Intake Manifolds

[Mopar2You]

hey, I am building the temp. 440 for my RR right now. I was wondering what kind of intake manifold I should run with it. I currently have a torker 440 for it. I was looking at the victor intake manifold if it was worth that much extra.

The intake will also be used on a 496 stroker once I'm finished building it. Any suggestions would be appreciated!

I will be running a set of 84 cc edelbrock RPM aluminum heads ons on it with stock 9.8:1 compression and a balanced cam (.480 lift and 280* duration at .006).

Thanx for the info!

Oh, this will be used on a 70 Plymouth RR weighing roughly 3800 lbs and have a 100hp nitrous setup on it, also has 5:13 posi rear end hooked to a 3500rpm stall converter. The motor is a temp till I get the 496 done, but it will be used at the strip so I can setup the RR's suspension.

[rumblefish360]

I don't think edel. released the new Victor yet. But I would save for it. Your combo sounds nice. That cam will be lite for the Victor and/or a 496cid engine.
The way it sits, the RPM would be better.
The suspention will also change a bit when the 496 hits the pavement.

[Mister Fiberglass]

JUST my opinion .......... FIRST - I would not use those heads since you will be having an "effective" compression ratio of LESS than 8.8 to 1.

[Mopar2You]

thats just for the mini 440 (the cam). i'll be running a roller in the 496 stroker.

is the torker as good as the RPM or should I do the upgrade? The victor is available now for the 440's. I saw it on their website, and the small block victor is available on Jegs.com.

I know the suspension will change a bit with the stroker, but we've never run the car so we wanna see how we act before we put a lot of horsepower to the ground.

Would the RPM or the Victor be a lot better than the Torker... or not really enough till i get to the 496 stroker?

Know what I mean, if not just ask.

Thanx!

[Mopar2You]

is there a way to stop the compression from dropping so much? the 84 cc chamber ones were the smaller of the too... I thought they were supposed to increase power, not hurt it!!??

[71383bee]

What Mister Fiberglass is refering to is that the aluminum heads will dissipate heat faster and give you a lower compression ratio. I have heard that with aluminum heads you should build the engine to about 1 point larger than your desired compression. Therefore a 9.8 to 1 compression will yield a 8.8 to 1. To get your compression up use low deck pistons or mill the heads. I think the edelbrock heads have a meaty deck so they can be easily milled to meet your needs.

Don't forget that if you mill the heads you also have to mill the intake side as well.

[JCFcuda]

A friend tested the victor on 11. to 1 flat tappet motor, it really seemed to like the high RPMs , on this app the M-1 make allmost as much HP and better torque . The jury is still out but I was hoping for big things with the Victor, Its a race only piece why didnt they make one for the domminator??????
Jim

[RogerH]

Yes, the Victor is a perfect choice for that engine combination. They are in production now, they were held up a little in R&D, but are in full production. The small block Victor has been available for a long time, its a old design that's been around a while.

There was going to be a domminator version of the 440 Victor, but was killed by upper management! Guess they didn't want to invest in the extra money to make it.

[Mopar2You]

I was told that with an aluminum head it dissipates heat faster, which ALLOWS you to run 1 point (apprx) higher with compression and not hurt the motor, so a 9.8:1 could run 10.8:1 and still be fine.

I could understand the 84cc chambers dropping my compression ratio though... will they drop it at all?

[cuda367]

There is only one manifold to use on any real High performance Rb and that is the Indy Cylinder head standard carb pattern manifold. It will out run any of the others. The B-1 is equal but a pain with all the adaptors. I know the first thing I'll hear is that it is for the Max wedge port, but the manifold comes small at the head port end and it is very easy to port match the head to the manifold.

[1972roadrunner]

i would have to go w/mister fiberglass and 71383bee on the compression deal...

i think a cooler temp gets a lower compression because the rings aren't expanded as much, so they can't hold much air (they don't seal well when cold)

vice-versa...when the cylinders are hotter (heads help the heat) the piston rings will expand more, therefore sealing better, and allowing greater compression...

if i'm wrong, someone correct me.

i'm 16 and this is what i have learned, and it just makes since to me...

(my $0.02)

[Mopar2You]

I'm 18, so I know how u feel 72RR. My father only knows about n/a, he doesn't know anything about turbo or aluminum heads, or superchargers, or nitrous .

I really dont know if aluminum heads would actually drop the compression or not... I guess I am going to find out . they supposedly gain (aluminum heads) around 40hp on a stock 440 (????).

