DJOHAGIN
02-19-2006, 01:02 PM
Foreword
This information is compiled from the old forum and the new one. The various posts and quotes are from different members and edited. This information is mostly for individuals seeking to install C-Heads on a 4.44” bore. Please let me know of any further information on this and/or errors. If you see your post, thank you for the excellent information.
Fitment of C-Heads
I'm wondering if when you mocked up the engine, did you put the heads on the 4.44 bore and see if the chambers were slightly wider or greater than your bore diameter. Did you put the heads on an empty block and look up the cylinder from underneath and check the fit of the chamber to the bore?
I did mock it up before hand and the chamber is slightly larger on the front and rear sides of the cylinder. I did have to run a 4.670 cosmetic head gasket to get the head to seal to the block properly, the Felpro 1018 with the 4.500 bore left the stainless compression ring inside the chamber at the places mentioned above. I really did not look hard at this until I went to put the engine together after the heads were cc’ed. Apparently they got opened up a little more than the first mockup.
You have to deal with the some issues. They are not a bolt on and go cylinder head.
Ford advises that the heads be used on 4.550" bores in their paperwork and you can see why they have to do that from their position. They have to assume most guys are just going to slap them on the engine and not take the time to mock-up and deal with the head gasket issues and chamber overhang.
On a 4.440 bore the exhaust valve is very close to the cylinder wall with an 800 lift camshaft and a 1.800 ex valve the side clearance is only .028!!! I don't know if an offset dowel would help any or not as it seems that there is no limit on the intake valve size just by glancing at it. The exhaust valve placement is the limiting factor as far as I can see on the 4.440 bore.
1.80 exhaust valve is maximum on a 4.440 bore and limit the exhaust lift to .775.
Special note: earlier versions of the C-460 had the valves spread .030. These would not be a good choice on a 4.440 bore unless you use a 1.75 exhaust valve diameter.
Valve Angles (New)
The valves in a C-460 head do not have any cant angle, like the factory stock heads from Ford did. Therefore in regards to notching the cylinder wall, as the C-460 exhaust valve opens and makes it's way towards full lift, it doesn't get any better. By that I mean the valve doesn't move away from the cylinder wall. If you notched the cylinder wall, it would have to extend down the wall, the full lift of the cam.
Additional machining required (New)
Spark plug holes have to be chased with a tap.
The 7/16" rocker arm subplate bolt holes all need to be tapped deeper. The holes are drilled deep enough, but they aren't tapped deep enough. They need a bottoming tap used on them.
The push rods rub the head. Charlie Evans (a member on this board) has a push rod program in order to grind intake pushrod clearance with his cnc porting service as an option because of that particular problem.
Another thing is that valve lengths can be all over the map due to core shift and machining shift. If you're shooting for a 2.100" installed height, generally 6.425" to 6.450" works for the intakes and 6.325 to 6.350" works for the exhausts. With W.W. Engineering rockers this will result in pushrod length being right around 10.100" + or - a little.
If you use all 18 bolts of the 18 head bolt pattern, I carry in stock the extra eight 7/16" bolts/studs that you need. Call Charlie @ (270)685-4654 if you want some. Make sure to use anti-seize on the inner four bolts/studs that screw into the alum. head in the lifter valley or they will lock up.
If you need thicker head gaskets and want Cometics or copper Hussey head gaskets, just e-mail Lem at; lem.evans@bfevansford.com
or call the guys in the parts department (270)278-2376 and they'll get them on the way.
Clearance of bore and exhaust, their effect on exhaust flow
Running a C-Head on a 4.440" bore, doesn’t that effect the exhaust flow in a negative way being that close too the cylinder wall?? Seems to me you would not get optimum flow out of it??
I guess it would but, my car goes 9.63 @ 141, weighing in at 3895lbs. The motor is 557 cubic inches and have not worked the bugs out of it yet.
The exhaust flow would suffer some. The real question though, is how much exhaust flow is "good enough" in order to get the job done? He has answered by giving his E.T. and mph and they are good, so obviously he believes the 1.800" valve is getting the job done. I think Kaase or somebody actually said you want the exhaust valve as close as possible to the cylinder wall, especially if it means you can move the intake valve further away from the wall.
Part of what makes the things work is that the exhaust valve is moved toward the cylinder wall to allow better position and size for the intake valves. One can make the valves smaller to fit lesser bores with a loss of flow/performance. Some of which may be a decent trade off in a smaller engine. At some point the ID of the seat will get too big for the small head exhaust valve, requiring seat removal and welding.
I am speaking in general terms.
The usual exhaust valve diameter is 1.900” when the heads were designed. Ford FRPP & Ferrea has them on the shelf as a catalog item in that size. I generally use a 1.900 or a 1.880 in those heads when I do them. What he has done is run a smaller than normal exhaust valve in the head because he's using a 4.440" bore. No problem. What head porters have learned in the past few years is that we can sacrifice exhaust flow in order to get better intake flow and these engines will still run damn good. This is sort of like the Ford Kaase SCJ heads in that the E/I ratio is not a theoretical ideal 70%, but more like 60%, but the engines still run better than expected, so much for theory.
