Hi... I have done lots of searching here and I have found lots of 3rd gen owners that run the Crane Powermax 2032 cam in their L98 engines. But the more I search the less I able to find a proper answer.

I have the Powermax 2032 cam and I plan on installing it in my newly rebuilt L98 roller block (about 500 miles on the engine now). It has been bored .40 over, so basically a 356 ci block.

My heads are stock 083 castings that have been ported/polished out as far as they will go. Also I have a set of 1.6 Roller rockers (which is working just fine with the stock cam) and a new set of hardened Comp push rods....

Exhaust is opened up.... free flowing from the headers on back to the Flowmaster 80 (with the potential of maybe installing a cutout for the track)


My questions...

1. What valve springs should I use with this cam/rockers? Can I go with a set of K-Motion K750s or the ones Crane suggests (99915 retainers, the 99846 valve springs, and the 99095 locks)?

2. Do I need new retainers and locks or will my stock retainers and locks be fine?

3. With 1.6 rockers, will I have to cut the guides down; or, use .050" offset keepers, and shim the springs up more to get the "spec" installed height.


I would like to hear from other 3rd Genners that have installed this cam with their stock heads and 1.6 rockers.

Any help/guidance would be appreciated!!


TIA!

 

TTT...anybody?

 

Cutting the guides down, almost definitely.

The 99846 springs I've used a few times in stock/near stock heads. They are very close to stock diameter, will fit in the stock spring pockets and work with stock retainers. However, they call for a taller 1.75" installed height (stock is 1.70") and you might not be able to get that tall without machining the pockets deeper, using longer valves or using +.050 keepers (at least on the intake side.... read on).

Now, your stock heads originally used rotator/retainers on all the exhaust valves. If you replace them with more typical non-rotator retainers you'll automatically open up your spring installed height by about .060" (to about 1.76-1.77")and then you can shim back up a little from there to hit the 1.75" spec. Pretty simple if you've ever set up valve springs before.

Now the intake side is a little different becuase it never used rotator/retainers in the first place. So there's not much you can do to open up the installed height over stock without machining the spring pockets a little deeper or using +.050" locks to buy you a little more installed height (or longer valves, but I assume you don't want to do that). Just make sure the taller keepers don't cause your retainer to interfere with the "fingers" on the self-aligning rocker arms (if you are even using self-aligning rocker arms). You never want the rocker to be pushing on the retainer- only on the valve tip.

Good luck!

 

Thanks Damon for the advice....

I am now wondering about the K Motion K750's.... here's the specs on those..

Installed Height (in) 1.700 in.
Seat Pressure at Installed Height (lbs) 130 lbs.
Open Height (in) 1.150 in.
Open Pressure (lbs) 395 lbs.
Outside Diameter of Outer Spring (in): 1.265 in.
Coil Bind Height (in): 1.050 in.
Damper Spring Included: Yes
Spring Rate (lbs/in): 482 lbs./in.


Here's the specs on the Crane 99846 springs

Installed Height (in) 1.750 in.
Seat Pressure at Installed Height (lbs) 125 lbs.
Open Height (in) 1.200 in.
Open Pressure (lbs) 383 lbs.
Outside Diameter of Outer Spring (in): 1.255 in.
Coil Bind Height (in): 1.100 in.
Damper Spring Included: Yes
Spring Rate (lbs/in): 428 lbs./in.




And here are the spring requirements of my 2032 cam...

Spring Requirements:
Closed 107 LBS @ 1.800 or 1 13/16
Open 276 LBS @ 1.360


Has anyone used the K750s? My local speed shop said I could use these.... would I have any issues with the K750s?

 

And in case you are wondering about the rocker arms...these are the ones I have installed.

Brand: COMP Cams
Product Line: COMP Cams Magnum Rocker Arm Kits
Part Type: Rocker Arms
Part Number: CCA-RP1418-16
Rocker Arm Mounting Style: Stud
Rocker Arm Ratio: 1.6
Rocker Arm Style: Roller tip
Stud Size: 3/8 in.
Shims Included: No
Rocker Arm Material: Steel
Self-Aligning: Yes
Rocker Arm Body Style: Standard
Rocker Arm Nut Style: Self-locking
Slot Style: Long
Maximum Spring Diameter (in): 1.500 in.

 

The 99846 springs are already a bit of overkill with that cam. Those K-motion springs are over the top. Stick with your original plan.

The correct springs for that cam, by the way, are these (also installed at a 1.75" installed height):

http://cranecams.com/index.php?show=...&lvl=3&prt=122

 

Would there be any drawbacks to using the K750s? Pros-Cons? I don't want to pull the heads off "again" if I don't have to...

 

Not trying to hijack your thread 87IrocZ but I am also considering this cam but in a 305 LB9. With the stock LB9 heads, would it be ok to run this cam with no machining, but with 1.5 roller rockers instead of 1.6's?????

 

Both springs are overkill for that cam but more pressure isnt always a bad thing. Atleast you know you have alot of pressure and are getting the best valve control you can

But too much open pressure could hurt stock lifters.

