The Edlebrock Head

[jsawduste]

Understand there is another thread......Some 15 pages long........That started with the announcement of the new head all the way to the first castings being delivered. Hopes, wishes, shipping delays are all well chronicled in those 15 pages.

If you guys don`t mind I`d like to start a specific thread for the product that is now being delivered. Observations, details, comments etc on what Edlebrock has delivered.

Seems the lifters will not pass through. Spark plug location may nullify boring the passages.
Weight ? Non-raised VC rail.

What springs are they coming with ? Not what was said but what Is actually installed ?
Quality of the valve job ? Porting potential, gasket matchup etc etc.

I`ll be the first to admit that I do not have a new Edlebrock head but I am building an engine around the new casting. At least I think I am over a prepped 7120. Let`s fill in some gaps with good solid information.

[Cheromaniac]

A bare stock iron head weighs 60lb and aluminum usually weighs about 45% less than cast iron, so I'd guess the weight saving will be ~27lb.

[mountaineerjeff]

Im disappointed that this thread hasnt taken off yet. im also very curious about the whole deal. anyone talked to edelbrock? is a higher performance head going to be available? how bout the rumors of a edelbroke intake manifold.

I would pay for a ported/polished "race" head and a even better flowing intake manifold. i wouldnt be upset with a $2,000 price tag. little more if we get a special valve cover and matching throttle body. Im really pumped about this edelbrock stuff...but i would hate to drop a few thousand on something and a better version come out in 2 months.

[SilverXJ]

There has been more coverage on this thread on NAXJA: http://www.naxja.org/forum/showthread.p ... 63&page=10

The valve cover rail isn't raised nor will the lifters fit through the bores.

[jsawduste]

Flying at 30,000 feet and looking down I am greatly disappointed in want Edlebrock has offered. Maybe looking at sea level thoughts might change as more heads get into end user hands and the performance increases reported.

For the price of a bare (or loaded) Edlebrock casting you can sure do a lot of work with a CI head. Tighten the quench up to the mid/upper 30`s and gain a bit of the compression the aluminum advantages was going to give. Granted the new combustion chamber is significant but is that chamber alone worth the effort ?

At the moment my engine build around the new head is on hold till more information comes out.


EDIT...Very pleased to read that Russ is posting the NAXJA forum. The impression I get is that he is also a bit disappointed with the head in an as shipped condition. Hoping some flow numbers come along soon.

[Cheromaniac]

The flow numbers are already out John but let's just say that they don't exactly blow me away:

http://www.edelbrock.com/automotive/mc/ ... jeep.shtml

#50169: Flow Numbers as tested by Edelbrock's SuperFlo SF-1020 flow bench @ 28" H2O
Valve Lift .100" .200" .300" .400" .500" .600"
Intake 66 123 179 221 241 237
Exhaust 63 103 127 144 151 155

The lack of a raised valve cover rail, and the pushrod holes not being big enough to fish the lifters out of the block without removing the head, are but two details that are disappointing.
The thought of a performance intake manifold is interesting, so it's a shame that all these ideas are only coming about almost a decade after the last 4.0L Jeep engine rolled off the production line following a 20-year run.
Has Edelbrock had its head stuck up its ass for the last 30 years?

Seems the lifters will not pass through. Spark plug location may nullify boring the passages.

The pushrod holes are too far away from the plug holes for the location of the latter to be the issue. If a smaller company like Hesco can make the pushrod holes bigger, I see no reason why a larger company like Edelbrock can't do the same.

[jsawduste]

Dino,
as I sure your aware, air flow benches are like dynos, no two are the same. While Edlebrock has published numbers can they really be compared without knowing the test parameters ? Even Edlebrock themselves has thought it necessary to publish a page about flow rates and how they are tested/compared.

http://www.edelbrock.com/automotive/mc/ ... data.shtml

Somebody like Russ who can swap several heads onto a common testing fixture would be a lot more meaningful then some random numbers published by the company that wants to sell a product.

Even the dyno chart Edlebrock uses is not much help. Why didn`t they include a stock engine as a baseline ?
http://www.edelbrock.com/automotive/mc/ ... jeep.shtml

As much as I hate to say it......I was all pumped up on this head business..........the failure (at least at this point)...........of this new head has left a very sour taste in my mouth.

For the cost of the new casting, prep work required to make it runnable I`d get me an engine with more then 6 cylinders.

Cannot believe I just wrote that but that is my mindset right now.

[jeepxj3]

I think that the bigger lifter holes and raised valve cover are overblown and not really needed.

Why do you need bigger lifter holes?
-if you have a bad lifter and need to change it? how ofter does this happen? rarely? and if you have a bad lifter you really might have other issues and should be pulling the head.
-to change the lifters when putting in a new cam? again if you are putting in a new cam you have other things going on and should be pulling the head.
-just saying that if you have the skill to pull the lifters, then you have the skill and knowledge to pull the head. You probably need a new head gasket anyway and new or arp head bolts for all that HP you gain with that new cam.

Why do you need raised valve cover? So you can run adjustable rocker arms
-why do you need adjustable rocker arms? Because you didn't measure and set up your pushrods correctly.
-you don't need adjustable rocker arms for the mechanical flat or roller lifters that we don't have.
-proper rocker arm setup and geometry and you don't need adjustable rocker arms.

So, a show of hands of how many of you have only needed to change your lifters and nothing else.
Except for our racing friends, a show of hands of how many really needed to use adjustable roller rockers.

