383 Aluminum Head Dilemma

[HT413]

Btw, E-Street are $1249 from summit.

http://www.ebay.com/itm/Edelbrock-E...Parts_Accessories&hash=item5af5bca9ea&vxp=mtr

Huh, good to know - that price I quoted was Jegs. Never would have guessed Summit was $250 cheaper than Jegs.

 

[natas33]

Good for you! Do you have any empirical data to back this up? Or are you just going by your gut feeling?

I say this because I have seen the cylinder head tests and have run my own 730 HP iron headed (906 heads) big block at 11.9:1 compression with 93 octane and can point you to the national magazine where it was recorded.

Awesome power from 906 heads! Sounds a bit familiar to something I read, yours the engine they forgot to turn on the cooling on the dyno run? Any special tricks to running that 11.9:1, reverse cooled? Or does it just work? Nah I don't have any data, just brainwashed by the aluminum hype ;) I had my own 600 HP 440 years ago with max ported 906's (no epoxy) flowed 320cfm on intake with milodon pro flows, but always ran race gas just because it was easily available and cheap back then and why run inferior gas when you could run good stuff. Just never been game to try an iron head on 93 octane over 10:1 CR.

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If the point / fact were " needing two more points in comp" were being implied, that would suggest everyone who has performed a cast iron to aluminum head swap has already lost performance as a result of heat loss through the cyl head...

If not raising the CR, they have. Why else would mopar say this. I believe what the mopar engineers said back then, because a lot of what they said I did, and it did exactly what they said.

98 Mopar performance parts catalogue....

"quote": Don't try to compare aluminum heads and iron cylinder heads at the same compression ratio; 11.5:1 in iron should be 13.5:1 in aluminum

followed by:

"quote": Don't run aluminum heads at low (8 and 9:1) compression ratios; aluminum rapidly conducts heat from chamber, reducing efficiency


seems to me like some of the todays aluminum head salesman don't want to admit this fact in fear of losing another sale ;)

 

[natas33]

they also wont tell you that a basic 440 with ported 906's/milodon pro flos and a 590 mopar solid on a prepped stock short motor with arp rod bolts will make 600hp.. and be perfectly streetable. they might not sell as many as those trick made in china for $2 parts then.

back in 98 mopar didn't lie. now they're all negotiating with chopsticks.

 

[67 B-body]

To the OP:
You will not loose HP by switching to aluminum heads...

NATAS33: There have been LOTS of good running 600hp 440's built over the years using cast iron heads that have been heavily worked over, and the trusty Ol 590 solid MP camshaft..... It's a great combination!
We'll just have to agree to disagree on the loss of performance just by going to any of the reputable aftermarket aluminum heads....

 

[67Satty]

Regarding the 75cc E Streets - it seems like at $1249 they would be a really good deal for someone who can use a 75cc chamber. From what I've seen posted elsewhere by Dwayne Porter, they have more of a heart-shaped chamber than the RPMs, the flow nearly the same as the RPMs at high lifts (as Edelbrock claims), and they even have the same hardware as the RPMs (the only difference being the valves).

I'm temped by them, but the 75cc chamber would put me at 10.75:1 static and my cam is only 238 @ .050 duration and I don't see myself going much past 255 @ .050 in a future cam swap so it might be too much dynamic compression for me using those heads.

But I bet they would help a lot of people with 383s and 8:1 440s out.

 

[Banzaiii67]

To the OP:
You will not loose HP by switching to aluminum heads...

NATAS33: There have been LOTS of good running 600hp 440's built over the years using cast iron heads that have been heavily worked over, and the trusty Ol 590 solid MP camshaft..... It's a great combination!
We'll just have to agree to disagree on the loss of performance just by going to any of the reputable aftermarket aluminum heads....

Seems as though Car Craft and others here have proved you will not lose hp when switching to aluminum heads from Iron heads, but all of these tests seem to be proven when over 10:1 compression.

On a personal note, I am finding it difficult with all the conjecture. Is it worth the coin to run aluminum heads with less than 9.5:1? Nobody in print or more knowledgeable than me have gone out on limb say, yeah you'll be good . Although this member on the board has a build similar to what my outcome would be.

CFster

'64 383
9.35:1 compression
Edelbrock RPM Heads 84cc
Edelbrock RPM Intake
TRW "heavy" pistons
Comp Cams XE275HL
Demon 750
TTI Headers 1-3/4”
TTI X-pipe Exhaust 2-1/2”


449hp@5800rpm and 473lb/ft@4500 (without the exhaust on the dyno)

My engine --> http://www.larrysautomachine.com/dyno/mopar383.html

I know it says 10:1, but it's more like 9.3:1.



