Re: turbo valvetrain?
 

run it till it breaks?

local guy built his turbo motor, used the head off his old NA motor or someshit that had seen revs in the 9k range with no problems... but with 20psi of boost and stock revlimit it ended up dropping a valve and nukin the hold motor...

here is something to think about: with a boosted motor there is X about of boost pressure pushing down on the head of that valve now that wasnt there with an NA application. so thats ~20psi of spring pressure that needs to be made up for. if its not then you could float the valves at a lower engine speed, bending valves, breaking them, and droppin them onto the pistons...

you can pick up a set of nice springs/retainers for like 225-300bucks. they will work fine with stock or aftermarket cams... or you can drop a valve on a B18C and be out several thousand dollars...your call...

Re: turbo valvetrain?
 

good point man, who makes a good trusted valvetrain for cheap then? ive seen skank2 and crower any sleeper sets guys are using that may be a lilttle cheaper.

Re: turbo valvetrain?
 

Rocket Motorsports :y

Re: turbo valvetrain?
 

solid O0

Re: turbo valvetrain?
 

Wow, tech in this thread is ------- scary. :l

NA cars like super light springs, but the spring has to be designed to follow the cam @ higher rpm. Despite what some people think, this has nothing to do with spring stiffness. Turbo cars like stuff springs, especially on the exhaust side. You can get away with stock springs and maybe a couple hundred extra rpms on a medium boost car, but not 9K. Also, if you aren't pushing a good bit of boost on a good sized compressor I doubt there is power above 8K-ish... but, as boost goes up a cam's powerband goes up.


Crower is pricey, and I don't care for how they trashed a lot of B-series engine with cams that broke due to ramp angle design problems, with zero warranty on the cam much less the engine, and Crower kept selling their cams anyway when they knew they were junk. Skank2 is middle of the road stuff, if the price is right and you can find out any specs on the springs go for it.

Rocket Motorsports springs are awesome low rate NA units... for all the turbo stuff Rocket Martin recommended Supertech stuff. Supertech has three springrates available for B-series, unless they've changed their lineup in the last 6 months. Go with their 85 lb/in springs, they are middle of the road stiffness AND a bump up from stock, should do you fine to 9K with a good powerband in the 300+ whp range. If you want past 9K go 100-110 lb/in springs and aftermarket valves and expect cams to last 500 miles, and all-around engine life to be shorter.

Re: turbo valvetrain?
 

i just installed some Rocket springs in an NA car and they where rated at 95lbs ???


you serious about the mileage? i plan on building my turbo motor to make peak power around 9200-9500rpms... the plan was to run the RM springs and probably the Mazworx V1 turbo cams... thoughts?

Re: turbo valvetrain?
 

95lbs, no ----? These aren't the single springs, are they? :-\

I'm really not up on cam selection, to be honest. Evans had so much luck running stock GSR/ITR cams in the 9000-9500 rpm range I can't see the expense of anything else. Especially when they become consumables with the high rate springs.

A caveat, 95lb/in is about what Trav-ASS' Ferrea's are rated at. He has killed B16, GSR, and Rocket M20 exhaust cam VTEC lobes. The problem is a combination of spring stiffness, high rpm, and the oil supply has turned to ---- between removing all sulfur and zinc compounds from most oils. There is a big jump in wear going from 9000 to 9500, and beyond 9500 it gets silly. The GSR cam lasted 1200 miles of 9000-9500, the Rocket 500 when he was spinning to a consistent 9700 and all the car saw was beating. There is an off chance the problem is in his cylinder head, but we changed rocker shafts, rocker arms, and upgraded to GSR LMAs with the Rocket cams... AND high spring pressure high rpm big power setups are known to kill cams.

Aside from a couple RLZ NA cars (JDM ITR with stage 3's + valvetrain, and a 2.1 liter 85X92mm) I haven't touched many cars that spun to 9500+. Half of what I've tuned were taken to 9K, the ones spinning 9200+ I can count using both hands. I think I've seen enough to have a pretty good grasp on the situation, but 50% of what I'm saying came from other people; predominantly Rocket and a little from Brad Z. Both are people I trust to know what they are about, though.

I thought Rocket was out of the business? Or did he just ditch the m24x forum to exist in the real world?

Re: turbo valvetrain?
 

Rocket is still in business from what i know, i got those specs off M24x.com...

----...well i just installed a set of Crower 63402s with those springs... sounds like they are pretty stiff...and if Crowers are as brittle as im hearing.... :-X

Re: turbo valvetrain?
 

Last I checked Rocket hadn't logged in for 6 months. There was a "goodbye this is my last post" thread in the main forum, and most of the site looked dead.

Crower fixed the problem with their cams a couple years back. It was ramp angle, not brittle.

Re: turbo valvetrain?
 

these where used so im not sure how old they actually are.... they have a sick ass ramp too...

http://home.comcast.net/~turbohf/cams004.JPG

Rocket has changed his name on HT...and is posting again...