Camshaft and Valve spring questions

[dsm2evo]

Hey guys I have two quick questions,

First how many of you guys run 272 cams and are you using aftermarket springs and retainers? The cams in question are BC 264/272 combo . I also have the BC springs and retainers to go with them but do not have a spring compressor so installing them is a bit of a task.

Second question is what are the stock cam specs of the evo 1 GSR . I have the "J" cams . I am looking for the duration of the cams and also the lift. I just want to compare it to my 264 and 272.

Thanks a bunch!

 

[dsm2evo]

anyone?

 

[Adam Harris]

It's not the size of cam it's the lift that f@ck shit up Why valve springs? Do you plan to rev to 9k or run 2.5 bar? Or have stupid lift cause stock springs will do 500bhp no problem

 

[doo doo]

Just measure the evo cams with some verniers- minus the base circle from the lobe height then mulitiply by 1.73 to get the lift. I think there's a couple of variations in the evo cams. The cam height in the manual is 34.91mm, my evo 1 cams measure at 34.88mm, not sure on the duration. So as the base circle is 30mm making the factory lift around 8.5mm. Factory spring tension is 54 pounds at 40mm installed height.

Just get a machine shop to install the springs and retainers and check the installed height also. If you havent already got 3rd gen lifters now is a good time to get those too. Depending on the lift of the BC's if you're not going to run big revs or biggish boost ( as already mentioned) you could get away with stock valve springs for now. You can buy a spring installer to do springs in the car (they're not too expensive) but doing the installed heights requires a bit more measuring gear and is a pain to do in the car (you need to take precautions to not drop a valve down the cylinder).