flow chart 906 heads

[RRSweden]

Hey. Does anybody have a flow chart for a standard 906 head?

Do they differ a lot from head to head or can I rely on some standard scheme?

 

[Garys1969RR]

Good question. Some members here have flowed them as well as done extensive porting on them. Search the threads for 906 or 915 head for good info. Seems to me that the intake port on the stock 906 head is around 220 CFM at .500" lift. The 915 intake port is reportedly the same shape/design as the 906 head. I have heard that a 906 intake port can be made to flow 320 CFM or more, with the proper modifications.

 

[IQ52]

The differ from head to head and port to port. After many tests the stock heads will be something like this.............

Lift..................In/Exh
.100...........61-63/50-62
.200.......126-130/95-107
.300.......188-189/130-131
.400.......218-223/146-148
.500.......227-234/155-158
.600.......232-235/158-164

 

[RRSweden]

Thank you IQ52!

 

[66Satellite47]

The differ from head to head and port to port. After many tests the stock heads will be something like this.............

Lift..................In/Exh
.100...........61-63/50-62
.200.......126-130/95-107
.300.......188-189/130-131
.400.......218-223/146-148
.500.......227-234/155-158
.600.......232-235/158-164

Very interesting & helpful. Stock ports really need help.

 

[Garys1969RR]

Yes, the factory heads in stock form do need some help. That's one reason why the 440s pull like a ton of bricks in the lower RPM ranges, then run out of breath quickly above 4000 RPM. The ports simply cant flow enough air to feed the motor! Alot of guys, myself included, have tried larger valves, 2.14" intake, and 1.81" exhaust. That is helpful as long as the throat area is also enlarged. There are alot of interesting articles and threads about improving port flow, and there are porting templates available if you want to do it yourself.

 

[RRSweden]

Thanks. Do you have a link to any good sites about porting heads? And/or link to templates?

 

[Garys1969RR]

I'm pretty sure Summit has the templates available. Seems like Hot Rod magazine had a long and thorough article spanning several months that detailed proper porting on the Mopar heads. Or just google: Porting Mopar Heads.

 

[IQ52]

http://www.hotrod.com/articles/cylinder-heads/
http://www.hotrod.com/articles/cylinder-heads-ii/
http://www.hotrod.com/articles/cylinder-heads-iii/

 

[66Satellite47]

I started porting my 906 heads (or 915) in 1975. The basic bowl port under the valve seat gains the most performance with no serious reliability issues. If you start getting more crazy, narrowing the valve guide diameter with a taper, and if you want to go nuts as I did you epoxy the pushrod lump area and the grind through and straighten the intake port. I should mention all of the severe modifications I mention really hurt your reliability. I got the power but broke many heads.

 

[IQ52]

These are different stages of port design we have done with the 906 head depending upon the effort extended. Some of these take weeks to do. It's why I recommend aluminum heads unless iron is required by the rules or for some personal reason you just must run iron. None of these have required welding or epoxy. We haven't done an all-out 906 head for 8-10 years. All of these are from our records on our flowbench.

Lift... stock I/E
.100......63/57......89/60......80/61......91/.....71/.....91/.....89/60
.200....137/103...168/124...161/126...157/...150/...165/...161/129
.300....187/145...218/170...219/175...217/...209/...219/...212/185
.400....216/168...249/200...262/201...250/...257/...272/...257/216
.500....224/176...260/217...280/215...276/...292/...299/...297/234
.600....232/183...258/228...297/221...290/...313/...325/...331/253
.700.....NA/NA....258/236...297/224...297/...321/...335/...347/264

Below was in 2011 using and old set of 906 we had done years before. If you scroll down to the La Roy Engines account you will get a brief description of what these heads can do on an engine that was blown up the day before because Comp Cams forgot to turn the water into the block before firing and running the engine. We ran the engine the following day with water back in the engine and 906 cylinder heads. We had 15 bent valves and 56% leak down in one cylinder. Those heads will still hold water to this day even after getting so hot the paint began burning off the cylinder heads because of no water in them.

http://www.hotrod.com/articles/mopp-1203-the-amsoil-mopar-muscle-engine-challenge/

http://image.hotrod.com/f/35960380+...ngine-challenge+laroy-engines-group-photo.jpg

 

[Garys1969RR]

I remember that problem with the engine getting hot, doing the field repair, and still getting it to produce 730 horsepower! Wow! I have a question I hope you will answer. Did you move the intake port window up on those 906 heads? My thought has always been that a higher, or raised, intake port window helps to make a smoother and straighter transition from the manifold runner into the intake port, especially at the top. Does raising the port window help the flow much? Thanks.

 

[IQ52]

Yes, we certainly did raise the port window and it did improve the flow on these heads.

 

[RRSweden]

Thanks again IQ52 for your answers!

It feels tempting to try and give it a go with the grinder, but on the other hand, pretty un-rewarding work, since I don't have a flowbench, and therefore never could tell if I improved anything or just made it worse.

 

[RRSweden]

But if it's ONE improvement you'd recommend me to do, that is quite easy achieved. What would that be?
(I'm gonna use a 2-plane stock manifold, #2806301 )

 

[IQ52]

One thing, easy to achieve......use a better intake manifold.

 

[Garys1969RR]

That's for sure! I'm sure you can gain a lot by installing the 2.14/1.81 intake/ex valves. And you really need to open up the throat area under the valve, as this is a restriction. The porting templates will help you do this, and gives you a guideline. A better way to go is to send your heads to IQ 52 and have them ported professionally.

 

[RRSweden]

That's for sure! I'm sure you can gain a lot by installing the 2.14/1.81 intake/ex valves. And you really need to open up the throat area under the valve, as this is a restriction. The porting templates will help you do this, and gives you a guideline. A better way to go is to send your heads to IQ 52 and have them ported professionally.

Shipping heads from Sweden and back will sure blow my budget ;)

 

[Garys1969RR]

Yea I was thinking that. How about some used Eddy heads from somewhere out there? I know they're probably hard to find in your area. 3 ways to go here, 1) use your heads as they are, 2) buy some aftermarket alum heads, 3) do some research, get a high speed grinder and port your heads. This can be fun, and can be rewarding. Good luck!

 

[Garys1969RR]

If you can pick up ANY iron big block head out there, do it. You can always practice on an old rusty one, or cut them in half and see where the water passages are.