Do you have any exhaust flow numbers that you would be willing to share?
I can't find my flow sheet, but they were 274 @.700 lift with a 1.75 stainless and 45 deg seats. I know that doesn’t sound too impressive, but this 514 went 8.30 in a door car @ 2650 lbs.seems to be running pretty well. It runs on a 4.440 bore with 2.40” intake valves.
With the 1.75 valve, did you have to install a smaller ID seat to make that work?
No, I used original seats, they just hang on, it isn't awesome visually, but it works very well.
Smaller exhaust and larger intake valves
Have you tried a smaller exh. valve say 1.800 and a bigger intake 2.500 or 2.550 to help the intake side out to get it to the 530 ish cfm range? I know these heads have a strong exh port, 380+ cfm, with the 1.900 valve.
I like the 2.450" intake valve. I think the size can get too big in a hurry given the rpm range the powerglide sportsman engines live in.
In regards to using a 2.500" intake valve in c-460 heads. The seats interlock anyway and the actual 45* seat surface of the intake valve is over on the exhaust seat, so, we'd have to be pulling and welding seats up and cutting new ones. That's a lot of trouble.
Cross-section sizing, port volumes, and flow quality
Is the port cross-section of the C-Head the same size/smaller/larger than CJ heads?
The intake port cross sectional area of a C-460 head is bigger.
Do the cross-section sizes dictate the torque peak and hp rpms?
The C-460 heads have a pretty big port cross sectional area out of the box, but then so does the cast iron Cobra-Jet head. Where do most people measure this cross-section? Some measure it at the port entry, but that's not where the smallest constriction is. Generally speaking it is either at the push-rod pinch or farther down the port at the crest of the floor.
Courtesy of ScottJ
The measurements are of the minimum height and width of the respective intake ports. This represents the choke point in the port.
CASTING-----------------------------------Width---Height
Iron CJ and P.I.-------------------------- 1.75" x 1.93"
395 cfm AR 1st gen aluminum CJ----- 1.84" x 1.74"
Stock D0VE------------------------------- 1.66" x 1.80"
365 cfm D0VE---------------------------- 1.74" x 1.85"
380 cfm D0VE---------------------------- 1.79" x 1.87"
Fuelie E7TE------------------------------- 1.75" x 1.52"
Stock D3VE------------------------------- 1.70" x 1.80"
If the choke points are close in size (AR aluminum CJ) and (365 cfm Dove) is the AR head flowing 30 cfm more because of the quality of the flow or because of the size of the port before the choke point?
The A-429 alum, probably has a 2.250" intake valve. Whereas the DOVE head probably has a 2.200" intake valve. IF there is a difference in valve diameter, that would account for some of the 30 cfm difference but certainly not all of it. More like 10-14 cfm.
What represents the better quality of flow? According to the Performance Professor Jim McFarland, the better quality is something that we should all strive for and is represented by a finer atomization of the fuel droplets and a more homogenous mixture throughout the chamber. No wet spots or puddling.
Courtesy of Charlie Evans
45 degree seats---2.45 intake and 1.9 exhaust valve---4.625 cylinder sleeve size---no exhaust test tube
C-heads out of the box
200 - 159/111 69%
300 - 227/150 66%
400 - 285/183 64%
500 - 327/201 61%
600 - 351/214 60%
700 - 367/221 60%
750 - 380/224 58%
800 - 380/225 59%
Bowl blend
200 - 154/111 72%
300 - 230/166 72%
400 - 306/217 70%
500 - 380/260 68%
600 - 425/270 63%
700 - 427/293 68%
750 - 418/299 71%
With out of the box performance, flow at .650 would only be around 359 cfm and with a bowl clean-up, 426 cfm. That is a 67 cfm improvement.
Did the cfm improvement come from enlarging the bowl's volume, or just knocking off the flash?
The C-460 head generally has a lot of core shift from the factory. There is always a pretty major mismatch between the casting and the seat insert. So there is more than "just a little" bowl blending to do. More than tootsie roll work. These heads are not for beginners. Once you get the head straightened out like what it is supposed to be, then the flow numbers really jump up and that's where your 67 cfm comes from.
Doesn't the length of the port effect port volume?
Example: The new SCJ exhaust ports are longer than the previous CJ heads. So, if both have the exact same cross-section from the exhaust flange to valve seat, the SCJ will measure more CCs.
The port volume data would be relative to only other heads in the same family. The length enters in to the equation. For example;
Port volume of a CJ style head would be relative to all other CJ heads, with the exception of the SCJ head, because Jon pulled the valve seat up in the cylinder. Likewise the port volume of all 3 of the A-460 heads would be relative only to each other, but not to CJ's or DOVEs because they have a raised port entry and require a different intake manifold completely.
If you were to make the cross-section the same in the intake port of a SCJ head and a C-Head, would both heads show the same flow, even though the C-Head has a better angle to the bowl? And again, if you did this, wouldn't the C-Head show more volume in the intake port because it is longer?
