Head thoughts

roadrunner69440 · Aug 15, 2019

all you racer guys and engine builders that have messed with heads, 906’s to speak of, what kind of flow numbers would you see by just adding a good performance valve? It’s easier to go pick up a set of tf 240’s but at $2100 I would like to explore options and get some of you alls input. 440- target hp 500-550. thanks guys

tmaleck · Aug 15, 2019

I went with Marsh Performance Sidewinder heads. $1300 complete all machine work done, valves and springs to match my engine specs. Couldn't do my 906's for that.
Tim

1 Wild R/T · Aug 15, 2019

tmaleck said:
I went with Marsh Performance Sidewinder heads. $1300 complete all machine work done, valves and springs to match my engine specs. Couldn't do my 906's for that.
Tim

Good Choice... 906's just aren't a good choice.... If you really want Iron heads I'd track down some 915's so you have a closed chamber....

But it doesn't sound like you are limiting yourself that way... I bought a set of Edelbrocks before all the great options came out, they are still a decent head but apparently the quality hasn't been as good lately & the price has gone up considerably from the $1100 delivered I paid...

Yeah, I think I'd call Todd @ Marsh

moparnation74 · Aug 16, 2019

1 Wild R/T said:
Good Choice... 906's just aren't a good choice.... If you really want Iron heads I'd track down some 915's so you have a closed chamber....

But it doesn't sound like you are limiting yourself that way... I bought a set of Edelbrocks before all the great options came out, they are still a decent head but apparently the quality hasn't been as good lately & the price has gone up considerably from the $1100 delivered I paid...

Yeah, I think I'd call Todd @ Marsh

I take it your referring to the big valve 915’s correct?.........there are two choices for 915’s...

roadrunner69440 · Aug 16, 2019

1 Wild R/T said:
Good Choice... 906's just aren't a good choice.... If you really want Iron heads I'd track down some 915's so you have a closed chamber....

But it doesn't sound like you are limiting yourself that way... I bought a set of Edelbrocks before all the great options came out, they are still a decent head but apparently the quality hasn't been as good lately & the price has gone up considerably from the $1100 delivered I paid...

Yeah, I think I'd call Todd @ Marsh

Thanks for your input. I don’t HAVE to stay with steel, I have a set of 906’s already done ( stock) with hardened seats and it’s killing me to just basically throw them away. In the end I’ll most likely go with a good aluminum head, I just wanted some good chat on the 906 performance options ( if there is such a thing)

1 Wild R/T · Aug 16, 2019

moparnation74 said:
I take it your referring to the big valve 915’s correct?.........there are two choices for 915’s...

And either set will be big valve with a quick & easy valve job... Fact is 2.14 & 1.88 are easy upgrades as well..

moparnation74 · Aug 16, 2019

1 Wild R/T said:
And either set will be big valve with a quick & easy valve job... Fact is 2.14 & 1.88 are easy upgrades as well..

I have seen 915’s not advertised correctly and asking more for the small valve version and buyers thinking they are the big valve heads....so a used set will likely be getting a valve job but I wouldn’t want someone to pay up for a set listed wrong......

33 IMP · Aug 16, 2019

For your first question: just adding a big valve on a 906, without a bowl blend after opening the throat up, gets you nothing,except a bill at the machine shop. I've seen tests showing a big valve making the flow worse, from bad valve seat work.
In my humble opinion..... if you just had some old 906s that needed everything done to them, then no way would i put money into them with really good aluminum heads as an option.
But! You say they are fresh with seats. Decent springs? 906s on a 440 with a big cam and decent compression can get to 500 fairly easily. 550hp is much easier with good aluminum heads. Is that 50hp worth $1500-$2100 ? Thats for you to decide.
As an aside, i just put $900 into freshening up a set of iron heads..... but they were a beautifully full ported set of max wedge heads, no way i spend that on unported 906.

Challenger340 · Aug 16, 2019

roadrunner69440 said:
all you racer guys and engine builders that have messed with heads, 906’s to speak of, what kind of flow numbers would you see by just adding a good performance valve? It’s easier to go pick up a set of tf 240’s but at $2100 I would like to explore options and get some of you alls input. 440- target hp 500-550. thanks guys

Rebuilt nicely with properly done Hone-Fit Bronze V/Guides, a nice 3 angle Job/75* throats blended into the Bowls working with 2.14"/1.81" SS Valves/Backcut we see 230's cfm around .500" lift, and into the 240's cfm with a bit of work from there.
No 2 Flow Benches are the same, for comparison OOTB Stealth's show us high 250's cfm on our Flow Bench and OOTB Edelbrock rpm's only 260's even though Edelbrock advertise them at "291" cfm.

Yes, you can work with 906's to make 500-550 hp and more, the question would be WHY ?????? Given it will cost you FAR MORE to bring the 906's up around 260 cfm for the 525+hp target that the mere $2,100 you are already averse to on the TF's ?
And NO.....
You are NOT going to see even 230's running over to a NAPA store type rebuild on the 906's with new Valves... ain't happening !

You want 500+ just go buy a Stealth, Eddy or Sidewinder and bolt them on OOTB, all will go there easily OOTB with the right Pistons & F.T. Hydraulic Cam.

Challenger340 · Aug 16, 2019

Why do people think they can go buy Big Valves, get their Cast Iron Heads "rebuilt"(usually as cheaply as possibly right), and somehow think they have the same Flow published by Shops that are doing... and are still really good at doing "performance" style work on Cast Iron Heads ?
just say'in....
hard trying to figure out how people think "Oranges" are somehow Apples ?

