2.00” or 2.02” intake valve in a 351w D0OE head?

[steve cowan]

Throat size…something I completely overlooked

Throats are 1.80”-1.84”, which with the current 1.94” valves gives 92.7-94.8%. A 2.00” valve after equalizing all the throats at 1.84” gives 92%…a 2.02 gives 91%. A 2” valve is going to be super tight though, putting the edge of the valve right against the chamber wall, and starts to get into the 18mm spark plug trough.

My wife likes to quote Frozen in these situations. Let it go, let it go…

They are door stops now in my opinion,
Larger throat 90% plus as an example can be used with steeper angles and is dependent upon application,
I don't think those heads qualify

[PRH]

For what it seems like the OP is usually doing with these milder builds, where he’s wanting distinctly more low end grunt......... I’d suggest warming up to the idea of aftermarket heads(like an E Street) and 4” stroke cranks(SBF).

Fairly mild 400” small blocks will get close to that 480-500ft/lb range(1.2-1.25 ft/lb per ci) without going nuts at all.
Some thought needs to go into the package, but nothing exotic needs to be used.

[Walter R. Malik]

I recently saw an ad for a "lot" of complete pairs of new cast iron M2 marine "2 bar" heads, stainless valves with Ford Racing springs and retainers, for only $300.00 for a pair. I think it was Facebook Marketplace.
Those have GT40 intake ports with early production exhaust ports which have the big thermactor boss; easily removed with minor porting.

I'll hunt for the ad and phone number if you are really interested.

[travis]

I recently saw an ad for a "lot" of complete pairs of new cast iron M2 marine "2 bar" heads, stainless valves with Ford Racing springs and retainers, for only $300.00 for a pair. I think it was Facebook Marketplace.
Those have GT40 intake ports with early production exhaust ports which have the big thermactor boss; easily removed with minor porting.

I'll hunt for the ad and phone number if you are really interested.

I appreciate it Walter, but can’t do it now. If they are available a little later I’ll definitely be interested

[mag2555]

Ok, here’s what a 1,96” valve looks like in a E7TZ head which is all I have SB wise on hand, and it does not have the big old plug, but if it did it still looks like it would work with a tad of grinding on the plug boss.

In them shot of the very ruffed in valve job the seat OD is at 1.940”

[travis]

I hauled the D0OE’s and some junk E7TE’s to the scrap metal yard this morning. It sucked throwing all that porting time away, but I learned a lot from hacking on them. One big thing I learned is cast iron SUCKS

Mag, have you flow tested those with the 1.96” valve? I’m down to 1 good set of E7TE’s on a running engine and 1 set of ported E5AE’s that I need to get resurfaced again. This damn Texas heat and humidity causes everything to rust

[mag2555]

No, I have not flow tested it because that was just a ruffed in valve job, but for you I will finish that work tomorrow and post the results for you in the evening.

Yes, fully and maxing out what you can do on some cast iron heads by hand totals up to 55 hours or more with the flow testing involved easy, and I still have very strong hands and can grind fast.

Yup even after fully painting up the heads on all surfaces with cast blast even while just while porting them I bag them up every time to keep the rust at bay!

[MadBill]

Ok, here’s what a 1,96” valve looks like in a E7TZ head which is all I have SB wise on hand...

If the gasket diameter is anywhere near the same as the bore dia., there looks to be significant room to 'sweep out' the chamber where it encroaches on the valve. I don't know if bore notching, a la some BBCs, is a viable option.

[Carnut1]

I hauled the D0OE’s and some junk E7TE’s to the scrap metal yard this morning. It sucked throwing all that porting time away, but I learned a lot from hacking on them. One big thing I learned is cast iron SUCKS

Mag, have you flow tested those with the 1.96” valve? I’m down to 1 good set of E7TE’s on a running engine and 1 set of ported E5AE’s that I need to get resurfaced again. This damn Texas heat and humidity causes everything to rust

E7TE's done well with 1.94" go about 220 cfm

[mag2555]

Travis here’s the results of getting that 1.96” in the E7TZ head.

