decide to roll the dice. I can't see it hurting anything?

Black Baja

iTrader: (2)

Octane Supreme is the only additive that actually has lead in it. All the other substitutes on the market are just that substitutes and contain no lead. We found it very beneficial adding 2stroke oil every fill-up at a 100:1 ratio. With general maintenance tear downs top ends looked much better. Mercury actually recommends a 2 stroke mix with there 1350&up motors. I think a lot of problems we have now is the fuel is simply to dry. They have taken all the lubricants out of it. Either buy race fuel, aviation fuel or add two stroke oil every fill-up two extend the life of the top end. No spark plugs do not foul out. You get a little puff of smoke at start-up and other than smelling like a weed wacker at idle you would never know the difference.