441 chevy heads

[don oconnor]

building a 255 hp 350 chevy super stock motor using the441 castings--is the chance of going into the waterjacket when installing roller cam springs? any suggestions------thanks

[ss chief]

What springs are you planning on using?

[Baprace]

Don , when I cut for bigger springs I use a .030 stock diameter valve shim located in stock position and I have cut 1.460 ( crane cam diameter ) and have never hit water, when you are done the head will have a step in the valve spring seat so the shim must stay in the stock location, I also sand the outside bottom coil to get rid of the sharp edges so the spring does not cut into the corners of the valve spring pocket, I have seen 1.530 springs on that style of head but I don't remember if the step was the same. Hope this info helps .

[MNracer61]

building a 255 hp 350 chevy super stock motor using the441 castings--is the chance of going into the waterjacket when installing roller cam springs? any suggestions------thanks

Just curious why the use of rollers? on 255 hp motor? YOu should be able to get well over that with stock style valvetrain?

My circle track motor with a 420 lift rule cam and 441's gets a little over 300 hp


Not trying to jump the thread but just curious.

[robert1]

The .030 shim is a must! Then as Baprace said radius the spring.

[needforspeed66gt]

I don't cut the spring pocket on those heads for big springs anymore - the ISKY Toolroom 295D fits in the stock location and can handle most cams out there. If I needed something more I would open the pad up to 1.375" and make a PAC 1521 dual spring for an LS application fit.

[ss chief]

The motor he is building should be in the 580- 600 hp range. The lift on the cam will exceed .750 lift. The 255hp is the stock rating. Typically the springs required are over 320 on the seat and over 1000 on the nose. Pac makes some double wire springs that are smaller than a 1.670 manley. I would stay .090 from the stock spring seat to be safe. You can run longer valves to get the installed height you need.

[JWRE]

Without dragging this post on, I'll just say this. A spring locater brazed or sometimes even epoxied in place, is a permanent fix for this problem.

[trmnatr]

building a 255 hp 350 chevy super stock motor using the441 castings--is the chance of going into the waterjacket when installing roller cam springs? any suggestions------thanks

Just curious why the use of rollers? on 255 hp motor? YOu should be able to get well over that with stock style valvetrain?

My circle track motor with a 420 lift rule cam and 441's gets a little over 300 hp


Not trying to jump the thread but just curious.

255hp engine built to SS spec, I would say is 550hp+

His heads may end up flowing ~300cfm I would say, I would say if they dont go 280cfm @28" with a 1.94" valve he is not gonna compete

[trmnatr]

building a 255 hp 350 chevy super stock motor using the441 castings--is the chance of going into the waterjacket when installing roller cam springs? any suggestions------thanks

Just curious why the use of rollers? on 255 hp motor? YOu should be able to get well over that with stock style valvetrain?

My circle track motor with a 420 lift rule cam and 441's gets a little over 300 hp


Not trying to jump the thread but just curious.

By the way, here is a general run down of the heads. Larry has posted pics of some 041 super stock heads, search on here for them. A thread I answered a question in about SS heads and they said they cant be oval, Then Larry posted a pic of the oval ports, just search my posts or his and you will find it

In general here are some facts about the super stock heads of the past, Im gonna give you some facts about super stock -291 heads, Larry could give you "CURRENT" info on them,
- 1.94/1.5 valves (thats what came in them)
- .200" longer valves usually
- oval intake ports, they are also raised
- 165cc intake runners, or less (which is one reason they go oval IMO)
- can be angle milled to 57.5cc, valve angle cant be changed in head and valve cover rail had to be left alone in the past
- 65cc exhaust ports, however talented guy like Larry and others who do these heads and the SS racers use Stahl headers, so then they need to put an adaptor plate on the head thats 1/2" or so thick and this increases the volume of the port, but is not seen by NHRA etc as part of the port (this may be different now)
- many are using 1.65" pivot length shaft rockers (i have them on my sbc) for more spring clearance along with a smoother arc

The stroke thing "WAS" the crank had to be with in .013" of the stroke (example, 327 3.25" stroke could be as much as 3.263")

The pistons are factory compression height, now as to what goes on here, not gonna say other than in the past they used to weigh around 340grams with a 80gram .875" pin and Manley Pro Series 5.7" rods

If you plan to do a Super Stock engine, get ready to throw $8500.00 in the heads, seats, guides, machine work, porting, welding, valves, springs, retainers, locks, shaft rockers and intake with porting

And if your doing alot of racing, you will want a back up set of heads. You may need them, they can break through at any time. The older ones that used 1.640" NexTek springs, have to be checked every couple runs by just pulling the covers

[6sally6]

building a 255 hp 350 chevy super stock motor using the441 castings--is the chance of going into the waterjacket when installing roller cam springs? any suggestions------thanks

Just curious why the use of rollers? on 255 hp motor? YOu should be able to get well over that with stock style valvetrain?

My circle track motor with a 420 lift rule cam and 441's gets a little over 300 hp


Not trying to jump the thread but just curious.

