SBC 23 degree, for all it's faults.

[Tom68]

Seems that fuellie heads are laughed at by some/many now.

23 degree valve angle necessitates a deep chamber that makes comp' harder to achieve.
It runs the airflow into the cylinder wall.
The resultant chamber needs a fair bit of timing to establish combustion.

OK, they're some of the bad points.

23 degree valve angle allows for a narrow V8 engine, great for replacing side valve Fords in narrow engine bays back in the day.
It allows for a low intake port, low downdraught carb height (gets you under a 1970's bonnet).
Raising the roof (ala Vortec) gets you past the pushrod pinch with better flow.

Roll it over (ala 18 degree) and you get a better attack at the cylinder end and an improved combustion chamber but you have to raise the port to get port flow.

Was the 23 degree head a pretty bloody good 50's 60's 70's and even 80's compromise for sub 350 ci engines ? History says it was.

And you gotta love the results people are getting now on big inch motors, probably not many doing it with a 70's low profile, but big numbers.

[Walter R. Malik]

Seems that fuellie heads are laughed at by some/many now.

23 degree valve angle necessitates a deep chamber that makes comp' harder to achieve.
It runs the airflow into the cylinder wall.
The resultant chamber needs a fair bit of timing to establish combustion.

OK, they're some of the bad points.

23 degree valve angle allows for a narrow V8 engine, great for replacing side valve Fords in narrow engine bays back in the day.
It allows for a low intake port, low downdraught carb height (gets you under a 1970's bonnet).
Raising the roof (ala Vortec) gets you past the pushrod pinch with better flow.

Roll it over (ala 18 degree) and you get a better attack at the cylinder end and an improved combustion chamber but you have to raise the port to get port flow.

Was the 23 degree head a pretty bloody good 50's 60's 70's and even 80's compromise for sub 350 ci engines ? History says it was.

And you gotta love the results people are getting now on big inch motors, probably not many doing it with a 70's low profile, but big numbers.

I have been really surprised that the 23 degree "Raised Runner" heads did not become more popular.
Just after the time they got really noticed, the 18 degree head came into being.

[Elroy]

Seems that fuellie heads are laughed at by some/many now.

23 degree valve angle necessitates a deep chamber that makes comp' harder to achieve.
It runs the airflow into the cylinder wall.
The resultant chamber needs a fair bit of timing to establish combustion.

OK, they're some of the bad points.

23 degree valve angle allows for a narrow V8 engine, great for replacing side valve Fords in narrow engine bays back in the day.
It allows for a low intake port, low downdraught carb height (gets you under a 1970's bonnet).
Raising the roof (ala Vortec) gets you past the pushrod pinch with better flow.

Roll it over (ala 18 degree) and you get a better attack at the cylinder end and an improved combustion chamber but you have to raise the port to get port flow.

Was the 23 degree head a pretty bloody good 50's 60's 70's and even 80's compromise for sub 350 ci engines ? History says it was.

And you gotta love the results people are getting now on big inch motors, probably not many doing it with a 70's low profile, but big numbers.

I have been really surprised that the 23 degree "Raised Runner" heads did not become more popular.
Just after the time they got really noticed, the 18 degree head came into being.

They were always just way too pricey for any purpose besides getting around class rules.

[mag2555]

Tom, you missed one very very important point here on your bad list of the 23 degree design.

That is further away the valve inclination angle is from being perpendicular to the piston top the smaller the valves will need to be.

That’s a real big power limiting factor!

[Walter R. Malik]

I have been really surprised that the 23 degree "Raised Runner" heads did not become more popular.
Just after the time they got really noticed, the 18 degree head came into being.

They were always just way too pricey for any purpose besides getting around class rules.

I think you were mis-informed, then. They certainly cost more than the cast iron offerings.
In aluminum ... A Brodix -11 was MORE money than the Raised Runner 10x ...

NOW, the Chevrolet 18 degree LOW PORT was a way to skirt rules and it was only offered for a few years.

[1980RS]

Seems that fuellie heads are laughed at by some/many now.

23 degree valve angle necessitates a deep chamber that makes comp' harder to achieve.
It runs the airflow into the cylinder wall.
The resultant chamber needs a fair bit of timing to establish combustion.

OK, they're some of the bad points.

23 degree valve angle allows for a narrow V8 engine, great for replacing side valve Fords in narrow engine bays back in the day.
It allows for a low intake port, low downdraught carb height (gets you under a 1970's bonnet).
Raising the roof (ala Vortec) gets you past the pushrod pinch with better flow.

Roll it over (ala 18 degree) and you get a better attack at the cylinder end and an improved combustion chamber but you have to raise the port to get port flow.

Was the 23 degree head a pretty bloody good 50's 60's 70's and even 80's compromise for sub 350 ci engines ? History says it was.

And you gotta love the results people are getting now on big inch motors, probably not many doing it with a 70's low profile, but big numbers.

I don't laugh at fuelly heads at all, they were good in their day, but the Vortec heads that came along in the mid-90's just showed how much better the 23 degree head could be. Gm should have kept the 16 degree valve angle the 348/409 engines had and made the pistons wright for those angle heads.

[Tom68]

That's appropriate.

327.jpg

[mag2555]

The problem with Chevies W motor heads is the big lack of pressure recovery due to having no chamber but for a small amount of time when the pistion is near TDC.

[Elroy]

I think you were mis-informed, then. They certainly cost more than the cast iron offerings.
In aluminum ... A Brodix -11 was MORE money than the Raised Runner 10x ...

Yeah i wasn't aware of that. I was thinking a long the lines of the Allpro, and even the old AFR raised runner, very pricey.