J-head to eddie swap?

-
63dartman

63dartman

Well-Known Member
Joined
Dec 11, 2005
Messages
2,230
Reaction score
24
Location
rio rancho, nm
On a stock 360 bottom end including pistons, what would be the performance gain going from the 1.88-1.60 j-heads to eddie heads? I am running the eddie rpm intake and spitfire headers with dual exhaust. Cam is a voodoo series .454/.475. I'm guessing the gains would come from the smaller combustion chambers on the eddies and the larger valves......would it be worth the expense to do the swap?
 
I did the same thing. Loved it. Combo was a tad different.
Went from 2.02 J's to OOTB Edel heads. And a purple cam.
The smaller chamber is more so for upping the compresion due to the heat loss of aluminum as well as getting a nnice quench area with the reduced chamber size. The quenched area is were the power comes from as well as better ports.
At the time I was running varrious purple cams.

I liken the gain as very much like going from stock iron heads to ported heads. Not a full port job, but a well preped deal.
 
thanks rumble, I probably won't have the cash for them until after Santa is gone but, I hope to have some around spring time.( I get a bonus around that time every year and it's my turn to spend it, wife got it last year) Do you know of any place to save some cash on them besides jegs and the likes?
 
cheapest I have seen them is at jegs, you really have to shop around. I wound up buying mine from Hughes engine, they were fair priced and they would also talk to me about the swap whereas summit and jegs just want to sell the part. You need the headbolts to go with the heads. I am impressed with the heads right out of the box.
 
The only way you are going to grain 100% from those heads is if you put a big cam and have alot of rpm,7500+ to make them work.Will their be a increase in power,just by bolting them on,YES,but no where near the power you would think of.One you never mentioned the max rpm you will shift at or driving use of the car?If its going to be a street car,well ported iron heads with match and porting and bowl work is the way to go and small valves.Lets asume you are going to buy them or have them all ready,and you have spent some 1300-1500$ on the heads and now want to port them a bit,add on some 6-800$.A set of matched iron heads made to your cam and driving can cost under 1000$.That means you got a extra grand of free parts to put on the car.The eddy heads do work,don,t get me wrong,but have to be used in the right applacation or there is no benifit,and then its marginal at best,even with the highter C/R,Mrmopartech
 
Mr.Mtech has a point. IMO, just get a cam in the RPM range your driving in and with as much lift as you can get to take advantage of the better flowing ports.
A custom cam is very very close in price to a off the shelf cam.
 
7500+ rpm on a stock 360 bottom end.....yikes. So if all my driving is under 6500rpm the eddies aren't going to give me much performance gain? The eddies out of the box say max lift of .575. would a cam with just over .500 lift give me enough lift? I want my car to have a decent idle and not alot of lopeyness(is that a word?) I just picked the eddies beacause of the combustion chamber size. I haven't seen any iron street heads with 65cc chambers that will just bolt on. I don't want to convert my valve train to magnum either. Anyone have any suggestions on good aftermarket iron small chamber heads with 2.02 intake valves?
 
The first thing you should ask yourself is why you want to go to 2.02 valves. You are going to loose a bunch of port veocity and that translates to a very sluggish bottom end. A big cam will only make matters worse until you think you have a giant marshmallow for a gas pedal. :) You could shave about .030 off the heads, run a .028 gasket, and for a quarter of the price of the Eddies, see some good gains with your curent combo. Do the "J" heads currently need rebuilding? If not, why waste money for something that isn't going to show that great a gain in your street car.
 
