600 HP 350 SBC?

[GARY C]

A run down on my Rectoval port, I have not cc'ed it because all of the stuff I used to cc has disappeared, not sure how to measure a Rectoval?
Flow is
2-140
3-200
4-244
5-277
6-300
7-303
7.5-305
Air speed from enter through port is 397, ssr apex floor is 418...Where to go from here?

Gary,
Is this a test head or are you going to use it on a engine?
What size is the port opening 1207 gasket ?? Looks big

I raised the ports they are 1.85 tall and 1.194 wide, it's hard to see in the first photo but the valve cover rails have been notched to accept a trim to fit gasket, hear is what a 1205 would look like on them. The intake is a raised runner cut to fit a standard head as per the picture but it will be raised to match the roof of the now raised port.

[GARY C]

A run down on my Rectoval port, I have not cc'ed it because all of the stuff I used to cc has disappeared, not sure how to measure a Rectoval?
Flow is
2-140
3-200
4-244
5-277
6-300
7-303
7.5-305
Air speed from enter through port is 397, ssr apex floor is 418...Where to go from here?

Gary,
Do you have DV's and my FLOW Program?

You would need port height, port width and what each corners radius is.

Stan

I have a version you sent me in 2017, I just sent you the original email,(email failed to go through), last time I tried to open it it wanted verification that I no longer have.

The port is 1.85 tall and 1.194 wide but I am not sure on the big top radius corners and the floor is a full oval.

[PRH]

It sure “looks” big for only 305cfm.

Well, I don’t mean “only 305cfm”....... but it looks bigger than I’d expect 305cfm to look.

I don’t see much high effort sbc stuff at my shop(I do mostly Mopar stuff), but here’s some numbers from an ootb cnc ported TFS 230cc head(uses a 1206 gasket) .....tested on a 4.00” bore-

Lift———int flow
.100—— 66.6
.200——140.8
.300——211.2
.400——258.0
.500——286.1
.600——290.5
.700——294.3

Here’s what they show...... tested on a 4.155 bore:

My flow #'s are on a bigger bore, probably 295 on a 4" bore, they are around 200cc.

I’m pretty sure I’ve never had a 200cc sbc intake port go anywhere near 295cfm....... so if you’re are that good, I’d say put them on and run them.

[Stan Weiss]

A run down on my Rectoval port, I have not cc'ed it because all of the stuff I used to cc has disappeared, not sure how to measure a Rectoval?
Flow is
2-140
3-200
4-244
5-277
6-300
7-303
7.5-305
Air speed from enter through port is 397, ssr apex floor is 418...Where to go from here?

Gary,
Do you have DV's and my FLOW Program?

You would need port height, port width and what each corners radius is.

Stan

Gary,
I have a new email address. I have sent you an email.

I am going to make an assumption that the bottom of the port is a continuous arc. That means the port width is the diameter and half the port width is the radius.

To double check that lay a straight edge across the port where the epoxy stops on both sides and measure from the middle on the straight edge to the bottom of the port.

1.85 x 1.194 = 2.209 sq in No corner radius

1.85 X 1.194 = 2.056 sq in No top corner radius and .597 for bottom corner radius

Stan
I have a version you sent me in 2017, I just sent you the original email,(email failed to go through), last time I tried to open it it wanted verification that I no longer have.

The port is 1.85 tall and 1.194 wide but I am not sure on the big top radius corners and the floor is a full oval.

[levisnteeshirt]

Grumpys and Smokeys books talk about 600hp level 350s ,, late 70s stuff ,, doesn't look difficult ,, Smokeys stock block Indy motor was 675 with a roller cam and mechanical FI , 355 ,, nothing really out there

[levisnteeshirt]

Grumpys and Smokeys books talk about 600hp level 350s ,, late 70s stuff ,, doesn't look difficult ,, Smokeys stock block Indy motor was 675 with a roller cam and mechanical FI , 355 ,, nothing really out there

[GARY C]

Gary,
Do you have DV's and my FLOW Program?

You would need port height, port width and what each corners radius is.

