-206 BBC large oval closed chamber heads

[pdq67]

What can these heads be made to flow?

pdq67

[bigjoe1]

Not as good as an AFR 300 CC oval port




JOE SHERMAN RACING

[pdq67]

Joe,

Sure, they don't flow all that good but that's not the point. But you are right..

I am thinking 454 work truck heads here is all. Their small 96.7 to 98 cc chambers should help increase the low CR of most 454 PU engines so should really help, "Bobby Farm-Boy", make more power.

Aren't these engines around 7.9 to 1 CR so if we get them up to like 9 to 1 or so great? And I have a pair of old -206's..

pdq67

[mag2555]

Intake flow wise the can top 300 cfm when ported and not fail a port wall in actual usage , that can make over 700 hp with enough Cam and Comp!
How much power are you in search of?

[HDBD]

When faced with a similar situation on my 94 dually I used 366 truck heads and blocked the rotators plus installed bigger valves. It worked very well.

[Alan Roehrich]

They'll flow enough to make a good running budget 454, or even 496, up to about 6,000. If you can do the head work yourself. I use them for those.

The problem is that on a 454, it has to have zero deck, and the heads still need 0.030" milled off of them to make enough compression with a flat top.

On a 496, you need a fairly big camshaft, into the 240 degree at 0.050" area for decent power and RPM from a budget street engine.

[Bob Hollinshead]

Alan, do you put 2.19/1.88 valves in them? Can you get near 10-1 compression with a zero decked flat top 454? My kid is picking up a 396 and thinking about using the heads on a 454 based build-I am thinking they are probably a closed chamber large oval but not sure what casting yet. What are the best large oval closed chamber castings to look for?

[pdq67]

Probably the old -215's.

But they are not true closed chambered heads because they have the sparkplug quench laid back stock.

Racer1320, (aka, Ed Bigley), used them and although way reworked they were dandy heads..

pdq67

[Alan Roehrich]

Alan, do you put 2.19/1.88 valves in them? Can you get near 10-1 compression with a zero decked flat top 454? My kid is picking up a 396 and thinking about using the heads on a 454 based build-I am thinking they are probably a closed chamber large oval but not sure what casting yet. What are the best large oval closed chamber castings to look for?

We have put the 1.88 valves in them. But honestly, the 1.725 valve flows plenty, remember a 427/425 Stock Eliminator engine has the same valve and makes 650HP with that valve and 0.520" lift.

You can get close to 9.6:1, at zero deck, 0.060" over, with a 0.042" gasket and a 4.44" bore diameter.

[Morgan85]

Has anyone flow tested a set of 206s?