I have a 2007 EVO SE, recently at about 4k RPM I lose power and black smoke pours out of the pipe. The local tuning shop says the stock valve springs are worn out. I have HKS 272 cams on it. Just want to know if anyone else has had this problem and if the valve springs were the fix.

Thanks Erv

 

i've never heard of this.... but then again what do i know
how long have you had the cams? do you rev past stock? how hard would you say you drive it...

 

well theres no such thing as a 2007 EVO but anyways what do you rev to? how long have you had the cams because you should be fine with hks 272 on the stock springs

 

the hks cams arent a aggresive cams where you need to upgrade your valvetrain but i mean maybe it could happen with those cams but i dont see it happein

 

i think what the shop told u was , VALVE SEALS not valve springs

 

No way the springs are worn out. The material used is quite amazing. The older 4g63 engines springs have been measured with 100,000 miles on them and the tension measures just as new ones.

 

2007 evo? i gotz to get me 1 of them

 

Match the springs for the cams you want to use. Too much spring is no good if you dont really need it. Just wears out parts faster.

I ended up puting in BLE solid lifters for the 10500RPM Cossi valvetrain installed cause the spring rate on these kept messing with the HL response rate. PITA but il take the noize over the contantly broken rockers....LOL

Now i need some custom performance cams from Greg @GSC and i should be done.....in time.

 

If it was the valve seals it would be white smoke due to oil, black smoke is fuel.
I've never heard of this problem, but thats not to say it can't happen. I would talk to another shop and get there opinion.

 

couldent of said it better myself!!!!!! AGREED take it to another shop to get another opinion