Getting back to the cam issue, where does the lobe centres and intake centreline come into the equation ?
I've only seen specs such as intake opens...intake closes...exh opens...exh closes... and duration @ .050.

Can you work out the lobe centres and I/C from these figures ?

I guess the guys with DOHC and adjustable pulleys can pick their own lobe centres?

How does a cam with the specs you suggest perform off boost, is it going to be similar to NA or worse until you're on boost.

Sorry for being niave, but I haven't had much to do with cams before, especially having to choose my own specs.

Mike

Generally a turbo cam doesn't need to be that great which is why 114+ l/s which gives a very wide power band, therefore nice under boost.With reverse cam timing helps spool as well...

What is reverse cam timing ?

With an aggresssive grind, a 220@050" cam should have closer to 270 adv. My mates cam is 219@050" and 273 adv.

To give you slightly more low end torque you install it on a 110 deg Intake Centreline. This advances the cam 4 cam degrees (8 crank degrees) from straight up provided the cam is ground on a 114 LSA.

Wide LSA cams tend to feel a little lazier IMO but are highly recomended for boost or NOS. They also idle better.

Also with the right cam and your factory 1.7 rocker ratio high lifts are easily attainable. But high lift taxes the springs more, you shouldn't need to go to much over 500" lift on a stock head. Sure Cams have a very good selection of cam grinds and Phil Duggan will virtually custom tailor a cam profile. He has done cams for many of the previous horse power hero champions (Judge, TTV8 to name a few).

Here is a selection of Ford cams.
Compare them...Unforunately no inline 6...
Cam OE Number Type Int Lift Exh Lift Int Dur Exh Dur Int Dur@.050 Exh Dur@.050 Lobe Centerline
289 4bbl C3AZ-6250-E Hydraulic .368 .380 182 187 109
289 HiPerf Mechanical .477 .477 228 228 114
255 V8 80,81 EOSE-6250-AA Hydraulic .380 .380 244 244 107.5
302 4bbl 1969 C9OZ-6250-C Hydraulic .460 .460 218 218 113
351C 4bbl 1972 D2ZZ-6250-B Hydraulic .481 .490 206 220 115
351W HO EOAZ-6250-A Hydraulic .444 .452 206 221 115
351W Lightning
82-84 5.0L HO

84-85 5.0L CFI
D3OE-6250-AA Hydraulic .416 .445 260 274 198 208 114.5
4.2L V6 Hydraulic Roller .445 .455 278 282 113.5
5.0L BASE E5AE-AA,F1AE-AA Hydraulic Roller .379 .395 244 256 107.5
5.0L Cobra F3ZE-6250-CA Hydraulic Roller .479 .479 270 270 209 209 118
5.0L HO 85-88 E5ZE-6250-AA Hydraulic Roller .444 .444 266 266 115
5.0L HO 89-95 E8ZE-CA,F1ZE-AA,F4ZE-DA Hydraulic Roller .444 .444 266 276 115.5
5.0L 79 GT D6OE-6250-AA Hydraulic .381 .397 244 256 107.5
5.0L Truck, Explorer F4TE-6250-BA Hydraulic Roller .422 .448 256 266 116
351W 2bbl Hydraulic .416 .416 260 260 114

Here is a selection of Ford cams.
Compare them...Unforunately no inline 6...
Cam OE Number Type Int Lift Exh Lift Int Dur Exh Dur Int Dur@.050 Exh Dur@.050 Lobe Centerline
289 4bbl C3AZ-6250-E Hydraulic .368 .380 182 187 109
289 HiPerf Mechanical .477 .477 228 228 114
255 V8 80,81 EOSE-6250-AA Hydraulic .380 .380 244 244 107.5
302 4bbl 1969 C9OZ-6250-C Hydraulic .460 .460 218 218 113
351C 4bbl 1972 D2ZZ-6250-B Hydraulic .481 .490 206 220 115
351W HO EOAZ-6250-A Hydraulic .444 .452 206 221 115
351W Lightning
82-84 5.0L HO

