Need Big block advice!

[1970FuryConv]

I am very late to the party, but I thought the major benefit of aluminum heads was better heat transition that created less chance of knock. Thus, the chance of knock in an engine with 9.5:1 compression would be significantly reduced from iron heads, if you used aluminum heads. I thought horsepower was more a matter of porting and flow than iron or aluminum.

I was considering aluminum heads mainly as an anitdote to poor quality gas.

I'm disappointed to hear that out-of-box quality for aluminum heads that would be used in a street-only car is so poor that they need to go to the machine shop before install.

 

[commando1]

I don't buy into this aluminum heat transfer detonation thingie either.
Anybody dispute iron is stronger?

 

[67Monaco]

Anybody dispute iron is stronger?

Yes.

 

[commando1]

How about Kryptonite?

 

[heyoldguy]

Aluminum vs iron heads.

In this first test they proved themselves wrong and still denied their results.

http://www.superchevy.com/how-to/83858-iron-vs-alloy-engine-heads/

These people were more honest.

http://www.hotrod.com/how-to/engine/ccrp-0602-iron-versus-aluminum-cylinder-heads-test/

In MOPAR heads there may be increased detonation resistance with aluminum heads, but it is probably because the aluminum heads have a better shaped combustion chamber than the factory iron head.

 

[commando1]

So in the material itself, it's used because it is cheaper to manufacture. Period.

Over in ChevyLand, most of the aftermarket heads can also be had in iron unlike MoparWorld. There's a reason for that. They need aluminum for the kids, showoff cars, and serious racecars where grams count. And they make iron heads for the smart guys.

 

[70bigblockdodge]

I think it is just because it is easier, cheaper, lighter plain and simple. When I was in Jr. High we casted aluminum handles for toolboxes that we made I seriously doubt we could have done cast iron.

 

[barnfind]

Oh well no being called a wanker still. Hey old guy thanks for righting this thread, without bashing any brand. Now if any of you want to buy aftermarket heads you now know someone to get them from prepped and ready to bolt on, again thanks.

I cant help it

https://www.youtube.com/watch?v=wxA2PVYNJVw

 

[1970FuryConv]

A quote from the Honest Article

Aluminum vs iron heads.

In this first test they proved themselves wrong and still denied their results.

http://www.superchevy.com/how-to/83858-iron-vs-alloy-engine-heads/

These people were more honest.

http://www.hotrod.com/how-to/engine/ccrp-0602-iron-versus-aluminum-cylinder-heads-test/

In MOPAR heads there may be increased detonation resistance with aluminum heads, but it is probably because the aluminum heads have a better shaped combustion chamber than the factory iron head.

I read the Hot Rod article and found the quote below at the end:
"We're not going to be quite so cocky about debunking the claim that you can run higher compression on pump gas with aluminum than with iron. Our test does not definitively prove that. It may not have even tested it. We can say with complete confidence that we did not encounter detonation at any point during our testing, even at 10.88:1 compression. That could be because the cam was pretty big, with an intake-closing point 79 degrees ABDC. With cranking compression in the 185s, it was not taxing the detonation point even with 91 octane. Also, the Engine Masters thing has pretty well demonstrated that a dyno seems to have far more detonation tolerance than do actual driving conditions in a car. So, ultimately, we don't think we pushed that limit enough to make a positive finding."

1) They say verbatim that they did not resolve the question of aluminum preventing detonation better.
2) This is a test of a non-street Comp Cams 306S (PN 12-445-4), a mechanical-flat-tappet grind with 260/260 duration at 0.050 tappet lift, 0.555/0.55-inch lift with Comp Pro Magnum roller rockers, and a lobe displacement angle of 110 degrees. Who runs a .555 lift, mechanical lifter cam in a street motor?
3) They ran the engine on a dyno, not long term in a street situation.

I'm not the original post writer, but the original question was essentially: How do I build a 1975 440 street motor, never to be used at strip, with good power and reliability without breaking the bank?
I thought in reading 8 pages of arguing that we never really answered the original question. I say this because I need to build a street, internal balance crank, 1969 440 for my heavy, 3.23 geared 1970 Fury convertible, which I intend never to take to the strip. Inconclusive non-street dyno results don't help me much in choosing heads.

How about this: given that I keep my open chamber iron heads and do a basic port and polish with hardened exhaust valve seats, what cam and piston combination would you run? Please be specific by providing manufacturer, model number, and specifications. Please also state whether I can run regular gas or have to run premium gas.

 

[heyoldguy]

I read the Hot Rod article and found the quote below at the end:
"We're not going to be quite so cocky about debunking the claim that you can run higher compression on pump gas with aluminum than with iron. Our test does not definitively prove that. It may not have even tested it. We can say with complete confidence that we did not encounter detonation at any point during our testing, even at 10.88:1 compression. That could be because the cam was pretty big, with an intake-closing point 79 degrees ABDC. With cranking compression in the 185s, it was not taxing the detonation point even with 91 octane. Also, the Engine Masters thing has pretty well demonstrated that a dyno seems to have far more detonation tolerance than do actual driving conditions in a car. So, ultimately, we don't think we pushed that limit enough to make a positive finding."

