CIS cams Vs S Cams

matty74 · matty74's Garage

I have a cis motor 2.7l I am rebuilding to RS spec.

JE pistons
webers
s cams

what is the difference between the CIS cams and S cams?

and will I get any better performance from DC40 cams over S Cams?

Jeff Alton · 12-15-2005, 01:24 PM

You will not be able to use either of those cams with the CIS. Too narrow a lobe center. Contact John, who makes the DC40 you are considering and give all the specs of the motor, and he will make a recommendation for you. The common plenum intakes CIS, 3.2 3.6 etc, don't get along to well with the more radical cams...

Cheers

matty74 · matty74's Garage

Thanks, what about s Cams Vs DC40 the engine is for street use?

kenikh · 12-15-2005, 01:42 PM

Quote:

Originally posted by matty74
Thanks, what about s Cams Vs DC40 the engine is for street use?

I believe Camgrinder recommends them as a better alternative to the S cams, especially for larger motors. At 2.7L w/ JEs (>9:1 comp?) the DC40s should have solid grunt and whail like a banshee. I am in the process of building a 2.2 (actually in the tear down stage) and am planning on going with DC40s, as well. If I were you, I'd go that way as long as you are designing your top end to handle sustained trips to 7500+ RPM. If not, you aren't going to be able to take advantage of the cams.

Jeff Alton · 12-15-2005, 02:18 PM

Are you still using the CIS? If so, forget those cam choices. Will not work. If you are using ITB's, MFI, or carbs. then I would use the DC40 over the S cam.

Cheers

kenikh · 12-15-2005, 02:20 PM

Quote:

Originally posted by catca
Are you still using the CIS? If so, forget those cam choices. Will not work. If you are using ITB's, MFI, or carbs. then I would use the DC40 over the S cam.

Cheers

Indeed; I was assuming carbs or ITBs.

matty74 · matty74's Garage

Yes Webers, (S Cams OR DC40), JE 9:1

camgrinder · 12-15-2005, 05:37 PM

The DC40 cams will have a wider powerband (3500 to 7500) than the S profile cams. They will also make more power and torque.
Set the compression ratio to 9-1 and go.
The DC40's will be easier to drive around town.

They will not work with CIS injection.

Jeff Alton · 12-15-2005, 05:45 PM

Ok, sorry, was confused by the reference to a CIS motor in your original post!

Cheers

RoninLB · 12-27-2005, 04:33 AM

Quote:

Originally posted by matty74
Thanks, what about s Cams Vs DC40 the engine is for street use?

Hope you live in a warm climate all year?

E-cams are a great street and highway cam. It pulls better than a stock 3.2 according to every 3.2 guy that has rode in her.