Stan

Gary,
I have a new email address. I have sent you an email.

I am going to make an assumption that the bottom of the port is a continuous arc. That means the port width is the diameter and half the port width is the radius.

To double check that lay a straight edge across the port where the epoxy stops on both sides and measure from the middle on the straight edge to the bottom of the port.

1.85 x 1.194 = 2.209 sq in No corner radius

1.85 X 1.194 = 2.056 sq in No top corner radius and .597 for bottom corner radius

Stan
I have a version you sent me in 2017, I just sent you the original email,(email failed to go through), last time I tried to open it it wanted verification that I no longer have.

The port is 1.85 tall and 1.194 wide but I am not sure on the big top radius corners and the floor is a full oval.

Yes I was guessing they probably under 2.0, the floor will have to come down some when I do the intake, I will probably just have to see where I end up.

[gmrocket]

Gary,
Do you have DV's and my FLOW Program?

You would need port height, port width and what each corners radius is.

Stan

Gary,
I have a new email address. I have sent you an email.

I am going to make an assumption that the bottom of the port is a continuous arc. That means the port width is the diameter and half the port width is the radius.

To double check that lay a straight edge across the port where the epoxy stops on both sides and measure from the middle on the straight edge to the bottom of the port.

1.85 x 1.194 = 2.209 sq in No corner radius

1.85 X 1.194 = 2.056 sq in No top corner radius and .597 for bottom corner radius

Stan
I have a version you sent me in 2017, I just sent you the original email,(email failed to go through), last time I tried to open it it wanted verification that I no longer have.

The port is 1.85 tall and 1.194 wide but I am not sure on the big top radius corners and the floor is a full oval.

That's a whole lot of work and probably get it sorta close.

Best way is with a planimeter. Trace the port or use a soft piece of solder to do the internal shape.

Then lay the solder on a piece of paper and trace the outer area. Then get your handy dandy planimeter and go around the outline stopping where you started

It reads out the exact area for you

I'll post pics and a video on how quick and accurate it is..it's the only way to do real odd shaped ports and get it exact

[GARY C]

gm, that sounds interesting.

[barnym17]

Grumpys and Smokeys books talk about 600hp level 350s ,, late 70s stuff ,, doesn't look difficult ,, Smokeys stock block Indy motor was 675 with a roller cam and mechanical FI , 355 ,, nothing really out there

Jenkins did it but he had a team of pros sweated every detail spent countless hours on porting the old 292 heads,welding and porting on the prostock versions and he only managed 500 to 550 in cup trim.I wish it was that easy for example I have a 355 with 11.5 to1 comp solid roller cam and a set of reed ported 292"s and according to my calcs based on et and mph shes only putting out about 450.The heads were state of the art in the early80's cost the original owner about 3000 in early 80's bucks.

[RevTheory]

gm, that sounds interesting.

Yeah, the solder trick sounds like it'll work. Find the length and enter it here https://www.omnicalculator.com/math/circumference

[KnightEngines]

You need around 2.2^" mcsa & 265-275cfm at max valve lift through intake & head to make 600hp - if the port if efficient.

[GARY C]

You need around 2.2^" mcsa & 265-275cfm at max valve lift through intake & head to make 600hp - if the port if efficient.

I haven't started on the intake yet but thats about where I expected I would end up.

[PRH]

If that’s a 1205 gasket on the heads...... then yeh, they’re def not as big as they “look” in that first pic.

As to the original question......
600hp from a 350...... with no rules to go by, I’d just take the path of least resistance.
12-13:1, something like AFR heads, good intake with a little work on it, roller cam, good pan....... shouldn’t be too hard.

[Stan Weiss]

gm, that sounds interesting.

Yeah, the solder trick sounds like it'll work. Find the length and enter it here https://www.omnicalculator.com/math/circumference

Shawn,

That calculator only works for a circle. The following from Gary's heads

► 1.85 * 1.194 = 2.2089 sq inches area

► (1.85 * 2) + (1.194 * 2) = 6.088 length

The 2.2089 sq in area produces a circumference of 5.26857

Stan