84-85 5.0L CFI
D3OE-6250-AA Hydraulic .416 .445 260 274 198 208 114.5
4.2L V6 Hydraulic Roller .445 .455 278 282 113.5
5.0L BASE E5AE-AA,F1AE-AA Hydraulic Roller .379 .395 244 256 107.5
5.0L Cobra F3ZE-6250-CA Hydraulic Roller .479 .479 270 270 209 209 118
5.0L HO 85-88 E5ZE-6250-AA Hydraulic Roller .444 .444 266 266 115
5.0L HO 89-95 E8ZE-CA,F1ZE-AA,F4ZE-DA Hydraulic Roller .444 .444 266 276 115.5
5.0L 79 GT D6OE-6250-AA Hydraulic .381 .397 244 256 107.5
5.0L Truck, Explorer F4TE-6250-BA Hydraulic Roller .422 .448 256 266 116
351W 2bbl Hydraulic .416 .416 260 260 114

Ahhh try this link...Calibrated better...
http://www.angelfire.com/theforce/racin ... moteur.htm

Thanks guys,

Its becomming a little clearer now.....

So I guess to install the cam in a 110 degree intake centre line you use a timing chain set with multi keyway drive sprocket and advance by 8 degrees at the crank ?

Mike

Get to use the dial indicator and the cam
card (hopefully included with the camshaft!). First, install a
lifter on the #1 cylinder's intake lobe. Set up the dial indicator
so that it is parallel to the lifter bore using the magnetic base
fixture and so that it is actuated by the lifter (make sure the
plunger of the dial indicator is contacting the rim of the lifter
body and NOT the plunger for accurate measurements and that the dial
indicator is slightly preloaded at zero lift. Rotate the crankshaft
by hand until the dial indicator shows maximum lobe lift, and zero
the indicator (by turning the faceplate until it reads zero). Rotate
the crankshaft clockwise until the indicator reads -0.030" and record
the degree wheel reading. Continue to turn the crankshaft clockwise
(almost two revolutions) until the indicator again reads -0.030" and
again record the degree wheel reading. The installed centerline is
halfway between those two numbers (add them together and divide by
two). The cam card provides you with the manufacturers suggested
intake centerline. Compare this with your installed centerline. If
you are within a degree then you're all done and you can finish
buttoning up the motor. If not, we've got a little more work to do.

Get to use the dial indicator and the cam
card (hopefully included with the camshaft!). First, install a
lifter on the #1 cylinder's intake lobe. Set up the dial indicator
so that it is parallel to the lifter bore using the magnetic base
fixture and so that it is actuated by the lifter (make sure the
plunger of the dial indicator is contacting the rim of the lifter
body and NOT the plunger for accurate measurements and that the dial
indicator is slightly preloaded at zero lift. Rotate the crankshaft
by hand until the dial indicator shows maximum lobe lift, and zero
the indicator (by turning the faceplate until it reads zero). Rotate
the crankshaft clockwise until the indicator reads -0.030" and record
the degree wheel reading. Continue to turn the crankshaft clockwise
(almost two revolutions) until the indicator again reads -0.030" and
again record the degree wheel reading. The installed centerline is
halfway between those two numbers (add them together and divide by
two). The cam card provides you with the manufacturers suggested
intake centerline. Compare this with your installed centerline. If
you are within a degree then you're all done and you can finish
buttoning up the motor. If not, we've got a little more work to do.
A multy index timing chain is needed to change cam timing...

Thanks EBXR8,

I have a dial indicator but don't know if it will reach all the way down into the lifter area on a crossflow 250, I assume you can do all this with the head, push rods and rockers installed and take a DI reading off the rocker ?
Or maybe not if the lifters are not pumped with oil ?

If a cam manufacturer specifes some other installed timing, would it still be good to set it up for 110 degrees IC, making it better for the turbo application ?

Hey, by the way, what sort of ECU are you running on your TT XR8 ?

Mike

May be I could use a piece of 3/4 bar, faced neatly, as an extension from the lifter, making sure it is sitting on the outer rim of the lifter.

Mike

Haltech E6K

With the head on I just use the pushrod, with out any valve spring pressure hydraulic lifter will not compressor enough to worry about.

Yeah you're right, the spring in the DI is feather weight anyway.

Mike