Hvymtlc5

What valve springs would you recommend for a BB with hyd 560/573 lift cam? Target RPM is 6000. Single, single with damper, Beehive?

Looks like the ones my machine chose for my project are binding and breaking push rods on my new engine...............

See post "motor damage after 5 miles - need advice"

GDaina

Contact the cam mfg and find out what pressure springs at the seat ...only the cam mfg knows the springs for their cams.

Looks like specs for a L-88 cam. If you get no answer from the cam mfg..maybe GM dual L-88 springs will work.

Ooops...is that a hydraulic or solid cam? if hydraulic, forget the L-88 springs

jackson

I agree ... contact the cam mfg for their recommended spring.

However ... Here may be a similar cam with its recommended springs & retainers ... from SpeedPro (aka Sealed Power & TRW) catalog:

BBC Hydraulic Flat Tappet w/ stock rocker arm ratio

cam P/N CS1140R: dur 234*/244* @0.050", .553"/.578" valve lift, lobe centerline 112*, power range 3K-6.5K, rough idle.

spring P/N VS1581: Dual w/ damper, OD 1.460", max lift .590", coil bind 1.200", 105# on seat 1.880", 338# @1.250"

retainer P/N VSR7015R: chromemoly, OD 1.370", inner spring dia 1.066", step height .100", valve stem dia 3/8", 7* locks.

Hvymtlc5

Got ahold of Edelbrock..... they recommeded the most expensive springs they have (well just about) . Is there a way to determine what I need based on lift so I can get some other brand?

DIP51

Maybe there is a reason for the springs that are "the most expensive". Don't cheese out on valve springs when you have a lot more $$$ below them!!!

bashcraft

Seems to me that your machine shop should be picking up the bill for this.

Cstraub69

Hyd flat with the OEM 3/8" heavy valves I would run around 120# on the seat and 320# Open. I would get matching retainers and machined valve locks for the application.

A single spring with a damper is what I would recommend. Beehive is not worth it especially with the heavy valves in OEM heads.

Chris

GDaina

what you have to know...what is the spring pressure at the seat at the installed height, then buy springs that have identical seat pressure...contact the cam mfg and find out what spring pressure is required for the cam.

Hvymtlc5

Edelbrock responded witht he following: Those springs should be set up at 1.880" and the pressure is 100lbs on the
seat.


What exactly does that mean?

Cstraub69

That means that when the retainer and keepers are installed on the valve that distance between the underside of the retainer on the first step (the largest OD) and the spring pocket is 1.880". At this installed height the spring should have 100# of pressure.

IMO, not enough seat pressure for that cam.

Issue here though is not the spring, it is the fitment of the spring to the OEM retainers. Ask E-brock tech if you can use those springs with OEM GM retainers.

Hvymtlc5

The springs are there now were made by PBM racing and rated at .0600 lift...which they said were good enough for my cam....I'm being told they're not.... and now the new machine shop says that my Comp Cams roller tip rocker is actually hitting the spring. Looks like everyhting has to be repalced. I've had these heads done 3 times now. I could have aluminum for what is invested in these..... I'm tired and disgusted of the whole thing.....but want to do it right this time.

GDaina

The cam, I assume is Edelbrock? If so, then look for springs that are 100 # at the seat installed. If Edelbrock says that's the spring for their cam, don't argue.

Regarding the rockers hitting the retainer, could be a number of things..Wrong installed height, rocker ratio more than 1.7.

Cstraub69

If thats a PBM 3500 spring then that spring must be used with aftermarket retainers. The OEM retainer step will not locate the spring and will allow it to move.

Now because the retainer step does not fit the spring this allows the spring to move when running. Most rockers only clear 1.625" springs so with a your spring diameter of 1.550", the spring doesn't have to move much before it hits the rocker.

Don't quite know where Belleville,IL is but I know of a guy in Glasgow, KY that is one of the best around when it comes to BBC. If you want his number let me know.

Chris Straub
Stef's Performance
www.stefs.com

Hvymtlc5

Going to try new retainers as suggested. The rockers were hitting the springs. I'm guess the movement caused the pushrod to bind and fail..only took five miles

mountainmotor

Are you using PC type seals ?

If so , you might want to think about using Clay Smiths dual interference fit springs set at 1.900 . Seat pressure of around 120 after the the springs take their normal set from run in and around 290-300 open at " those " lifts will provide adequate control and long life .

Alot of the springs out there are nearly on/off types like the single Z28 type springs . I like the types that are more progressive in design and they are about a must for the hi intensity nonsymmerical lobe being used these days .


Isky has springs galore if you cannot allow yourself to run the above or are not using PC seals . Some of the best around .

Cstraub69

Mountain,
I can't tell if the valve guide boss has been cut for the PC seals but if I had to guess I would say they haven't. I agree a good Viton posi seal is great for oil control and longevity.