Performance Valves

[ignoreance]

So in my quest for building a better cylinder head I have been doing some research and think that this may work I haven't ordered the valves yet Cuss I'm talking to my neighbor about it (He owns a Cylinder head shop)

But the pre data would indicate that you can change to larger valves with out having a custom order..... Nice


Stock Valves are as follows.

1.720" head 4.73 +/- .005 Over all length .3415+/-.005 Stem Diam .100+/-.005 Valve seat width .050 margin and last .270 On the tip length

1.420" head 4.375 +/- .005 Over all length .3415+/-.005 Stem Diam .200+/-.005 Valve Seat width .070 margin and last .300 On tip length

And the nice non custom performance upgrades are From the Buick v6

1.500" .3415 stem diam 4.725 Over all length .270 Tip length (30° x 7/16" Back cuts or under head) .075 margin .090 valve seat width 20° Dish 98 grams


1.710 .3415 stem diam 4.730 Over all length .270 Tip length (Pro Flo: 12° x 3/8" Back cuts or under head) .065 margin .080 Valve seat width 7° Dish 95 grams

What’s this mean you loose .010 on the intake not as important as getting rid of the exhaust which you will gain .080 and still leave .070 between valve margins.

Also the intake I should point out is a pro flo so that means the stem diam is reduced coming out of the valve guide increasing flow.

The last is you may have to change out retainers but who gives a crap about that.

These are Manley Valves and should work. From all my calcs yes the exhaust is a .010 shorter but you know what the seat lock is moved up so there isn't any problem with coil bind and would be good to the same valve lifts if not more than the stockers...

I hope this benefits you guys as I know it will me.

[SappySE107]

You can use the 1.8/1.52 3800 valves. You need to cut the seats for the new size though or its a waste of time. You can fit a 1.84/1.42 combination as well though you will need a new intake seat.

[ignoreance]

In the Iron heads ? Also I was reading back through some of the other posts about heads and about a month ago he talks about it but doesn't say want the specs are her is the link to that post

http://60degreev6.com/showthread.php?t=34932

Looking at the iron head even if you cut in a new valve seat you will be laping the margin close and cause stress cracking between the valves. the valves aren't splayed like the Alum. I have seen it before max you usally want to push seat margins on iron heads max of .050 for street duty. Everybody has there tolerances and what there willing to work with is it true you could probably even use the 1.775 buick valve face but leaves .0375 assuming every cylinder head and seat is exactly the same in every combustion chamber and usally there is casting/machine differences of at least .002 in every cylinder hell i get +/- .005 on the valve measures I pulled from each chamber.

Cutting a new valve seat would improve the seating and reduce cracking but not quite in my streetable zone for daily duty besides there. is always more to gain by porting exhaust than intake. Show me how many motors will out flow on the exhaust side of the heads or at least match them on the intake?

[SappySE107]

Oops, sorry. Not used to iron head stuff:P Different valve stem diameters so they aren't compatible.

[Guest]

I am guessing this post was meant for the aluminum heads.

My freind Jon talked with a GM engineer who worked on some prototype stuff back in the day. I guess a janitor brought him a set of V6 60 degree iron heads with 2.02 valves for the intake. I guess it was on a test engine, and then ended up being thrown in the dumpster out back. I guess that was GMs practice back in the 80s instead of crushing things.

Last I heard, the heads were still under the guys desk at GM.