[Mister Fiberglass]

Hay guyz.........alum heads (other than the weight savings) COST you power !!!!.....if the flow rates are the same.

With the Eddy heads - since the heads flow better - they MAKE you power BUT if you could get the same flow rates out of a set of iron ones - those iron ones WOULD be a better piece.

OTHER than the weight savings,

[RogerH]

Hmmm...think I'd better jump in here.....

First, I have never heard of a 'effective' compression ratio. That is a static number, and what ever it is set up as, that is what it will be. If you kept everything the same and put on the same size chamber heads, the ratio stays the same, whether its aluminum heads or iron. I think what is meant by being able to run 1 point higher compression with aluminum heads is that the chamber designs are better, you don't have to worry about hot spots causing pre-ignition or knock, so you can run more compression in the enigne.

Yes, aluminum does heat soak more then iron, but aluminum heads are constructed thicker then iron heads, a thicker deck and the general wall thickness of aluminum heads is higher. I bet you wouldn't see much difference.

I also don't beleive that with an equal flowing head, iron will be a better choice. With the 440 chyrsler heads we tested, a ported iron head that flowed the same as the aluminum heads was down 15-20 horsepower. That was with iron heads that would cost over $2000 with the port work and out of the box aluminum heads that would cost just over $1200.

There will always be a debate over what runs better, iron or aluminum. The problem you run into is that you would have to do a back-to-back test with the exact same head, just with the different material. But I do not know of any that are that way. For the most part, aluminum heads have more design work in them that make them a better head.....most iron heads are designed for production cars and made in high volume. One advantage of iron is that you do not need a valve seat, just machine the valve job in the iron, which leaves room for better blending from the valve to the port.

RogerH
Design Engineer
Edelbock Corp

[71383bee]

Roger I just want to point out that the combination that you guys tested, at least the one outlined in your website, is a relatively mild combination. I think if you used a combination that is pretty popular like a good streetable Comp cams or Hughes grind with a Performer RPM and a good Demon 850 or Holley street avenger you would see a large difference between the edelbrock heads and the 906's. As it is always stated on this site from a lot of smart people. No one part is going to make a huge difference, it's the right combination of parts that's going to matter. I think that the edelbrock heads are excellent because they expand the limitations of your engine combinations. Don't get me wrong there are several guys who are running strong with ported and polished stock iron heads (Me included!), but if the same amount of work was put into a set of edelbrock heads...wow there would be a substaintial difference i imagine.

Just food for thought

[Mister Fiberglass]

First...I should make it know that I am not a design engineer for anything! I am sure that you know TONS more than I about this subject but I have gotten some input from people at Dart and CTC who have run extensive tests in the past. Also - I am familiar with a racer in northern OH who has run a ton of tests on the Indy heads - iron vs the alum......and he would NOT run the alum pieces IF they were given to him.

"effective" compression ratio?.........maybe I am not using the proper term BUT what I mean in essence is that you can use a higher compression ratio on a alum headed engine using the same gas as a iron-head. In fact - according to the data that I have heard - you HAVE to run a higher compression ratio to see the same power output. Are you aware of a OEM engine that is almost 11 to 1 that uses pump 86 octane?

I have always been told that (given the same flow rates and even with that added 1 point comp ratio) that a iron head will produce more power since the deck and valve seat areas do not move as much.

But you are saying the exact opposite???..........I am all ears !!

[RogerH]

Mister Fiberglass----

I don't think that alone, you can state that a equal flowing iron head vs. aluminum that the iron will be better. There are a lot of factors involved. Combustion chamber design, port area, port shape, etc. There are probably cases where a iron head of the same flow as a aluminum head will make more power, and vice versa.

I agree that you can run more compression with aluminum heads, but I don't think that you will lose power vs. iron heads if you don't bump your compression up by one point over stock.

71383----

Makes a very good point, the whole combination is what makes the difference. I know we could probably publish different combinations to show the potential of the heads....but I don't have any call in those decisions. But then magazine articles usually investigate them better than we do. More of a push to get the product out the door than into testing a lot of combinations. Its all a $$$ issue. But the correct combination is very important. You can put on a incorrect intake manifold and just kill your performance. Everything needs to be matched. The intake runners should be sized for the engine setup to get the correct intake velocity, that way you can fill the cylinder the best.

I have talked to Indy Cylinder Heads, but mainly on manifold stuff. Working on a Super Victor for the small block, that'll work great for a stroked 360 in a race or drag race setup.

[72Challenger]

I'm no design engineer either, but I have been building engines for over 30 years, and I've noticed a few things through experience.