I'd run a manley 22410 single spring which is 130 at 1.75" but a much more friendly 320lbs open at 1.20 inch. Great spring for a great price

Comp 941's are nice too. 150 bucks and 130 on the seat, 350 open

Another great bet is the Isky 235D's. 1.26 diameter, 130lbs on seat, 320 open, same specs as the Manleys for alittle more money but Summit has them in stock while the Manleys are not in stock.


Cam will fit fine on the stock heads with 1.5 rockers, however with 1.6's lift now becomes .496 at the highest, so you will need the guides cut down or shim .045 and run .050 offset locks to raise the assembly over the guide. Should give you .510-.520 lift safely for that cam

 

We have the Manley 22410-16 spring and 23651-16 and 23652-16 (+.050") retainers in stock. I'm staring at them on my shelf right now.

 

Well... I have a good "racing engine" guy lined up to give me a hand.... he has built many SBC to varying degrees of performance... from a simple stock rebuild to a serious performing SBC getting him down into the 11's on motor.... he is the guy that ported my L98 heads and I trust what he is doing.....

I have no choice on my cam now, I have the 2032 and its getting installed along with the 1.6 RRs... so I will swap the cam out and get that all out of the way, he said to give him a call when I am ready to size up the valve springs/heads.... hopefully we won't have to take off the heads but if we do it won't be much more work at that point...

Still on the fence on what springs/retainers/locks to use though....

 

either of the above choices will be fine, just need to ensure that those heads will clear that lift. i'd shim the springs up with .050 offset locks or the offset retainers and run .045 shims since they only make .015's, .030's and .060's it seems. Check the installed height and verify where its at. anywhere from 1.70-1.75 will be fine, as long as you clear that cam lift. install shims/springs and the cam, then rotate the engine over abit and watch the valves as they open. Go to max lift and look to see if there is clearance between the retainer and guide boss.

I think you'll be fine as long as the assembly is shimmed atleast .045 over stock height. you'll have to get a valve spring height micrometer to be sure of your stock installed heights and shim accordingly from there.

 

Did some more digging online... what do you guys think of these two kits from Crane?


My cam specs for springs are as follows:

Closed 107 LBS @ 1.800 or 1 13/16
Open 276 LBS @ 1.360


First kit I came across by Crane that might work....

PN 11308-1

Valve Spring PN 99848-16
Steel Retainer PN 99915-16
Recom’d installed spring pressure and height (valve closed): 114 lbs.@ 1.700”
Open checking pressure and height: 340 lbs.@ 1.200”
Maximum recommended valve lift and RPM : .510” - 6500 RPM

Valve Springs 99848 specs

Installed Height (in) 1.700 in.
Seat Pressure at Installed Height (lbs) 114 lbs.
Open Height (in) 1.200 in.
Open Pressure (lbs) 340 lbs


Next Kit which if I can remember from my conversation with Crane last year was the kit they recommended?? Think I will have to give Crane another call....

PN 11309-1a
(H-11 material, Saturday Night Special)
Valve Spring PN 99846-16
Steel Retainer PN 99915-16
Lock PN 99095-1
Recom’d installed spring pressure and height (valve closed): 125 lbs.@ 1.800”
Open checking pressure and height: 383 lbs.@ 1.200”
Maximum recommended valve lift and RPM: .600” - 7500 RPM

Valve spring 99846 specs

Installed Height (in) 1.750 in.
Seat Pressure at Installed Height (lbs) 125 lbs.
Open Height (in) 1.200 in.
Open Pressure (lbs) 383 lbs.

 

i know that crane 846 is abit overkill but you cant go wrong with alittle too much spring, especially after they heat cycle and lose some pressure over time

i think its pricey at 169 for the set of springs if i remember right. for another 20 bucks you can get beehives that are superior to most all springs.

those 848's arent bad either. check the prices on those, they might be the better bet.

But any of the above mentioned springs in this thread will work great.

 

Well according to Summit/Jegs...

Crane kit 11309 (846 springs,retainers, locks) cost $197.95


Crane kit 11308 (848 springs,retainers,locks) cost $99.88


Other than the difference in the specs on the 846 springs, I do see that the 846 springs are made from H11 tool steel, while the 848's do not specify that... that must be the difference of $100!

 

oh its a kit? i thought it was springs only.

Thats not too bad then. H11 tool steel is a good quality spring material. So whichever you chose, they both will work well

 

I just installed a set of the 846's with my 2032. I'll be starting the engine for the first time with these this week.

 

Hey mnorton... what rockers do you have in your heads? 1.5s or 1.6s? Are they stock L98 heads?

Any clearance issues? Things to watch for?

I would like to hear back from you after you fire it up...

Stan

 

I'm using Comp Cams 1.52 Steel Roller tips and World Products 305 S/R heads so I really couldn't tell you what specific issues you might have with stock heads. I did have to run offset keepers on the retainers to keep the installed spring height in the 1.80 ballpark. The offsets also gave me the clearence that I needed for the roller tip to retainer surface.

It should be running this week, maybe even today!