Additionally this is off Hughes website

Quick Facts: Aluminum vs Iron

Weight: Aluminum heads weigh about 45 to 50 lbs., a pair, less than iron heads Durability: "Ported iron heads can crack if the engine is badly over-heated". Yes this is true, but if the engine got that hot the aluminum head would have melted or been badly warped. The seat rings would have also fallen out, but the head might not crack. Anyone who lets his engine get that hot deserves to buy new heads or have an expensive repair bill Reparability: This is a trick question. Yes, aluminum heads are easier to repair if the damage is very bad and that is a good thing because they are much more fragile and more prone to damage than a hard, iron head Cost: Aluminum heads cost more, and then there may be the hidden cost of raising the compression ratio Airflow: You get very similar airflow results from ported, stock heads and "stock replacement" type heads. With raised port cylinder heads, the sky is the limit Power: Power depends on what you have to start with, or what else you plan to do to the engine. If you have low compression (9.5:1 or less) and are not going to change pistons or mill the heads to restore the cylinder pressure, save some money and go with the ported iron heads. If you are starting on a fresh engine with higher compression ratio pistons, want to lose some weight and the budget can handle it ---go ported aluminum. There is another power consideration; most of the aluminum heads have a closed combustion chamber which is far superior to the OEM heads with their open chamber design. However, if the piston is not at 0.000" deck, the chamber design has very little effect.

If all this sounds like we don't like aluminum heads, the truth is quite the contrary. Aluminum heads are cleaner, easier to port and they look trick next to an iron head. If you make a mistake on an aluminum head, it is easy to fix. If you drop it on your toe it doesn't hurt as bad. Porting aluminum also keeps the shop cleaner, what's not to like? We just want you, our customer, to get the right cylinder heads, iron or aluminum. After all you, the customer, are the ones paying for this web-site, thanks for the he

 

[natas33]

Hughes has some good info there. Run zero deck height with alumium heads you will run ok. 383's good rod ratio has more piston dwell at TDC than other engines which also helps with low CR's. With a 6.76 440 rod in a 383/400 even more so.. 2:1 rod ratio.. another thing that the stroker crank salesman will also argue with all day long, rod ratio. Short rod engines run fine, but need more CR to compete with a long rod engine and also wear the bores quicker. Mopar engineers knew what they were doing with their long rods, tall decks, and big journals, all of which resulted in lower CR big torque very reliable engines.

 

[IQ52]

Awesome power from 906 heads! Sounds a bit familiar to something I read, yours the engine they forgot to turn on the cooling on the dyno run? Any special tricks to running that 11.9:1, reverse cooled? Or does it just work? Nah I don't have any data, just brainwashed by the aluminum hype ;) I had my own 600 HP 440 years ago with max ported 906's (no epoxy) flowed 320cfm on intake with milodon pro flows, but always ran race gas just because it was easily available and cheap back then and why run inferior gas when you could run good stuff. Just never been game to try an iron head on 93 octane over 10:1 CR.

Yep, it's the engine they forgot to turn on the water to. We ran eleven dyno pulls the next day with 58% leakdown and 15 bent valves and it still made the 730 HP.

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If not raising the CR, they have. Why else would mopar say this. I believe what the mopar engineers said back then, because a lot of what they said I did, and it did exactly what they said.

98 Mopar performance parts catalogue....

"quote": Don't try to compare aluminum heads and iron cylinder heads at the same compression ratio; 11.5:1 in iron should be 13.5:1 in aluminum

followed by:

"quote": Don't run aluminum heads at low (8 and 9:1) compression ratios; aluminum rapidly conducts heat from chamber, reducing efficiency


seems to me like some of the todays aluminum head salesman don't want to admit this fact in fear of losing another sale ;)

MOPAR WAS WRONG! It's true that aluminum will conduct heat faster but NO ONE has ever shown in an internal combustion engine on the dyno, that you lose power with the aluminum head if you keep the compression ratio the same. I have looked for any test like that.

BUT......I HAVE seen the dyno tests where they used the same engine, same shape combustion chamber, same cc's, same port flow, same intake manifold and carburetor and same compression ratio............and the aluminum head made MORE horsepower than the iron head.

 

[natas33]

MOPAR WAS WRONG! It's true that aluminum will conduct heat faster but NO ONE has ever shown in an internal combustion engine on the dyno, that you lose power with the aluminum head if you keep the compression ratio the same. I have looked for any test like that.

