[Jack Ferris]

I'm trying to find replacement valve springs for the 87 cc E head that will work with the 236-242 HR cam. The Comp 977-16's are standing out. Any other suggestions?

[tom s]

Jack,just be sure they are in the 150 lb range.Tom

[Scott65]

Check out the crane 99893 if you'd like another option.

[Steve C.]

Comp 977 at what installed height ?

In discussion with the OF cam, and I don't remember if hyd or solid roller lifter. It will vary.

"...in most applications we use the Crane 99893 valve spring, installed at 1.790-1.810", I set the intakes on the tighter side of the tolerance, I test all the springs and always put the ones with the higher pressures on the intake valves, since the intake valves weigh more and also have the momentum of the charge pushing on the back side of the valve while the exhaust valve if anything has pressure pushing or drawing it closed and the valve is lighter. On my digital InterComp spring tester the seat pressures on a new set of springs will range from 147-157 lbs typically @ 1.800" and 380-390 lbs @ 1.200" open pressure."

Posted by Dave Bisschop

My comments ...

No matter what brand just remember never trust catalog stated pressures, they can and do vary. Test them at your intended installed height with the retainers you plan to use.


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[ta man]

Originally Posted by Scott65

Check out the crane 99893 if you'd like another option.

I have a perfect set with retainers and keepers they have a few passes and miles on them.

[AG]

Or Crane 99892 which have a lower CB at 1.035" compared to the 99893 at 1.080".

[Jack Ferris]

Installed will be 1.870. The 977’s show 155#@ 1.900. I typically see a 5-10# loss of installed pressure from advertised after compressing the spring in a vise for a period of time.

[Scott65]

I can't remember for sure, but I believe at 1.800 the cranes are around 160. Which I think is a good starting number for the reasons you mention about initial losses occurring. Sounds like either spring would work good properly shimmed for your installed height, pressure wise. Don't know your requirements as far as where coil bind will come into play for you.

[Jack Ferris]

The cam is .520/.540 w/1.5’s
I think both springs will bind around .600.

[Scott65]

7The cranes won't. I'm at ~.630/.640 I/E. I did the math before I went 1.65. It's a pretty generous amount of lift it can accommodate. May need to look at where both would put you as far as open pressure for your valve lift. That may determine which is better.
Edited to add: The fact that Dave Bisschop liked these for the application makes me feel like they were a solid choice. He installed these on mine when he did the port work. That being said, it was ~10 years ago. There may be a better option now.

[Jack Ferris]

Good to know. I was going by memory and that is not always accurate. The gentleman I’m doing this build for has 1.65’s that he wants to use so it sounds like the Crane spring is the way to go.

[Steve C.]

Do your math. Note the distance from coil bind with the Crane 99893 spring.

"Depending on the intended use and the spring and cam-lobe design, coil-bind safety margins can now vary from 0.015 to 0.120 inch, with tighter numbers predominating on very stiff valvetrains. Anything more than 0.150 inch may cause spring surge, which can greatly reduce the available spring load needed to close the valve."

https://www.hotrod.com/articles/how-...rance-is-safe/



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[Jack Ferris]

I always do!

[Scott65]

Steve made a more technical explanation of what I was trying to say. I actually made mine a better fit by going to 1.65 and putting it in a place where its utilizing the biggest part of the range of the spring. I have ~.080-.090 clearance from coil bind. Dave installed them based off of my 1.5 numbers of ~.580 lift. Which is approximately where it sounds like Jack's customer wants to end up with his 1.65 change. Again, there may be better options available today. But these "work".

[Skip Fix]

The 99893s I got did not make 140 seat at 1.790 IH on my 72cc E heads without some shims on my Rimac tester(and I have a calibration spring for it). Part of why I'm going with just 1.5 rockers on that build. I mixed and matched inners and outers to get close to the exact same and I want to think added a 0.030 shim under the cup.

[Steve C.]

With the 99893 spring installed at 1.870" and a 0.580" lift cam it will be too far from coil bind.


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[Scott65]

Absolutely. But it shouldn't be installed at 1.870. 1.800 would be the target. Spring cup, shim whatever, to 1.800. Even -.050 locks.

[Steve C.]

And as Skip pointed out, never trust published catalog specs. They will vary from batch to batch. I've tested a set of Lunati springs that had 20-25 lbs more seat pressure than they were rated at. Comp 995's are famous for that. Take the time and effort to test new springs at their actual verified installed height with their retainers in place.



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[Skip Fix]

I have a set of the better Manley roller springs that the set is all over the pace for pressures. I had them cryo'd an DFL coated before I got my tester so I could not send them back.

The SBC Fast Burn heads I picked up for the 97 truck motor are set for a HR and only have 85 on the seat! Same for the LS srpings on the newer Fast Burns rated at 90 @ 1.800

[Scott65]

Originally Posted by Skip Fix

I have a set of the better Manley roller springs that the set is all over the pace for pressures. I had them cryo'd an DFL coated before I got my tester so I could not send them back.

The SBC Fast Burn heads I picked up for the 97 truck motor are set for a HR and only have 85 on the seat! Same for the LS srpings on the newer Fast Burns rated at 90 @ 1.800

Smaller, lighter valves maybe?