I just dropped my heads off at the machine shop for my hemi and asked some questions on my valve job because a retired machinest who stopped by my shop took a peak at them and said that the contact area for intake valve to seat isn't wide enough. He said that on his performance engines he set them at close to .100 on the 45. My machinest says he puts the intakes at .060. So what do you guys do?

I'm far from a professional. .060 sounds a lot better to me though.

As I understand it, the wider margin flows less but last longer like in a street build and the narrower margin flows best but doesn`t last as long. And of course multi angles are favored for flow which =more power.............

The guy doing my heads does a 3 angle on everything. Grandmas 4cyl or grain truck. Just checkin on width. I agreed with the way he explained it for how wide he makes them. Thanks for the input.

I`d say he`s leaving power on the table cos a few I know do as many as 5 angles and even heard of more but I`m no machinest so,..........

It depends on the heads, wedge or Hemi, on which works best I agree with Dominc on the longevity of the V.J., I had to learn that the hard way To narrow doesn't last very long at all on the street, .060 on a wedge head might last 1200 miles, maybe less .080 will last on the street, .100 on the exhaust seats and valves will transfer more heat to the seats than .080 will

When Jason installed my 2.19 intakes he gave me a multi-angle racing v-job which he said should go 20,000 miles no problem..........

This question is in regards to the hemi heads off of old smoky. Street car. Prob never see the track.

Whatever seals and last the longest I guess...........

Just my opinion, but when it comes to my own cars durability and reliability trump ultimate power every time. Actually even when we're talking about race cars most of people on this board when they talk about race cars are referring to drag racing bracket cars. In bracket racing winning usually depends more on consistency, predictability, and reliability than it does on being the fastest car on the track. High performance always involves a trade off between maximum possible power and durability. Even in a "heads up" environment eg. Pro Stock, Nascar, Indy Car etc. you have to be able to go rounds or make it to the final lap to win. Bottom line go with a wider seat for street use and longevity.

So if I'm understanding it correctly, go 080 on intake and 100 on exhaust. I'm looking for making it live on the street. To much money in this thing to go for every hp.

.060 is fine!

I have always made my intakes about .060 and never no problems. I like the exh a bit wider about .080 to disipate the heat fast enough but to wide is more chance of carbon building on the seat over the years and more area to keep sealed as the miles get put on. Ron

as two points of reference.....

i remember being in Bartons shop many years ago(late-80's) when he was still up in the Montreal area, and saw some SS/AA heads he was working on there.
the intake valve seats were just a very, very thin pencil line.....probably around .015" wide at most, right on the very edge of the valve.

on the other end of the spectrum, that old SBC Pro Stock engine book by Grumpy Jenkins specified the intake seat width to be .100" wide......and that was for a true max effort application.

so whats the right width seat???
its just another example of the many, many things that are engine related that fall into the "it depends" catagory.