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Iron head test starting on '78 440.

IQ52

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I'm switching this over to it's own thread from the 440 Source head thread.

There has been a recent surge in curiosity about the power you can get with rebuilt factory iron heads.

We've a dyno day coming up at our shop to introduce the people around here to the advantages of an engine dyno (it's the first one in the entire county). It's kinda an open house for people to see an engine run on the dyno. Seems some people think it has something to do with dinosaurs.

So we've scheduled a weekend to put a cast crank 440 engine on the dyno and try different heads, cams, intakes and exhausts without changing the compression on the 440 (even if it turns out to be 7.3:1). I have always maintained that higher compression isn't mandated in every engine build, even if you are trying for 500 or so horsepower.

We don't know what all will be included, but some of the candidates are 516 heads with 2.14/1.81 valves, 346 heads stock and with valve changes and additional work, 915 heads, 906 heads have been offered by a member, and whatever else we dig up (flow figures will be provided). Looked on the shelf the other day and there is a new MP .509 in the box so it'll get it's chance against the stock '78 cam. That is, IF the stocker isn't worn out when we tear down the 440 to freshen it.

All this will take much longer than one day on the dyno, but if everthing goes according to schedule, Saturday the 14th will begin the dyno runs. Gonna be hot dogs, burgers, pop and there will be some door prizes for those in attendance who guess closest to the horsepower and torque in the different configurations on Saturday.

If you have some ideas that you would like tested, lets hear them. If we have the parts, MAYBE we can incorporate them in the tests. No piston changes are planned for the tests.

When we're done testing, the 440 is going in a really clean '72 Satellite Sebring and we'll sell the package. The Satellite has a 440 in it now from when I bought the car, but, someone else built it, and it has a vibration from a mish-mash of engine parts that never were balanced.
 
Sounds like a great idea. My question would be is there any way to determine how much more horse power you would get just by raising the C/R on any given head/engine combination? My only reference is a 440 with flat top pistons, zero deck, 915 ported heads, TM-7 intake, Holley 780. Cam @.590 lift, 310 degrees duration, about 10.5 to 1 C/R ran mid 14s in a 65 Belvedere. Blew the motor, so took the top end and put them on a 413 with Arias 14cc dome pistons, and an Isky cam .510 lift, 292 duration. 13 to 1 C/R the car ran high 12s. Only changes were more C/R, less cam and fewer cubic inches. Looking forward to the results of your test runs. This was at 5600 feet elevation. You are at 5000 feet there in Idaho? Ok Thanks.
 
very cool thread idea IQ52... suggestion; maybe after you do the iron head test comparisons... then test some OOTB Stealth's & OOTB RPM's or any progression of your porting on those 2 styles of popular bolt on Aluminum heads or any others you have & could throw on there... if you can, but probably don't have any OOTB heads still... just too see what the differences are on a bolt on, real world, street car type engine build, with a stocker type low compression bottom end... see how much different your outcomes are, compared to all the claims... if not, it's no big deal, just an idea or thought, I know it's allot of work, probably allot of cost associated too... I wish I lived closer, I'd be there for sure, I'd even help you cook them burgers & dogs too...LOL... maybe even help on the parts swap if you let me anyway... good luck, I'm looking forward to this thread, no matter what you test.... your resident pest Budnicks
 
I would love to see that, but it's a long way to go for a few hot dogs and a bunch of noise. LOL
Good luck and I hope you have a great day, looking forward to results.
 
I will be interested in the results of this test. I built a stock ext. balanced 1978 440. It is a low buck project. Started with a 75,000 mile short block( complete engine $100 ) An unidentified cam with .475 lift ( free) 516 heads with larger ex. valves and hardened seats( cost of machining and parts involved ?) Steel shim gaskets to make approx 9.5:1 compression.($50) New RPM performer Eddy intake ( already had) 750 Holly double pump ( $125) new stock type timeing chain set ( $40)
I sounds real good , but Dodge it is in is not quite ready for the road test.
I will be real interested in what you can do with that low of compression..............................MO
 
Sounds fun! Wish I lived closer.

What I would love to see would be bone stock, unported, stock-sized valves iron heads vs. OOTB Stealth and OOTB RPMs and then vs. ported iron and ported Stealth and ported RPM or any combination of the above.

Open chamber vs. close chamber iron would be cool to see also.
 
Sounds like a great idea. My question would be is there any way to determine how much more horse power you would get just by raising the C/R on any given head/engine combination? My only reference is a 440 with flat top pistons, zero deck, 915 ported heads, TM-7 intake, Holley 780. Cam @.590 lift, 310 degrees duration, about 10.5 to 1 C/R ran mid 14s in a 65 Belvedere. Blew the motor, so took the top end and put them on a 413 with Arias 14cc dome pistons, and an Isky cam .510 lift, 292 duration. 13 to 1 C/R the car ran high 12s. Only changes were more C/R, less cam and fewer cubic inches. Looking forward to the results of your test runs. This was at 5600 feet elevation. You are at 5000 feet there in Idaho? Ok Thanks.

There should be tests and information all over the internet of what horsepower difference you get with a compression ratio change only. If I'm being generous I'll say you get 4% increase with one more point of compression. For a 400 HP engine, if you raise the compression one point, from 9:1 to 10:1, you'll see 12-16 HP increase. It's the reason if I'm building a pump gas engine for someone else I keep the compression ratio into the really safe range, it just doesn't cost that much horsepower.

One of the more intense question will be answered during these tests, "How many times can you reuse a FelPro 8519 PT1 head gasket?" With all the head changes we plan, we'll have a stack of them on hand, but we're gonna reuse them until they are really worn out.

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Sounds fun! Wish I lived closer.

