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Re: VALVE SPRING COIL BIND QUESTION [Re: BradH] #2661010
05/31/19 04:58 PM
05/31/19 04:58 PM
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Queensland Australia
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moparmacka Offline OP
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W5 heads
Ferrea 5.165 6000 series 11/32 Stem 2.08 and 1.60
Comp tool steel retainers with X2 -0.100 moly locks
Allegedly the lobe is a modern design and is improvement on the old 420 lobe
There are a lot of engines over here using that lobe and some spinning them to 8000 with no float issues. Mopar, Chev, Ford and GM Holden engines.
Got me stumped!

Re: VALVE SPRING COIL BIND QUESTION [Re: Cab_Burge] #2661011
05/31/19 05:00 PM
05/31/19 05:00 PM
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moparmacka Offline OP
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I have been told the 427SR lobe family is a modern lobe design. A so called improvement on the old 420 lobe family.

Re: VALVE SPRING COIL BIND QUESTION [Re: B1MAXX] #2661013
05/31/19 05:02 PM
05/31/19 05:02 PM
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Was assembled with new exhaust seats, fresh 3 angle job and new guides. All was mint when checked and installed.

Re: VALVE SPRING COIL BIND QUESTION [Re: moparmacka] #2661045
05/31/19 07:46 PM
05/31/19 07:46 PM
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Val-haul-ass... eventually
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BradH Offline
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Originally Posted by moparmacka
I have been told the 427SR lobe family is a modern lobe design. A so called improvement on the old 420 lobe family.

Not sure that I was looking in the latest Crane lobe catalog, but there wasn't a 427 series. There is a 428 series, which is described only as an aggressive oval track design.

Maybe you need to look into whether a different spring might be required to keep things under control. Not sure what else to suggest at this time.

Re: VALVE SPRING COIL BIND QUESTION [Re: BradH] #2661112
06/01/19 06:26 AM
06/01/19 06:26 AM
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Tulsa OK
Bad340fish Offline
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What is stopping you from adding more shim?


68 Barracuda Formula S 340
Re: VALVE SPRING COIL BIND QUESTION [Re: Bad340fish] #2661126
06/01/19 07:40 AM
06/01/19 07:40 AM
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Val-haul-ass... eventually
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Originally Posted by Bad340fish
What is stopping you from adding more shim?

He's already close to the minimum installed height for the combination described: 1.870 with .640 net lift means he's down to .080 before coil bind, per the 1.150 spec for that spring.

Re: VALVE SPRING COIL BIND QUESTION [Re: BradH] #2661133
06/01/19 08:09 AM
06/01/19 08:09 AM
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Apollo, PA.
B1MAXX Offline
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Sounds like a spring change is the next best step. I'm pretty sure a comp 944 would fit right in there and put you around 270 closed .

Re: VALVE SPRING COIL BIND QUESTION [Re: moparmacka] #2661221
06/01/19 12:21 PM
06/01/19 12:21 PM
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Pattison Texas
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Possible rocker arm geometry problem, call Mike at B3 racing.


1968 Charger COLD A/C Hilborn EFI
512ci 9.7 compression, Stealth heads, 4.10 gear A518 ODtrans 4100lb,10.93 full street car trim
2020 T/A 392 Stock 11.79 @ 114.5

Re: VALVE SPRING COIL BIND QUESTION [Re: CSK] #2663841
06/08/19 06:44 PM
06/08/19 06:44 PM
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moparmacka Offline OP
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He was the reason I went T&D in the first place.

Re: VALVE SPRING COIL BIND QUESTION [Re: B1MAXX] #2663842
06/08/19 06:44 PM
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moparmacka Offline OP
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I’ll have look!

Re: VALVE SPRING COIL BIND QUESTION [Re: BradH] #2663846
06/08/19 06:50 PM
06/08/19 06:50 PM
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moparmacka Offline OP
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Crane told me it was a SR lobe with 0.427 lobe lift.
Wondering if the reduce base circle of 1.050” and relatively short duration 304(266@50) and 308(270@50) with only 0.427 lobe lift makes for an inherent aggressive lobe design.
Just try to cover all bases.

Re: VALVE SPRING COIL BIND QUESTION [Re: moparmacka] #2663985
06/09/19 09:42 AM
06/09/19 09:42 AM
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Val-haul-ass... eventually
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BradH Offline
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Does it transition from "OK" to "Chaos" over only a few hundred RPM, or can you see things in the data getting progressively worse over maybe the last 800-1000 RPM until it comes unglued?

I still think you need to explore other spring options.

Re: VALVE SPRING COIL BIND QUESTION [Re: BradH] #2663990
06/09/19 10:10 AM
06/09/19 10:10 AM
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So. Burlington, Vt.
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From where I sit........ which is from a position of having not tested any of your stuff...... it certainly appears as though that spring, in that application, with that cam/RR ratio........ isn’t a match made in heaven.

