valves for 401 heads

[69jav]

I am building a 401 for a 69 jav project want know if my heads can be machined for larger valves and if so,what may work best. They are 77 heads # 3231475.I plan to do some port work, just want some good ideas...thanks

[msalaba]

The book "Performance American Style" has a pretty good section on increasing valve size and porting diagrams. It is a good book and worth the price. You can find it on e-bay.

They put 2.04/1.75" valves as the max diameter. 4.91" length and .310" diameter. Any race engine builder should be able to source valves for you.

[fifesjeep]

Yup, Less weight and bigger valves is a good thing.... to a point. I guess knowing what Compression Ratio you want and knowing the characteristics of how the heads flow at different lifts will dictate what cam/performance you're looking towards. What's you plan with this motor?
I'm wondering how much head work and money it will take to purchase quality valves their required parts along with the machine work associated with fitting these valves... then the deshrouding process, new guides etc.

[tufcj]

The way I've always looked at it is the valves are 2.025" and 1.650" diameter stock. Those are slightly bigger than the ones in Chevy "Fuelie" heads. I think the money would be better spent on proper port/polish and seat work, maybe have valve guides done for slimmer stems to save weight instead of bigger valves.

Bob
tufcj

[fifesjeep]

I'm with you.. that's why I said "to a point"... There is performance to be gained by larger valves but for the stock flow charateristics I think it would be best to port/polish/blend... like tufcj mentioned. I'm curious to see how much CR/lift/duration he's planning on running.

[Lenni AMC]

Hello I have two 401 s one stroked to 443 cui and I bought a set of Crysler 440 head valves 2,08 and 1,74 and they fit very well but I doubt that you can go Bigger on the Steel AMC head

[69jav]

Thank you all for the input,I have built a number of motors for other people in the past but this is the first amc build and the first that is for my own project.I am looking for a tough street partial strip combo that will make people rethink their opinion of the awesome AMC brand. I was thinking around 11:1 CR and 540 lift 308 duration. Has anyone tried anything like this? Oh yeah......my friend Matt at bulltear tells me they are gearing up for some iron head porting equipment in January that I plan to take advantage of!

[wyrmrider]

have you thought about a 30 degree intake seat?
for cam see the
Engle catalogue first (who ground the cams for the Traco can am engines...)
or special order from crower, comp, crane
the catalogue grinds are sometimes production chevy grinds...BVVC
you're not thinking of a mechanical roller are you?
mechanical
hyd?
hyd roller?

[69jav]

Actually I am looking at all options....Mechanical and mechanical roller are on top of my list,I don't mind the need for periodic adjustments....I welcome it!!