If the minimum cross sectional area of a SCJ head and a C-460 were exactly the same, the C-460 head can be expected to flow more air due to its port being raised. Airflow does NOT like tight/small turn radiuses, therefore the higher port C-460 head will flow better.
If you draw the same volume of air (cfm) through a smaller cross section port the air will be moving faster. Air speed = low end torque.
Generally that would be the case to a large degree, but cam and manifolding plays their part also.
You stated that the intake port cross sectional area of a C-460 head is bigger than any cast iron head, so low and mid-range torque would be hurt a lot on a 460 cubic inch engine. Kind of like the street Boss 429? Is this correct, or does the port shape help to overcome this?
It's possible that the head may be too big for a 460 CID engine, and that the ports may be lazy unless you really twist the engine tight. I don't think it would make a responsive street head. In that respect it would be like the Boss 429 you mentioned. Still, on the other hand, it should do better than the Boss 429 because of the better port design. The port entry is raised much higher than the Boss 429. This entry is generally measured by the height of the port's floor above the deck surface, or relative to the deck surface. The original Boss 429 head's port floor was about 5/8" above the deck surface and the C-460's port floor is about 2" above the deck surface. So you can see it's a raised port. As better heads are developed, you're always going to see the ports being raised higher and higher. Thus the overall height of the head becomes taller and taller.
Single plane manifold
Has anybody ever flow a single dominator manifold for c-460 heads? I was wondering if it keeps up with the port in the heads or is it a restriction.
The manifold hurts flow 30 cfm @ .800" lift and 8 cfm @ .300" lift.
How much did the heads flow that the manifold was bolted to?
Intakes, average of all 8 ports at 28" H2O on a 4.600" bore are;
.200=157
.300=238
.400=316
.500=384
.600=431
.700=464
.800=478
.850=480.
Just wondering how restrictive the casting was, it looks to me like it would be good.
I don't feel that the intake port sees the manifold runner as much of a restriction, if any, on the "C" package. Getting the air turned into the runner entry may be the real issue. When a 1050 carburetor with bigger throttle bores was installed, the end cylinders really liked it over the stock 1050. If there was enough time, a multitude of spacer types and bigger carbs available (1150/1250) I think the flow #'s would have looked better. All of this is moot unless there is another single plane one carb manifold to compare to. Who knows what is really going on in side a running engine at WOT with the pulsing and the introduction of the heavy fluid (gas) into the mix. With its equal length runners and above the runner venturi position it's easy to see why a tunnel ram does what it does. I just did not want anyone to mistake that speck of flow data that I posted, as wisdom.
Tunnel ram (New)
Has anyone run a tunnel ram to see how much more power can be made over a single dominator?
I talked to kaase about that hp wise. They said you would be looking a 60 to 80 hp over a single four.
What kind of issues am i going to deal with in changing from the single 4bbl manifold to Charlie Evan's adapter and the A460 tunnel ram?
There aren't any "issues" except for the deck height of YOUR block, and that holds true in regards to the proper fitment of any intake manifold. With block deck heights ranging from 10.28" to 10.32" and all points in between, it effects the proper fit of any intake manifold in regards to how high or low it sets and the proper alignment with the port.
The adaptors thick enough to fit a new SVO block with the 10.32" deck height. If your block is very much shorter, then you may need to either mill the intake surface of the heads, or mill the intake surface of your manifold, or thin the adaptor plates by milling them. That's the three options.
Also want to issue a caution that not all distributors will clear. Some will and some won't. The stock 429-460 Ford Duraspark with small cap clears just fine. Other than that, you are on your own.
Charles Hamiton is a BB Ford racer in Baltimore MD that is using a set of A-460 to C-460 adaptors. His engine builder Mark McKeown and him made a 1070 Hp with his engine and the TFS A-460 tunnel ram on C-460 heads. Mark used an MSD crank trigger and the low profile "big cap" distributor and he did have to do a good bit of machining on the thermo housing of the TFS manifold in order for the MSD low profile distributor to clear.
Cost of C-Heads to other heads
In regards to using the C-460 heads for the benefit of the shaft mounted rocker arms and stable valve train. Remember that shaft mounted rockers are available for CJ heads and A-460 heads also. It's just that most people don't use them due to the cost factor.
Flat-Tappet, C-Head, 4.40" Bore Engine
To partially answer your question about lower rpm performance from a C-460 motor, here are the dyno results for our C-460 engine when it had an Ultradyne flat tappet cam, 4.4 bore, 4.2 stroke, 11:1 CR, 1X4bbl, almost no head work. These numbers came with 110 octane and 36 degrees total advance, we were able to run it on 92 with either 32 or 34 degrees (can't remember). Unfortunately, I do not have the data from 92 octane test (this was several years ago). I think all we did was check to see if it was feasible. We typically ran this motor with a 50/50 mix of 92 and 110. Cam specs (same for both intake and exhaust): 0.663" lift with 1.8 rockers, 259 duration @ 0.050, 292 duration @ 0.020, 112 lobe separation.