I doubt fiddling with the installed height is going to fix it(but never say never).

I’ve tested many SBC’s with similar lift cams, using stud mounted rockers in Dirt modifieds that would go to 8K with less spring than you have........ and many of them used fairly aggressive cams.

With what you’ve got into springs/retainers/locks, etc....... it might be less $$$ to use a different cam profile and keep the springs.

If I were to look at different springs, I’d be tempted to try something with a damper..... or perhaps if you have enough available installed height, something like the new conical springs.

The only “SR” lobes I see in the lobe master catalog are designated “street roller” profiles(nothing with that lift though).
Perhaps the high rpm stability wasn’t a primary design parameter for that series of lobes....... and they just aren’t all that happy at high rpm.

Quote
short duration 304(266@50) and 308(270@50)


Do you know the checking height for the 304/308?
If it’s .020”......... that’s not an aggressive lobe at all...... at least the intensity near the seat doesn’t look to be.

Even an old Comp hi-tech.420 would be 302/306 @.020 for 266/270@.050........ and those lobes are pretty smooth.

Do you know, or did you check the duration @.200?


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: VALVE SPRING COIL BIND QUESTION [Re: BradH] #2664228
06/10/19 12:19 AM
06/10/19 12:19 AM
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Queensland Australia
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moparmacka Offline OP
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Yep, chaos in a few hundred RPM.

Re: VALVE SPRING COIL BIND QUESTION [Re: fast68plymouth] #2664231
06/10/19 12:30 AM
06/10/19 12:30 AM
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moparmacka Offline OP
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Yes, the checking point is at .020. And stupid me didn't check the numbers at 200.......

Re: VALVE SPRING COIL BIND QUESTION [Re: moparmacka] #2664539
06/10/19 08:18 PM
06/10/19 08:18 PM
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Melbourne , Australia
LA360 Offline
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That info should be in Crane's lobe master catalogue??


Alan Jones
Re: VALVE SPRING COIL BIND QUESTION [Re: LA360] #2664633
06/11/19 12:44 AM
06/11/19 12:44 AM
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Apparently not.

Re: VALVE SPRING COIL BIND QUESTION [Re: moparmacka] #2664746
06/11/19 11:38 AM
06/11/19 11:38 AM
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Val-haul-ass... eventually
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BradH Offline
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Was the cam a custom-ordered directly from Crane (or through a Crane dealer) based on Crane's recommendation for your combination? If so, have you contacted Crane about what you saw on the dyno?

Or, dare I ask, was this a cam that someone had already and "this ought to work" determined why that's the one you used?

I'm starting to think Dwayne's suggestion that it might be cheaper and make more sense to change cams is good advice.

Re: VALVE SPRING COIL BIND QUESTION [Re: BradH] #2664755
06/11/19 12:02 PM
06/11/19 12:02 PM
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So. Burlington, Vt.
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fast68plymouth Offline
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I think the next step would be to contact Crane and see if they can provide the .200 number.
It might help shed some light of the ramp speed of the cam.

Couldn’t hurt to get their recommendation for open/closed spring loads for the RPM you’re looking to turn, and see how it compares to what you’re running.

The bottom line is....... the cam may not be a very good match for the springs in that valvetrain combo.

It doesn’t sound like you tried revving it any higher.
It may just have a “fuss point” around 7k, and that it might have been okay higher up.

I understand the reasoning behind the current love affair with giant pushrods....... but I look at it as..........if you don’t need them...... it’s just extra weight the springs have to control. You only need what you need.
Imo, your pushrods are way way overkill for what’s in the rest of the valvetrain....... and there is extra weight there that I wouldn’t have added to that system.

Quote

You could hear a flutter at 7000. The dyno reflected this with a squiggly line then suddenly drops off. Also tips of valves have a snow angel pattern.


Engine or chassis dyno?


68 Satellite, 383 with stock 906’s, 3550lbs, 11.18@123
Dealer for Comp Cams/Indy Heads
Re: VALVE SPRING COIL BIND QUESTION [Re: fast68plymouth] #2664775
06/11/19 12:56 PM
06/11/19 12:56 PM
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Val-haul-ass... eventually
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Quote
short duration 304(266@50) and 308(270@50)

FWIW, this is what my COMP RX measures:
Seat at .018" lash (.012" lobe) = 315
SAE duration at .018" lash (.016" lobe) = 307
.020 = 300
.050 = 266
.100 = 232
.200 = 184
.300 = 136
.400 = 68

Peak lift .434"

If you can get more data for your lobes, it's something in the same duration range to compare 'em to.

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