CLASS RACER FORUM - dual valve springs

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Re: dual valve springs

Quote:

Originally Posted by Jody Lang (Post 418391)

And you're only getting 35-40 runs out of the Nexteks?

I was told by a reputable Class engine builder that some have had problems with the doubles.

I had a set of those fail Manley NexTek springs pretty quickly. The engine had about 22 dyno pulls, and 25 passes on it. In fact, I'm not sure those springs were ever really controlling my valvetrain. The cam was not even close to radical. No expense was spared in building the lightest and best possible legal valvetrain, either. There was not a used piece in it, all the valvespring parts were new from Manley bought as a package at their suggestion. New Ferrea valves, new T&D rockers, and new Trend 7/16" x 0.165" wall pushrods, new Comp Endure-X lifters. The geometry was set up and verified by a Super Stock cylinder head specialist with 50 years experience. The failure ended the season, and did about $3K damage. I had run a set of Comp 26000 series springs the year before, for 50 passes or so, plus a dozen dyno pulls, and despite breaking a couple of inner springs, the rest of the valvetrain was fine.

Re: dual valve springs

Alan, were they set up per the "distance from coil bind" method?

Also were they losing pressure before they broke?

Thanks

Re: dual valve springs

I was told, by a gentleman from PAC to set mine up .050" from coil bind. They do live longer that tight. Makes for like 360/370 on the seat, like 1010/1015 open. The label on the end of the box shows set up at 2.1" but they live longer set up tighter. Maybe a harmonics deal? Don't know, but they last longer like that, so that's how I run them. Last set died by 64 passes, they were not set up that tight. This new set will be. Has been like that every time.

Re: dual valve springs

Back when I was running I had 947 Comp springs triples, they were set up tight 1.850 were 2.00 340 to 350 on seat. They would last two seasons or 200 runs without a problem with 9200 rpm shifts, pushrods are dual taper 7/16. It all depens on your camshaft and how everything is set up in your valvetrain. I was told a long time ago you can't put enough spring on your motor along as you good parts to go along with them. Tom

Re: dual valve springs

My pac #1356 are at 340 lbs.@2.075.Ten pull on dyno,30 pass. I don`t know if they drop again and again .Is there a safe limit ?

Re: dual valve springs

Quote:

Originally Posted by Jody Lang (Post 418391)

And you're only getting 35-40 runs out of the Nexteks?

I was told by a reputable Class engine builder that some have had problems with the doubles.

I have ran the Manley 1.5 and after a season they had only lost about 10 #

Re: dual valve springs

Quote:

Originally Posted by Alan Roehrich (Post 418422)

Was this a stocker or SS'er?

Re: dual valve springs

Quote:

Originally Posted by 69Cobra (Post 419705)

Was this a stocker or SS'er?

Sounds like a SS situation....