I run 4v open chamber heads on my 410 stroker. If I 'gave up' on these heads and wanted to run run aftermarket...is there actually anything in the market that I could simply bolt on? aka...has similar combustion chamber size/valve setup, would work with my Strip Dommy intake and my 4v headers and actually has better flow (no edlebrocks please)? I have just under 11:1 compression now so I don't think I can really up the compression any with a smaller chamber. I am 'evaluating' other alternatives to get more power out of my motor.

Nick
http://www.dodgestang.com>

IIRC CHI has an option for factory closed chambers

what size headers ?

It currently peaks at 7100 RPM with Fordpowertrain headers (they are swap headers for the installation of the 351c in a 65 mustang). 410 cubes.

Nick
http://www.dodgestang.com

you can pull em !

Nick if you want to KEEP and use your strip dominator intake , your 4v headers and use similar valve sizes as your current head look into the Chi- 4v - 228 heads. these heads are a direct bolt on using standard head bolts or studs and std headers bolt up to the exhaust and come with the current cnc'd chi chamber shape and flow figures which should improve your performance.

I will look into them because this is all installed in a 65 mustang that still has the stock shock towers I have to be careful with aftermarket heads because quite frankly if they reposition the header AT ALL it won't fint anymore....the question remains though of if they have a similar CC combustion chamber to keep compression relatively static but since it sounds like the rest is close enough to be a bolt on I at least have a product and I can ask the manu about

Nick
http://www.dodgestang.com>

Nick there seems to be a mixing of cylinder heads in some of these posts as the Chi 3v heads are mentioned which have raised intake and exhaust ports - not strip dominator or possible std. header compatible.the Chi 4v 228 heads have a std. 68cc chamber but can be ordered with a cnc profiled 4v chamber (74 cc's) shape very similar to the closed chamber heads. go to Chi's website and all the info is there on this head configuration.

http://www.chiheads.com/3v_225cc.php

so you can stick w stock slugs .It also says that a cnc chamber is standard no additional charge ?

at 7100 you'll be into sonic choke with a 2.4 head ,668fps theoretical . did you want to lower the operating range ?

Sonic Slug?

I 'thought' that by changing the heads I would be able to create more power through out the operating band of the cam...meaning it will still peak around 7100 RPM (or possibly a little higher because of the improved flow) but it would also generate power a little quicker at a lower RPM again because of the improvement over the stock 4v.

This is all just in the thought stage right now. The next trip to the track will tell me if I hit my 11.9 goal or not and whether or not I need to consider some more changes to the combo.

Nick
http://www.dodgestang.com

Nick do not worry about not being able to turn the Chi heads at high rpms. I am using the CHI 218 head on a 436 inch motor. On the dyno it made peak power at 6800 so I figured a shift point of about 7100 for optimum performance. Man was I wrong. I run a glide in my car and shift at 7600 now out of low and cross the finish line at 7700. I kept moving the shift point up 100 rpms at a time until I just would not go up any more. I think it will go faster yet if I would turn it even more, but I am too chickensh*t to turn it any harder. I can not explain why it is this way, but it is. Theories, formulas, and dynos all have there place, but in the car going down the race track is the true test and these heads exceed what alot of people think they will do.

Just look at what John at Chi has done with an out of the box head in their car. His (Frank's) car at over 3500 lbs and leaf springs has been 9.70's at over 138 or 139. John from Chi and Mark from MME used to try and help people understand by answering questions on the internet, but so maney people kept bashing them that they have pretty much stayed away. It is a shame it came to that.

You might have some people start talking about CSA, MCSA, Sonic choke, and port velocity. This stuff is all over my head, I am just a Texas redneck who loves racing. From one racer to another these heads flat work, you just need to get with someone like John (CHI), Mark (MME), or Ty (TLI) and listen to them and follow their advice because they know how to make these heads work best.

Sorry for the long post, but this my personal, hands on, race with them every weekend experience. If you look around on this board you can find some other very good examples of how well these heads work.