BUT......I HAVE seen the dyno tests where they used the same engine, same shape combustion chamber, same cc's, same port flow, same intake manifold and carburetor and same compression ratio............and the aluminum head made MORE horsepower than the iron head.

Funny i've heard people say the exact opposite, that iron heads make more horsepower in the same spec. Each to their own, at the end of the day everyone can run what works for them, and a good port shape and flow and camshaft selection is what will make the power regardless of iron or alum head and nit picking on 1 or 2 points of CR.

I still believe mopar because i see no reason on why they would been wrong in what they said. The same engineers developed all the other mopar performance parts which actually worked exactly as they said they would. And Hughes is also saying basically the same thing about iron vs alum.. and theyre making money from selling cnc ported alum heads. So it doesn't look like the have any reason to be putting out the wrong info.

On another note, i was just reading a guy that bought brand new top dollar 15 degree brodix sbc heads that flow 380cfm to use on 800hp n/a engine and they were porous and had water squirting out on the dyno first time he run them. You would think brodix would be better than that after so many years of selling alum heads that worked. All this now cast in China deal is rather off putting, these parts aren't exactly cheap. Makes me not even want to run any aftermarket connecting rod if it's not an Oliver or Carrillo. Think i'd rather gamble with prepped factory mopar rods that were forged back in 1970, to 8000rpm, than chinese metal. At least when you spend $ on chinese alum heads they can be repaired. the short motor.. if a rod or crank goes.. its for the scrap.

 

[99ss]

LOL... I've never heard an aluminum head wont make as much power as an iron head....NEVER heard that.

heads make the power and its all about airflow... An engine is an air-pump... the more air you feed it the more power you make

Of course you need all the valve events to be timed correctly. Better flowing heads make more power.. thats why they are ported and improved upon year after year... valve angle valve material, springs .. controlling the valve-train and not getting float. It all coincides together.

Its not the material... its the design and implementation.... maybe iron heads held more heat and caused pre ignition more is why the compression is lower? The fuel mix can only take so much before it ignites..... But it has never been said to me you need to run more compression with aluminum heads over an iron head... But I will ask

Answer: Not really but you can probably run a wee bit more with aluminum due to I guess less hot spots


Side note... if you want a bump in compression just mill the heads

 

[Banzaiii67]

IQ52 pointed out to me that they just tested the 75cc E-Street heads in the most recent (December) issue of the Mopar Muscle for those following this thread..

The specs on the engine before the heads were striking similar to mine and probably others.

69 C body with AC and PS.
8.5:1 Compression on Stock 383
Comp XE268 Cam
Performer RPM Intake
Edel 750
TTI 1 7/8 Headers

Before the heads: Peak numbers at the wheels: 244HP/314TQ
After the heads and Comp pro magnum 1.5 rockers: Peak numbers at the wheels: 273HP/333TQ

 

[Budnicks]

Regarding the 75 cc Eddie RPM heads, i just called eldelbrock and they are being manufactured, no longer on back order. The rep said summit and Jegs have em.

They also have the Estreets in 75cc now. Both Jegs and summit have them too.
75cc Estreets $1473.99 for the pair
75cc RPM's $919.99 each
http://www.edelbrock.com/automotive_new/mc/cylheads/chrysler/bb_estreet.shtml
http://www.edelbrock.com/automotive_new/mc/cylheads/chrysler/bb_perf_rpm.shtml
http://www.summitracing.com/parts/edl-60829
http://www.jegs.com/i/Edelbrock/350/60829/10002/-1

I see in the new Summit Racing catalog effective thru Dec. 31st 2013... E-Street #EDL-5090 210cc int./70cc exh. port volume Chrysler B/RB 361-440 Aluminum 75cc Combustion Chamber heads, supposedly good from idle to 5500rpm range {as is or, out of the box} with 2.14"int/1.81"exh. valves, 0.600" max lift for $1,299.50 {same ports shape as the RPM's, just not hand blended, like the RPM's} with "supposedly 291cfm intake flow & 217cfm exhaust flow @ 0.600" lift, according to their website, I haven't seen or used any personally yet, I hope our resident Mopar Cylinder Head & Engine building Professional/Expert IQ52, gets some soon & does a real world, un-biased flow & dyno tests, the report his findings...

 

[99ss]

IQ52 pointed out to me that they just tested the 75cc E-Street heads in the most recent (December) issue of the Mopar Muscle for those following this thread..

The specs on the engine before the heads were striking similar to mine and probably others.