RPM HP Tq.
4500 580.9 678
4600 593.4 677.5
4700 610.5 682.2
4800 627 686
4900 640.1 686.1
5000 664.6 698.1
5100 676.9 697.1
5200 688.9 695.8
5300 704.6 698.2
5400 714.5 694.9
5500 727.5 694.7
5600 739.7 693.7
5700 753.2 694
5800 754.2 682.9
5900 758.3 675
6000 762 667
6100 766.1 659.6
6200 770.4 652.6
6300 785.3 654.7
6400 796.2 653.4
6500 797.2 644.1
6600 Peak 802.5 638.6
Can you give some more details on that build?
The numbers came from the dyno at Huffaker Engineering. I never raced it with 92 octane, just did a dyno test. It was a stock block and it had cracked cylinders by the end of each year I ran it. We also had symptoms of valve float on the cylinder walls. We probably ran it for too long on a set of valve springs. I was using the engine for road racing. It might have gone for quite a long time in a street/strip application.
I'm not sure how much more detail I can muster. I wish I could remember exactly how big the valves were. It had aluminum rods, I think it was an LA Crank, it had a wet sump, C-460 manifold, and 4-into-1 headers.
Part of the reason for using C heads in the stock block, flat tappet application was upgrade potential. Harold's view was that a relatively unimproved C head was still quite good compared to other alternatives and that while expensive, the valve train would support endurance needs.
Having implemented some of the upgrade potential, such as port optimization, a roller cam, a bit more compression (now 12.6:1), a 4.56" bore (different block) and a 4.25" stroke, the engine now makes over 950hp through the mufflers at a still reasonable/sustainable 6,700 rpm.
What size are the valves in the 4.560" bore?
I believe they are 2.44/1.87
Performance of C-Heads from 2 members
First let me explain my reasoning for using the C heads on the 557. They have pretty decent numbers right out of the box. They take a little work but what doesn't? I was looking more at a head that would work decent but still let me use it on a bigger cubic inch motor at a later date, kind of an investment so to speak. Small chambers and shaft rockers in which also was factored in for future use. It was a little pricy but now I have them.
The heads are bowl blended, short turn worked a little on the intake side, and I matched the entry to the gasket for about 1 1/2" in, catridged rolled the entire port and removed very little casting flash to make them appear symmetrical to the eye. Exhaust side has a bowl blend and cartridge roll finish all the way out.
Heads were put on a flow bench at Kuntz & Co. This is where the valves were installed and the valve job was performed. They did no port work at all with the exception of cc-ing the chamber and blending the seat to the chamber.
Flow numbers as follows;
Intake: 2.400 dia. @ 28" water
.300 - 245.85
.400 - 323.18
.500 - 383.52
.600 - 422.86
.650 - 440.00
.700 - 451.35
.800 - 468.78
Exhaust: 1.800 dia. @ 28" water
.300 - 161.35
.400 - 194.00
.500 - 229.75
.600 - 290.05
.650 - 298.98
.700 - 309.63
.800 - 318.19
If they are flowed by Jim Kuntz, you can be sure the info is accurate. Based on my testing of the C-460 heads and comparing flow numbers, I believe your info is accurate. These are good flow numbers relative to your application on the 557 CID engine. I suspect that the most important thing you did on the intake side was to lay back the short side radius some. Out of the box these heads tend to stall around .600" -.700" lift with just a bowl blend.
They are on a 557 with a single four intake and a 1250 dominator, flat top pistons, light tension rings with a vacuum pump, 6.800 steel rods and a billet 4.500 crank. Roller cam with a 114 lobe separation and 278* / 292* @ .050 with a lift in the upper .700 lift bracket. Home built step headers 33" long, 2" - 2 1/8" - 2 1/4" into a 4" collector with an X pipe and mufflers that are also 4". This is in a 65 Galaxie that weighs 3895lbs with me in it. I run a C-4 with a 10" converter, 4.86 gears, and 31 X 10.5W slicks. Car has gone some 9.63's @ 141 with the 1250 on it. 60's in the 1.35 to 1.36 range off the footbrake.
I don't think he has any more work in putting his C-heads on his 557 then I had putting SCJ heads on my 512 as far as machine work and little nuances. If I had a ‘65 Galaxie with the engine bay he has, I'd have C-heads. Their physical size (both width and height) is large by extra large. I think his results in his heavy car speak volumes on what these heads are capable of on a relatively low-rpm/high torque engine.
Something I think that helps too are these cylinder heads are sufficient as well as efficient. Meaning they are big enough to get the job done but also are a proven power maker on just about anything even without a lot of work done to them.
I have learned a lot from this forum. If I would have gone with the A-head and had them cnc programmed I feel that I would have had a head comparable to what I have now but minus the titanium valves and shaft rocker system. Price wise I actually did better considering I have an upgradeable baseline C head right now. I wanted a car that would turn heads and run a good number yet still retain all its glass and interior. I have done what everyone else still thinks is impossible.
