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Heres the story, i`m running a 496 chevy, JE pistons with BB2-plus cnc ported heads, one 1150 Barry Grant dominator carb. camshaft duration is 311/315, @ .050 is 280/284, lift is .757/.757 with a 7-4 firing order swap. springs are 1.635 O.D. 280# @2.00, 850# @1.150, bind 1.070. titaniun retainers with 10 deg. locks. i have about 50-60 passes on these springs. the boat runs consistent O`s in the 10 sec. class. now heres the problem, last week i was going to adjust the valve lash before going to the Poplar Bluff, Mo. race. i found a broken spring on the #4 intake. it probably broke on my last pass of 2007. these are double springs and both of them were broken. i replaced the spring and went to the race. on my first qualifying pass the boat stumbled at the starting line and it ran a 10.25 E.T. on the second pass i cut a .177 light and all was going well until it fell off about 3/4 track. this pass was a 11.40. after getting back to the pit and pulling the valve covers i found 5 more broken springs. the #6 intake valve had its keepers and retainer knocked completely off but the stem is still about 3/4 inch visible but frozen in its guide. i`m lucky it did`nt completely drop. hopefully the seat and guide is`nt screwed up too badly. i havent pulled the head yet. i`ve never loosened the spring pressure during the off season but i do bump the motor over about once a month. now my question is; how long is the life expectancy of these springs? what do you guys do during the off season? these are Manley springs and now i`m thinking maybe Comp. Any recommendations or questions? i`m all ears and thanks in advance. richard..........
 

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E-7 Sheepdog (ret)
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IM Amatuer opinion, you are pushing the snot outta those springs and probably should replace them every year. How many seasons was "50-60 passes"?

I think you have your answer. They'll last 50 to 60 passes before they start breaking.

You got a warning with the ONE that broke, than ran it more. Hope nothing really bad got damaged.
 

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Smokin, i think you`ve hit the nail on the head. i got my warning but did`nt take heed. :|err Sleeper, i really never thought about harmonics. the motor is truning 6500 rpm at wot. the spring pressure is 850# @ 1.150 . i`m figuring with a .757 lift cam minus the .020 valve lash, its depressed to 1.263 so i really do`nt know what the spring pressure is at full lift. sure wish i had a pressure tester but those things are outta my reach price wise. looks like i`ve got some homework to do and will loosen those things off during the winter. thanks guys for the replies. :)hand
 

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Resident Ford Nut
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these will prolly out last your boat
http://www.iskycams.com/productdisplay.php?productnumber=9945RAD&sku=2994&hdwt=31101&loc=101&dealer=no
3 seasons in a blown circle boat spinning more R's and have not more than 15 lbs ----killed a set of Manely Nexteks in 3 races
I've said it before: There's a reason those springs cost so much....they are worth it.

Unless you are running a 180 gram intake valve or something like that, those spring pressure's seem excessive for a 6,500 rpm engine :)bulb Because that cam is not all that wild, I don't think ?

I'm glad gn7 has had the same experience as I have had with the Isky Tool room line.