69 C body with AC and PS.
8.5:1 Compression on Stock 383
Comp XE268 Cam
Performer RPM Intake
Edel 750
TTI 1 7/8 Headers

Before the heads: Peak numbers at the wheels: 244HP/314TQ
After the heads and Comp pro magnum 1.5 rockers: Peak numbers at the wheels: 273HP/333TQ

29 hp is nothing special but you would notice the difference

 

[Banzaiii67]

I see in the new Summit Racing catalog effective thru Dec. 31st 2013... E-Street #EDL-5090 210cc int./70cc exh. port volume Chrysler B/RB 361-440 Aluminum 75cc Combustion Chamber heads, supposedly good from idle to 5500rpm range {as is or, out of the box} with 2.14"int/1.81"exh. valves, 0.600" max lift for $1,299.50 {same ports shape as the RPM's, just not hand blended, like the RPM's} with "supposedly 291cfm intake flow & 217cfm exhaust flow @ 0.600" lift, according to their website, I haven't seen or used any personally yet, I hope our resident Mopar Cylinder Head & Engine building Professional/Expert IQ52, gets some soon & does a real world, un-biased flow & dyno tests, the report his findings...

Here ya go.. From another Mopar related forum via Dwayne Porter

OOTB flow numbers, Edelbrock valve job, no modifications:

lift----I/E
.100--62.6/51.4
.200-122.0/100.4
.300-183.0/137.6
.400-230.3/166.6
.450-249.4/177.8
.500-261.8/185.2
.550-268.1/191.4
.600-274.8/195.1
.650-278.6/198.4
.700-282.3/201.3

 

[Budnicks]

Here ya go.. From another Mopar related forum via Dwayne Porter

OOTB flow numbers, Edelbrock valve job, no modifications:

lift----I/E
.100--62.6/51.4
.200-122.0/100.4
.300-183.0/137.6
.400-230.3/166.6
.450-249.4/177.8
.500-261.8/185.2
.550-268.1/191.4
.600-274.8/195.1
.650-278.6/198.4
.700-282.3/201.3

Thanks I will have to check that out, do you have a link ??... {what forum} that's not bad #'s for $1300 & way better than any stock Iron head will have, unless well ported & larger valves are installed... That's a good starting point, if that's what your looking for, everyone's flow bench will give slightly different #'s too, you really can't race flow benches... I wonder, did he/they flow test them with an exhaust tube/header or thru an intake port or what ?? I'm just curious...

 

[67Satty]

http://board.moparts.org/ubbthreads/showflat.php?Cat=0&Number=7749277&page=0&fpart=2&vc=1

There's some good pictures of what the chamber looks like on this thread too. Getting really tempted by these. With a Summit discount code and free shipping, and maybe less work to make right before running them, they could end up being cheaper than Stealths yet flow better.

Only thing that gets me is the 75c chamber putting me at 10.75:1 static compression.

 

[67Satty]

Help a brother out, what's the secret hand shake?

If you aren't logged in or a member, all you have to do is click on the link I posted, then click on the link on the top of the post that says "attachment" to see the picture.

 

[Banzaiii67]

Here's my thought process.

A: Replace the XE274H cam with something with less duration with the hopes that A/F mixture and is improved. $

B: 1) leave the cam, replace the heads with E-Street heads, increase compression, but with standard head gasket .065 quench $$

2)leave the cam, use 516 heads with steel shim gaskets, increase compression, maintain .045 quench. $$

C: Tear the engine out. Deck the block, re-ring the pistons, touch hone the cylinder walls. Reassemble with same cam, and piston (if possible), retain stock 346 heads <-- all I could afford at that point). $$$

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If you aren't logged in or a member, all you have to do is click on the link I posted, then click on the link on the top of the post that says "attachment" to see the picture.

I was talking about the summit discount code, than I deleted the post because I wasn't sure if you wanted to post it for everyone to see

 

[67Satty]

Oh, I don't know about any Summit code as of right now. When I called Summit, the guy said the 5090 E Streets were $1249, and the catalog I just got lists them as $1299 for some reason. At some point this winter there will probably be a 10% off code or sale at Summit and if/when there is you could end up getting the E Streets for the same price as Stealths shipped to your door when you factor in Summit's free shipping on orders over $99.

 

[IQ52]

29 hp is nothing special but you would notice the difference

I don't have the magazine right here with me, but when they switched to the 75cc E-Street heads, they gained 30+ hp and 20+ tq, TO THE REAR WHEELS. The 383 was being tested on a chassis dyno.