Simply put...
CAST V/Guides have typically.002" to .0025" clrc OOTB... and can very quickly wear in on fire up .005" to .001" more then that depending on the Valve stems used.
The Valve GUIDE determines the concentricity that can be maintained by the Valve with the Valve SEAT, and how fast those seat angles will wear away or WIDEN as it wipes away under a sloppy V/Guide ?
Just say'in....
CAST V/Guides do NOT support performance style Valve Seat work PERIOD, and even if one tried it wouldn't last a week in operation before it's gone and Flow is reduced until the seat width reaches equilibrium width for the now sloppy V/guide.

PRHeads · Aug 16, 2019

It comes down to these questions:
- do you have a fresh set of rebuilt stock heads that are complete and ready to bolt on, prepared to the level necessary for the goals set?
- are they going on a period correct rare car worth big money, and you really want to maintain the cars originality?
- are you running the engine in some sort of racing series where the stock heads are required?

If you can’t answer positively “yes” to any of those questions....... don’t bother with stock heads.
Unless it’s a personal challenge type of situation, and you’ve acknowledged to yourself that you’re going to spend more, and end up with less....... and you’re okay with that.

If you think that won’t be the case....... you’re kidding yourself.

roadrunner69440 · Aug 16, 2019

33 IMP said:
For your first question: just adding a big valve on a 906, without a bowl blend after opening the throat up, gets you nothing,except a bill at the machine shop. I've seen tests showing a big valve making the flow worse, from bad valve seat work.
In my humble opinion..... if you just had some old 906s that needed everything done to them, then no way would i put money into them with really good aluminum heads as an option.
But! You say they are fresh with seats. Decent springs? 906s on a 440 with a big cam and decent compression can get to 500 fairly easily. 550hp is much easier with good aluminum heads. Is that 50hp worth $1500-$2100 ? Thats for you to decide.
As an aside, i just put $900 into freshening up a set of iron heads..... but they were a beautifully full ported set of max wedge heads, no way i spend that on unported 906.

Thank you for your input. This is the kind of real life info and truth I’ve been looking for. Not to down play some of the other guys info, it was interesting as well

roadrunner69440 · Aug 16, 2019

PRHeads said:
It comes down to these questions:
- do you have a fresh set of rebuilt stock heads that are complete and ready to bolt on, prepared to the level necessary for the goals set?
- are they going on a period correct rare car worth big money, and you really want to maintain the cars originality?
- are you running the engine in some sort of racing series where the stock heads are required?

If you can’t answer positively “yes” to any of those questions....... don’t bother with stock heads.
Unless it’s a personal challenge type of situation, and you’ve acknowledged to yourself that you’re going to spend more, and end up with less....... and you’re okay with that.

If you think that won’t be the case....... you’re kidding yourself.

First question,kinda they are ready to bolt on but only stock. Not sure what real hp you can get from a stock head ( I’ve heard 500?? I’m reluctant) second and third questions,NO! Thanks for your input

wyrmrider · Aug 16, 2019

You got some real advice from the other posters
You can get a lot of HP from a stock head
as Stroker McGurk said
"The only thing that beats cubic inches is cubic money"
problem running a high hp open chamber stock head is the amount of $$$ porting and big cam to make it work makes it not useable as a street/ strip option
that's IMHO

PRHeads · Aug 17, 2019

roadrunner69440 said:
First question,kinda they are ready to bolt on but only stock. Not sure what real hp you can get from a stock head ( I’ve heard 500?? I’m reluctant) second and third questions,NO! Thanks for your input

If your heads are currently in the “refurbished to stock specs” condition, and you’re looking to make 500hp from a stock stroke 440........ you’ll still be money ahead(and make more power) by getting aftermarket heads.

If you outline what the gist of your intended build is like, a few on here can probably give you a good idea of what kind of power you can expect.

wyrmrider · Aug 17, 2019

as PRH says- power is in the heads
and in this case can be more cost effective on an absolute basis and definitely on a $$$ to performance analysis
BTW you can but do not just add a 2.14 valve there is no gain without doing the matching valve job (talking all the angles here) and opening up the throats
easy if you have access to a modern seat and guide machine like a Serdi
that said you can get a new (and higher) seat with the larger valve with no extra work except grinding the seat if all you have are stones
if you do any of these seat changes check your spring installed height
in fact check anyway and also see if your stems come out the same height
anything way off is a clue

Cranky · Aug 17, 2019

Went 10.60's with max ported big valve 906 heads on a stock stroke 440.....660 lift roller cam, 4500 stall, lots of gear etc etc etc.....back in the 80's. Back then aftermarket heads just weren't around so you had to use factory cast heads. When I finally got a set of Eddys, I checked them both against each other and they flowed pretty much the same....but the Eddy's had a better chamber and port design. Guess which one would be a better head? Anyways, if you're looking for good street performance without spending a wad of money on them, at least to a valve pocket job. If you have any old heads laying around to practice on, have a good die grinder (they can be had in electric too), get some bits and go for it. Mopar heads have a sorry bowl as cast and machined (area just under the valve) and just doing smoothing that out will produce decent butt feel. And yes, outline what you want to do with the car as PRH suggested.

Head thoughts

roadrunner69440

Well-Known Member

tmaleck

Well-Known Member

1 Wild R/T

FBBO Gold Member

moparnation74

Well-Known Member

roadrunner69440

Well-Known Member

1 Wild R/T

FBBO Gold Member

moparnation74

Well-Known Member

33 IMP

FBBO Gold Member

Challenger340

Well-Known Member

Challenger340

Well-Known Member

PRHeads

Well-Known Member

roadrunner69440

Well-Known Member

roadrunner69440

Well-Known Member

wyrmrider

Well-Known Member

PRHeads

Well-Known Member

wyrmrider

Well-Known Member

Cranky

Banned Henchman #27

Similar threads