Sleeper CP :D
 

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Heres the story, i`m running a 496 chevy, JE pistons with BB2-plus cnc ported heads, one 1150 Barry Grant dominator carb. camshaft duration is 311/315, @ .050 is 280/284, lift is .757/.757 with a 7-4 firing order swap. springs are 1.635 O.D. 280# @2.00, 850# @1.150, bind 1.070. titaniun retainers with 10 deg. locks. i have about 50-60 passes on these springs. the boat runs consistent O`s in the 10 sec. class. now heres the problem, last week i was going to adjust the valve lash before going to the Poplar Bluff, Mo. race. i found a broken spring on the #4 intake. it probably broke on my last pass of 2007. these are double springs and both of them were broken. i replaced the spring and went to the race. on my first qualifying pass the boat stumbled at the starting line and it ran a 10.25 E.T. on the second pass i cut a .177 light and all was going well until it fell off about 3/4 track. this pass was a 11.40. after getting back to the pit and pulling the valve covers i found 5 more broken springs. the #6 intake valve had its keepers and retainer knocked completely off but the stem is still about 3/4 inch visible but frozen in its guide. i`m lucky it did`nt completely drop. hopefully the seat and guide is`nt screwed up too badly. i havent pulled the head yet. i`ve never loosened the spring pressure during the off season but i do bump the motor over about once a month. now my question is; how long is the life expectancy of these springs? what do you guys do during the off season? these are Manley springs and now i`m thinking maybe Comp. Any recommendations or questions? i`m all ears and thanks in advance. richard..........
Hey guys, Just an old guy here responding to a problem Iv'e heard many times in the past, take it for what it's worth!!!! Driver A takes boat for last romp of the year and has a great time. Boat b gets parked in garage and kissed good-night till it warms up. Driver A wakes boat up after a good long sleep and Boat B has valve train problem. Now comes the fun stuff. Boat A has sat and not turned a revolution for awhile. Meanwhile the valves have stayed adjusted and ready for your'e wake-up call! If you turn the motor over on occasion, great but did the motor warm-up to operating temp? In valve adjust you will have some open some closed and some in limbo. It maybe a pain in the a$$ for some,but if you back of the adjustment of the lifters, springs and valve train it will last alot longer!!! Just something to think about. M
 

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E-7 Sheepdog (ret)
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As much lift and spring pressure as you are running, un-loading them in the off-season would be a great thing to do.

I don't do mine, BUT, I'm not running anywhere near the setup you are.

If you know your closed pressure (on the seat), and know the per-inch spring rate, you can calculate close enough your wide open pressure.

The "850# at 1.150" " is really pretty useless.

As an example, I run 150# seated, 400#/inch Isky springs, .565" lift.

Calculator says: aprox. 376 pounds full open.

Whether this is worth a damn or not:
From the 2" and 1.150" measurements,

280# @ 2" height.
850# @ 1.150" height.
.850" spring stroke.
570 pounds change in that .850" stroke.

math says:
670 pounds (and change) per inch spring compression.

What is the installed height of the springs, and, if possible, the seated pressure?
 

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Discussion Starter #10
the installed height is 2.00 and the spec. card says 280 lbs. they are/were manley nextek springs. i paid $240.00 for them in early 2005.
 

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E-7 Sheepdog (ret)
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OK, 280# seated.
670# per inch.
787# at full lift (roughly).

I'm thinking the Tool Room Spring advice is good. That's a mean setup in my world. Going to take pretty top-dollar springs to live long at that, and back the adjustment to zero in the off season and forget starting it.
 

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Heres the story, i`m running a 496 chevy, JE pistons with BB2-plus cnc ported heads, one 1150 Barry Grant dominator carb. camshaft duration is 311/315, @ .050 is 280/284, lift is .757/.757 with a 7-4 firing order swap. springs are 1.635 O.D. 280# @2.00, 850# @1.150, bind 1.070. titaniun retainers with 10 deg. locks. i have about 50-60 passes on these springs. the boat runs consistent O`s in the 10 sec. class. now heres the problem, last week i was going to adjust the valve lash before going to the Poplar Bluff, Mo. race. i found a broken spring on the #4 intake. it probably broke on my last pass of 2007. these are double springs and both of them were broken. i replaced the spring and went to the race. on my first qualifying pass the boat stumbled at the starting line and it ran a 10.25 E.T. on the second pass i cut a .177 light and all was going well until it fell off about 3/4 track. this pass was a 11.40. after getting back to the pit and pulling the valve covers i found 5 more broken springs. the #6 intake valve had its keepers and retainer knocked completely off but the stem is still about 3/4 inch visible but frozen in its guide. i`m lucky it did`nt completely drop. hopefully the seat and guide is`nt screwed up too badly. i havent pulled the head yet. i`ve never loosened the spring pressure during the off season but i do bump the motor over about once a month. now my question is; how long is the life expectancy of these springs? what do you guys do during the off season? these are Manley springs and now i`m thinking maybe Comp. Any recommendations or questions? i`m all ears and thanks in advance. richard..........
Hey R/T. just another brain fart, When the heads were set up was coil bind checked for that much lift???????????? M
 

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Discussion Starter #13
ol guy, the spring specs said that the bind height was 1.070 i`m thinking with a .757 lift minus the .020 lash adjustment i am compressing to 1.263 leaving .193 before bind. i`ll definately never buy manley springs again. i had one spring broken from last year and replaced it but 5 more broken springs in two runs? the guy i bought them from was on vacation last week. we`ll have a serious talk in the morning. i`m now thinking isky springs since they are so highly recommended.
 

