562 possible cam swap

A-460 block
TFS 325 CNC heads
TFS 4500 intake
1250 dominator
4340 4.300 stroke crank
6.8 H beam rods
4.560 bore
14.1 compession
solid roller bullet cam 280-292 112 lobe sep .786-785 lift R311B.454.4/R326.454
2-1/8 headers with 4 inch collector
29x10.5 tire 4.10 gears glide and a tight converter. 5.91 motor and 9.24 1/4
5.34 @ 132 on a 275 shot ;car is 3240pnds

im looking at a new cam ,it a 285-303 .050 on a 113.5 lobe sep .821 in ans .813 ex lift
what do you guys think about the cam swap, good move or bad

are you planning to spray more

What's the installed height on springs?

whatbumper wrote:are you planning to spray more

at the most 325 shot,

Those heads do flow that high and since your not spraying a very large shot I would think the new cam would be great but maybe one of the gurus will chime in.

Are the heads ported? If so, what do they flow?

Lem,

Aren't those the new cnc TFS Streets? If they are I think on a honest bench they will go around 405-410 cfm. And the chamber is several cc's bigger.

IDT-572 wrote:Lem,

Aren't those the new cnc TFS Streets? If they are I think on a honest bench they will go around 405-410 cfm. And the chamber is several cc's bigger.

My bad....i did not see the CNC part of it. I really do not have an opinion being that I have no hands on with that package. Wonder why the chamber got much bigger?

I found these numbers which look about right.

401 @ 800
287 @ 800

I had a port flowing close to 400 cfm on the proto type head and had an exhaust port at 283 cfm, this was on Mikes bench with no chamber work.

I'm guessing you have solid data from the existing cam regarding valve clearance to the crown and radial? Otherwise it sounds like a logical progression unless the exhaust opening event begins to have issues with all that combustion pressure backing up in the port. Will it see much of a change at .200?

I'm running a cam close to that on my engine, with a 200 shot and all is well. But the cross sectional area is smaller on the streets and they don't have as much flow as mine either.

I would say it will be fine on the spray but slower on the engine.

IDT-572 wrote:I'm running a cam close to that on my engine, with a 200 shot and all is well. But the cross sectional area is smaller on the streets and they don't have as much flow as mine either.

I would say it will be fine on the spray but slower on the engine.

i dont really wont to slow it down N/A much. the new cam grind is a bullet cam that mark speced , he said it was a motor cam. looks like a nitrous cam to me
. I dont wont to mess the engine up with the wrong cam spraying
either.

I'm no pro by any means, but from what I'm learning, I would have to agree with Blake. I would say if one is gonna rely on the spray for most of the passes, that to sacrifice a little N/A power would be irrelavent if it was going to benefit even more from spray. If you want the best of both worlds, if it were mine, I would cam it for N/A power, and just "crutch" it with the spray. From what I've learned about the BBF and spray, until one gets around that 350+ range with the spray, it's not really necessary to run a nitrous spec'd cam.

IDT-572 wrote:I'm running a cam close to that on my engine, with a 200 shot and all is well. But the cross sectional area is smaller on the streets and they don't have as much flow as mine either.

I would say it will be fine on the spray but slower on the engine.

It's hard to say in that we can't see the @ .020" & .200" duration #s for his cams. If the 401/287 est. is correct that be a 72% exh. port...so if this thing is sure enough 14:1 I'm thinking 284*/298* 113 LSA would be a good trade off between being mean on engine and a liking the spray ~ J.Y. Kelly cam. HXL or DSS intake lobe.

Lem Evans wrote:

IDT-572 wrote:I'm running a cam close to that on my engine, with a 200 shot and all is well. But the cross sectional area is smaller on the streets and they don't have as much flow as mine either.

I would say it will be fine on the spray but slower on the engine.

It's hard to say in that we can't see the @ .020" & .200" duration #s for his cams. If the 401/287 est. is correct that be a 72% exh. port...so if this thing is sure enough 14:1 I'm thinking 284*/298* 113 LSA would be a good trade off between being mean on engine and a liking the spray ~ J.Y. Kelly cam. HXL or DSS intake lobe.