1) They say verbatim that they did not resolve the question of aluminum preventing detonation better.
2) This is a test of a non-street Comp Cams 306S (PN 12-445-4), a mechanical-flat-tappet grind with 260/260 duration at 0.050 tappet lift, 0.555/0.55-inch lift with Comp Pro Magnum roller rockers, and a lobe displacement angle of 110 degrees. Who runs a .555 lift, mechanical lifter cam in a street motor?
3) They ran the engine on a dyno, not long term in a street situation.

I'm not the original post writer, but the original question was essentially: How do I build a 1975 440 street motor, never to be used at strip, with good power and reliability without breaking the bank?
I thought in reading 8 pages of arguing that we never really answered the original question. I say this because I need to build a street, internal balance crank, 1969 440 for my heavy, 3.23 geared 1970 Fury convertible, which I intend never to take to the strip. Inconclusive non-street dyno results don't help me much in choosing heads.

How about this: given that I keep my open chamber iron heads and do a basic port and polish with hardened exhaust valve seats, what cam and piston combination would you run? Please be specific by providing manufacturer, model number, and specifications. Please also state whether I can run regular gas or have to run premium gas.

Sure, we built this one.

http://www.forabodiesonly.com/mopar/showthread.php?t=293381

 

[67Monaco]

Please be specific by providing manufacturer, model number, and specifications. Please also state whether I can run regular gas or have to run premium gas.

Since we're being asked to do homework..

http://bit.ly/1IP3toI

 

[70bigblockdodge]

The book by Chuck Senatore is a good one IMHO.

 

[tallhair]

Since we're being asked to do homework..

http://bit.ly/1IP3toI

I haven't used that one for a while but is totally appropriate here

Well done Bill

 

[1970FuryConv]

Book learning vs the Real World

Since we're being asked to do homework..

http://bit.ly/1IP3toI

I appreciate the book references, but I did not ask you to do any research. I have already built 2 440 engines, along with engines of other sizes. I was looking for real world experience. Book learning is nice, but it's no substitute for someone saying, "I have used this particular product and it worked."

BTW, I agree with you on aluminum heads. I respect Steve Dulcich just about as much as any Mopar writer. Here is my research and excerpts from 2 of his articles. The first is from Hot Rod magazine, 10/2014, and involves building a 440, not a Chevy. The second is from Mopar Muscle magazine in 2013 on Detonation and how to avoid it. Both articles are very informative, although the 440 article is directed toward an A-Boby. Both say that the aluminum head helps prevent detonation, allows higher compression, and has better design than factory iron heads.
http://www.hotrod.com/how-to/engine/1412-how-you-can-build-a-stout-537hp-street-440/
Up top, some of the factory combo's shortcomings start to become apparent. Although the valvetrain offers excellent geometry and is quite capable, the cylinder heads it was bolted to were marginal for an engine of the 440's displacement. Even the best of the standard big-block heads really delivered small-block–sized airflow. While extensive porting of the factory iron can remedy this situation, the economics involved dictate that a replacement set of cylinder heads is the most practical upgrade. The upshot here is that a cylinder head swap to aftermarket aluminum heads will support a higher compression ratio, improving detonation tolerance by virtue of the material's better thermal characteristics and the elimination of the outdated open-chamber design of the factory iron.
http://www.hotrod.com/how-to/engine/mopp-1302-tech-pump-gas-power/
Up until this point we have been discussing factors to maximize the pump-gas potential of an engine, without even getting inside the engine. The cylinder head plays a key role in determining detonation tolerance. Just by switching to an aluminum cylinder head, a useful increase in compression ratio of up to a full ratio point of compression can be employed. Beyond the material itself, the combustion chamber design is a factor here, with compact chambers, small volumes and plugs moved inwards to a more central position generally able to get more pressure and power out of an octane point.

 

[commando1]

Ok. My 2¢.
Clean and check the block.
Stock rotating train.
Valve job on stock heads.
A torque grind cam from anybody except Comp.
Eddy Performer intake and 750 carb.
Stock everything else.
Attention to detail!

Very boring.
And it works.

You asked....

 

[heyoldguy]

I appreciate the book references, but I did not ask you to do any research. I have already built 2 440 engines, along with engines of other sizes. I was looking for real world experience. Book learning is nice, but it's no substitute for someone saying, "I have used this particular product and it worked."

