I would like facts about head comparisons and your opinions about them. With everything being equal as to factory stock, and no work (porting etc...) what are the better heads and why, 441, 882, double hump...etc??? I know I'm missing a bunch of casting numbers or nick name heads but if somebody could fill me in on some that I'm missing and compare them as to why they are better (your opinion or facts). Is it chamber size, flow quantity, specific angle, valve size, over all weight........what makes one casting number better than others? Which ones are better for street/pure stock, sportsman, and/or modified? I appreciate any help.
facts and opinions wanted
- Thread starter reigne927
- Start date
smaldirt28
Well-Known Member
The best casting numbers for cars that can run a closed chambered head are 461 or 462 heads. There are also a few more castings that are closed chambered heads. These heads are 64cc combustion chamber (stock). It will increase naturally if they have been milled or surfaced quite a few times. Where as a 882 head isn't a closed chambered head and is 76cc combustion chamber. I think there is also a 497 angle plug head that has a stock casting with casting numbers. Came from GM with a special package i think on the old corvettes. The "double hump" heads are the ones you want though if you can run a 64cc or less head. The 461, 462, and 497 are all double humps. Like i said there are also a few more but i don't know them off the top of my head. All the heads though weight about the same. Now when you go to say Dart heads they are quite a bit heavier than stock heads. Hope all this helps clear up some of your questions.
Tom
Tom
Chevy head flow numbers
This is just a opionion.....I'll start at the top and go down(stock), The Vortec flows 218 cfm In. and 150 Ex., until the vortec the "Turbo" 292 head was top dog(I dont have flow numbers for it handy) it was a chevy replacement for the 492's. The 292 "Turbo" and the 034 "Bowtie" head were both offered thru GM but were never factory installed on a vehicle. The 492 "Double hump" cylinder head was originally installed on special high-performance small-blocks such as the 302ci Z-28 and 350ci LT-1 is best at 210 in. and 145 ex. (186 was a 70' LT1 )The "Fulie" heads have ruled for years.....I don't have on hand the flow numbers for the 461,462 and etc double humps but I believe they all flow close to each other, But the 492 is still above them. Even though they do bump up compression because of the smaller chamber there down fall to me is there prone to cracking between the valves.
If a open chamber head is going to be used (unshrouds the valves)the more common are the 441,487 and 993 they all flow around 203 in. and 142 ex., alot of people drop on a set of 305 to bump up compression but they sacrifice flow doing it, the 450,601 and 416 heads all flow around 165 in. and 115
There are alot of variables to which head will perform the best for a given situation and there are alot of heads that chevy produced that can be used, these are only a few I have on hand at the present time. Other people on here may be able to offer you some better head casting numbers, just trying to help out.
If I were to build one myself I would search for a set of 492's if I were using the standard intake or the preferrd Vortec if your track rules allowes them.(special intake and machine work required) this is my opionion
This is just a opionion.....I'll start at the top and go down(stock), The Vortec flows 218 cfm In. and 150 Ex., until the vortec the "Turbo" 292 head was top dog(I dont have flow numbers for it handy) it was a chevy replacement for the 492's. The 292 "Turbo" and the 034 "Bowtie" head were both offered thru GM but were never factory installed on a vehicle. The 492 "Double hump" cylinder head was originally installed on special high-performance small-blocks such as the 302ci Z-28 and 350ci LT-1 is best at 210 in. and 145 ex. (186 was a 70' LT1 )The "Fulie" heads have ruled for years.....I don't have on hand the flow numbers for the 461,462 and etc double humps but I believe they all flow close to each other, But the 492 is still above them. Even though they do bump up compression because of the smaller chamber there down fall to me is there prone to cracking between the valves.
If a open chamber head is going to be used (unshrouds the valves)the more common are the 441,487 and 993 they all flow around 203 in. and 142 ex., alot of people drop on a set of 305 to bump up compression but they sacrifice flow doing it, the 450,601 and 416 heads all flow around 165 in. and 115
There are alot of variables to which head will perform the best for a given situation and there are alot of heads that chevy produced that can be used, these are only a few I have on hand at the present time. Other people on here may be able to offer you some better head casting numbers, just trying to help out.
If I were to build one myself I would search for a set of 492's if I were using the standard intake or the preferrd Vortec if your track rules allowes them.(special intake and machine work required) this is my opionion
racin90
Well-Known Member
Thanks for adding that fourbar..about the special intake part..i have seen people...way too many..try to make the old style manifolds work on the vortec heads...and..it wont. And every 492's ive seen..are cracked. Best to go with the vortec's if rules allow them. Great post too!!
Is there a real noticable difference between straight plug or angle plug heads?
