Need help choosing cam for Supercharged 331

Just wanted some opinions for a cam choice for my combo:

Hydraulic Roller Camshaft
331 with 9.12:1 compression ratio
Scat 9000 Crankshaft, I-Beam rods
Probe Dished Pistons
Powerdyne supercharger (6-9psi max)
Edelbrock Performer RPM heads (2.02" intake, 1.60" exhaust valves)
.575 max valve lift
30 lbs injectors
3.73 rear end gears

Still need to get:

70-80mm Mass Air Meter calibrated to 30 lb injectors
1.6 or 1.7 roller rockers

I want to make some power, but I also want it to be streetable. So I guess that means a smooth idle and a 112 degree lobe separation to keep it computer friendly.

If you need any more information, let me know. I'm really fighting with myself over this. I'm afraid that whatever I pick will be the wrong choice.



<font size=-1>[ This Message was edited by: 89Trooper on 1/28/04 4:58pm ]</font>

I'm going to assume this is a roller cam block.
Page 80 of the latest Comp. Cam catalog has the XE274HR listed.
This has excellent street manners with a small lope at idle.
I think this is the same cam that Richard Holdner uses in an awful lot of his sbf combo's.

_________________


<font size=-1>[ This Message was edited by: 85mike on 1/28/04 3:14pm ]</font>

Yes, sorry... I added it above in my specs...

I was looking at the Comp Cams catalog. The XE274HR sounds good, but why shouldn't I use one of the BLOWER cams like the 284HR or 276HR?

I see that all the Blower cams have a 114 degrees lobe separation. I read that you shouldn't go over 112 degrees. Is this only in naturaly aspirated engines?

Thanks for any help.

If you want to keep it computer friendly and have any need to keep it smog legal...the FMS E303 is a great unit. If you compare it to many of the aftermarket cams, there are very few differences.

You may want to tune the install a bit, byt using high ratio lifters (1.7) either on the exhaust only or both intake and exhaust.

If you are not that concerned about smog...look into the Anderson Ford line of supercharger, N2O cams

I just read that for blower applications, it is better to go to 114 degree lobe separation so the overlap is LESS. That way you don't blow the intake right out the exhaust. That would explain why all the Comp Blower cams have 114 deg sep.

Here's the book.
5.0 Dyno tests.
S.A. Design books. By Richard Holdner
Less than $15.
[addsig]

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2004-01-28 04:56, 89Trooper wrote:
I read that you shouldn't go over 112 degrees. Is this only in naturaly aspirated engines?

Thanks for any help.
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>
You shouldn't use less than 112* LSA on EFI equipped engines since it doesn't provide enough vac signal for proper idle.

Now I'm confused. Here is a quote from an article about cams in the latest 5.0 Mustang mag:

"The computer can't handle the erratic vacuum signal produced by a lobe separation angle GREATER than 112 degrees. And, because we are running these cams with our EEC IV management, this was a limit we needed to respect."

And here is a quote from the Mustang Performance Handbook:

"Supercharged engines require a WIDER lobe separation angle than normally aspirated engines. With a pressurized intake system, the need for lobe overlap is significantly reduced."

So, am I right in saying that GREATER LSA = LESS overlap?



<font size=-1>[ This Message was edited by: 89Trooper on 1/29/04 1:38pm ]</font>

<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2004-01-29 01:37, 89Trooper wrote:
Now I'm confused. Here is a quote from an article about cams in the latest 5.0 Mustang mag:

"The computer can't handle the erratic vacuum signal produced by a lobe separation angle GREATER than 112 degrees. And, because we are running these cams with our EEC IV management, this was a limit we needed to respect."</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>
This is wrong.
<TABLE BORDER=0 ALIGN=CENTER WIDTH=85%><TR><TD><font size=-1>Quote:</font><HR></TD></TR><TR><TD><FONT SIZE=-1><BLOCKQUOTE>
On 2004-01-29 01:37, 89Trooper wrote:
So, am I right in saying that GREATER LSA = LESS overlap?
</BLOCKQUOTE></FONT></TD></TR><TR><TD><HR></TD></TR></TABLE>Yes.