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OK flame away.........

In the PS89 boat we run an Engle cam, springs, retainers........Two years ago we replaced the springs...........AFTER 15 YEARS!!!!!!!!!........Engle did a test, one year, fully collapsed in a vice in the backyard.....NO difference. We ran Engle springs for two decades, dropped 300 rpm. For $100. Engle replaced the springs, newer version, 225 on the seat, Rs came right back.......I never back them off, maybe I should just to seal the engine, but never have. 2 decades of circle racing without a valvetrain failure, go figure!...........That says a lot for Engle Cams..........I'll never use anything else, even free.......Ray
 

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E-7 Sheepdog (ret)
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One hell of a good setup there MP, Engle may well be great idea as well. Sure can't fault experience like that one.
 

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The Isky Tool Room springs are a very high quality part and may be worth the $$. I used them in our SBC drag car with no complaints. However, the Manley Nextec springs are also really good springs. I have a bunch of friends using them in drag applications with no problems, including myself. I do back my valves off in the off season, but not during race season.
Your lift/duration numbers don't seem out of line, but some cams have very quick ramps and end up being spring killers. If you've got a lot of experience with that cam and know it to be fairly easy on springs, it might be the harmonic issue that Sleeper pointed out. If not, the cam may be a spring killer and 50-60 passes might be it. Certainly, that's the case with modern Pro Stock engines.
A "on the engine" spring checker is a great tool. I check my springs about every 10-15 passes, shim the soft ones to keep them where I want them. If the springs start to soften up and start bouncing on the seat, that can eat them up. If this is going on, you'll often see reversion discoloration into the runners of the intake .. Hope you find your answers.
 

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what's your rocker setup?? jesel? rollers with stud girdle?? rollers with no girdle???

my cam was very similar to what you described, made over 600 passes with the same springs - never had a problem, except one time had a stud break, so replaced all the studs. that's with rollers and girdle.

you need good springs, but the springs need to move straight up and down...
 

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Discussion Starter #18
you guys have sure given me some good pointers. i`ll be armed with good questions tomorrow when i talk to the guy who sold me the springs. ( have i got a spring killer camshaft? harmonics? ) i forgot to mention that on most of the broken springs it was both the inner and outer. the heads i have are brodix BB plus 2, cnc ported, mid-lift roller rockers and brodix stud girdles. the geometry is good. i`ve just never heard of anyone breaking 5 springs on one run after 3 seasons of great performance. i was very lucky that the whole motor was`nt destroyed and i really do`nt have the money right now to build another. the only reason i`m able to run the 10 sec. class with this motor is because its in a 265 lb. earl smith texas tunnel hull. thanks again and my ears are still open to suggestions/comments.
 

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What kind of pushrods ? Diameter, wall thickness ?
You have a ton of room between max lift of valve compared to max lift of spring.
You may want to call Isky and/or Pac and/or PSI or etc and let someone that knows valvesprings intimately help you out.
 

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In the PS89 boat we run an Engle cam, springs, retainers........Two years ago we replaced the springs...........AFTER 15 YEARS!!!!!!!!!........Engle did a test, one year, fully collapsed in a vice in the backyard.....NO difference. We ran Engle springs for two decades, dropped 300 rpm. For $100. Engle replaced the springs, newer version, 225 on the seat, Rs came right back.......I never back them off, maybe I should just to seal the engine, but never have. 2 decades of circle racing without a valvetrain failure, go figure!...........That says a lot for Engle Cams..........I'll never use anything else, even free.......Ray
No flames, the cam just doesn't sound as if it is a very aggressive roller profile. As was mentioned before some cams are spring killer's and valve seat killer's it would seem yours is neither. Just a nice smooth profile.

Roller or solid flat tappet ?

Sleeper CP :D
 
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