Roller Valve Spring vs FT Valve Spring

[Jadaharabi]

My question is.
Will the valve springs on my heads that are 125 on the seat and 300 lb at .550 lift with a FT cam work with a roller cam with .480 lift?
What is the difference between a roller cam valve spring and a flat tappet valve spring?

 

[yellow rose]

The spring rate is usually less with a SFT spring and with that little on the seat and .480 lift you’ll have nothing over the nose.

That might be a bit sketchy at a pretty low RPM.

Just my .02

 

[PRH]

Solid or hyd roller?

 

[Jadaharabi]

Hydraulic

 

[PRH]

The main issue is..... the hyd roller lifters are pretty heavy, especially the retrofit style, so it takes more load to keep everything in control.

So, 125/280-ish will work up to some rpm point with a hyd roller cam, but unless the cam profile is rather tame...... there’s a good chance the valvetrain will start to get unhappy at a fairly modest rpm(low-5000’s).
Where it actually happens will be mostly dependent on the cam profile.

 

[yellow rose]

Hydraulic

Well that’s a bit different. That’s not that low.

 

[Jadaharabi]

I'm wanting to put the roller in a 1990 roller motor. It will have 1.5 factory rockers and ported heads with edelbrock alum head valve springs(1.80? Installed height)

HR-286d-SBM Short Snout Magnum

Advertised Duration
In. 286
Ex. 298

Duration @ .050
In. .227
Ex. .234

Valve Lift 1.6
In. .512
Ex. .512

Lobe Lift
In. .320
Ex. .320

LSA
112

It's a Texas regrind.

 

[Garrett Ellison]

Is that with the P/N 5767 springs, 9736 retainers, and 9611 locks? What type or diameter are the valve seals?

 

[Jadaharabi]

Is that with the P/N 5767 springs, 9736 retainers, and 9611 locks? What type or diameter are the valve seals?

If that is what Edelbrock used that would be them. I think the seals are .530 or something like that Teflon?

 

[PRH]

At a minimum, I’d shim the springs up to achieve 135-140lbs on the seat.

 

[318willrun]

Usually roller cams have more spring pressure than a FT when comparing equivalent lifts/duration.

 

[Garrett Ellison]

Do you know the inner spring seat height (the one with the .755 diameter) of the retainers? If you can come up with that, I can find out what a set of Melling VS-2203 springs (.745 I.D. .900 O.D. & 1.77 free length) or equivalent added as an inner spring would add to your seat and open pressures and what locator it would need to shim it up with. The downside is it’s about a $100 upgrade, and there’s possibly a set of springs available for less than that. But a different set of springs is probably going to require a different set of retainers, so it still may be the lowest cost option. Shimming would be the lowest cost option, by far.

 

[furrystump]

The stock eddy valve springs were just on the edge of being adequate for the advertised limit to begin with, not a big safety margin.

 

[flyfish]

Roller cams need more seat pressure than solid flat tappets....they need more spring pressure overall to control the weight, but in this particular case more seat pressure at a minimum. Main thing with rollers is you don't want them to bounce...and they are quite heavy, which is why they need more spring to control things.

 

[MOPAROFFICIAL]

Roller cams need more seat pressure than solid flat tappets....they need more spring pressure overall to control the weight, but in this particular case more seat pressure at a minimum. Main thing with rollers is you don't want them to bounce...and they are quite heavy, which is why they need more spring to control things.

Last lunati hyd roller I set up was 135 lbs @seat.

 

[Jadaharabi]

Do you know the inner spring seat height (the one with the .755 diameter) of the retainers? If you can come up with that, I can find out what a set of Melling VS-2203 springs (.745 I.D. .900 O.D. & 1.77 free length) or equivalent added as an inner spring would add to your seat and open pressures and what locator it would need to shim it up with. The downside is it’s about a $100 upgrade, and there’s possibly a set of springs available for less than that. But a different set of springs is probably going to require a different set of retainers, so it still may be the lowest cost option. Shimming would be the lowest cost option, by far.

What would be a good single spring with damper that I could put on these heads with my roller cam?

 

[Garrett Ellison]

I'm looking for the inner step diameter of the 9736 retainers, and I will go from there with Mr. Wallace's spring calculator. Do your valve springs have a damper? We also need to confirm beyond a doubt those are the P/N's for the components.

 

[Jadaharabi]

I'm looking for the inner step diameter of the 9736 retainers, and I will go from there with Mr. Wallace's spring calculator. Do your valve springs have a damper? We also need to confirm beyond a doubt those are the P/N's for the components.

They are just a spring and damper. There is no innerspring.
I'll have to check on what the spring number is cuz I don't know off the top of my head.

 

[Garrett Ellison]

Okay, I apologize, I misread your question and I caught where you ad said OTB magnum heads. My Bad! I will get back to you once I get all the figures together from the Edelbrock spec sheet.

 

[Jadaharabi]

Okay, I apologize, I misread your question and I caught where you ad said OTB magnum heads. My Bad! I will get back to you once I get all the figures together from the Edelbrock spec sheet.

Never said magnum heads. Said la roller motor. It has 308 heads. I want to put in a bigger cam.

 

[Garrett Ellison]

Okay, thank you, and I see! Yes, spring P/N would be helpful. Did you buy them as a set of springs and retainers such as the Edelbrock 5895 kit?
Complete Sure Seat Valve Spring Kit for Chevy 396-402-427-454 V8
Edelbrock Sure Seat Valve Spring Kits 5895

 

[Jadaharabi]

Okay, thank you, and I see! Yes, spring P/N would be helpful. Did you buy them as a set of springs and retainers such as the Edelbrock 5895 kit?
Complete Sure Seat Valve Spring Kit for Chevy 396-402-427-454 V8
Edelbrock Sure Seat Valve Spring Kits 5895

These were take off from heads that Hughes was building for people. They're brand new Springs retainers, keepers and valves.

 

[Garrett Ellison]

Okay, I got you! The item we need to confirm is the Edelbrock 9736 retainers. If that's the case, you can go with a set of 5845 Edelbrock valve springs. These were what Edelbrock ran on the hydraulic roller version of these heads with the 9736 retainers with 150 closed at 1.800 installed height, 420 open at .580 open.
Edelbrock Sure Seat Valve Springs 5845
https://www.edelbrock.com/sure-seat-valve-springs-5845.htm
I'm looking over other options but it appears that Edelbrock went out of their way to design spring retainers for an outer spring inside diameter no one else manufactures.

 

[Krooser]

Comp, Summit, Speedway and others sell a 1.460 spring...common size.

 

[Garrett Ellison]

That's true, but that 1.06 inch diameter on the retainer register is what bites you. Always good to have a valve spring positively located. I'm sure there's some allowance there, but I don't think that’s a good place for gambling! Now if you change retainers, you can do what you want, but the initial payout is exponentially higher.