This information is compiled from the old forum and the new one. The various posts and quotes are from different members and edited. This information is mostly for individuals seeking to install C-Heads on a 4.44” bore. Please let me know of any further information on this and/or errors. If you see your post, thank you for the excellent information.
Fitment of C-Heads
I'm wondering if when you mocked up the engine, did you put the heads on the 4.44 bore and see if the chambers were slightly wider or greater than your bore diameter. Did you put the heads on an empty block and look up the cylinder from underneath and check the fit of the chamber to the bore?
I did mock it up before hand and the chamber is slightly larger on the front and rear sides of the cylinder. I did have to run a 4.670 cosmetic head gasket to get the head to seal to the block properly, the Felpro 1018 with the 4.500 bore left the stainless compression ring inside the chamber at the places mentioned above. I really did not look hard at this until I went to put the engine together after the heads were cc’ed. Apparently they got opened up a little more than the first mockup.
You have to deal with the some issues. They are not a bolt on and go cylinder head.
Ford advises that the heads be used on 4.550" bores in their paperwork and you can see why they have to do that from their position. They have to assume most guys are just going to slap them on the engine and not take the time to mock-up and deal with the head gasket issues and chamber overhang.
On a 4.440 bore the exhaust valve is very close to the cylinder wall with an 800 lift camshaft and a 1.800 ex valve the side clearance is only .028!!! I don't know if an offset dowel would help any or not as it seems that there is no limit on the intake valve size just by glancing at it. The exhaust valve placement is the limiting factor as far as I can see on the 4.440 bore.
1.80 exhaust valve is maximum on a 4.440 bore and limit the exhaust lift to .775.
Special note: earlier versions of the C-460 had the valves spread .030. These would not be a good choice on a 4.440 bore unless you use a 1.75 exhaust valve diameter.
Valve Angles (New)
The valves in a C-460 head do not have any cant angle, like the factory stock heads from Ford did. Therefore in regards to notching the cylinder wall, as the C-460 exhaust valve opens and makes it's way towards full lift, it doesn't get any better. By that I mean the valve doesn't move away from the cylinder wall. If you notched the cylinder wall, it would have to extend down the wall, the full lift of the cam.
Additional machining required (New)
Spark plug holes have to be chased with a tap.
The 7/16" rocker arm subplate bolt holes all need to be tapped deeper. The holes are drilled deep enough, but they aren't tapped deep enough. They need a bottoming tap used on them.
The push rods rub the head. Charlie Evans (a member on this board) has a push rod program in order to grind intake pushrod clearance with his cnc porting service as an option because of that particular problem.
Another thing is that valve lengths can be all over the map due to core shift and machining shift. If you're shooting for a 2.100" installed height, generally 6.425" to 6.450" works for the intakes and 6.325 to 6.350" works for the exhausts. With W.W. Engineering rockers this will result in pushrod length being right around 10.100" + or - a little.
If you use all 18 bolts of the 18 head bolt pattern, I carry in stock the extra eight 7/16" bolts/studs that you need. Call Charlie @ (270)685-4654 if you want some. Make sure to use anti-seize on the inner four bolts/studs that screw into the alum. head in the lifter valley or they will lock up.
If you need thicker head gaskets and want Cometics or copper Hussey head gaskets, just e-mail Lem at; lem.evans@bfevansford.com
or call the guys in the parts department (270)278-2376 and they'll get them on the way.
Clearance of bore and exhaust, their effect on exhaust flow
Running a C-Head on a 4.440" bore, doesn’t that effect the exhaust flow in a negative way being that close too the cylinder wall?? Seems to me you would not get optimum flow out of it??
I guess it would but, my car goes 9.63 @ 141, weighing in at 3895lbs. The motor is 557 cubic inches and have not worked the bugs out of it yet.
The exhaust flow would suffer some. The real question though, is how much exhaust flow is "good enough" in order to get the job done? He has answered by giving his E.T. and mph and they are good, so obviously he believes the 1.800" valve is getting the job done. I think Kaase or somebody actually said you want the exhaust valve as close as possible to the cylinder wall, especially if it means you can move the intake valve further away from the wall.
Part of what makes the things work is that the exhaust valve is moved toward the cylinder wall to allow better position and size for the intake valves. One can make the valves smaller to fit lesser bores with a loss of flow/performance. Some of which may be a decent trade off in a smaller engine. At some point the ID of the seat will get too big for the small head exhaust valve, requiring seat removal and welding.
I am speaking in general terms.
The usual exhaust valve diameter is 1.900” when the heads were designed. Ford FRPP & Ferrea has them on the shelf as a catalog item in that size. I generally use a 1.900 or a 1.880 in those heads when I do them. What he has done is run a smaller than normal exhaust valve in the head because he's using a 4.440" bore. No problem. What head porters have learned in the past few years is that we can sacrifice exhaust flow in order to get better intake flow and these engines will still run damn good. This is sort of like the Ford Kaase SCJ heads in that the E/I ratio is not a theoretical ideal 70%, but more like 60%, but the engines still run better than expected, so much for theory.
