Cylinder head questions

[72Fury]

I just tore my *you could drive it to Mexico 440 if I did'nt have to feed the cows* engine that I bought. Proof again that you rebuild anything that you don't personally see running. A bent pushrod, stuck valve, a combustion chamber that looks like a head gasket blown with a surprise in every cylinder. Mice drippings and nuts packed inside the intake & exhaust. Anyways I dropped the short block off at the machine shop yesterday.

My question is the heads. #346. I will be replacing the valve guides, springs, valves etc. Is that a decent head for a engine build of around 450 hp, torque mainly? Or ditch them and start with something else? What about aluminum heads, like Edelbrock?

 

[70bigblockdodge]

They are as.good.as 906 heads the new stainless valves will help reliability and flow the most( one piece and already back cut) yes you will end up with probably 700 in your heads and aluminums are double that, with aluminum you need to increase comp ratio to stay at same power level as iron due to the aluminum heads losing heat quickly. So if your sticking with basically stock replacement on bottom end and a relatively low lift cam (under .500 lift) you will lose power with aluminum heads.

 

[72Fury]

That's good news. I'm changing the pistons, so I will be bumping the compression ratio up some. Some of the aluminum heads on ebay are around $1000, I don't know if they are any good or what problems they have though (if any). The engine is going in the 72 Fury so I'm after torque more so than hp. I'm not after any under hood bling on a police car restoration, so something cast iron might be better anyways. Just figuring out costs vs performance.

 

[Moparhead]

440Source makes aluminum heads for $1000. We are putting them on a buddies 383. Unfortunately it will be a little while before I can give my performance observations. I have edelbrock rpms on my 440 and they work great. That said, the number you are trying to reach is easily attainable with iron heads. Unless you are looking for weight savings, it's tough to justify aluminum in your scenario.

 

[70bigblockdodge]

I agree wieght savings on a 4500 cbody is counter productive

 

[commando1]

If the only way you can afford to go aluminum is by using 440 Source, you're way better off staying with your iron.

Posted via Topify on Android

 

[Moparhead]

If the only way you can afford to go aluminum is by using 440 Source, you're way better off staying with your iron.

Posted via Topify on Android

Those heads have good flow numbers, not quite as good as the Eddys and not near Indy. They are good entry level heads if you need the ease of porting and the weight savings. For C bods, not needed, but some folks do try to haul these sleds down the track ;)

 

[commando1]

Do a search on Moparts for "440 Source heads" and 50% of the replies are from guys who had quality issues with them and had to tear them down or return them.
Way too high a %-age for me to even think about using them.

FWIW: 440S sent a set of Eddy heads to China and said "make these". Boxed in China, shipped to 440S and then directly to the buyer.

 

[detmatt]

Iron heads all the way, it's the best bang for the buck for these cars IMO.

 

[70bigblockdodge]

I don't diagree with you on % of complaints but I'm sure there are a lot of people out there that used them don't ever say a thing cause they worked fine. Most of the problems you hear are because people are idiots and can't think for themselves and don't double check just out of box on the engine torque them down. Attention to detail is most important you are the final Q.A. inspector.Or you can pay vic to pay someone to inspect them for $500.

 

[has2bmopar]

I bought 2 sets of the Stealth 440 Source heads, a set of Edelbrock smallblock heads, Mopar smallblock heads, Indy EZs and Indy Legend 426RA heads all new and 1 set of Indy SRs used.

The 440 Source heads need to have the springs, locks and retainers replaced with something that won't fail the 1st season or the first 1/4 mile pass in some cases. By the time you replace these parts you have spent the same as if you had bought the Edelbrock or Mopar heads in the first place.

You also have to clearance the pushrods and they don't have helicoils... Not an issue with Edelbrock, Mopar, or Indy and likely any manufacturer who's business is engineering and building heads vs one's business that is stealing anothers product/engineering and copying it.

Even this being said, my biggest reason for selling my 440 Source heads and vowing never to use anything to do with 440 Source was the horrid customer service and getting the shaft by returning an absolutely unusable 440 Source aluminum waterpump housing. If you want to meet a condescending $hithead just deal with Mr. Happy guy after you have already made your purchace.

The 346 falls between the 906 and the 452, already has hardened exhaust seats, and in my opinion should serve well in this build.

If you are building a '72 or newer 440 you should be looking at some pistons with about .200" more compression height than the originals.

 

[rexus31]

If you are going to go with the Stealth heads, make sure the head gaskets properly fit the heads. I was planning on putting these on my 383 but decided against because every head gasket I tried hung over in a couple of the combustion chambers. Also, as mentioned above, you have to change the springs, locks and retainers. I'd go with a nice set of 906's or 452's but your 346's should work fine for what you are wanting.

On a side note, I was also going to go with the 440 Source roller rockers until I saw horror stories online regarding the roller tip failing, turning the rocker into a pitch fork that eventually lets the locks free, thus dropping a valve and blowing an engine. I wound up going with the stock rocker assemblies.

 

[heyoldguy]

They are as.good.as 906 heads the new stainless valves will help reliability and flow the most( one piece and already back cut) yes you will end up with probably 700 in your heads and aluminums are double that, with aluminum you need to increase comp ratio to stay at same power level as iron due to the aluminum heads losing heat quickly. So if your sticking with basically stock replacement on bottom end and a relatively low lift cam (under .500 lift) you will lose power with aluminum heads.