Note that this 1.96” Pontiac valve is a 30 degree seat.

Here’s the details before I post the flow test numbers.

Valve seat OD 1.950”.

30 degree seat width .045”.

45 degree 1st bottom cut .050. Deep.

60 degree bottom cut .308” deep.

Throat diameter at bottom of 60 1.554”.

30 width on valve .158”.

The only other work I did was to take 2 minutes to Boat tail the valve guide somewhat.

The flow numbers will be listed as stock, then with 1.96” and then flow gain.

Flow @ 28”
.100” 52. , 65. , +13

.200”. ,95 , 122.8, +27.8

.300”. 132. , 157, +25

.400”. 143 , 162 , +19

.500”. 159 , 167 , +8

[Walter R. Malik]

Travis here’s the results of getting that 1.96” in the E7TZ head.

Note that this 1.96” Pontiac valve is a 30 degree seat.

Here’s the details before I post the flow test numbers.

Valve seat OD 1.950”.

30 degree seat width .045”.

45 degree 1st bottom cut .050. Deep.

60 degree bottom cut .308” deep.

Throat diameter at bottom of 60 1.554”.

30 width on valve .158”.

The only other work I did was to take 2 minutes to Boat tail the valve guide somewhat.

The flow numbers will be listed as stock, then with 1.96” and then flow gain.

Flow @ 28”
.100” 52. , 65. , +13

.200”. ,95 , 122.8, +27.8

.300”. 132. , 157, +25

.400”. 143 , 162 , +19

.500”. 159 , 167 , +8

When I have done this, I slightly ground the valve to a .060" wide, 37.5 degree seat; like the IHC has.
Very similar results.

[travis]

I hauled the D0OE’s and some junk E7TE’s to the scrap metal yard this morning. It sucked throwing all that porting time away, but I learned a lot from hacking on them. One big thing I learned is cast iron SUCKS

Mag, have you flow tested those with the 1.96” valve? I’m down to 1 good set of E7TE’s on a running engine and 1 set of ported E5AE’s that I need to get resurfaced again. This damn Texas heat and humidity causes everything to rust

E7TE's done well with 1.94" go about 220 cfm

My concern with going that far would be life expectancy. I think the short turn is pretty thin in places…I’m not sure about anywhere else

[travis]

Travis here’s the results of getting that 1.96” in the E7TZ head.

Note that this 1.96” Pontiac valve is a 30 degree seat.

Here’s the details before I post the flow test numbers.

Valve seat OD 1.950”.

30 degree seat width .045”.

45 degree 1st bottom cut .050. Deep.

60 degree bottom cut .308” deep.

Throat diameter at bottom of 60 1.554”.

30 width on valve .158”.

The only other work I did was to take 2 minutes to Boat tail the valve guide somewhat.

The flow numbers will be listed as stock, then with 1.96” and then flow gain.

Flow @ 28”
.100” 52. , 65. , +13

.200”. ,95 , 122.8, +27.8

.300”. 132. , 157, +25

.400”. 143 , 162 , +19

.500”. 159 , 167 , +8

Did you blend that step in the bowl, or leave it as cut?

[PRH]

I’m thinking that on a SBF for a warmed over pick-up truck or DD/mild hot street car, a set of heads that had 1.9-ish intake valves that flowed in the 190-200 range by .500 lift would be more than sufficient to feed a combo that offered a significant seat-of-the-pants improvement over the stock power plant.

The overall combination, along with getting the carb tune and ignition curve dialed in are going to be at least as important(if not moreso) as an additional 15-20cfm out of the heads.
Proper gearing and converter selection will also play a big role here.

If the heads you’re contemplating using will require “a lot” of porting to approach the 190-200 by .500 mark......... I’d probably try and find better heads to start with.

I’ll admit, my personal experience in porting of OE SBF heads is very limited, especially in the last 15 years or so....... so maybe my expectations are wrong about what is or isn’t realistic about what can be easily achieved out of the OE castings.

[mag2555]

Travis, like I posted no blend work was done, it was flow tested like you see in my photo with just the partial valve guide rework.