Can worked J heads ever flow as well as the Edelbrocks?

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Kram1976

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I found some worked J heads on CL with this disc.

They are professionaly ported and polished. Never ran on an engine. .202/.160 swirl polished Feria valves. Double springs good for .750 lift. Have $1200 into them looking to get $725 for the set.

I am wondering if they are worth it?
Street rod 71 or 72 340 depends on who you ask build date of 1-21-71. Any insight here also would be appreciated.
Some very occasional strip action but mostly street. Some day I want to put a Indy perf. blower on it mostly for looks eg. low boost. I still want to drive it often on the street.
Are these a better deal or should I save up for the aluminum heads?

I just have stock 340 heads with the 1.8 and 1.6 valves now is it worth 500 for them if he will take it? and sell my stock ones on ebay? They look very well done.
I also dont know what the c ratio is as I purchashed this car as is.
Are there any high ratio engins made in the first part of 71 as 72 model engins?
 
They can move some good air (250+) but it takes some work-
Better choice is to start with the Edelbrock heads for what your doing IMO.
2013-02-18%2018_14_07-1.jpg
 
Yes. They can be made to flow as well as out of the box eddys, but I don't believe they can ever flow as well as ported eddys. Justin can expound on that a bit more since he does it. Maybe he will chime in.
 
Mildly ported J's should do as well as the Edelbrocks OOTB stated flow rates. Which in its self is a problem because it is not what they flow. Fully ported J's can do real well. But the super aggressive carving needed to get there can kill there desired effect for a great street machine.

All the above with a grain of salt and a little give and take.
A lot depends on the builds parts and objective. If your looking to make 400/430 HP, the iron heads are capable! This is not a problem and not does it require big cams and over the top pArts and compression ratios.
 
Fully ported RPMs will flow around 300cfm at .500" lift. I have never seen or heard of a stock head getting anywhere near that. I just dont think it can happen without welding or epoxy and who the hell would want to do that?
 
MRL Performance said:
Fully ported RPMs will flow around 300cfm at .500" lift. I have never seen or heard of a stock head getting anywhere near that. I just dont think it can happen without welding or epoxy and who the hell would want to do that?
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x2. It's all about spending the cash. You can make Js flow that much. But it's a **** load of work and cash for an iron head so thin it's not going to last long.
 
If you check them out and they can
be used in your app, $350 a head would
be hard to beat.
Couldn't hardly rebuild stockers for that.
Aluminum might let ya run a little more compression
if that is needed.
 
There's nothing wrong with making use of your ported J heads. They may not offer the higher ceiling performance level of the Edel. Heads but they can perform well. You can run into the 12's with a stock port J head.
 
MRL Performance said:
Fully ported RPMs will flow around 300cfm at .500" lift. I have never seen or heard of a stock head getting anywhere near that. I just dont think it can happen without welding or epoxy and who the hell would want to do that?
Click to expand...

I am certain it's been done before. When Edelbrocks didn't exist.
 
Can J heads flow as well as Eddys ? Yes, 240-250 cfm isn't to difficult as long as the porter actually knows what they are doing.
 
skrews said:
Can J heads flow as well as Eddys ? Yes, 240-250 cfm isn't to difficult as long as the porter actually knows what they are doing.
Click to expand...

Key words: know what they are doing.

Example: we have a set of ported x heads that LOOK like a work of art. Too bad they flow about 10 cfm LESS than untouched x heads.

I would never by ported heads unless it was from a proven head guy with a flow bench or...I could take them to someone I trust with a bench and see what they did flow.

The price is cheap if they're ready to run, but ask if the seller has flow numbers and confirm them if a commercial shop did them.
 
^ Exactly I have seen some heads that look great but don't flow for ****, and vise versa.
 
I've got a set of 308's that I had ported, they ended up flowing 264cfm at .500". The bench used lined up pretty well with published specs for a few different stock heads that were flowed on it, so the numbers should be pretty close.