I agree, with you pulling that much exhaust out of it you have dropped the overlap enough to make it work on both
N'A and spray. And those two lobes lend themselves to building torque also compared to other lobe family's with the same @.050 numbers.

I'm still not sure the CNC Streets will tolerate the cam that the P-51 will, they have raised the bar as far as SCJ style heads go.

Yep, that 285/303/113.5 lsa deal may have 68* of overlap which is more than it'd have to have natural and too much for the hose i.m.o.

IDT-572 wrote:

Lem Evans wrote:

IDT-572 wrote:I'm running a cam close to that on my engine, with a 200 shot and all is well. But the cross sectional area is smaller on the streets and they don't have as much flow as mine either.

I would say it will be fine on the spray but slower on the engine.

It's hard to say in that we can't see the @ .020" & .200" duration #s for his cams. If the 401/287 est. is correct that be a 72% exh. port...so if this thing is sure enough 14:1 I'm thinking 284*/298* 113 LSA would be a good trade off between being mean on engine and a liking the spray ~ J.Y. Kelly cam. HXL or DSS intake lobe.

I agree, with you pulling that much exhaust out of it you have dropped the overlap enough to make it work on both
N'A and spray. And those two lobes lend themselves to building torque also compared to other lobe family's with the same @.050 numbers.

I'm still not sure the CNC Streets will tolerate the cam that the P-51 will, they have raised the bar as far as SCJ style heads go.

From what I have witnessed, the TFS heads need about 4 degrees more on the intake side than the P-51 heads.
These were TFS heads ported to about your max listed TFS numbers; not the CNC 325's.

[quote="Lem Evans"]

IDT-572 wrote:I'm running a cam close to that on my engine, with a 200 shot and all is well. But the cross sectional area is smaller on the streets and they don't have as much flow as mine either.

I would say it will be fine on the spray but slower on the engine.

It's hard to say in that we can't see the @ .020" & .200" duration #s for his cams. If the 401/287 est. is correct that be a 72% exh. port...so if this thing is sure enough 14:1 I'm thinking 284*/298* 113 LSA would be a good trade off between being mean on engine and a liking the spray ~ J.Y. Kelly cam. HXL or DSS intake lobe.

i was thinking about shooting 325 this weekend with the 280-292 but im a little gun shy
.020 .050 .200
311/280/197 IN. 326/292/209 EX 62 degree overlap
318/285/203 IN. 340/303/215 EX 67 degree overlap

you got my attention with the 284-298
flow chart below
http://static.trickflow.com/global/images/chartsguides/t/tfs%20airflow%20powerport%20325%20ford%20429%2C460.pdf

Is a dss lobe to aggressive for a 2.25 steel intake valve with 1.73 rocker ? if not whats a good ex mate lobe?

2-1/2" intake valve..... is that a typo?

Lem Evans wrote:2-1/2" intake valve..... is that a typo?

yes ,i fixed it, sorry

10SHOTS wrote:

IDT-572 wrote:I'm running a cam close to that on my engine, with a 200 shot and all is well. But the cross sectional area is smaller on the streets and they don't have as much flow as mine either.

I would say it will be fine on the spray but slower on the engine.

i dont really wont to slow it down N/A much. the new cam grind is a bullet cam that mark speced , he said it was a motor cam. looks like a nitrous cam to me
. I dont wont to mess the engine up with the wrong cam spraying
either.

Looks like a nitrous cam to you? If it was a spray only cam it'd need to be on 115* lsa i.m.o.

Lem Evans wrote:

10SHOTS wrote:

IDT-572 wrote:I'm running a cam close to that on my engine, with a 200 shot and all is well. But the cross sectional area is smaller on the streets and they don't have as much flow as mine either.

I would say it will be fine on the spray but slower on the engine.

i dont really wont to slow it down N/A much. the new cam grind is a bullet cam that mark speced , he said it was a motor cam. looks like a nitrous cam to me
. I dont wont to mess the engine up with the wrong cam spraying
either.

Looks like a nitrous cam to you? If it was a spray only cam it'd need to be on 115* lsa i.m.o.

That's what I was thinking. It looks like a decent grind to me. With the small 375 shot it will still work fine in my opinion. If more nitrous was being thrown at it then a dedicated grind would be needed.