Chris

Thanks Chris for having faith and running the engine. I know you were skeptical at first, but thats to be understood. Your car is running well, about as I expected and you are indeed still going to find more in it. Thanks for the kind words and not bashing the builder or parts supplier because your calculator or internet search engine did not agree with what you originally expected. There are still bashers out there, but its nice to see that someone who actually spent their hard earned money is satisfied. I nor anyone esle can satisfy, the keyboard or track grandstand experts.

Send us a pic of the car for our office wall to put with our other racers pics!, I'd love to have one.

Mark McKeown
McKeown Motorsport Engineering, Inc.
http://mmeracing.com

Yes Mark I am very please with the performance of the motor. It has performed flawlessly and been deadly consistent. It has won money at all but one race this year and is currently leading the points at my home track. This past weekend I went to a bigger money 1/8 mile race. I made 6 out of 8 passes in the right lane and the car only varied .007 at the 330 ft and the two passes that I went to the finish line under full power it went 6.2611 and 6.2614. Even a knucklehead like me can turn on win lights with consistentcy like that. LOL I know that there is more left in it, but I have put a larger tire on it now for the summer heat which has slowed it down a little now. Later this year once things start to cool off again I am going to be trying different fuels and gears to put the car into the 9.50's.

As soon as someone gets a good picture of the car this year I will get one up to you.

Chris

Joe. 2.4" is also the MCSA at our intake manifold face. It is the same on both our 4150 and 4500 manifolds.
Formulas are usually a good "indicator" or starting point when designing an engine, but are only as good as the information you input. No amount of formulas will ever replace practical first hand experience and R&D. Having said that even when we are done testing on the dyno we always validate it in our car.
We have a roller cam 429 pump gas engine that we have been doing R&D on here with our 225cc OOTB heads and our 4500 OOTB manifold. The heads are our 221424 roller cam package and they come with the intake opening on the heads, port matched. This makes the MCSA at the port entrance about 2.9" and the restriction then becomes the intake manifold face where the MCSA is 2.4".
With 2.4" MCSA at the manifold face this engine made 740hp at 7200-7300rpm depending on the dyno run. We just made a new larger runner system for our 4500 manifold that increased the MCSA to 2.9".
In our dyno testing the original smaller manifold kept with the new one to 6500rpm even though the new one has an extra .5" more area throughout the runner system. At 6500rpm the engine makes 725hp and the new larger manifold begins to carry the engine better from there on, for a 100-200rpm increase in rpm, and a net hp gain of 20hp over our original manifold.
In the car the original smaller manifold always runs faster when we turn it to 7800rpm. The car weighs 3500lbs and has run 9.72 at 139 Mph best.
We soon hope to be in the 9.60s at 140mph with the new manifold.
So as you can see a 408 will definately not be rpm limited as you have suggested.

All pro stock and NASCAR head designers are keenly aware of cross sectional areas throughout the intake tract . All O.E.M. designers account for these things and then subsequently develop them further to a number of ends one of which may be reducing noise , nonetheless, these things must be accounted for in some way , carefully recorded and analyzed if anyone expects to carry on with research and development .

If you have tuned the 408 so it will peak as late as 7800 rpm then how does this head work on 351's ? would not they have to be turned tighter to yield the same hp ? was it not the goal of the 3v head to reduce cross section to make them more broadly usable compared to the 4v on a typical ~6 liter build ?

Joe the 3V heads come in many port configurations, so to suggest that one head might do the same job on a variety of different engine combinations is not right.
Regardless you offered a formulae that is misleading, and further more, the thread as I read it was about our 4V 228cc heads, which have a far bigger MCSA anyway.

at 7100 rpm the 225 cc 2.4 min cross section head would realize a THEORETICAL 668 fps .

fps = .00353 X rpm X stroke X bore squared / cross section

668 = .00353 X 7100 X 4 X 4^2 / 2.4

This formula may not be perfect but it is in broad use and if you have some improvement upon it I would love to hear it.

The speed of sound in the temperature range an engine works at is commonly held to be ~1200 fps

It is also widely believed that the energy consumed in pulling a mass of air and fuel in excess of .55 mach is more than would be gained in possible volumetric efficiency improvements .