By the way, here is a general run down of the heads. Larry has posted pics of some 041 super stock heads, search on here for them. A thread I answered a question in about SS heads and they said they cant be oval, Then Larry posted a pic of the oval ports, just search my posts or his and you will find it

In general here are some facts about the super stock heads of the past, Im gonna give you some facts about super stock -291 heads, Larry could give you "CURRENT" info on them,
- 1.94/1.5 valves (thats what came in them)
- .200" longer valves usually
- oval intake ports, they are also raised
- 165cc intake runners, or less (which is one reason they go oval IMO)
- can be angle milled to 57.5cc, valve angle cant be changed in head and valve cover rail had to be left alone in the past
- 65cc exhaust ports, however talented guy like Larry and others who do these heads and the SS racers use Stahl headers, so then they need to put an adaptor plate on the head thats 1/2" or so thick and this increases the volume of the port, but is not seen by NHRA etc as part of the port (this may be different now)
- many are using 1.65" pivot length shaft rockers (i have them on my sbc) for more spring clearance along with a smoother arc

The stroke thing "WAS" the crank had to be with in .013" of the stroke (example, 327 3.25" stroke could be as much as 3.263")

The pistons are factory compression height, now as to what goes on here, not gonna say other than in the past they used to weigh around 340grams with a 80gram .875" pin and Manley Pro Series 5.7" rods

If you plan to do a Super Stock engine, get ready to throw $8500.00 in the heads, seats, guides, machine work, porting, welding, valves, springs, retainers, locks, shaft rockers and intake with porting

And if your doing alot of racing, you will want a back up set of heads. You may need them, they can break through at any time. The older ones that used 1.640" NexTek springs, have to be checked every couple runs by just pulling the covers

Real green-horn question but.......are the 3947040(327) heads the SAME as the 441 heads...with the exception of the two "humps" on the outside?!
Thanx
6sally6

[MNracer61]

Real green-horn question but.......are the 3947040(327) heads the SAME as the 441 heads...with the exception of the two "humps" on the outside?!
Thanx
6sally6

The 441 head is an open charber 76cc head. the 040 is a 64cc closed chamber head. The 040 would probably be similar to an 041 head but without accesorie holes.

[randy331]

- 1.94/1.5 valves (thats what came in them)

- 165cc intake runners, or less

His heads may end up flowing ~300cfm I would say, I would say if they dont go 280cfm @28" with a 1.94" valve he is not gonna compete

300 cfm thru a 1.94" valve?
300 cfm thru a 165cc port? a 23* 40 year old design port?
1.94" valve, with a 90% throat, and 11/32" valve, would be 130 cfm ^2" at the throat. And I'd think in a class where less CCs is important, one would keep the throat small.
300 cfm thru a 165cc port, would be an AVERAGE port speed of around 390 fps. How fast would the fastest areas be?
300 cfm would be around 162 cfm ^2" for an AVERAGE of the port, meaning the small places flow more than that.

Like to see this head on my bench.

Did this happen on the same bench that a 4150 carb flowed 1200+ cfm on? Somewhere I remember reading that happened.

Randy

[trmnatr]

- 1.94/1.5 valves (thats what came in them)

- 165cc intake runners, or less

His heads may end up flowing ~300cfm I would say, I would say if they dont go 280cfm @28" with a 1.94" valve he is not gonna compete

300 cfm thru a 1.94" valve?
300 cfm thru a 165cc port? a 23* 40 year old design port?
1.94" valve, with a 90% throat, and 11/32" valve, would be 130 cfm ^2" at the throat. And I'd think in a class where less CCs is important, one would keep the throat small.
300 cfm thru a 165cc port, would be an AVERAGE port speed of around 390 fps. How fast would the fastest areas be?
300 cfm would be around 162 cfm ^2" for an AVERAGE of the port, meaning the small places flow more than that.

Like to see this head on my bench.

Did this happen on the same bench that a 4150 carb flowed 1200+ cfm on? Somewhere I remember reading that happened.

Randy

Nope, they are not 30 year old ports

Have you ever seen an Oval port GM 291, 461, 492 head for Super Stock?

They are OVAL ports as they have to stay in a given volume (165cc) and the OVAL port allows them to be more effective in the port when working with a head rule, this is why they get $5000+ to do them too

[maxracesoftware]

- 1.94/1.5 valves (thats what came in them)

- 165cc intake runners, or less

His heads may end up flowing ~300cfm I would say, I would say if they dont go 280cfm @28" with a 1.94" valve he is not gonna compete

300 cfm thru a 1.94" valve?
300 cfm thru a 165cc port? a 23* 40 year old design port?
1.94" valve, with a 90% throat, and 11/32" valve, would be 130 cfm ^2" at the throat. And I'd think in a class where less CCs is important, one would keep the throat small.
300 cfm thru a 165cc port, would be an AVERAGE port speed of around 390 fps. How fast would the fastest areas be?
300 cfm would be around 162 cfm ^2" for an AVERAGE of the port, meaning the small places flow more than that.

Like to see this head on my bench.

Did this happen on the same bench that a 4150 carb flowed 1200+ cfm on? Somewhere I remember reading that happened.

Randy

the #041x's only Flow between 250 to 265 on my Bench
i've never yet seen a #441 or #441x or #041x Flow over 265 CFM on my Bench

250-260 CFM on my Bench is good for 9.90's to 10.10's @ 3330 Lbs in SS/IA
or 9.885 ET in SS/HA
which is also 550's to 585 Peak HP on my SF-901

....from the CHEVY362.PMD file in PipeMax ,

362.661 Cubic Inches @ 7200 RPM with 104.0 % Volumetric Efficiency PerCent

Required Intake Flow between 252.2 CFM and 266.6 CFM at 28 Inches
Required Exhaust Flow between 172.9 CFM and 195.0 CFM at 28 Inches

once you get more than 265 cfm on my bench at only 163-165 cc port volume
in 5.200-5.300 port length
it won't make hardly anymore Peak HP

if it were possible to get a real 300 CFM out of 165CC's in 5.168 Port Length
it would actuall make LESS Peak HP because port velocity would be way too fast !

it would make more HP with 265 CFM than 300 CFM