Which cams?

[Shane@DBPerformance]

BC 288: 288/288 ; 0.468"/0.478"



Damn, that is some lift for a DSM cam. I am surprised it will supposedly work with the BC single springs. Usually over .425" you have to worry about the valve guides.

[Super Bleeder!!]

And anything over 264 grind you will need spring/retainer upgrade. Not from the revs or rpms...but the lift of the cams will cause stock springs to bind.

HKS 264s and 272s have the exact same lift. 9.8mm exh 10.2mm int

Im not so sure stiffer springs are required for HKS 280s either. At least i cant find any literature with them specifically saying YOU NEED SPRINGS TO RUN THIS CAM.

[Wizard]

Part # Description Duration @ .050" Gross Lift w/1.7
STOCK Stock Turbo Cam 174 / 165 .366" / .343"
HKS264 HKS 264 187 / 186 .392"/.374"
HKS272 HKS 272 195 / 195 .399"/.379"
546/547 Web Cams 206 / 206 .400"/.385"

I also found supposedly the actual spec cards from HKS:

264 Intake
Max Valve Lift - 10.3mm (0.4055")
Centerline at 0mm vavle lift 105 deg
Intake Valve timing at 1mm (0.0394")
Valve opens at 2 deg BTDC
Valve closes at 28 deg ABDC
Valve Centerline 105 deg (WRONG - 103 deg)
264 Exhaust
Max Valve Lift - 9.8mm (0.3858")
Centerline at 0mm vavle lift 117 deg
Exhaust Valve timing at 1mm (0.0394")
Valve opens at 42 deg BBDC
Valve closes at -12 deg ATDC
Valve Centerline 117 deg (CORRECT)

272 Intake
Max Valve Lift - 10.3mm (0.4055")
Centerline at 0mm vavle lift 105 deg
Intake Valve timing at 1mm (0.0394")
Valve opens at 6 deg BTDC
Valve closes at 32 deg ABDC
Valve Centerline 105 deg (WRONG - 103 deg)
272 Exhaust
Max Valve Lift - 9.8mm (0.3858")
Centerline at 0mm vavle lift 111 deg
Exhaust Valve timing at 1mm (0.0394")
Valve opens at 36 deg BBDC
Vavle closes at 2 deg ATDC
Vavle Centerline 111 deg (WRONG - 107 deg)

I cant find any stock valve spring coil bind limit, but guessing it would be around .450". And it would be a nice safe bet the the measly $200 on a basic upgrade springs/retainers would give you insurance. Not to mention, the stock springs are not new and their numbers have surely faded over time. IE: Weaker and more prone to break or bind. Bad time find to this out is after you put your multi$$$k motor together and first good pull over 6k and a valve fails to close in time.

Just upgrade and you'll be safe.

Wiz

[JET]

How would an old spring be more succeptible to binding? Just because you wouldn't do it, doesn't mean it is necessary. The stereotypes for the cam companies are off also. Nothing against you Wiz, but you always come on here stating your opinions as hard fact and everyone should do what you say. You are far from a DSM guru and your opinions are not fact.

[Pushit2.0]

I also run the Crower 415s, I use our single valve springs, same specs as a Crower spring, ~50lbs seat pressure and ~170ish at .4" lift. I put in some .040" shims under my springs to get the pressure up to the 210lbs @.435 lift that the cam card says it needs. I also shaved down the weight of my retainers a few grams to help at high RPM. My cams showed just under the advertised lift at the valve, I think it was .435" (.438") on the intake and .425" (.429") on the exhaust side. But the duration from .05" was 6 deg longer on the intake and 4 deg on the exhaust side. I am happy with my cam/spring/retainer combo they are holding up fine and making good power all the way to 9500rpm. Also Crower springs will coil bind around .955" over all height and be around 260lbs, I think mine are around 1.095" at max lift on the intake side right now.

~John

[Matt D.]

Just buy my HKS 280s and be done with it.

[Wizard]

How would an old spring be more succeptible to binding? Are you kidding? You really think a stock valve spring with over 100k miles has the same tension and resilience as a new spring? It's called wore out.....think about it. A wore out valve spring will 'bottom out' or not return to its original position more easily than a new stocker...Some never come back to the OEM free length ever so it's shorter than stock. Same idea as wore out coil springs that cause a car to sag and bottom out easily.

And I never state my opinions as fact...I just provide data as to what I feel would be a good choice. But, in the end it all comes down to the user. They don't have to listen to me...but there are others that believe the same as I do. Why push the edge when you can be safe?

No one here is a complete guru as you put it. But, I feel i'm rather knowledgable and have plenty of creditials and experience to back it up. What exactly in your book defines a guru? And why the need to come into a 'helpful' post with data and numbers just to bash on me? Do I know you? Or better yet, do you know me? Doubt it.

Back on topic.....

Wiz

[JET]

Are you kidding? You really think a stock valve spring with over 100k miles has the same tension and resilience as a new spring? It's called wore out.....think about it. A wore out valve spring will 'bottom out' or not return to its original position more easily than a new stocker...Some never come back to the OEM free length ever so it's shorter than stock. Same idea as wore out coil springs that cause a car to sag and bottom out easily.

Wiz

Wow, you need to learn what coil bind is. I agree that the springs will be weaker over time, but that doesn't have a thing to do with coil bind. Coil bind comes from the coil being too big and the cam having too much lift, causing the coil to bind. This obviously can't happen unless you think the spring grows over time.

Maybe it is just the way you word your post, but to say Webcams are good and Crowers should stick to NA cams because they can't make power on a turbo car is wrong. Several of us are making good power on Crowers.

[Super Bleeder!!]

FPs are Comp Cams actually.

http://store.forcedperformance.net/merchant2/graphics/00000001/data/101100_FPCam1.pdf

[Kracka]

woot time to sneak into hughes garage and steal some cams!

Stay off my cams!