.55 X 1200 = 660

Do You have a problem with this formula ?

your quote-----
"Regardless you offered a formulae that is misleading,"

how are those formulas misleading ?

your quote-----
"and further more, the thread as I read it was about our 4V 228cc heads, which have a far bigger MCSA anyway. "

When did you reach this conclusion ? it must have been after you posted this ..

"Joe. 2.4" is also the MCSA at our intake manifold face. It is the same on both our 4150 and 4500 manifolds.
Formulas are usually a good "indicator" or starting point when designing an engine, but are only as good as the information you input. No amount of formulas will ever replace practical first hand experience and R&D. Having said that even when we are done testing on the dyno we always validate it in our car.
We have a roller cam 429 pump gas engine that we have been doing R&D on here with our 225cc OOTB heads and our 4500 OOTB manifold. The heads are our 221424 roller cam package and they come with the intake opening on the heads, port matched. This makes the MCSA at the port entrance about 2.9" and the restriction then becomes the intake manifold face where the MCSA is 2.4".
With 2.4" MCSA at the manifold face this engine made 740hp at 7200-7300rpm depending on the dyno run. We just made a new larger runner system for our 4500 manifold that increased the MCSA to 2.9".
In our dyno testing the original smaller manifold kept with the new one to 6500rpm even though the new one has an extra .5" more area throughout the runner system. At 6500rpm the engine makes 725hp and the new larger manifold begins to carry the engine better from there on, for a 100-200rpm increase in rpm, and a net hp gain of 20hp over our original manifold.
In the car the original smaller manifold always runs faster when we turn it to 7800rpm. The car weighs 3500lbs and has run 9.72 at 139 Mph best.
We soon hope to be in the 9.60s at 140mph with the new manifold.
So as you can see a 408 will definately not be rpm limited as you have suggested"

You mention 2.4 and 225 a number of times in that post. You also state that that particular head is good out to 7800 on a 408 as I read it .

THAT seems misleading to me .I don't doubt you can turn one that tight , it is common practice to overrev in drag racing so you "fall back on the peak ".

why did this engine peak at 6800 ?


I can all but gaurantee you that most professional head porters would suggest something a little bigger and a little more ambitious if I called tham and told them I wanted to turn 7800 rpm with a 408 !

This is like da ja vu....
I will let you guys trash it out, I've had my "turn" in the past...there is more to it than meets the eye.

Joe you say your formulae is not perfect. If its not "perfect" then it can be misleading.

I spoke of the 225 head as an example, as it is the one that you applied your "formulae" to. I wanted to show you an example of what 2.4" MCSA can support in a real world situation, rather than just theoretically.

It still doesnt change the fact that the example you were trying to give someone did not apply to his particular cylinder head choice.

Nowhere did I mention that the 225 head is good to 7800 on a 408. This is what I said.
"In the car the original smaller manifold always runs faster when we turn it to 7800rpm."
This reffers to our 429 in our car. Nowhere did I mention 7800rpm in relation to a 408.


I have given you examples of what increasing MCSA did on our 429 so you can correlate the information with your formulae.

Dustins engine is low on static compression. Increasing it alone would allow his engine to rpm a little higher. The headers, cam etc need to be designed for higher rpm also. If you look closely, Dustins engine goes rich in the higher rpm. His BSFCs are alittle high as it climbs in rpm. Tuning that out may have also increased rpm peak. Regardless his combination is probably not suited to a far higher peak hp rpm anyway. So its not just the cylinder head that determines peak hp rpm.

You may be able to guarantee me that head porters would reccomend something larger. I can assure you there are those that wont also. And it can be done succesfully both ways.

Heres an example of a new engine we are doing and what the program Pipe Max reccomends for MCSA

We are building this new engine to test our C-400 Kaase heads.
The engine is a 3.750 stroke 4.155" bore 6.125" rod 13-1 roller cam deal.
We entered all the information into Pipe Max to give us an idea on what to do with headers.
Interestingly Pipe Max comes up with 2.461 sq.in as the Smallest useable Port CSA and 2.707 as the recomended Port CSA. Now thats for a peak hp rpm point of 8000 on a 408 with 110% volumetric efficiency.

