Paulyy

This is my idle. at about 850-900 rpm just for comparison.

refresh951

Pauly - Sounds good. What is the int and exh lift on your cam?

Paulyy

I have no idea. I don't have specs for it and stupidly i didn't measure lift when the head was off.
its similar to yours as i got told.

did you get modified lifters?

refresh951

Modified lifters were not necessary. However, I could not have put my cam in a car with the stock head as coil bind clearance would have been an issue.

My guess is that your cam is very similar to this JME cam:

8SR/S314 944 2V for stock valve sizes or 8SR/27714 for larger intake valve Best power band 3800-6900 rpm. 900 rpm idle. .502 IN cam lift & .475 EX. with near stock base circles. Uses race valve springs. Motronic chip must have rev limit raised for best results. To 490bhp with race exhaust, larger turbo, larger injectors, raised fuel pressure, larger fuel pump. Needs custom Motronic chip or aftermarket engine management. No equivalent competitors cam. Used where lift is unrestricted but racing cam is allowed

Paulyy

I'm assuming it's more similar to the other one you've posted. he stated "should be good till 7400 rpm"

I have modified lifters to accommodate for extra lift. by using the stock lifters, the oil fill will miss the oil feed hole and lifters wont pump.

the exhaust side didn't need modified lifters.

Thom

That's a lot of overlap you have with this cam Shawn, more than twice the overlap on the 9R cam. If anything I would suggest you to keep a close look at your EGTs.
I saw ~1250°C in the cross pipe during an Autobahn run with a cam slightly less aggressive than yours, and this is why I reverted to the 9R cam. Playing with cam timing had little to no effect. Where you are I assume you might not be able to bring the car in a similar sustained high speed environment though.

333pg333

Thom, I suspect that this cam has 114o LSA therefore giving it less overlap?

Thom

Overlap is a function of LSA and durations. Both cams have a LSA of 114deg but the B13/8SR-14 has much longer durations than the 9R.

refresh951

The base circles for both the intake and the exhaust on my cam were reduced wrt stock by 0.110". Therefore my lifters sit 0.055" farther up in the cam tower and do not miss the oil supply. Because of the reduced base circles, I spent a lot of time looking at tip heights, lash caps and coil bind to make sure everything worked out all the way through.

If your intakes need special lifters, your base circles must be a long ways from stock. If that is the case and you are not running lash caps, you must have longer valve stems?

refresh951

Thanks for the input. Really just guessing at this point as I have no hard data other than lift. Dave at CEP has not responded to any of my requests for info. I plan on doing a lot of testing in the next couple weeks. It has been very educational thus far.

Paulyy

This might give you some info.



Here's the cam next to the stock one. (left stock)

refresh951

Pauly - Those tip heights are within the factory spec of .537" +/-0.015". Your new cam looks like it has smaller base circles (just like mine). Gap must be accounted for in your lifters rather than lash caps.

refresh951

My car is now ridiculously fast.

Thom

What I do to measure duration is rotate manually the cam in the housing with a degree wheel and checking how much it rotates between the bottom and the top position of the lifter. Bit of a ghetto method but pretty cost-effective.

333pg333

I am fairly positive that Shawn's cam is similar or the same as the one on our motor from last year. Specs here.

Street engine(3.1lt motor) IN EX
Seat duration with 0.004" lash 293° 282°
0.050" duration 252° 242.8°
Gross lift 0.537" 0.502"
Hyd valve lash 0.004" 0.004"
Net Valve lift 0.532" 0.498"
LSA 114°

Sorry about it appearing a bit messed up. It fits fine when I put that in my post but it scrambles once posted. But you get the drift.