Do you have any exhaust flow numbers that you would be willing to share?
I can't find my flow sheet, but they were 274 @.700 lift with a 1.75 stainless and 45 deg seats. I know that doesn’t sound too impressive, but this 514 went 8.30 in a door car @ 2650 lbs.seems to be running pretty well. It runs on a 4.440 bore with 2.40” intake valves.
With the 1.75 valve, did you have to install a smaller ID seat to make that work?
No, I used original seats, they just hang on, it isn't awesome visually, but it works very well.
Smaller exhaust and larger intake valves
Have you tried a smaller exh. valve say 1.800 and a bigger intake 2.500 or 2.550 to help the intake side out to get it to the 530 ish cfm range? I know these heads have a strong exh port, 380+ cfm, with the 1.900 valve.
I like the 2.450" intake valve. I think the size can get too big in a hurry given the rpm range the powerglide sportsman engines live in.
In regards to using a 2.500" intake valve in c-460 heads. The seats interlock anyway and the actual 45* seat surface of the intake valve is over on the exhaust seat, so, we'd have to be pulling and welding seats up and cutting new ones. That's a lot of trouble.
Cross-section sizing, port volumes, and flow quality
Is the port cross-section of the C-Head the same size/smaller/larger than CJ heads?
The intake port cross sectional area of a C-460 head is bigger.
Do the cross-section sizes dictate the torque peak and hp rpms?
The C-460 heads have a pretty big port cross sectional area out of the box, but then so does the cast iron Cobra-Jet head. Where do most people measure this cross-section? Some measure it at the port entry, but that's not where the smallest constriction is. Generally speaking it is either at the push-rod pinch or farther down the port at the crest of the floor.
Courtesy of ScottJ
The measurements are of the minimum height and width of the respective intake ports. This represents the choke point in the port.
CASTING-----------------------------------Width---Height
Iron CJ and P.I.-------------------------- 1.75" x 1.93"
395 cfm AR 1st gen aluminum CJ----- 1.84" x 1.74"
Stock D0VE------------------------------- 1.66" x 1.80"
365 cfm D0VE---------------------------- 1.74" x 1.85"
380 cfm D0VE---------------------------- 1.79" x 1.87"
Fuelie E7TE------------------------------- 1.75" x 1.52"
Stock D3VE------------------------------- 1.70" x 1.80"
If the choke points are close in size (AR aluminum CJ) and (365 cfm Dove) is the AR head flowing 30 cfm more because of the quality of the flow or because of the size of the port before the choke point?
The A-429 alum, probably has a 2.250" intake valve. Whereas the DOVE head probably has a 2.200" intake valve. IF there is a difference in valve diameter, that would account for some of the 30 cfm difference but certainly not all of it. More like 10-14 cfm.
What represents the better quality of flow? According to the Performance Professor Jim McFarland, the better quality is something that we should all strive for and is represented by a finer atomization of the fuel droplets and a more homogenous mixture throughout the chamber. No wet spots or puddling.
Courtesy of Charlie Evans
45 degree seats---2.45 intake and 1.9 exhaust valve---4.625 cylinder sleeve size---no exhaust test tube
C-heads out of the box
200 - 159/111 69%
300 - 227/150 66%
400 - 285/183 64%
500 - 327/201 61%
600 - 351/214 60%
700 - 367/221 60%
750 - 380/224 58%
800 - 380/225 59%
Bowl blend
200 - 154/111 72%
300 - 230/166 72%
400 - 306/217 70%
500 - 380/260 68%
600 - 425/270 63%
700 - 427/293 68%
750 - 418/299 71%
With out of the box performance, flow at .650 would only be around 359 cfm and with a bowl clean-up, 426 cfm. That is a 67 cfm improvement.
Did the cfm improvement come from enlarging the bowl's volume, or just knocking off the flash?
The C-460 head generally has a lot of core shift from the factory. There is always a pretty major mismatch between the casting and the seat insert. So there is more than "just a little" bowl blending to do. More than tootsie roll work. These heads are not for beginners. Once you get the head straightened out like what it is supposed to be, then the flow numbers really jump up and that's where your 67 cfm comes from.
Doesn't the length of the port effect port volume?
Example: The new SCJ exhaust ports are longer than the previous CJ heads. So, if both have the exact same cross-section from the exhaust flange to valve seat, the SCJ will measure more CCs.
The port volume data would be relative to only other heads in the same family. The length enters in to the equation. For example;
Port volume of a CJ style head would be relative to all other CJ heads, with the exception of the SCJ head, because Jon pulled the valve seat up in the cylinder. Likewise the port volume of all 3 of the A-460 heads would be relative only to each other, but not to CJ's or DOVEs because they have a raised port entry and require a different intake manifold completely.
If you were to make the cross-section the same in the intake port of a SCJ head and a C-Head, would both heads show the same flow, even though the C-Head has a better angle to the bowl? And again, if you did this, wouldn't the C-Head show more volume in the intake port because it is longer?
