4K Valve Springs High Rpm ?

[crispyke35]

Hey All i have been doing some thread trawling and I'm getting alot of info but not many definitives.

 

my situation is engine will hit 8000rpm, and valve lift of over 0.400" . running this in a 4k and decent cam measured approx 30-35 / 70 - 75 . Understand that this info is a little general but help and experience with different combo's and set ups would be brillant.

 

Options i have found in the threads:

 

202 holden single valve springs. do not know if need addtional work to fit?

 

Crow cams 4220 dual valve springs (apparently same as A series datto engines ? )

 

and other reports of TRD dual valve springs (i'd expect not going to happen with limited time i have).

 

anyone who has tried this or has reports of high revs and valve springs I'm really in need of some more definitive info

 

also what work was required to fit them etc.

 

Some threads I have found useful thus far:

 

 

5k Valve Springs In A 4k And 3k

http://www.rollaclub.com/board/topic/20044-5k-valve-springs-in-a-4k-and-3k/

 

4k valve springs upgrade

http://www.club-k.co.nz/Forums/viewthread.php?tid=16631

 

Valve Spring Bind

http://www.rollaclub.com/board/topic/50718-valve-spring-bind/page__hl__%2Bvalve+%2Bspring+%2B

 

Valve Spring Discussion - Who's Used What?

http://www.rollaclub.com/board/topic/38950-valve-spring-discussion-whos-used-what/page__hl__%2Bvalve+%2Bspring+%2B

 

Matching Valve Springs To A Motor

http://www.rollaclub.com/board/topic/16926-matching-valve-springs-to-a-motor/

 

Cheers

Edited March 6, 2012 by crispyke35

[coln72]

Used to run std 5k springs in my club car. Forgotten exact cam specs but from memory it was a Wade 169 grind (hydrolic). The springs were happy at 7500rpm. That is what I set the shift light at and would go to 8000rpm if I was felling mean.

[Evan G]

crow cam 4220 double valve springs. $100 and be done

[crispyke35]

Used to run std 5k springs in my club car. Forgotten exact cam specs but from memory it was a Wade 169 grind (hydrolic). The springs were happy at 7500rpm. That is what I set the shift light at and would go to 8000rpm if I was felling mean.

 

thanks for that info definitely helpful, assume this was in a 5k engine? Wade 169 seems very close to what cam grind I'm running so i'd say this may be an option

 

 

crow cam 4220 double valve springs. $100 and be done

 

the question still remains who has tested them? i see 'philbey' has commented he has had success (in a 5k) but i am really after more info on specific set ups, as coln72 helped out with. i have been reading alot of 'in my opinion' and 'heard this works' without much direct results from testing & own usage hence this post.

 

if you have used them Evan G i'd be keen to hear your results and set up they were used in

Edited March 6, 2012 by crispyke35

[Token]

I have the Crows Cam Dual's in my 4k. The Car is my Daily/'Khana bitch and sees 7.5 - 8k 20 runs a day on 'Khana days (at least once a month) (two drivers).

I'm not 100% on the Cam specs, we just gave it to an old 'rolla guy in Canberra and said, make it awesome, and then I lost the spec sheet. Lift was around .400, peak power around 6.5 - 7k (but given the gear ratios in the 'rolla alot of the time we just run out in 2nd rather then shift to third)

 

I can't say I've compared them with anything but a stock, and tired, 3k, but I certainly have no reservations about thrashing the old girl. In fact, I can't say I've even thought about valve springs since I build the engine.

 

Token

[crispyke35]

I have the Crows Cam Dual's in my 4k. The Car is my Daily/'Khana bitch and sees 7.5 - 8k 20 runs a day on 'Khana days (at least once a month) (two drivers).

I'm not 100% on the Cam specs, we just gave it to an old 'rolla guy in Canberra and said, make it awesome, and then I lost the spec sheet. Lift was around .400, peak power around 6.5 - 7k (but given the gear ratios in the 'rolla alot of the time we just run out in 2nd rather then shift to third)

 

I can't say I've compared them with anything but a stock, and tired, 3k, but I certainly have no reservations about thrashing the old girl. In fact, I can't say I've even thought about valve springs since I build the engine.

 

Token

 

Legend exactly the kinda info I'm after, cheers

[Evan G]

the 4220 have 100 lbs of seat pressure compaired to the stock springs of 50lbs

 

[philbey]

the question still remains who has tested them? i see 'philbey' has commented he has had success (in a 5k) but i am really after more info on specific set ups, as coln72 helped out with. i have been reading alot of 'in my opinion' and 'heard this works' without much direct results from testing & own usage hence this post.

 

if you have used them Evan G i'd be keen to hear your results and set up they were used in

 

Yes I run the 4220s in my 5k and I run a lot more lift @ .480

 

I dispute whether you even need to change them, I ran stock springs at that lift for 18 months as a daily driver before I broke one, and I suspect it was more due to age. The rule of thumb in the FAQ appears to pure speculation.

 

There is also a common misconception that dual springs sap more power than singles, this is not necessarily the case: while they have a higher seat pressure, you'll probably find they run a lower nose pressure due to the lower spring rate than a fat single. Do the math on the 4220s and you'll understand.

 

Long and short, 4220s dropped straight into my 5k and should do for the 4k, perhaps some shimming to bring up to desired seat pressure and you are off. Forget milling out pockets and all that snot.

[crispyke35]

Yes I run the 4220s in my 5k and I run a lot more lift @ .480

 

I dispute whether you even need to change them, I ran stock springs at that lift for 18 months as a daily driver before I broke one, and I suspect it was more due to age. The rule of thumb in the FAQ appears to pure speculation.

 

There is also a common misconception that dual springs sap more power than singles, this is not necessarily the case: while they have a higher seat pressure, you'll probably find they run a lower nose pressure due to the lower spring rate than a fat single. Do the math on the 4220s and you'll understand.

 

Long and short, 4220s dropped straight into my 5k and should do for the 4k, perhaps some shimming to bring up to desired seat pressure and you are off. Forget milling out pockets and all that snot.

 

Cheers mate this finalised my decision. I ordered a set of 4220's from crow cams today, so will report back when i get the motor together and going.

[crispyke35]

Hi all got the head back from engineers and the 4220 dual valve springs fit perfect into the 4K head without needing any work.

 

next step will be testing phase and finding out what rev's they enjoy