dual valve springs

[Jody Lang]

Originally Posted by Ed McLawhorn Jr.

Jody, it's a set of heads I bought used prep by layer. The spring currently on heads are the manley nextek 221447 spring. spec (350# at 2.0 installed ht.)

Ed

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.

[Ed McLawhorn Jr.]

Originally Posted by Jody Lang

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

No Jody, I have only heard good things from the nexteks in respect to durability. I'm in the middle of a re-build project and bought the used heads with springs already on them. I thought I would look at losing some weight on the valve side before final assembly. My comment regarding 35-40 runs was I did not want to install dual springs and have to have to replace after only 35-40 runs.

Ed

[Ed Wright]

I don't see you having a problem with the PAC dual springs. I have four sets that have a full season on them that still check OK.

[Alan Roehrich]

Originally Posted by Jody Lang

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.

[Jody Lang]

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

Also were they losing pressure before they broke?

Thanks

[Ed Wright]

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.

[Tom Meyer]

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

[69Cobra]

Originally Posted by Alan Roehrich

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.

Was this a stocker or SS'er?

[ss wannabee]

Originally Posted by 69Cobra

Was this a stocker or SS'er?

Sounds like a SS situation....

[Jim Hanig]

Originally Posted by Jody Lang

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 #