If the minimum cross sectional area of a SCJ head and a C-460 were exactly the same, the C-460 head can be expected to flow more air due to its port being raised. Airflow does NOT like tight/small turn radiuses, therefore the higher port C-460 head will flow better.
If you draw the same volume of air (cfm) through a smaller cross section port the air will be moving faster. Air speed = low end torque.
Generally that would be the case to a large degree, but cam and manifolding plays their part also.
You stated that the intake port cross sectional area of a C-460 head is bigger than any cast iron head, so low and mid-range torque would be hurt a lot on a 460 cubic inch engine. Kind of like the street Boss 429? Is this correct, or does the port shape help to overcome this?
It's possible that the head may be too big for a 460 CID engine, and that the ports may be lazy unless you really twist the engine tight. I don't think it would make a responsive street head. In that respect it would be like the Boss 429 you mentioned. Still, on the other hand, it should do better than the Boss 429 because of the better port design. The port entry is raised much higher than the Boss 429. This entry is generally measured by the height of the port's floor above the deck surface, or relative to the deck surface. The original Boss 429 head's port floor was about 5/8" above the deck surface and the C-460's port floor is about 2" above the deck surface. So you can see it's a raised port. As better heads are developed, you're always going to see the ports being raised higher and higher. Thus the overall height of the head becomes taller and taller.
Single plane manifold
Has anybody ever flow a single dominator manifold for c-460 heads? I was wondering if it keeps up with the port in the heads or is it a restriction.
The manifold hurts flow 30 cfm @ .800" lift and 8 cfm @ .300" lift.
How much did the heads flow that the manifold was bolted to?
Intakes, average of all 8 ports at 28" H2O on a 4.600" bore are;
.200=157
.300=238
.400=316
.500=384
.600=431
.700=464
.800=478
.850=480.
Just wondering how restrictive the casting was, it looks to me like it would be good.
I don't feel that the intake port sees the manifold runner as much of a restriction, if any, on the "C" package. Getting the air turned into the runner entry may be the real issue. When a 1050 carburetor with bigger throttle bores was installed, the end cylinders really liked it over the stock 1050. If there was enough time, a multitude of spacer types and bigger carbs available (1150/1250) I think the flow #'s would have looked better. All of this is moot unless there is another single plane one carb manifold to compare to. Who knows what is really going on in side a running engine at WOT with the pulsing and the introduction of the heavy fluid (gas) into the mix. With its equal length runners and above the runner venturi position it's easy to see why a tunnel ram does what it does. I just did not want anyone to mistake that speck of flow data that I posted, as wisdom.
Tunnel ram (New)
Has anyone run a tunnel ram to see how much more power can be made over a single dominator?
I talked to kaase about that hp wise. They said you would be looking a 60 to 80 hp over a single four.
What kind of issues am i going to deal with in changing from the single 4bbl manifold to Charlie Evan's adapter and the A460 tunnel ram?
There aren't any "issues" except for the deck height of YOUR block, and that holds true in regards to the proper fitment of any intake manifold. With block deck heights ranging from 10.28" to 10.32" and all points in between, it effects the proper fit of any intake manifold in regards to how high or low it sets and the proper alignment with the port.
The adaptors thick enough to fit a new SVO block with the 10.32" deck height. If your block is very much shorter, then you may need to either mill the intake surface of the heads, or mill the intake surface of your manifold, or thin the adaptor plates by milling them. That's the three options.
Also want to issue a caution that not all distributors will clear. Some will and some won't. The stock 429-460 Ford Duraspark with small cap clears just fine. Other than that, you are on your own.
Charles Hamiton is a BB Ford racer in Baltimore MD that is using a set of A-460 to C-460 adaptors. His engine builder Mark McKeown and him made a 1070 Hp with his engine and the TFS A-460 tunnel ram on C-460 heads. Mark used an MSD crank trigger and the low profile "big cap" distributor and he did have to do a good bit of machining on the thermo housing of the TFS manifold in order for the MSD low profile distributor to clear.
Cost of C-Heads to other heads
In regards to using the C-460 heads for the benefit of the shaft mounted rocker arms and stable valve train. Remember that shaft mounted rockers are available for CJ heads and A-460 heads also. It's just that most people don't use them due to the cost factor.
Flat-Tappet, C-Head, 4.40" Bore Engine
To partially answer your question about lower rpm performance from a C-460 motor, here are the dyno results for our C-460 engine when it had an Ultradyne flat tappet cam, 4.4 bore, 4.2 stroke, 11:1 CR, 1X4bbl, almost no head work. These numbers came with 110 octane and 36 degrees total advance, we were able to run it on 92 with either 32 or 34 degrees (can't remember). Unfortunately, I do not have the data from 92 octane test (this was several years ago). I think all we did was check to see if it was feasible. We typically ran this motor with a 50/50 mix of 92 and 110. Cam specs (same for both intake and exhaust): 0.663" lift with 1.8 rockers, 259 duration @ 0.050, 292 duration @ 0.020, 112 lobe separation.
