906 vs 452 heads on 440

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440DART1970

1970 Dart 446ci Swinger
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I'm building a 440 10.35 compression with a mild cam.
If I had the choice between a 906 head and a 452 head what Would be better for 500 horsepower street application?
 
this may help you decide Cylinder Heads Flow Data at 28" H2O
Manufacturer /Part Number Port/Vol
Intake / Exhaust Valve Size Intake / Exhaust Combust. Chamber Volume .100"
Intake / Exhaust .200"
Intake / Exhaust .300"
Intake / Exhaust .400"
Intake / Exhaust .500"
Intake / Exhaust .600"
Intake / Exhaust .700"
Intake / Exhaust .800"
Intake / Exhaust Average
Intake / Exhaust
Chrysler #452 Iron 200/62 2.080/1.740 N/A - 142/- 208/- 244/-
502 hp 264/-
543 hp - - - 214.5
N/A
1.320
Chrysler #452 Iron 200/62 2.080/1.740 N/A - -/103 -/132 -/143 -/146 -/148 - - -
Chrysler #518 Iron 233/77 - N/A - 159/- 222/- 262/-
539 hp 284/-
584 hp 295/-
607 hp
658 hp 300/-
670 hp - 253.7
N/A
1.288
Chrysler #906 Iron 200/62 2.080/1.740 80 - 142/- 208/- 241/-
496 hp 262/-
539 hp 270/-
555 hp
603 hp - - 224.6
N/A
1.350
Chrysler #906 Iron 200/62 2.080/1.740 N/A - -/98 -/127 -/143 -/150 -/154 -
 
452 is basically a 906 with hardend seats.
My problem is on the 452s...2 valves need new seats. or I also have a set of 906 that may be ok. My 440 motor came from a 78 RV home with the 452s on it.. I was told more water passages for better cooling?? what to do..
 
10:35 with iron heads? Ping city brother....Be prepared to use a lot of octane boost.
 
i believe you also will need hardened valve seats to run modern pump gas, and i have to agree unless you are running a pretty serious cam you may be looking at a bit too much compression to run on pump gas if that is the goal
 
10.35:1 compression with 452 or 906 heads is a pretty loopy idea.

This cam is to be mild with a lope? Sounds like a Thumpr or a Whiplash Cam. Both of those are a very bad idea with 10.35 compression. More information please.

452 is basically a 906 with hardend seats.

Neither head stock will have a significantly different head flow or power potential but they are quite different in design and the 906 has way more flow when ported correctly.
 
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I'm building a 440 10.35 compression with a mild cam.
If I had the choice between a 906 head and a 452 head what Would be better for 500 horsepower street application?

By the time you get a 906 or a 452 set of iron heads ready to make 500 horsepower, with a mild cam (or a radical cam for that matter), you could have bought set of better aluminum heads. Well, unless you own a head porting shop.
 
Air in, power exploited as completely as possible, and air out.
If the work was done well to a modern, high quality level, and the camshaft is big enough with properly matched components, you should be at 1hp/inch. If you're not, something is off. You need about 220cfm at .500 a cam that opens the valve far enough for long enough, and enough efficiency that it's all put to good use and you're there. The more power you want, the more critical each piece of the puzzle is.
I do not feel that high static is a help if you're running open chambered heads. Something in the 9.5-9.8:1 is plenty. That's because a smaller cam will work better with available fuels and average tuning. I've run as high as 10.8 with iron open chambers but you better be spot on with the tune-up and any load of cheap pump fuel could throw a wrench in that tune. I wouldn't recommend it because static ratio simply is not needed. So given your 10.3 static, I'd be looking at cams with at least 250* @ .050 and you will still want to make sure you get quality pump fuel at 91-93 octane and tune it very carefully. A cam of that size, with lightly modified (read as stage 2 ported) iron heads that can move 250-260cfm at the cam's max lift, with the matched intake and exhaust components, with good ring seal, will make 500hp.
 
Air in, power exploited as completely as possible, and air out.
If the work was done well to a modern, high quality level, and the camshaft is big enough with properly matched components, you should be at 1hp/inch. If you're not, something is off. You need about 220cfm at .500 a cam that opens the valve far enough for long enough, and enough efficiency that it's all put to good use and you're there. The more power you want, the more critical each piece of the puzzle is.
I do not feel that high static is a help if you're running open chambered heads. Something in the 9.5-9.8:1 is plenty. That's because a smaller cam will work better with available fuels and average tuning. I've run as high as 10.8 with iron open chambers but you better be spot on with the tune-up and any load of cheap pump fuel could throw a wrench in that tune. I wouldn't recommend it because static ratio simply is not needed. So given your 10.3 static, I'd be looking at cams with at least 250* @ .050 and you will still want to make sure you get quality pump fuel at 91-93 octane and tune it very carefully. A cam of that size, with lightly modified (read as stage 2 ported) iron heads that can move 250-260cfm at the cam's max lift, with the matched intake and exhaust components, with good ring seal, will make 500hp.
That's along the lines were shooting for. My buddy's been building motors for over 30 years and this is exactly what we got planned. we live near Englishtown Raceway park in NJ 1/4 mile track so even race gas is readily available to bump octain number up a bit.
My main question was that i was not sure the difference between a 906 and the 452 heads because 2 of my 452 head valve seats took a bit of a beating snd instead of redoing valve seats i also have a set of 906 to use so my question is 906 or 452 seems they are pretty much the same
 