I'm just interested in if there is a head out there that I can bolt in place of my stock 4v open chamber heads which are in the neighborhood of 73.9-76.9cc since I am already quite close to 11:1 and it is a street motor that has to run on 93 octane.

The other points of interest are the intake (want to use a non-chi intake and it appears that is covered) and the exhaust ports have to be in the exact stock location otherwise the motor will not longer fit in the car. It appears with cursory evaluation the 4v chi heads with the cnc option will be ok for the intake and the exhaust and close in terms of compression but for continued argument sake if my current heads cc out at 77cc and the new ones would be 74cc how much would that affect compression? It is a straight up factor meaning the percentage dif in CC is roughly the percentage dif in compression (so just under 5% change?)

The only other item of concern is the 'relocated spark plug' location. As expected changing plugs is already difficult in my car but I have worked out a way to do it without pulling the motor up...how is the spark plug relocated (up or down) in relation to the stock head configuration and has the angle of attack change (pivoted up or pivoted down?)





Nick
http://www.dodgestang.com>

Hi Nick
Your compression ratio is not a problem. This year we have a new feature that I havent yet posted on our website. All the chambers come to the shop semi finished and we CNC cut every one of them. This allows us to give you just about any chamber volume you need by moving the CNC program up and down in the cylinder head, without having to deck the head face at all. We can go from as small as low 50s to high 60s with the 3V Chamber and if you need something larger we can go as big as high 70s with the 4V chamber.
The spark plugs have been moved down towards the centre of the chamber. The original spark plug sits higher, or closer to the head face.
If you need any further information feel free to email me at sales@chiheads.com.

I 'assume' your system picked up nick at dodgestang dot com and dumped it into a spam folder somewhere.

Nick
http://www.dodgestang.com

the formula I'm using is in there, I believe .

What larry meaux said is he has seen engines operate higher than sonic choke and they did OK .

These were probably not any ports based on oem castings .

It might be that Dustin's motor peaked where it did because the port velocity was ~640fps.

In any case if you are using Meaux's software and Kaase's input in developing these C-400 heads you could really have a winner ! Kaase seldom uses a calculator or flowbench he's the polar opposite of an analytical type like Meaux , but his stuff works .

Joe if we can support 740hp through a std manifold opening, then I doubt Dustin's motor will have gone into any type of choke at his hp level. I dont believe motors go into choke. Once they reach .55 mach this becomes the limiting factor and is not really considered " sonic choke" as such.

Jon's work is a class act, and we are very lucky to have had him devote his time to developing what is probably the best port configuration you could hope for from a std Cleveland casting.

The intake port flows 340cfm@.500"lift and 400cfm at .750-.800" lift. The intake opening has a MCSA of 3" and is the exact same size as our intake gasket opening, which is near exactly the same as our normal port opening. Its kind of hard to believe he got a smallish port opening like that to pass that much air. Chamber volume is in the low 40cc range.
Its the kind of work you always hear about, but only rarely see.


We will have these heads on a customers motor in the next few weeks.
Ill try and keep everyone informed on its progress.

those sound very enticing .

340@.5 is 90 cfm persqin ! if it has a 2.19 . that's very good right up there with an sc1/d3 !

and a 1.65" exhaust. The heads do take custom length intake and exhaust valves and will only be available CNC ported.

may NOT mean at the throat ! that program was developed by him in developing S/S chevies and mopars he may be reffering to the "pushrod pinch" which is not your concern .

Yo may already know this but just in case.

manifold flange Joe. Once you have port matched the intake opening on the cylinder head, the standard manifold opening then becomes the restriction or the MCSA.