BTW, I agree with you on aluminum heads. I respect Steve Dulcich just about as much as any Mopar writer. Here is my research and excerpts from 2 of his articles. The first is from Hot Rod magazine, 10/2014, and involves building a 440, not a Chevy. The second is from Mopar Muscle magazine in 2013 on Detonation and how to avoid it. Both articles are very informative, although the 440 article is directed toward an A-Boby. Both say that the aluminum head helps prevent detonation, allows higher compression, and has better design than factory iron heads.
http://www.hotrod.com/how-to/engine/1412-how-you-can-build-a-stout-537hp-street-440/
Up top, some of the factory combo's shortcomings start to become apparent. Although the valvetrain offers excellent geometry and is quite capable, the cylinder heads it was bolted to were marginal for an engine of the 440's displacement. Even the best of the standard big-block heads really delivered small-block–sized airflow. While extensive porting of the factory iron can remedy this situation, the economics involved dictate that a replacement set of cylinder heads is the most practical upgrade. The upshot here is that a cylinder head swap to aftermarket aluminum heads will support a higher compression ratio, improving detonation tolerance by virtue of the material's better thermal characteristics and the elimination of the outdated open-chamber design of the factory iron.
http://www.hotrod.com/how-to/engine/mopp-1302-tech-pump-gas-power/
Up until this point we have been discussing factors to maximize the pump-gas potential of an engine, without even getting inside the engine. The cylinder head plays a key role in determining detonation tolerance. Just by switching to an aluminum cylinder head, a useful increase in compression ratio of up to a full ratio point of compression can be employed. Beyond the material itself, the combustion chamber design is a factor here, with compact chambers, small volumes and plugs moved inwards to a more central position generally able to get more pressure and power out of an octane point.

Yeah, that's what they say. Have you ever seen them test it? I posted the only two articles I've ever found that anyone tested it in an internal combustion engine.

 

[67Monaco]

Actually you did ask for research. You wanted manfacturer, model numbers etc etc. There's so much information on the Web just do a frigging search. If you can't figure out If you're going to need premium gas or not from a particular combo, maybe you should do more reading. Instead of oldguy doing all your work for free, maybe offer to pay the man for the knowledge he's earned through the years.

He's already given you a bundles worth.

 

[commando1]

I just picked up a 440 out of a truck. The engine is a 1975 and is in great shape, never molested and had a documented 56k on it. Upon tear down I noticed how clean the engine was. The hone marks on the cyls still look fresh. Unfortunately from what I've read the 70's bb are dogs. Low compression and poor performing cams. I'd like to do a "low budget" build and get some more power out of this thing. Crank bearings and journals are perfect as are the cyls so blocks getting cleaned, new bearings getting installed, new rings, reuse pistons, more aggressive cam and aluminum heads and intake. I found a set of new heads with 72cc combustion chambers for $1000 on ebay. I'm guesstimating around 11:1 compression with these heads. What so you guys think? Not trying to make a race engine but would like more power. This is going I be a cruiser but I'd like to get on it once in a while, no track time though. Thx

I reread your opening post. Twice.
Do a nicely detailed REBUILD with a cam that has a similar grind to the the 6pack engines and throw a Performer (not a Plus) intake and carb on it.

You seem absolutely determined to mess things up.

 

[1970FuryConv]

I reread your opening post. Twice.
Do a nicely detailed REBUILD with a cam that has a similar grind to the the 6pack engines and throw a Performer (not a Plus) intake and carb on it.

You seem absolutely determined to mess things up.

Just to be clear. I did not make the original post. Nor do I know the person who did. I just thought that someone on this thread would have cam/piston rec from their experience, so I wouldn't have to start from ground zero.
My initial 1969 440 plan on a very tight budget:

• Focus on torque more than HP because I really only need performance zero-80mph
• Clean block thoroughly and inspect carefully
• Retain original pistons and not bore, if possible
• Use a Comp Cams kit: XE256 might give regular gas a chance. XE262 would be better performance, but probably require premium. (I used to Mopar Muscle articles for guidance)
• Retain original iron heads. Have valve job done and rebuild with Comp's valve springs, retainers, and locks
• Edlebrock dual plane
• Holley 750
• DUI ignition
• HP manifolds, if I can get them and 2.5" exhaust
• 727 Stock torque converter, stock valve body with shift kit
• 3.23 8 3/4, Sure Grip

As far as asking my question on page 8/9 of this thread, I regret not starting a new thread. The tone of this thread was too angry. Please remember: we're all on the same side. We all love c-bodies.

 

[commando1]

Just to be clear. I did not make the original post. Nor do I know the person who did. I just thought that someone on this thread would have cam/piston rec from their experience, so I wouldn't have to start from ground zero.
My initial 1969 440 plan on a very tight budget:

• Focus on torque more than HP because I really only need performance zero-80mph
• Clean block thoroughly and inspect carefully
• Retain original pistons and not bore, if possible
• Use a Comp Cams kit: XE256 might give regular gas a chance. XE262 would be better performance, but probably require premium. (I used to Mopar Muscle articles for guidance)
• Retain original iron heads. Have valve job done and rebuild with Comp's valve springs, retainers, and locks
• Edlebrock dual plane
• Holley 750
• DUI ignition
• HP manifolds, if I can get them and 2.5" exhaust
• 727 Stock torque converter, stock valve body with shift kit
• 3.23 8 3/4, Sure Grip

As far as asking my question on page 8/9 of this thread, I regret not starting a new thread. The tone of this thread was too angry. Please remember: we're all on the same side. We all love c-bodies.

It gets confusing.

That build you just summarized looks like a very good build. Very sensible for a C-body driver. Have you heard all the bad reviews of poor Comp Cam quality?