It sounds like bigger lifter holes and raised valve cover is to make up for laziness. oops I said it.

I agree it really doesn't cost anything for these changes, but why? To accommodate the less than 5% that need it?
Better is why didn't they install the bigger seats that would accommodate bigger valves? probably cost difference is pennies.
Better is why they didn't install more appropriate valve springs tension for the majority of guys putting this head on a stock cam'd engine.
This would accommodate more than 80% of the users.

[jsawduste]

Not going to get into a debate.

Each individual user has his or her own needs and desires. What is important to some is not so much to another.

I see the whole thing as a promised steak dinner and what was served up is sloppy joes from old hamburger on a stale bun.

[SilverXJ]

Why do you need bigger lifter holes?
-if you have a bad lifter and need to change it? how ofter does this happen? rarely? and if you have a bad lifter you really might have other issues and should be pulling the head.
-to change the lifters when putting in a new cam? again if you are putting in a new cam you have other things going on and should be pulling the head.

To check on the condition of the lifters, to replace a single internally failed lifter (happens more often than you know), and to swap out the cam for another one.. people do change cams out for other reasons other than failure.

Why do you need raised valve cover? So you can run adjustable rocker arms
-why do you need adjustable rocker arms? Because you didn't measure and set up your pushrods correctly.

Is that what you think adjustable roller rockers do? Make up for an incorrect pushrod length?

Adjustable rockers will in no way make up for an incorrect pushrod length. You have to have a correct push rod length even with adjustable rockers. You often need a longer push rod when using adjustable rockers on the 4.x. What roller rockers do is give you a true 1.6:1 rocker ratio instead of the all over the map stock rockers. Exact preload and adjustable preload over every single lifter. Less valve guide side loading. All this results in a more precise and stronger valve train. An added benefit is less friction. Less friction= less heat conducted into the oil & the combustion chamber.

-you don't need adjustable rocker arms for the mechanical flat or roller lifters that we don't have.

How are those two items related in any way? You need a roller cam for roller rockers? How did you come to that conclusion? BTW, there are mechanical lifters available.

-proper rocker arm setup and geometry and you don't need adjustable rocker arms.

Geometry from the less than precise stock arms? Why even bother? If the valve to rocker geometry is so out of wack that the stock arms are showing something you have other problems.

This is suppose to be a performance oriented head and should accommodate common performance needs and parts. It not a bad head, but there is much room for improvement. So far we have marginally increased flow, a thicker surface, aluminum construction and a redesigned combustion chamber. It an okay start.

[Cheromaniac]

This is suppose to be a performance oriented head and should accommodate common performance needs and parts. It not a bad head, but there is much room for improvement. So far we have marginally increased flow, a thicker surface, aluminum construction and a redesigned combustion chamber. It an okay start.

The first 4.0L engine came out almost 30 years ago and was an instant hit, but it needed to evolve to stay ahead of the game. Instead it was stuck with ~190hp from 1991-2006 while other SUV rivals forged ahead with more modern and powerful powerplants. Sure there were external bolt-on mods and performance cams available but no aftermarket heads nor intake manifolds?
Edelbrock and other manufacturers could have developed heads and intake manifolds during the 1990s when the 4.0L Jeep population was increasing and they would have had more sales, so coming up with a merely OK head 10 years after the engine went out of production in the face of a declining population of 4.0L Jeeps is like shutting the stable door long after the horse has bolted. By the time Edelbrock come up with an improved design (if they do), there'll hardly be a market left to buy those heads.

[6TIME]

I think that the bigger lifter holes and raised valve cover are overblown and not really needed.

Why do you need bigger lifter holes?
-if you have a bad lifter and need to change it? how ofter does this happen? rarely? and if you have a bad lifter you really might have other issues and should be pulling the head.
-to change the lifters when putting in a new cam? again if you are putting in a new cam you have other things going on and should be pulling the head.
-just saying that if you have the skill to pull the lifters, then you have the skill and knowledge to pull the head. You probably need a new head gasket anyway and new or arp head bolts for all that HP you gain with that new cam.

Why do you need raised valve cover? So you can run adjustable rocker arms
-why do you need adjustable rocker arms? Because you didn't measure and set up your pushrods correctly.
-you don't need adjustable rocker arms for the mechanical flat or roller lifters that we don't have.
-proper rocker arm setup and geometry and you don't need adjustable rocker arms.

So, a show of hands of how many of you have only needed to change your lifters and nothing else.
Except for our racing friends, a show of hands of how many really needed to use adjustable roller rockers.

It sounds like bigger lifter holes and raised valve cover is to make up for laziness. oops I said it.

I agree it really doesn't cost anything for these changes, but why? To accommodate the less than 5% that need it?
Better is why didn't they install the bigger seats that would accommodate bigger valves? probably cost difference is pennies.
Better is why they didn't install more appropriate valve springs tension for the majority of guys putting this head on a stock cam'd engine.
This would accommodate more than 80% of the users.

Lol! But... Why pull the head if all you want to do is a cam swap? V8 guys don't pull both heads for kicks and giggles just to swap a cam out.. They would if they had to though! If I had a fresh HG in there and it was sealing up fine why bother it just because the lifters won't fit thru the holes? lol! Absolutely no reason. Enlarged pushrod holes should have been added as well as a few other things. Maybe they'll make some changes down the road..

[nicpaige]

Has anyone verified that the pushrod holes cannot be opened up to allow lifter extraction without getting into plugs and ports?