Here are some intake airflows from our flowbench. These are generalities and flow from different ports on the same head will be different. Also sometimes the 452 will flow a little better than the 906 and sometimes the other way around as in this case.

Lift..........906.........452

.100.......66 cfm...61 cfm
.200........130.........130
.300........189.........188
.400........222.........213
.500........234.........227
.600........237.........230

Do a valve job only on the heads and you would probably not be able to tell the difference in the power they would make.
 
Ah. ok. In terms of as-cast as Jim's info shows - they are pretty much the same. Personally I prefer porting the 346/452s but to each their own. Any head can be tweaked by a high quality performance valve job and if it was me I'd put exhaust seats and larger valves in it regardless. So the intake seats would be re-cut anyway. I don't think you can go wrong either way.
 
By the time you get a 906 or a 452 set of iron heads ready to make 500 horsepower, with a mild cam (or a radical cam for that matter), you could have bought set of better aluminum heads. Well, unless you own a head porting shop.

Absolutely. x2

I did a 440 with 906 heads. I had about 1,200 IIRC into a fully ported and blueprinted set of 906's. Keep in mind this was 20 years ago, so add for inflation. I had dome pistons with a static compression of 10.5:1. The cam was [email protected], .557 lift on a 112LCA installed 2 degrees advanced. The timing was 18/36 all in at 2,500. That engine made 467hp and 514tq with a crap intake and too small a carb. Close to that magic 500 number.... That engine ran on pump premium.

That engine also ended up leaking in 5 out of 8 cylinders and needed to be torn back apart and fixed with epoxy.

Unless your build requires iron heads it's tough to beat aluminum heads. Especially when they can be bought for 1,000 a set...assembled!
 
Iron heads are not fun to do. Aluminum heads are highly recommended over porting iron heads. This is an estimate for the price you'd pay for the service and the approximate flows you get for working your 906 iron heads in our shop. Bronze guides, hard exhaust seats, new stainless steel valves, valve job, balanced combustion chambers, heads surfaced and porting to the level indicated.

Seals, retainers, locks, locators and springs are an extra.

260 cfm @ .500" lift.........................................................................$1,400
275-280 cfm @ .500" lift..................................................................$1,850-$1,900
290 cfm @ .500", 310 @ .600", 321 @ .700"...................................$3,100
299 cfm @ .500", 325 @ .600", 335 @ .700", 340 @ .800"..............$5,100

346, 902, 452 heads will not flow to the cfm listed in the upper ranges of the 906 heads.

Oh, and I have cleared out some space in my conversation box for those of you who were unable to reach me.
 
By the time you get a 906 or a 452 set of iron heads ready to make 500 horsepower, with a mild cam (or a radical cam for that matter), you could have bought set of better aluminum heads. Well, unless you own a head porting shop.
I work in the machine shop where we build performance racing engines. . To get the heads to do what he wants will probably cost him about 2500. Clean and inspect them. Do a leak down. Hardened Seats new Bronze valve guides. Oversize stainless steel valves three angle valve job port polish and deck the head. If it’s not a numbers, matching engine I would just get a nice set of Indy, aluminum heads. That will save you about 80 to 100 pounds of weight they will flow better and they ard easier to work on.
 
I work in the machine shop where we build performance racing engines. . To get the heads to do what he wants will probably cost him about 2500. Clean and inspect them. Do a leak down. Hardened Seats new Bronze valve guides. Oversize stainless steel valves three angle valve job port polish and deck the head. If it’s not a numbers, matching engine I would just get a nice set of Indy, aluminum heads. That will save you about 80 to 100 pounds of weight they will flow better and they ard easier to work on.
Trickflow heads will allow for a better variety of manifold choices over Indy.
 
Giving the choice between a 906 or a 452 head, since this is what the thread is about I'll take the 452 heads over the 906 any day of the week.

While I don't have any flow sheets I am sure the way my 452 heads are done would make a TFS head look bad. However most are not going to take an iron head to that extreme.

Tom

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