Overhead?

[jasonsevilclone]

I know you can overcam, overcarb, but is it possible to overhead? I'm about to build a 383 and I have started giving a lot of thought to the heads. The various big block castings will all put out good numbers if you massage them properly, the 346 and 452's especially. Then I looked up the figures on the edelbrock heads and I thought "wow lotta flow no work a little pricey but hell having a pair of stock heads worked over isn't going to be free anyway". I guess my question is this- would edelbrock heads be overkill for a 9 or 10:1 383 with a mild+ cam or would the money be better spent on working over the stock heads. The flow on the edelbrock's looks really good but would I need it? I want to build an engine that really burns rubber but I want it all to work well together. Oh yeah I also drive this car every day and would like to keep double digit mpg, but 400+ HP would be nice. Thaks for your suggestions. Jason.

[6 packin]

That would be a great investment. They will work good on the engine. Theres no such thing as over cam or over carb.......just need more motor.....LOL just kiddin. The heads will work great.

[dwc43]

There is a such thing as over cam over carb and yes over head too. The edels are also aluminum and they need an extra point of compression to run right. For example say you run a 9 to 1 engine with cast iron heads and want to jump to aluminum then you must bump up to 10 to 1 for them to work at full effiecency. And you need the cam lift to match the flow of your heads. It the heads are capable of flowing for a .700 lift race cam and you use a .484 they wont be as good as the stock ones with the same .484 cam. This is really all stated in over simplified fashion here , but you get the point easier that way.

[ehostler]

The EB heads do NOT require an extra point of compression. First off, the EB heads can be had in 84cc or 88cc. You want the 84cc heads. That is a much smaller chamber than the 452 head (anywhere from 88cc - 92cc). What is great about aluminum heads is tht the 452 head will begin to ping on pump gas at around 9.5 - 10:1 compression ratio. The EB heads will not ping until 10.5 - 11:1 compression ratio.

Herb McCandles did a test on the EB heads and found them to be great, right out of the box on a mostly stock engine. He ran these heads against a pair of Aerochamber 452s and found that the EB heads were superior. It would have cost more money to upgrade to the Aerochamber heads to the same specs as the EB heads than the cost of the EB heads. Then you will still be limited on your compression ratio and/or type of fuel. Herb also equalized the compression ratio between the two heads, for his testing.

If you upgrade the heads to the EB heads, don't expect any difference unless you do someting about the intake and carb. The EB Performer RPM was found to be a great match with these heads. Top it off with a BG Speed Demon and you've got a great combo.

[rumblefish360]

ehostler, jasonsevilclone;

The heads do not reqire the extra point of comp, but the engine might depending of many many variables as you know.
The alum. heads release more heat than the iron heads. The heat loss should be veiwed as a loss of power.
Apple to apple comparision of heads, lets just say 452 castings for arugement sakes, the aluminum unit makes less power.
To have the alum. head equal the iron heads powr level is to add about 1pt. of comp.

jasonsevilclone;

Air flow quality (velocity) over quanity (CFM).
At this point, for big blocks, I bail out and hand it over to the "Been there done that" people.

[ehostler]

Well, as Herb McCandles has many more years of experience than the rest of us, I will take his word for the HP & torque numbers that he got with the EB heads compared to the 452 heads using a dyno that belongs to Indy racing (as I recall). If you do a search of this forum, you will find where I reposted all of his results.

[ehostler]

Here is a repost of the numbers the Herb got.Argue all you want, however I will take the word of Herb and Ken Lazzari over most other people, any day...

Originally posted by ehostler
The article was in the September 2002 issue of MOPAR MUSCLE.

The article is by Herb McCandless. If you don't know who he is, he was well known for his work with Sox & Martin. He also is known as the owner/operator of McCandless Performance

This engine used a cast pistion at .060 down with 5cc valve notches. He retained stock 440 rods. The cam was a comp cams 21-244-4.

The heads were AeroHeads 906. The had the bronze valve guides, new springs, and 2.08/1.74 valves. The heads were at 86cc with a .022 head gasket. This brought the compression to an effect 9.2:1.

This is a basic factory stock engine.

Added to that was the Performer RPM intake and the 1 7/8 TTI headers.

That combo was run by Ken Lazzari at Indy Cylinder Heads.

The Super Flow Dyno measured a max of 399 hp @ 5,000 RPM and 477 lb-ft od torque at 3,700 RPM.

He then replaced the 906 heads with the 6092 heads (fresh out of the box). The 6092 heads measure 84cc, when you add in the thickness of the compostion gasket, you end up with about the same volume/compression ratio.

The next run on the Super Flow Dyno measured 456 hp at 5,200 RPM and 514 lb-ft of torque at 3,800 RPM.

Nown then, by the time you have machine your stock heads for the 2.14/181 valves, bought the larger valves, installed the heaver spring, and then cleaned up the ports, you have spent more money than you would have for the EB heads.

Like all heads, the EB heads have room for improvement. After some mild port, bowl, and valve seat work, they will be superior to any iron head (and cost alot less).

As a direct bolt on, the EB head is the most cost effective bang for the buck head on the market.

[dave571]

They will work well, for minimally more cost than working over an iron set.

The benefits:
being a great head for bigger, better stuff later.
Can be run with more compression, but is not required.
Closed chamber design
will not hurt you as long as you plan the rest of your combo to match, especially the cam

A great choice, especially if you shop around on costs. I saw them advertised here recently for under 1100 canadian. I thought, "how can one go wrong? All I need now is 2200 bucks."

[sixpackgut]

dont forget about the 50 lbs off the front end.

[rumblefish360]

ehostler;

No ing here. That head will do what the advertise.
Here is my point. "Apple to apple comparision of heads, lets just say 452 castings for arugement sakes, the aluminum unit makes less power. "
The edel.'s flow better period. This is where the heads make more power.
Are edel.'s the best bang for the buck? I'll allways say yes, go get them.

[6 packin]

It would be hard to overhead a Big Mill Mopar, the factory heads are not known to flow that well compared to Ford and Chevy heads. If a 396 Chevy with such huge runners, compaerd to even 906 heads, still makes for a pretty good running engine, I dont think that the Eddy heads would hurt bottom end torque, which is what were looking at here right? If it hurts a engines torque by 15% on the bottom and increases output and power in the hig revs by 25-35% there isnt no question about getting them should they? As far as the aluminim head vs steel head compression, I must say that if i were going to build a street/track engine I would go with the extra point in compression thats one of the good things about those heads. I my self know that if carbed and cammed right there is no problem running 10.5:1 on a steel head engine running pump gas. And that being so, running 9.5:1 on a aluminum head would be a waste of power knowing that you could run at least 11:1 with the right combo. Just my thoughts.

[dwc43]

Thanks 6 packin that's my point. Why use the head if your not going to use it all like it was intended to be used. The extra point will make the numbers even better than a stock cr would. Just a waste of money as I see it if you dont use the head to it's fullest potential.

[Blygy]

WOW.. I'm with Dave.. I need $2200.. The motor they used sounds like mine.. (382HP @4700 and 475 TQ @ 3500).. a set of eddies will really wake this thing up..HEHEHE.

Blygy

PS Dave where did you see them advertised at????

[dave571]

I saw them on special in the local Bargain Finder. The ad was for Mopac Auto Supply. There is one in edmonton too.

I can't remember when the sale expired.

the part number advertised was the one, for the complete head assembly(valves ect) You still need rockers with that.

[ehostler]

If you want, you can still use your existing rockers and shafts with the EB heads, you do need the proper ARP head bolts or studs.