That said, I agree with the above statements regarding having them flowed. If they haven't been flow tested, you have NO idea how they'll perform. And then there's always the wildcard, even if they have been flowed it depends on the flow bench used. Just like dyno's, flow benches are all a little different, and some are definitely more optimistic than others...
 
Before answering the question I must apologize to SGBARRACUDA. He has been waiting MONTHS for his STG VI heads without complaining. We have been dealing with crisis after crisis and emergency after emergency and are now getting back closer to normal.........Oh, I dunno, maybe emergencies and such are normal around here.

We have flow figures for J heads that we did maybe 8-10 years ago, just experiments back then, and haven't needed them or any reason to attempt any further developement because of the availability of aluminum heads. I would think there is more flow yet to be had from the J with what we have learned since then. Been kinda stuck on the big blocks for a long while.

Lift..............OOTB Edelbrock RPM....................Ported J

.100...................65......................................78
.200..................127....................................139
.300..................178....................................187
.400..................217....................................232
.500..................237....................................270
.600..................248....................................292


Unless someone can provide you with a flow sheet and some kind of a benchmark, like flows before porting, or a OOTB standard from another head on the same flowbench, you never really know what you are getting.

Double springs good for .750" lift is a possible red flag. The springs may be good for that, but is the head good for .750" lift? Most J heads, even when ported, stall around .450"-480" lift. And if they really have that workable on a J head (you may well need a longer valve stem) you may have some valve geometry issues unless something special has been set up rocker arm wise. Just be careful.
 
J heads have had problem with being porous. I did my own and had to get a new head because oneleaked into the water jacket. Hughes won't do other than mild bowl work and polishing because of that issue on J's
 
There's a lot of guys running j's into the 11's. the F.A.S.T. Racers use them and are getting around 290 cfm that's with 2.05 intake valves and a lot of work and money! Nothing more uglier than that squared off chunk of aluminum sitting on a nice sb.
 
It's not that hard to get 250-260 from them without getting really exotic. Those are my "Stage IIs" with 2.05/1.65 valves but just to return castings to ready-to-be-ported state with valves will cost $900. If there's $1200 into them ready to run that's not anywhere near what I'd say is top level porting. You have to have decent valves & you have to have decent machining in addition to the port work. But eventually you hit that wall where the minimum cross section restricts. So then you have the epoxy. Then the longer valves. Then the rocker hold down blocks and offset rockers... Then you really need to work the exh side because it flat out sucks and getting air in is only most of the battle... So it's up to what you want to spend. I've seen some work in books by Batten that predates W2s and is pure art for lack of a better term. But unless your class says you have to run those heads (SE, SS, FAST, etc), for 2/3 the money you can get a better chamber, lighter materials, and both intake and exh ports designed from the get-go to flow well.
 
Interesting stuff......Sure do miss StrokesHimself340 when a topic of cylinder heads pops up....
 
EL5DEMON340 said:
There's a lot of guys running j's into the 11's. the F.A.S.T. Racers use them and are getting around 290 cfm that's with 2.05 intake valves and a lot of work and money! Nothing more uglier than that squared off chunk of aluminum sitting on a nice sb.
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wrong

if you have a race bracket that requires iron heads, then you have to use them. if you have a factory show car you can do porting to keep them stock.

if you dont have money for a decent set of aluminum heads, spending the cash on porting iron heads is kinda sorta the same thing.

now if someone gave you a set of W2's free or something then maybe it would be worth it. on the J's i dont see it as saving you any money in the long run.

just my 2 cents
 
Since you can port in the FAST class, the next restriction is the exhaust manifds. This requires creative cam events.
 
What's wrong? In the 70's they use to stick 2.19 intake valves in the t/a head in pro stock. Nobody's going to do that now a days but the head will work.
 
EL5DEMON340 said:
What's wrong? In the 70's they use to stick 2.19 intake valves in the t/a head in pro stock. Nobody's going to do that now a days but the head will work.
Click to expand...
:wack:
A 2.19 and 1.6 won't fit do to valve spacing, the valves diameters would overlap one another.
 
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