Refresh951's Hybrid Ultra Stroker Build
#1669
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Thread Starter
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
#1670
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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
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
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.
#1671
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.
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.
#1672
Rennlist Member
Thom, I suspect that this cam has 114o LSA therefore giving it less overlap?
#1674
Rennlist Member
Thread Starter
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.
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.
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?
#1675
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Thread Starter
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.
#1677
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Thread Starter
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.
#1679
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.
#1680
Rennlist Member
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.
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.