I've heard there is a power difference depending on where the intake and exaust valves are located (left or right) in the combustion chamber. How does this make a difference. what is the better combination, and why?
If a stock rocker arm is 1.5 and you exchange it for a 1.6??? how much lift does this actually make and does it increase the amount of flow into the combustion chamber?
Does anybody know what the flow amount increase is of a valve from 2.02 to say 2.03 and how exactly is it measured? (the opening of the port or the physical valve size itself?
Why are some valves better than others?
What is a "normal" valve cut and how is it different than a 3 angle valve cut? Why is a 3 cut better?
I am aware of this stuff, I just don't know what or why certain things are better than others that seem like such a small or insignificant change.
I appreciate any help and thank you to you guys who responded earlier to this thread.
I've heard there is a power difference depending on where the intake and exaust valves are located (left or right) in the combustion chamber. How does this make a difference. what is the better combination, and why?
If a stock rocker arm is 1.5 and you exchange it for a 1.6??? how much lift does this actually make and does it increase the amount of flow into the combustion chamber?
Does anybody know what the flow amount increase is of a valve from 2.02 to say 2.03 and how exactly is it measured? (the opening of the port or the physical valve size itself?
Why are some valves better than others?
What is a "normal" valve cut and how is it different than a 3 angle valve cut? Why is a 3 cut better?
I am aware of this stuff, I just don't know what or why certain things are better than others that seem like such a small or insignificant change.
I appreciate any help and thank you to you guys who responded earlier to this thread.
smaldirt28
Well-Known Member
I've heard there is a power difference depending on where the intake and exaust valves are located (left or right) in the combustion chamber. How does this make a difference. what is the better combination, and why?
Does anybody know what the flow amount increase is of a valve from 2.02 to say 2.03 and how exactly is it measured? (the opening of the port or the physical valve size itself?
The intake and exhaust valves can't be swapped around. So what you see with valve locations in the heads is what you get.
About valve sizes too. I have never heard of a 2.03 valve. The valve sizes as i know of only go from 1.94-2.02-2.05 and on and on. No 2.03 though. And i think the valve size if measured from the actual physical size of the valve itself. Not positive but that is what i would assume since valve seets wear etc.
Hope this answers at least a couple of your questions.
Tom
Does anybody know what the flow amount increase is of a valve from 2.02 to say 2.03 and how exactly is it measured? (the opening of the port or the physical valve size itself?
The intake and exhaust valves can't be swapped around. So what you see with valve locations in the heads is what you get.
About valve sizes too. I have never heard of a 2.03 valve. The valve sizes as i know of only go from 1.94-2.02-2.05 and on and on. No 2.03 though. And i think the valve size if measured from the actual physical size of the valve itself. Not positive but that is what i would assume since valve seets wear etc.
Hope this answers at least a couple of your questions.
Tom
Sorry, I worded the valve size question poorly. I tried to ask about how much flow increase there is for each .01 (hundredths of a size increase) Since there is no 2.03 I guess I have to ask about flow increase from 2.02 to 2.05.
Also, I was on JE Piston site and there are diagrams showing pistons with larger (intake) and smaller (exhaust) valve reliefs in different combinations (left/right right/left etc...) which showed the difference between a SBC and SB2 etc... I was just wondering why or how the difference in the SB2 combination produces more power just from changing the position of the valve?
Also, I was on JE Piston site and there are diagrams showing pistons with larger (intake) and smaller (exhaust) valve reliefs in different combinations (left/right right/left etc...) which showed the difference between a SBC and SB2 etc... I was just wondering why or how the difference in the SB2 combination produces more power just from changing the position of the valve?
I don't know if anybody else can see my previous post but I can not for some reason and it's happened to me a few times, I also can't see/read some other peoples posts, so I'm posting the same thing again.
Sorry, I worded the question of the valve size/flow increase poorly. I was trying to ask about flow increase of each .01 (hundredths). Since there is no 2.03 valve size, what is the flow increase from 2.02 to 2.05?
Also, I was on the JE Piston site and there are diagrams of the difference in valve locations of a SBC and SB2. I was just wondering why or how the difference of valve location or combination can produce more power?
Sorry, I worded the question of the valve size/flow increase poorly. I was trying to ask about flow increase of each .01 (hundredths). Since there is no 2.03 valve size, what is the flow increase from 2.02 to 2.05?
Also, I was on the JE Piston site and there are diagrams of the difference in valve locations of a SBC and SB2. I was just wondering why or how the difference of valve location or combination can produce more power?
I have to agree with Mod15. The Vortec is the better way to go.. If you are limited to older heads, the 487 flows best of the stock production heads. The 492/292's are replacements and were not released on stock vehicles. therefore they may not be allowed in your rules if they state STOCK production head.