First, for 1972roadrunner, it's not the piston temperature and ring sealing that affects the ability to run more compression (well actually it does, but changing heads isn't going to change this). It's because of the fact that when a gas is compressed, it heats up. The hotter a gas is, the more likely it is to detonate. Aluminum heads dissipate heat faster, so the intake charge is less likely to detonate at the same compression. Or look at it another way, you can use a higher compression and still have the same cylinder pressure.

I think the term "effective compression ratio" is meant to refer to cylinder pressure. This is affected by many factors, primarily the cam profile. A longer duration cam bleeds off more intake charge due to overlap, thus allowing more compression ratio than a shorter duration cam. That is, the higher compression ratio is necessary to obtain the same cylinder pressure with the wider cam profile.

This also could be why some people have found more power with iron heads than with aluminum. Assuming that they didn't change their chamber volume when they switched to aluminum, they lowered their cylinder pressure, and reduced their performance. As was pointed out earlier, it's the total package that makes power. If you just switch head material but everything else remained exactly the same, I would expect iron to make more power due to higher cylinder pressures. But as RogerH duly notes, nothing ever remains exactly the same. The aluminum heads are generally better engineered because they are using newer technology. As for what the upper limit is, ask yourself this:

What are NASCAR and NHRA Top Fuel heads made of?

[RogerH]

72Challenger----

Very nice post! I still consider myself a 'rookie' when it comes to engine knowledge, even though I have been working on them for a while. There are many different factors to take into consideration....kinda like putting a puzzle together, you have an idea what the end product should be, now just try to piece it all together.

NHRA and NASCAR use aluminum heads, I doubt that they even considered iron, just from a weight stand point. IRL and CART use aluminum also, and I know CART uses a magnesium cam cover (valve cover, but also holds the overhead cams on the engine and the top motor mounts). You'd have to be a championship body builder to lift a NHRA head made from iron....and they are HUGE heads and made from billet material.

RogerH

[Mister Fiberglass]

It was a late nite last night and a early morning THIS morning so my brain might be a little slow today BUT..............

It has been shown in the market that ALOT of comanies are getting into the casting "market" these days........look at the EXPAND of the Eddy product line and even Mopar made that "new" 8 3/4 housing...........must be cheap to do that - VERY limited market out there for that piece.

EQUAL flow would be the whole "package".............you are saying that at the SAME compression ratio that an alum head will make MORE power than a iron one? How about all of the potential NEGATIVES?..........gasket problems and valve seat issues?

We are not talking about the obvious weight savings. THAT is clear to all.

[Mopar2You]

wow.. this went WAY over my head! I'm really just confused now

I guess I am just going to find out when I put the heads on, and when I put on the victor.

Thanx for all the info though...

[72Challenger]

Mister Fiberglass, I think you misunderstood me. With everything exactly equal except for the material, the iron, not the aluminum, would make more power due to higher cylinder presure. That is UNLESS you started with a combination optimized for aluminum. Then the iron head would have TOO MUCH pressure and would detonate, reducing power.

My point was that due to the thermal conductivity of aluminum, you need a higher static compression ratio to maintain the same cylinder pressure.

Of course it is very difficult to have everything but the material exactly equal. I believe the race W2 and aluminum W5 heads do meet this spec. If anyone wants to finance the buildup, I'd be happy to dyno test the same engine with nothing changed but the heads, and post the results.

[Mister Fiberglass]

72 .....ME thinks that we are BOTH on the same page IF NOT the same paragraph !!

That guy in OH...........he uses a set of heads on a S/C doorslammer that are 50+lbs? heavier and will NEVER go to the alum ones. He won't even TALK about the alum ones NOW that he has run those comparisons.

I myself have never done these tests. I speak only from reports from reliable sources. ................

GOOD topic here Guyz.....Thx, Eric

[Magnum440]

Mopar2you, I dont think you'll be disappointed in the Victor/E-Brock head combo. I have not heard anybody dispute the prevailing "conventional wisdom" that 72 Challenger so eloquently laid out in his post. So very important, if you want to burn pump gas and still have a healthy cam. If octane is no object, then maybe a case for iron heads can be made. I've heard the point Mr Fiberglass made before. Alluminum can "move" and seats should be checked. But the case for aluminum in racing motors is a very strong one--ease of porting, repair, etc , etc. For these reasons, I dont see a big return to iron castings, IMHO.

BTW, RogerH, is it true "They" put the kaibash on the 4500 Victor --was considering replacing my Team-G with one.

