closed chamber vs open chamber

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txstang84 said:
I think I recall that experiment--wasn't the goal to get a hp/ci out of a stock bottom end?
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This was for an open house so the public could see what we were doing here in our shop. Fed everybody hot dogs, hamburgers, chips and pop. They got to watch each change and guess the resulting torque and horsepower. We then awarded small prizes or cash to each person that got the closest to the correct horsepower or torque after each change. We made 8 or 9 changes that day including a cam change. The cylinder head swap was the final change.
 
AJ/FormS said:
so then, to what do you attribute the nice performance increase? Strictly the port work?
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Mostly the work we did to the heads. The compression increase may have given us 4 hp of the total.
 
A ported 516 against a stock 906, naturally I would expect a modified head to beat a stock one. Always like reading IQ52's posts, intetesting stuff.
 
IQ52 said:
This was for an open house so the public could see what we were doing here in our shop. Fed everybody hot dogs, hamburgers, chips and pop. They got to watch each change and guess the resulting torque and horsepower. We then awarded small prizes or cash to each person that got the closest to the correct horsepower or torque after each change. We made 8 or 9 changes that day including a cam change. The cylinder head swap was the final change.
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Almost sounds like an episode of Engine Masters w/Brule, Dulcich, and Freiburger...
 
txstang84 said:
Almost sounds like an episode of Engine Masters w/Brule, Dulcich, and Freiburger...
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Years ago you should have seen the look on Brule's face when were running a 906 headed 383 at 480 HP on Westech's dyno and he was saying, "Why in the world are you only running at 8:1 compression with this engine?" He was just shaking his head in disbelief as we explained we pulled a 383 from a demolition derby car and slapped a cam and some ported heads on the short block and put it on the dyno.

Oh yeah, eventually that same 383 setup made 525 hp when we did some other tuning on it at a dyno in Idaho Falls, ID. Years later we bought the same dyno from Westech that the 383 ran on the day that Brule thought we were nuts. I guess maybe we were!
 
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Open ----closed is referring to the combustion chamber of the head. Closed is smaller and a heart shaped(small combustion chamber, the open has the fill circle of the combustion chamber easily seen (bore of the piston in most cases). Nothing to do with intake......
By the way 516's as on the 67 383's are closed but use small valves, the 915 have large valves from stock and closed chamber. 516's are ok if you open up to bigger valves....more $$$$ is all.
 
MOPAROFFICIAL said:
The 516 without a good amount of work would come up short against the 906,
You made the right decision in my opinion.
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My question from post 44. Still unanswered.

What kinda "work" would you recommend to better the 516.......considering that might be the only head someone has?
 
RustyRatRod said:
My question from post 44. Still unanswered.

What kinda "work" would you recommend to better the 516.......considering that might be the only head someone has?
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I realize that this isn't an option for you Rob, but, Dad said the easiest way to get something done is to have someone else do it. So, the "work" that should be done?..........Box 'em and ship 'em!
 
IQ52 said:
I realize that this isn't an option for you Rob, but, Dad said the easiest way to get something done is to have someone else do it. So, the "work" that should be done?..........Box 'em and ship 'em!
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If everything pans out, I may have some 4V Cleveland heads for you to work on.
 
RustyRatRod said:
If everything pans out, I may have some 4V Cleveland heads for you to work on.
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Yeah love to do that for you. Have a friend standing here that says he has a set of 4V heads he'd love sell you so you can save the shipping here.
 
IQ52 said:
Yeah love to do that for you. Have a friend standing here that says he has a set of 4V heads he'd love sell you so you can save the shipping here.
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If they are closed chamber and in good condition, I may be interested. Like they always say, ya got pitchers? lol
 
RustyRatRod said:
My question from post 44. Still unanswered.

What kinda "work" would you recommend to better the 516.......considering that might be the only head someone has?
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RustyRatRod said:
My question from post 44. Still unanswered.

What kinda "work" would you recommend to better the 516.......considering that might be the only head someone has?
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For instance if you want 275+ cfm w/2.08 out of ANY of them , you have to lay that short turn WAY back, further than the entry level guy would feel comfortable with. Another int port like that is the slant six, a lot of guys don't know what to do with those to get in the 190's w/1.70 even.
Work the 516 ex to the larger valve with seats, open bowls and blend to runner size, straight up from the seat on the exh short side and just roll the top to the floor where it straightens. I bet thats clear as a bell, right? Would have to show you.
 
MOPAROFFICIAL said:
For instance if you want 275+ cfm w/2.08 out of ANY of them , you have to lay that short turn WAY back, further than the entry level guy would feel comfortable with. Another int port like that is the slant six, a lot of guys don't know what to do with those to get in the 190's w/1.70 even.
Work the 516 ex to the larger valve with seats, open bowls and blend to runner size, straight up from the seat on the exh short side and just roll the top to the floor where it straightens. I bet thats clear as a bell, right? Would have to show you.
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Actually yes, that does clear it up quite. I'm not as think as you stupid I am. About a lot of things.
 
My 2cents.
906 best bet. Ported better. Big cam running above 5000 rpm
On street. Can't beat it. But better have compression.
 
RustyRatRod said:
If they are closed chamber and in good condition, I may be interested. Like they always say, ya got pitchers? lol
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These be them. Are they is, or is they ain't?

Ford Cleveland heads 001.jpg
Ford Cleveland heads 002.jpg
 
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