It is unfortunate but most of this information on aluminum heads is false. Seach as I may, I cannot find any facts backing up these continually perpetuated myths. Below are two articles where this horsepower loss was tested and found to be not so. So surprised were some of the testers, they denied their own findings and surmised they must have done something wrong. They were wrong.....in that they didn't believe their own results.

If you can afford the aluminum heads, by all means buy them. Even at lower compression ratios you will get an increase in power. But be advised, all aftermarket heads should be properly prepared by a knowledgeable cylinderhead technician. Too many aftermarket heads have valve guides too tight, seats out of round and sealing surfaces that are not flat.

I have found the 440 Source valve springs to be consistently closer in pressures than the Edelbrock RPM springs. The 440 Source valve locks and the assembly procedures result in damage to the valve stems below and at the locking groove and I've had to replace many 440 Source valves when I dis-assembled them to prep them.

Any of the aftermarket aluminum heads will out flow a rebuilt factory iron head unless your technician is very proficient in porting iron heads. You can't just slap in bigger stainless valves and call it good. You may get some improvement but it will be nothing compared to a prepped aluminum head.

The early Stealth heads had a problem with the gaskets overhanging the combustion chamber. The later heads have had the combustion chamber reduced in size (from 84 to 80 cc's) and if you use the FelPro 8519 PT1 head gasket it shouldn't be a problem.

As to the aluminum weight difference, any reduction in weight in our heavy C-Bodies would be beneficial in handling, fuel economy, acceleration and braking.

http://www.carcraft.com/techarticles/ccrp_0602_iron_versus_aluminum_cylinder_heads_test/viewall.html

http://www.chevyhiperformance.com/techarticles/83858_iron_vs_alloy_engine_heads/

 

[70bigblockdodge]

I agree BUT too many people buy what the magazines tell them to buy if you put ootb aluminum head on a stock engine with a magnum/6-pack cam if you gain 10% your lucky your said right in your post rebuilt iron and prepped.aluminum maybe I misunderstood the original question, sorry, alum has its place but I don't think that's the level he is shooting for. I can put a 605 Indy motor in a 77 newyorker but it will not be as much fun and deinatly go faster in a duster.

 

[72Fury]

I'm not against building more hp. If it's there for close to the same price or a little more, then why not. I'm thinking about H beam rods instead of redoing the stock rods for example. The pistons are low, low compression so they will obviously go. The car is not going to be a drag racer, but I sure would like that strong mid range torque pull that a 440 can do. I looked into extrude honing, but that is terribly pricey for what looks like marginal improvements.

 

[Moparhead]

I hope the component failure issues with the 440S heads are the exception and not the rule! Maybe attributed to bad rocker/stem alignment? Too big a cam, bottoming out on the valveguides? My buddy went with those heads to get the performance gains and save a little money. Certainly won't be a savings if the valvetrain fails. He's committed to using them so we'll see. The motor is going into his 4sp 70 RR and it WILL be driven enthusiastically, if there will be a failure he will find it lol

 

[heyoldguy]

I'm not against building more hp. If it's there for close to the same price or a little more, then why not. I'm thinking about H beam rods instead of redoing the stock rods for example. The pistons are low, low compression so they will obviously go. The car is not going to be a drag racer, but I sure would like that strong mid range torque pull that a 440 can do. I looked into extrude honing, but that is terribly pricey for what looks like marginal improvements.

Raising the compression will help, but maybe this will help with worries about low compression.

http://www.forabodiesonly.com/mopar/showthread.php?t=249866

 

[rexus31]

I hope the component failure issues with the 440S heads are the exception and not the rule! Maybe attributed to bad rocker/stem alignment? Too big a cam, bottoming out on the valveseats? My buddy went with those heads to get the performance gains and save a little money. Certainly won't be a savings if the valvetrain fails. He's committed to using them so we'll see. The motor is going into his 4sp 70 RR and it WILL be driven enthusiastically, if there will be a failure he will find it lol

Possibly attributed to being designed and manufactured in China.

 

[Moparhead]

Possibly attributed to being designed and manufactured in China.

Certainly possible, but I would expect more casting related issues. Component failures can be caused by many different things, craftsmanship is one, assembly is another, mismatched components, etc

 

[heyoldguy]

I hope the component failure issues with the 440S heads are the exception and not the rule! Maybe attributed to bad rocker/stem alignment? Too big a cam, bottoming out on the valveseats? My buddy went with those heads to get the performance gains and save a little money. Certainly won't be a savings if the valvetrain fails. He's committed to using them so we'll see. The motor is going into his 4sp 70 RR and it WILL be driven enthusiastically, if there will be a failure he will find it lol

The failures are the exception, and every cylinder head made by man will have a failure rate.

I have tested RPM, Victor, 440S Stealth & Super Stealth, Indy EZ, 440-1, RHS and others. None of them are ready to run out of the box, they all must be checked and prepped.

I prefer the RPM over the Stealth, but prepped and/or ported they will deliver equal performance and reliability. Sometimes the $400-$500 difference in starting point will give the nod to the Stealth, even though the Edelbrock is cast and machined in California, good ol' USA. If you don't mind cheaper ("entry level") Edelbrock components, want a small bump in compression without changing pistons, the Edelbrock 5090 75cc E-Street head is a good option.