Heres a problem:If a eddy head flows for example 320cfm,thats great.But if you only have a cam that can only use 80% of that,and the rating up to that piont is only a half dozen pionts above the stock heads,and you know you can do bowl work and match and porting to a good degree,whats the piont of buying the eddy heads at 1400+$.If you intend to use the big cam and have the heads on a big cube motor,high reving motor,go for it.In the real world of the street/highway driving,velocity is the king of the road,weather small block or big.Keeping that constant from idle to 6500rpm is the key to all your problems.Very few of us run the over 525 lift cams,and I would say that 80-90% of us are street people.So why build a race motor to go get a case of beer and the kids,and you do not run a street motor to compete in nascar,right.Lets step back,think and not over kill our motors and be happy mopar people and beat every little rustang/marshmaro and rice burners out there,mrmopartech
 
Edel. Chry. S/B...100....200..........300.......400.......500......600.....
Head flow

#60179, #60779 69/64 129/108 188/142 232/171 249/183 251/190

Heres the data from Edelbrocks site. Lets not quibble the numbers on what you read or actually got elsewhere.
The intire...(SP!) curve is better than stock heads. Porting stock heads can be cheaper than a head purchase. But for the most part, these numbers are better than most pocket ported heads flow values that I have read.

The waste, ethier finacial or other comes in not useing the most you can. This is where often I will say stay with a pocket ported iron head. Duration of a cam dictates the RPM band of which it operates in. This is where you choose your cam.

You should be real in your thoughts to this question. "At what RPM do I drive at on the Hwy? AKA Cruise."
This answer puts your cam choice "In the ball park" of what you should be looking at. Theres a 4* - 6* duration of variance. (Approx) @ .050 in the cam choices your looking at. This represents approx. 500 - 700 RPM (Manufacturers specs on this vary per type of cam weather Hyd. , Mech. or roller. Each manufacyure has a slight variance as well. But there all close to each other.)

Next thing to look at is lift. Since these Edelbrock heads flow well to .500 and then start to level off with only a 2 cfm rise between .500 to .600 lift, you can safely make excellent use of a cams lift in this area. Less lift would be the waste. 2 cfm is nothing. However, 250 is able to make excellent power.

The heads volume isn't to large for a 360 at all. The thing that will make the bottom end spongy is the duration. Have run the purple 292/.509 cam, I can tell you this cam is spongy down low until the "Power band of the cam" comes in. From there on out, it's on like Donkey Kong.

From above;

Mrmopartech says; The only way you are going to grain 100% from those heads is if you put a big cam and have alot of rpm,7500+ to make them work.
Click to expand...
Not many people are getting 100% from there current heads ethier. It's a catch 22 and moot at this point to bring it up that your not getting the full use from your current set of heads. If you can run low 11's or high 10's with your J's in your full inteior and bodied car, your getting the most IMO.
Mr.M-tech isn't suggesting you run 7000 plus to get your moneys worth on these heads. But he is suggesting a second look at the iron heads which isn't a bad idea.
You'll have to decided if you want a new set OOTB to bolt on and go with room to go bigger or port what you have to the level your looking for. Which will mean reporting if you want to go bigger.

After looking up your cams RPM band, I have to honestly say that a 1.88 pocket ported J head is what you should be looking at for your current combo.

I'll say it again, I think the Edel. heads will be a nice improvemnet over what you have. I do not think the valve size is to big, or the ports to large to destroy velocity, but I muself would look at porting the J's.
 
wow, very informative posts from oldvart, Mrmopartech, and rumblefish360. Thanks for giving me some useful guidance on the head swap....I guess the question now is where can I get good head work performed here in NM? I would also be willing to entertain a new set of j-heads with the work already done, I guess you can never have to many spairs.
Now another question is can I have heads built that will perform at my current level and still have plenty left for maybe a larger cam later?
 
Problem solved,make a post to BJR,and ask him to help you,the deal is done,so call bobby at 1-770-443-8874,this is his NEW shop number and will help you to chose the right amount of head work,mrmopartech

One question to ask your self,why does a person buy heads from a guy some 2500-3000 miles away,and not from some one locally?
 