What I would love to see would be bone stock, unported, stock-sized valves iron heads vs. OOTB Stealth and OOTB RPMs and then vs. ported iron and ported Stealth and ported RPM or any combination of the above.

Open chamber vs. close chamber iron would be cool to see also.

Sadly this is going to, at least in the beginning, test how much horsepower you can get with the factory iron heads in various states of porting. We've been throwing away 516 heads for years now simply because they aren't very good. But a lot of people want to run them just because they are going to get a smidgen of compression increase, bah! So we'll work them over and see what they will do. We've seen the difference on the flowbench, differences in valve seat angles, but we have no real test to see where it makes a power difference, if any. Some test results may not be revealed just so we can have some secrets.
 
Sounds like a fun weekend, wish I were closer. I'm interested in all the dyno results, but most interested in the iron head results.
 
The 440 in my car is low compression with unknown .030 over cast pistons. Never did any measuring when the heads were off years ago when I installed MP "shim" head gaskets. Cam is an old MP 284/.484 installed 4 deg advanced.
Would like to upgrade a little and have though about closed chamber heads but the way it sounds the little gain in compression wouldn't help make more power.
I will be looking forward to the test results.
 
The 440 in my car is low compression with unknown .030 over cast pistons. Never did any measuring when the heads were off years ago when I installed MP "shim" head gaskets. Cam is an old MP 284/.484 installed 4 deg advanced.
Would like to upgrade a little and have though about closed chamber heads but the way it sounds the little gain in compression wouldn't help make more power.
I will be looking forward to the test results.

Just changing the COMPRESSION might not yield that much horsepower, but any compression rise in the old smoggers would at least be helpful, IF you haven't installed a head with more compression but less flow. The thing you also get with some smaller combustion combustion chambered heads is a more efficient combustion chamber. Bingo, more power still. Don't give up on a closed chambered head just yet.

We're still trying to decide if we're going to run the 516 heads stock and then go to valves and porting or just jump right into a valved and ported 516 head.
 
I haven't decided on which route to take. Thinking a basic 440 with 500hp would do just fine.

Guess I would like to see you run the 516's in stock form, then stock with valves, then ported. But hey it's your show...
 
Jim,
I will get those 906 heads to you next week, maybe Wednesday if that will work. Will be cutting wood up around Stanley.
 
My vote is for bone-stock iron with just a good valve job as a control/starting point to see just what the porting and additional CFM flow does to the power numbers on the dyno.
 
I too wish I was closer even if to help turn wrenches. I have some parts to throw at this event (as long as I get them back) if you are interested. FedEx makes it a small world.

I also have a set of 906's that I only pocket ported but those need guides, seats and the rest of the work that goes with. I'll be really curious how a set of home pocket ported heads will do. I can send those to you after I finish the porting on the other head and just pay you to do the rest of the work. I think this will be of particular interest for the DIY crowd and hopefully demonstrate some good results by just blending the bowl and not over porting without a bench.

I also have a set of bench ported and heavily cut 915 heads done by Lou Vignogna. I plan to run those with an old Isky RR1012B cam with 11:1 compression. If you want to test these I can send them too. The heads have the flow numbers.
 
I too wish I was closer even if to help turn wrenches. I have some parts to throw at this event (as long as I get them back) if you are interested. FedEx makes it a small world.

I also have a set of 906's that I only pocket ported but those need guides, seats and the rest of the work that goes with. I'll be really curious how a set of home pocket ported heads will do. I can send those to you after I finish the porting on the other head and just pay you to do the rest of the work. I think this will be of particular interest for the DIY crowd and hopefully demonstrate some good results by just blending the bowl and not over porting without a bench.

I also have a set of bench ported and heavily cut 915 heads done by Lou Vignogna. I plan to run those with an old Isky RR1012B cam with 11:1 compression. If you want to test these I can send them too. The heads have the flow numbers.

Yep, we can handle it.

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Jim,
I will get those 906 heads to you next week, maybe Wednesday if that will work. Will be cutting wood up around Stanley.

We should be around.

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My vote is for bone-stock iron with just a good valve job as a control/starting point to see just what the porting and additional CFM flow does to the power numbers on the dyno.

We for certain will have at least one set of bone stock heads tested, just not sure which ones we will use.
 
This sounds like an event I would love to attend. Will this be Sat and Sunday? Sept 14 and 15? Will it go into Monday? What about starting Friday the 13th? Lol. A 2 or3 day event would make it worth the trip up there from Denver. Ok Thanks for offering some thing like this to the Mopar Guys.
 
I don't want to sound like a dumbass, but I'll ask anyway. What is the difference between the heads 906 516 916 etc? I'm a MOPAR virgin.
 
I don't want to sound like a dumbass, but I'll ask anyway. What is the difference between the heads 906 516 916 etc? I'm a MOPAR virgin.

516 heads are the old closed chamber design with a flat "old style" intake port. Valves are 2.08" / 1.60"

915 heads have the same chamber as the 516 but a much improved intake port. Valves are 2.08" / 1.60" and 2.08" / 1.74" for HP. As far as I understand it, the 915 head port design was changed based on recommendations of Harry Weslake (as in Gurney/Weslake fame).

906 heads have an open chamber just like you see on all the 70's vintage heads but the same intake port as the 915. Valves are all 2.08" / 1.74".

For some reason, and I have to believe it's emissions related somehow, the 346 and 452 went back to the flat intake port floor just like the 516's. On a dry flow bench these heads may all flow equally, but under actual conditions (wet flow) the 915 and 906 might have an advantage over all the other iron heads.
 
Hey IQ, don't you think that compression ratio is a law of diminishing returns area? I.E. a bump from 7:1 to 9:1 is going to make much more difference than going from 12:1 to 14:1?
 
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