Hey John,
I know my engine is low on static and dynamic compression so that probably played a role in it. But, I wasn't going to switch pistons to get my compression up even further. They were milled about 0.060" to get the chambers down to about 58cc. As for my combo, its pretty much right where Scott designed the cam for. We went a big upper end power band, due to my 5000 rpm converter, but wanted it to peak at about 6800-6900 with a max rpm of about 7000. I think we accomplished that goal. I'm guessing with a little more cam and more compression, it could've made 715 or so pretty easily. But, on the dyno, we did mess with trying to make it leaner, mostly played with air bleeds once we got close on jetting and the engine didn't like to go any leaner. Maybe the little lens on the Super Flows air turbine was a little dirty??? But yeah, we tried to lean it up a bit and it responded with lower V.E.#'s and peak power and where they peaked at went down. I'm betting that if we would've started getting a little deeper into the carb, we could've snuck a few more ponies out of it. But, I thought setting it up on the dyno, letting the engine run for 25 minutes under slight load, then 5-10 minutes of varying load at rpm, adjusting valves, timing changes, and jet changes in 4 hours and still getting 14 pulls in wasn't too bad. The best tuning will come at the track.

"The headers, cam etc need to be designed for higher rpm also."
Oh yeah, do you think that a 2" primary tube header with a 3.5" collector isn't really made for going over my 6800 peak? I know the cam isn't made for revving that high, but I would've thought the headers were plenty big????

http://www.supermotors.org/registry/vehicles/detail.php?id=6723 -1982 F100 351c 4v

http://www.supermotors.org/registry/vehicles/detail.php?id=6727 -1977 F150 460 Burnout Truck

Wow if you made 14 pulls in 4 hours and changed something between each pull you were humping it!!!! Dustin I think you did a great job with your motor, and with the current crank and rods in your motor I personally would not be searching for more power or rpm. When are you going to have it out at the track?

Chris

Chris, only the last, probably 8 pulls had changes. The first couple were light pulls, to like 5500, then we richened it up a little to be safe and started going for broke. I know what you mean about rods and crank. Scat says they wouldn't be worried about it since they claim the crank and rods are rated to 750hp and 7500 rpms. But, I'm about 75hp short of that and I'm gonna have the limiter at about 7000-7100 I think just to be safe. I've been gone with work and stuff so haven't had a chance to work on it. The engine is in the truck, but nothing is really hooked up yet. Hopefully its on the road within the next two weeks and I think the next test-n-tune is June 7th but I'm not positive on that.

http://www.supermotors.org/registry/vehicles/detail.php?id=6723 -1982 F100 351c 4v

http://www.supermotors.org/registry/vehicles/detail.php?id=6727 -1977 F150 460 Burnout Truck

Hey Dustin
I offered a couple reasons as to why you may not rpm a little higher.
Im not saying your far off where you should be, or that your header choice is wrong, but rather offering a couple of points on why it "maybe" could have run a little higher. These are meant as examples and not as a criticism, as I know the cylinder head and manifold combination you have is capable of supporting a higher peak rpm. I know this as we have proven it many times ourselves on much larger engines.
If your engine guy designed it to run to 6800-7000rpm then thats probably why it didnt run higher, rather than head MCSA, as was suggested earlier in the thread. That is the point I was trying to make.

What is the 'expected' / 'desired' header tube primary size for 7k RPM on a 4v headed 410 motor. I've long suspected that my header might be part of what is holding back a lot of power in the motor.

Nick
http://www.dodgestang.com

4V's like big primaries. I would run (atleast) 2" on your engine...

Hi John,
I figured you weren't critizing some of the components. I just thought you were maybe saying my header size was too small. Reason I said something was because I was running 1.75" primary tube headers before and kept kicking around the idea of going with bigger headers or not. Well, I decided on the 2" primary headers and I think it was a very wise choice since the engine made a lot more power than I thought.

http://www.supermotors.org/registry/vehicles/detail.php?id=6723 -1982 F100 351c 4v

http://www.supermotors.org/registry/vehicles/detail.php?id=6727 -1977 F150 460 Burnout Truck

Here's what CHI say about their 228cc 4V head exhaust port:
"4. All new 220+cfm "UNI" Exhaust Port will fit either 2V or 4V headers with NO port matching, and features true Standard Height Exhaust Port & bolt locations."

And about the CNC option:
"Owners of raised dome, high compression pistons to suit 4V closed chamber heads, can now order CHI heads with a 4V CNC chamber. Our 4V CNC chambers are 74cc in volume and retain our relocated spark plug location. These can also be ordered as an option by people that require increased chamber volumes for blown or stroker applications. The need to replace those high compression 4V pistons is now a thing of the past."