I have a set of eddies when they first came out. I had them flowed before i ported them and they only flowed 227 @ 550 lift. At 600 lift they fell off big time. They say a stock x head flows 218. In stock form there will not much difference except comp ratio. The eddies need more comp to get the same power has a iron head. If you are building a street motor consider a set of magums they will work better on the street. Harry
 
I would have to agree with having your iron heads ported. You can do a lot of work to them and get good numbers for way less than the eddies. I also remember reading a post here a while back where one fella actually went a little slower with the aluminum heads. Hard to believe but with the loss of a point in compression and the wrong cam choice, it is very possible. I ported my J heads myself in my garage and used the 2.02 intakes and got a flow of 212 @ .500, not fantastic but I really didn't go wild on the port job. I have another set of 360 heads that I am porting more radical but still using the 1.88 valves and will have them flowed to see what happens.
 
Mrmopartech said:
One question to ask your self, why does a person buy heads from a guy some 2500-3000 miles away,and not from some one locally?
Click to expand...

I visited Bobby myself and we talked for clearly 1/2 the day away on port flow and valve sizes alone. While I have to say we were in agreeance over 90% of the time, the other %5 was just past my been there done that experiance.
I just don't have it.
He'll set you up well. It's really nice when you deal with a MoPar only racer. He does do other brands of heads/manufactures, but his car is a MoPar and stays a Mopar.
 
duster harry said:
I have a set of eddies when they first came out. I had them flowed before i ported them and they only flowed 227 @ 550 lift. At 600 lift they fell off big time. They say a stock x head flows 218. In stock form there will not much difference except comp ratio. The eddies need more comp to get the same power has a iron head. If you are building a street motor consider a set of magums they will work better on the street. Harry
Click to expand...
I went from a set of stock J heads to an OOTB Eddy set and noticed no difference.
 
thanks, I am going to give BJR a call. As far as why send your heads 2500-3000 miles? I guess it's a matter of trust. Who knows, maybe BJR will recommend someone closer.
 
Dartman, I agree with the 'staff' on this one. Yes...give Bobby a call. He will set you up right. I have talked with him on the phone myself and he is a VERY sharp guy. He is one of the very few people that I would let touch my heads and I do all of my own head work...as you can tell by my handle there. 'J''s on my bench ( flow benches are like dyno's no two are alike). Flow 200-212 range stock (2.020). 230 or so bowl ported and will easily go over 250 with good deep port work. I don't know how much HP you want to make , but 250 cfm will get you just about 500 with the right components. No need to lay out the big bucks for expensive aftermarket hardware. Unless you just want to. Good luck and give us an update please, we are all still learning... Terry.
 
Believe me, I AM STILL LEARNING! This being my first REAL muscle car. I have learned quite a bit from this forum about mopars in general. I must be doing something right though.......(it's still runnning). I am not looking for 500hp out of my engine. Just something to pin my skinny *** to the seat when I nail it. I know I am going to have to address alot more than just the engine sooner or later. I am running 3.23 gears with 205/60/15 street tires and a pretty whimpy 904. I really want to get it out to a track this spring just to see what she will do. Again, I want to thank all of you for sharing your knowledge and helping me out along the way.
 
A buddy of mine went from 360 J heads, untouched, to a set of edelbrocks with no work to them, and went from 13.10 to 12.20 in the 1/4 mile. He also put a set of comp. roller rockers on at the same time.
 
What the others are saying is true for you, 63. On a mild combo, you will lose going to a bigger and better port, and a chamber designed to have the piston very close to it, as opposed to down in the bore with a dish. I'd keep the 1.88s, and have a good porter do a little work. A lot of good work will get expensive, and on yours, isnt needed. The first $200 you spend on porting gets the best results. The rest comes on a sliding scale, the more performance, the higher the cost. There's some debate about whether or not spending the $$ on aluminum is "right", "excessive", and "a good deal". But the end result is, you need a head that fits your budget and will work to get the goals you want. On some, factory iron can work. On others, ported iron will work. But a properly matched engine system will work the best. I've never seen a car lose power going to aftermarket heads. But I dont install them where they are not needed, or straight from the box. Also, I have seen plenty of engines with aftermarket heads not make the numbers they should. Who's to say why. My experience leads me to doubt it's just the heads.
 
You must log in or register to reply here.
-

Back
Top