RPM HP Tq.
4500 580.9 678
4600 593.4 677.5
4700 610.5 682.2
4800 627 686
4900 640.1 686.1
5000 664.6 698.1
5100 676.9 697.1
5200 688.9 695.8
5300 704.6 698.2
5400 714.5 694.9
5500 727.5 694.7
5600 739.7 693.7
5700 753.2 694
5800 754.2 682.9
5900 758.3 675
6000 762 667
6100 766.1 659.6
6200 770.4 652.6
6300 785.3 654.7
6400 796.2 653.4
6500 797.2 644.1
6600 Peak 802.5 638.6
Can you give some more details on that build?
The numbers came from the dyno at Huffaker Engineering. I never raced it with 92 octane, just did a dyno test. It was a stock block and it had cracked cylinders by the end of each year I ran it. We also had symptoms of valve float on the cylinder walls. We probably ran it for too long on a set of valve springs. I was using the engine for road racing. It might have gone for quite a long time in a street/strip application.
I'm not sure how much more detail I can muster. I wish I could remember exactly how big the valves were. It had aluminum rods, I think it was an LA Crank, it had a wet sump, C-460 manifold, and 4-into-1 headers.
Part of the reason for using C heads in the stock block, flat tappet application was upgrade potential. Harold's view was that a relatively unimproved C head was still quite good compared to other alternatives and that while expensive, the valve train would support endurance needs.
Having implemented some of the upgrade potential, such as port optimization, a roller cam, a bit more compression (now 12.6:1), a 4.56" bore (different block) and a 4.25" stroke, the engine now makes over 950hp through the mufflers at a still reasonable/sustainable 6,700 rpm.
What size are the valves in the 4.560" bore?
I believe they are 2.44/1.87
Performance of C-Heads from 2 members
First let me explain my reasoning for using the C heads on the 557. They have pretty decent numbers right out of the box. They take a little work but what doesn't? I was looking more at a head that would work decent but still let me use it on a bigger cubic inch motor at a later date, kind of an investment so to speak. Small chambers and shaft rockers in which also was factored in for future use. It was a little pricy but now I have them.
The heads are bowl blended, short turn worked a little on the intake side, and I matched the entry to the gasket for about 1 1/2" in, catridged rolled the entire port and removed very little casting flash to make them appear symmetrical to the eye. Exhaust side has a bowl blend and cartridge roll finish all the way out.
Heads were put on a flow bench at Kuntz & Co. This is where the valves were installed and the valve job was performed. They did no port work at all with the exception of cc-ing the chamber and blending the seat to the chamber.
Flow numbers as follows;
Intake: 2.400 dia. @ 28" water
.300 - 245.85
.400 - 323.18
.500 - 383.52
.600 - 422.86
.650 - 440.00
.700 - 451.35
.800 - 468.78
Exhaust: 1.800 dia. @ 28" water
.300 - 161.35
.400 - 194.00
.500 - 229.75
.600 - 290.05
.650 - 298.98
.700 - 309.63
.800 - 318.19
If they are flowed by Jim Kuntz, you can be sure the info is accurate. Based on my testing of the C-460 heads and comparing flow numbers, I believe your info is accurate. These are good flow numbers relative to your application on the 557 CID engine. I suspect that the most important thing you did on the intake side was to lay back the short side radius some. Out of the box these heads tend to stall around .600" -.700" lift with just a bowl blend.
They are on a 557 with a single four intake and a 1250 dominator, flat top pistons, light tension rings with a vacuum pump, 6.800 steel rods and a billet 4.500 crank. Roller cam with a 114 lobe separation and 278* / 292* @ .050 with a lift in the upper .700 lift bracket. Home built step headers 33" long, 2" - 2 1/8" - 2 1/4" into a 4" collector with an X pipe and mufflers that are also 4". This is in a 65 Galaxie that weighs 3895lbs with me in it. I run a C-4 with a 10" converter, 4.86 gears, and 31 X 10.5W slicks. Car has gone some 9.63's @ 141 with the 1250 on it. 60's in the 1.35 to 1.36 range off the footbrake.
I don't think he has any more work in putting his C-heads on his 557 then I had putting SCJ heads on my 512 as far as machine work and little nuances. If I had a ‘65 Galaxie with the engine bay he has, I'd have C-heads. Their physical size (both width and height) is large by extra large. I think his results in his heavy car speak volumes on what these heads are capable of on a relatively low-rpm/high torque engine.
Something I think that helps too are these cylinder heads are sufficient as well as efficient. Meaning they are big enough to get the job done but also are a proven power maker on just about anything even without a lot of work done to them.
I have learned a lot from this forum. If I would have gone with the A-head and had them cnc programmed I feel that I would have had a head comparable to what I have now but minus the titanium valves and shaft rocker system. Price wise I actually did better considering I have an upgradeable baseline C head right now. I wanted a car that would turn heads and run a good number yet still retain all its glass and interior. I have done what everyone else still thinks is impossible.