74cc shouldn't be too far off from what you have I'm guessing, depending on what all has been done to your current OCs.

I agree with what Chris Minchew said about the CHIs; those heads are right, they are as advertised, and flow what CHI says they do OOB. I have a set of AFD 4Vs, and they are way less than stellar OOB, and far from what is shown on the web-site, as far as flow. I just freshened my co-worker's 380cid Clevor (4.02 X 3.75), and the only real change was a set of 225cc 3V CHIs, OOB. He's mad at me now, 'cause the chassis is being overpowered, BIG-time ('71 Comet GT).
Some people on the forum have posted about their swapping to CHIs from their deadly serious, max effort iron heads and not seeing any appreciable gains, but if you changed "up" from milder irons on your Fastback, I'd be surprised if you didn't get a bunch of extra power. I know after my one experience hands on with 'em, my next (if ever) set of aftermarket canted valve heads will be CHIs.


"If you're under control, you're not going fast enough." ---Parnelli Jones on Trans Am racing.

Dang I go racing for a day and come back and you guys have been busy on this subject.

John good to see ya here again! Can't wait to here the progress with the new heads. Should be very impressive. When you say new manifold are you saying that you have a different manifold on your engine this year from last year? If so what part number. Again glad to see you back on the board and hopefully things will remain civilized.

Chris

Hey Chris
The manifold is totally new. It is the same external casting with a new larger runner system. I havent had a chance to add it to the website. Ill get the dyno graphs from the before and after test and post them soon. We havent as yet run the manifold in the car. That will happen in the next few weeks to a month also.

Cool let me know how the new intake works out. Would be very interested in the new intake if it shows a gain going down the race track.

Chris

Nice to hear from you! The new manifold will be for 4500 only or the 4150 also? I'm going to do a build with a buddy. Doing a head and maniold selection. New "225" heads or a great deal on a set of 28M heads? Will manifolds interchange? What is the height and width of the intake port on the "225" head and is the location changed? 408ci. Thanks Mike.

Most people just dont chase 700+hp with 4150s anymore. Cylinder head choice will be dependant on your final hp target.

Below is the before and after graph from the dyno test we ran between on our new 3.5" 4500 and our old 3.0" 4500 manifold.

Wow, after 6500 rpms, the manifold really helps the power take off more. Looks like it would really help if you had the cam to pull the higher rpms.

Hey Chris, I KNOW this manifold is calling your name!!!

http://www.supermotors.org/registry/vehicles/detail.php?id=6723 -1982 F100 351c 4v

http://www.supermotors.org/registry/vehicles/detail.php?id=6727 -1977 F150 460 Burnout Truck

Dustin it's not just calling my name it's screaming at the top of its lungs!!!!! Looks like the manifold would help me break the 140 mph barrier that I can't get past right now.

John thanks for the info and for making me spend more money!!! LOL I also appreciate all the R&D that you do to help us make improvements to our C motors. Is the manifold the same price?

Chris

Ok, so its SCREAMING your name. Is your current manifold a 4500 or 4150 manifold? Wonder how my engine would like a 4500 series and a Dommy bolted to it for at the track????

http://www.supermotors.org/registry/vehicles/detail.php?id=6723 -1982 F100 351c 4v

http://www.supermotors.org/registry/vehicles/detail.php?id=6727 -1977 F150 460 Burnout Truck

Chris we are hoping that this will also push us over 140mph. I know if we get in good air we will run 140, but this manifold may help us achieve it in a little more average conditions.
It will be intereting to see what difference it makes in the car. Manifold will be around the $575 mark plus freight. Our strong Australian dollar coupled with your weak USD, is making it more expensive to deal with the States. Without giving in and heading for Asian shores (which I will never do, unlike some) our prices will always be a little higher.

But you can bet it will be tested and proven, not just made up dyno tests and theories when you buy from us.

Dustin my current manifold is a 4500 top. When I get the new manifold you are welcome to try my current manifold and see how it works out on your motor.

John I feel the same way, if I can get that really good air night and I jet up for it, that the car can run 140 now. But I am always looking for ways to go consistently faster. I do not mind paying a fair price for something