Valve installed height.

[69Stu]

I have a pair of cylinder heads that have been set up with a valve installed height of 1.500".
The cam (Web 86c) and rockers (Pauter 1.5:1) are giving me 0.585" of lift at the vale which is getting into coil bind territory with the current valve springs.
I have been looking at the JPM and CB650 springs. But the CB650 minimum installed height is recommended at 1.510" minimum.
Can anyone tell me if there is a minimum installed height for the JPM springs? The rest of the JPM measurements suggest that they will have plenty of clearance before coil bind.

Thank you.

[K-Roc]

Try a different set of retainers ( different brand ) you can probably gain the intalled height you need this way.

CB 650 is the spring to use  ( far best bank for the buck no question )

Cheers

[Jim Ratto]

The old Berg retainers for their triple-wound springs were great for getting more travel with. Not sure if they're still available.

[neil68]

I've run both JPM Oteva springs and now CB VW650 springs on the same MS250 heads with 0.599" lift, and no issues.  This has worked well for over two hundred 1/4-mile races, plus a few thousand miles of street driving.

When I swapped out the JPM springs for the VW650's, I found that they were virtually identical:  same diameter, etc, so I left the installed height the same 1.5"

[Jim Ratto]

For a street engine, strictly street, running no more than 7000, .455" @ valve, 44mm ss intake, is there any merit running the CB 650? I've run Bugpack 4046's in my engines for 20 years and only issue is losing pressure. I'm looking for 165lb @ seat (1.550) and ~280-290lb over the nose.
Are you guys having better longevity with 650 over a typical dual?
Cam is 272 @ .050, 304 @ seat to seat, .405 @ cam.
Curious if 650 are overkill or will they be a value as far as life.

thanks

[K-Roc]

Jim if your only running .455 lift at valve I wouldn't  think you would require them, I can tell you that they are a good quality American made spring.  And  work very well on .600" + lift applications with standard length valves.

Cheers

[69Stu]

Thanks for all the info.

I have had contact with JPM and have decided to give these springs a try.
They will suite my current application and also give me a bit of growing room change the cam and increase the valve lift at a later date.

Cheers.

[spanners]

Oteva is the Brand name of the best quality Swedish v/s wire, it can't be beat and most quality v/springs are wound from it, I would guess CB also, hence the CB-650 measures up just the same as the many other makes using it, but they may not advertise the fact, in section it will be ovaled slightly to get the lift required, as Jim says, why overkill the valve train? I also use Bugpack springs and  change them bi seasonly or 12 hours service, my spec is 7200 rpm max x 550 lift on Web 86c, installed height is 1.530.  I cut the spring seat to run a base shim, be carefully tho, they can break through the in port if they are minus the hump, my valve train is not the lightest,  and it can be improved weight wise I know, but the Bugpack v/s are good kit, also berg retainer 281a gives much added installed height, I seem to recall over .100" extra....

[Jim Ratto]

About 12-13 years ago, I ran a set of ERCO triples in VW 040 castings. First against a Clay Smith 280' @ .050/.600" steel cam, then against hard weld 86C. They were a bear to set up. Getting enough travel in head rquired careful shimming and had to deepen spring seating surface in floor of head on 1 intake and 1 exh. Ran them .070 from bind (from memory), took an entire weekend, using Berg "drill press method" but once they were in they'd go to 7700 limiter over and over and over with the CS cam, but I felt they were overkill with 86C. I've run the 86C in four different motors in my car, all, except the one time with triples, against Bugpack 4046, shimmed to .050-.070 before bind. They just die though. They go in 165-170 @ seat and come out under 125. 
My next cam isn't going to be anything like the 86C so no need for the big lb, just looking for longevity.

[spanners]

Hmmm, Jim, I'm worried about my Bugpack springs now, I've heard before they can go soft,  I'm gonna check on them, I have 6 weeks before I'm out, the motor was running away with me last time out, I had on a new exhaust with a flow master silencer,  laminar flow cool shell job, well impressed and very good quality, it had so much extra low end and mid range it was untrue, I thought I was riding the limiter more as it picked up so quick off the lights, and it was smoking up the inside wheel out of slow/medium turns, now I think I'd best check the seat pressures, they have 5 hours on them, hopefully it was just on the limiter with the better engine response,  i could run a lot more cam but don't want much over 7200 rpm,  I'm at 2.5 ltr and like the torque of the 86c for the circuits, as you say,  it HAS to be reliable and run for the whole season, I've also heard the Scat springs go soft too., we have a Berg dealer here, I may speak with him..