[sanborn]

Well, I guess I will jump in too; even though my dog isn't in this fight! I second what Roger said but for a different reason. Don't know anything about the Edelbrock BB heads; but surely the combustion chamber is of a better design than the stock BB cast iron head.

Don't know if most folks realize this but the shape, back cut and spark plug location makes a significant difference in spark advance, HP and torque. And, the stock BB cast iron design is UGH!

Yeah, in theory the aluminum dispates combustion heat more effectively and could cause some power loss but there are lots of ways to combat that; thicker deck, thermal barriers, etc.

I would rather use the aluminum aftermarket head over a stock OEM head even if the cost is twice as much.

[sanborn]

Well, I am getting old. I didn't realize there was a Page 2 to this topic. Looks like the subjects have changed somewhat. My earlier comments were directed to a comparison between "stock" OEM BB head castings versus the Edelbrock aluminum casting.

Now, if we are comparing an aluminum versus cast iron head of the same design, combustion chamber, etc. the story becomes somewhat different. The iron head will produce more power than aluminum all things being equal. But, be careful what you wish for in all but a pure race application. A thick deck, cast iron head of up to date technology can produce very good power at a compression ratio much lower than you suspect especially on the street. And the cast iron head gets really hot especially in sustained racing and can be prone to cracking. But, drag racing is not sustained racing.

Someone asked a question about Nascar and NHRA Pro Stock heads. They are aluminum for one reason-General Motors. All this occurred almost 30 years ago. When Nascar went to the small block engines (and NHRA went to the small block Pro Stock) the cylinder heads required were cast iron. And, the engine builders went about their merry way porting, welding, etc. the cast iron heads. This was all fine except the GM casting was a 5 head stud design whereas the Ford and Mopar was 4 bolt. The 4 bolt design allowed the head to have more "beef" around the intake/exhaust runner, providing a more rigid casting and much less prone to cracking. I remember very well when GM Nascar teams spent $3000 labor on a set of heads and got only one race out of them before cracking whereas the Ford and Mopar teams kept running the same heads race after race after race. I know, I was there!(I was racing GMs at the time!) And I understand the NHRA guys were having the same problem. SOOOOO, GM being the diplomatic, kind people they are said "Either you open the heads up to allow for aluminum replacements OR WE WILL TAKE OUR BALL AND GO HOME! Remember at that time GM had 60% market share! Guess what; Nascar and NHRA both rolled over! It's been aluminum heads ever since.

Even today, a good large set of Dart cast iron replacement heads for a GM weigh in at over 50 lbs. each, Whereas the Mopar W2 weighs about 42-43 lbs. Know where the extra beef is, around the intake/exhaust runners to get the rigidity where it's needed.

[RogerH]

Originally posted by Magnum440
BTW, RogerH, is it true "They" put the kaibash on the 4500 Victor --was considering replacing my Team-G with one.

kaibash? Guess I haven't heard that term before.....If you want, send me an email.

And if anyone else has any questions, especially on Edelbrock parts, feel free to send me an email, I don't know everything, but there is a weath of knowledge just a few steps away.

Great topic too!

RogerH

[rumblefish360]

First, an aluminum head is easy to repair. Should a problem arise like a piston letting lose, the head can be repaired.

2. The reason for lower performance is due to heat lose through the aluminum. The metal allows the heat to escape very quickly. Heat in the chamber makes power.

[Mopar2You]

oh, the 906 heads I have are dead stock other than a mild rebuild (cleaned up and stuff) vs these edelbrock RPM heads. I'm assuming I will definetly get more power out of the Edelbrock heads the way they are vs. the 906 heads (unless they are heavily ported)??

by the by, I think this was mainly about various intake manifolds and if the victor was better than my torker.


Thanx for all the info though, it kinda blew my mind

[Doug Wilson]

This is really a good thread. To add another dimension to the discussion: All of the arguments have a lot of validity leaning toward iron heads, BUT, when you look at someone who has a budget - where do you get the most "bang for the buck"? When I was going through the process of figuring out where I should spend the money on the 340, my conclusion was that, starting with initial cost of the heads - j or x iron - then achieving equivalent performance through porting, polishing, etc., I concluded that it was a slam dunk in favor of the Edelbrock assembled heads. I spent $1245 including shipping and it would have cost almost double that to achieve the same specs with the iron heads. Plus, I saved about 40 pounds on the front end as a bonus!

I know the thread is about big blocks, but I suspect that the arguments are valid for them as well.