Time to go Stage II!

[norbs]

Not worried about the lifters so much its the valve seats, pounding up in the heads.

 

[Alky V6]

To use the recommended Crower spring and retainer, I'll have to use a -.050 keeper and .090" of shims, along with a spring seat cup.

 

[Chris Hogeland]

Don on most springs you will lose 10 to 20 psi after they run for no longer than 10 min. Just some thing to think about.

 

[Alky V6]

Don on most springs you will lose 10 to 20 psi after they run for no longer than 10 min. Just some thing to think about.

Ah, yes, you're right about that. Good point. Dang. I really don't want to shim more than .090.
Looking for another spring.

 

[Chris Hogeland]

Ah, yes, you're right about that. Good point. Dang. I really don't want to shim more than .090.

I don't like shim more than .060. Might want to see if they have A spring that you would not have to shim so much.

 

[Alky V6]

I'm going to go with the 2.100 installed height with the Crower spring.

Dual spring w/damper
O.D./I.D. Outer: 1.615/1.175"
O.D./I.D. Inner: 1.060/.775"
Installed height: 2.100"
Spring rate: 530 lbs/in
Part #68755
Color code: Gold
Free length: 2.665"
Wire dia: .225/.147"
Material: Super Clean Silicone
Coil bind: 1.190"
Retainer: #86068 10 degree Ti +.100
Spring seat cup: #68955
Lock: #86110X2 10 degree -.050"

Pressures;
Seat @ installed height (2.100"): 287 lbs
At .700" lift (1.400" spring height): 671 lbs

This is for a rpm limit of 8,000 with stainless valves, 9,300 rpm with Ti valves.
Max lift: .700"
Clearance to coil bind: .183" @ 2.068" installed height.

Available room: 2.150"
Retainer: +.100"
Spring seat cup thickness: .068"
Lock: -.050"
Shim: .064"

2.150 + .100 - .068 -.050 - .064 = 2.068". A .032" fudge factor (17 lbs.).
edit: I measured the actual thicknesses for the spring seats and the shims, and adjusted some figures above.

 

[Alky V6]

I just finished measuring the valve guides to work on ordering some valve seals. The guide tube area for the seals measure 3/8" high and the intake OD measures .498" and the exhaust OD measures .530".
Can anyone clue me into why the two different guide ODs for the valve guide seals?
Also, the OD on the exhaust guide has multiple grooves.

edit: I found that they make PC seals for both diameter valve guides, so I have to assume that the person who setup the heads before me were using two different springs for the intake and the exhaust, and needed a little more clearance for the ID of the intake spring they were using.

 

[Chris Hogeland]

Most of the time the ex is bigger because it has to deal with all the heat.

 

[Alky V6]

Most of the time the ex is bigger because it has to deal with all the heat.

Makes perfect sense. Thanks, Chris.

 

[Alky V6]

Picked up the springs and things this morning. Got a nice surprise. They come chamfered from the factory. Nice. I hate having to chamfer springs.

 

[Alky V6]

I'm wondering how much chance a top ring has to flutter if you're running a lot of positive pressure on the top of the piston? Even during overlap, pressure on the top of the piston will be quite a bit more than the pressure underneath a piston at 40+ psi boost levels. I might go with 1/16" top rings for the strength and added heat transferring capacity.

 

[norbs]

I'm wondering how much chance a top ring has to flutter if you're running a lot of positive pressure on the top of the piston? Even during overlap, pressure on the top of the piston will be quite a bit more than the pressure underneath a piston at 40+ psi boost levels. I might go with 1/16" top rings for the strength and added heat transferring capacity.

Smart move you need some durability....

 

[Alky V6]

A picture of the chamfering on the new springs. The spring in the background is from a set that came with a set of Stage II street ported heads I have.

 

[Alky V6]

10 degree, -.050" valve locks.

 

[Alky V6]

Springs and things.

 

[Alky V6]

Comparing the race spring to the street spring.

 

[norbs]

Donnie can you post a graph of spring pressure vs valve guide wear vs miles. I been looking on the net with no luck.

 

[turbobitt]

Comparing the race spring to the street spring.

View attachment 166805

I'm surprised you went with the 10 degree stuff. From what I understand, the retainer x-section is comprimised and could crack comared to the super 7 stuff. I was thinking of upgrading to the super 7 stuff with the new ultra lightweight steel retainers. I guess they are more expensive than the TI stuff.

Allan G.

 

[Alky V6]

I'm surprised you went with the 10 degree stuff. From what I understand, the retainer x-section is comprimised and could crack comared to the super 7 stuff. I was thinking of upgrading to the super 7 stuff with the new ultra lightweight steel retainers. I guess they are more expensive than the TI stuff.

Allan G.

I've used Super 7 in the past and really liked it. The Stage I used Super 7. I would have gone with Super 7 in this application too, but Crower didn't have a retainer that fit the spring choice correctly in Super 7.
I could see where the cross section of a triple spring retainer might be iffy, but the dual spring retainer has a good bit of meat to it.

 

[Alky V6]

Donnie can you post a graph of spring pressure vs valve guide wear vs miles. I been looking on the net with no luck.

I don't know where I'd find a graph like that.