First, a little history...

- Bought CNC Inc heads w/ Rev 1115 springs in 9/99
- Hydralocked the engine in 7/00. New (and current) cam is a 218/226 527/535 112.
- Broke three 1115 springs over the course of about a month, about a year later. Replaced individually as needed. Third trashed my engine 24 hours before scheduled complete replacement. Replaced with another set of 1115's as 26918 not available at the time, other vendors springs having similar failures, and I knew what to expect from these springs.
- Broke a spring last June on a road trip. Broke down in southern Illinois (I live in Florida). Ordered replacement 918's from Thunder. Dealer installed with retainers provided by vendor who rebuilt hydralocked engine.

The springs I received last June did not have a stripe on them. The odometer had exactly 61000 miles on it at the dealership when replaced. They were never heat cycled per se. I had autotap with me so I sat in the car with it idling for about 10-15 minutes looking for anything odd. I had some misfires due to a slightly bent valve stem, but I took the chance and drove it _straight_ home, just stopping for gas and an hour of sleep.

Replaced the bent valve with about 63000 miles on the odometer. Valvetrain seems a bit noisier since then. We didn't do the procedure about rotating the crank before tightening the rockers (or whatever it is).

Car now has about 74K miles on it. I'm really paranoid about another summer disaster. I've read some isolated discussion on how long roadtrips are harder on springs...can someone elaborate?

I plan on making that same roadtrip again in June. I want to change springs again, should I stick with the 918's? 295-D's? I don't like the idea of prematurely changing them. However, there doesn't seem to be a good way to predict failure other than educated guessing.

TIA! <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

I'd like to know the answer to the same question, as I'm going on the Hot Rod power tour with a 232/228 .598/.588 cam running 918s. I'm definately bringing some spare springs and adequate tools.

 

I'm curious how a long road trip is harder on springs. Your just cruising at relatively low rpm's. Is this really true?

J.

 

Yes, typically 6th gear below 2000RRPM's. I don't understand the correlation either. Only one break happened on the roadtrip, and it may have been coincidental with the mileage on the 1115 springs being in the upper teen's.

How many miles on the 918's, Chris? Tell me which tools you're taking and I may just do the same. Congrats on the trophy @ SLP Day, btw!

 

Jim,
Do me a big favor man...pull the head's off...and machine the spring pad's for 987 dual spring's! lol...it break's my heart everytime I hear about you breaking another valvespring..I have the 987 dual spring's now and couldn't be happier.and Chris...I would do the same thing if I where you..the 918's are just scary running that monster lift cam of your's...single spring's just make me nervous..I drove to the top of georgia from orlando with my 987's and my .568"/.573" and I even ran the car 4 times at south carolina raceway..then drove home without a single fear in mind <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> ...by the way chris, how are those head's coming along?

 

Hey Carter,

Long time! Going to be @ H(o)(o)ters Saturday?

Hard to deal with the downtime getting the pockets machined on the daily driver. I spoke with Louis Gigliotti (hope I didn't butcher that too bad) and he says their using Manley doubles in the stock pocket with their G5X2 - and it comes with the necessary new seats, etc.

How do you feel personally with a dual in the stock pocket vs. a dual in a larger diameter pocket?

Are the 295-D's a single or dual? fits in stock pocket?

I want a solution where I get 50K miles on them <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> And if none's available, someone better start altering the laws of physics <img border="0" alt="[bang head]" title="" src="graemlins/gr_banghead.gif" /> <img border="0" alt="[cheers]" title="" src="graemlins/gr_cheers.gif" />

 

Hey Jim,
Yeah I will be out at hooter's this weekend..as i'm sure you will be as well (since it's like your backyard lol).The better deal would be to go for a larger pocket i.e. larger diameter spring's can handle more..but the manley's would do much better than 918's...and hey if the spring does happen to break,the dampner will hold the valve up untill you can get to safty (instead of your work parking lot <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> )The 295-D's are dual spring's I beleive..but I have heard the inner's don't live too long..I heard thunder racing takes out the inner dampner's and run's them as a single spring(but could just be a rumor?) My best guess would be to go with a stock pocket dual spring..just because of the time it takes to machine the spring pad's for a larger spring and I know it's your daily driver so it would be easier as well...Anyway's..oh also, you should try a new cam with the spring's...I know you are content with your current cam somewhat, but I feel there is a good 20-25 rwhp left in your combo if not more...if I remember right your cam is like 219/228 .528/.534?..something like that..try out a 226/232 .570"/.575" 112..you should gain a noticable amount with that AND with dual spring's you should have good spring life <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> see ya saturday!

carter

 

Carter - I sent e-mail to your AOL address. If you already replied I'll followup tomorrow - somethin's fubar on my PC and I can't check it from home. If you didn't already reply you can send it PM or my home e-mail instead.

Jon - I've done the loop around the Florida coastline, and been in twelve other states. My baby's a road ***** <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> I need to step it up if she's gonna see another 36 before she dies!

<small>[ April 02, 2003, 06:31 PM: Message edited by: JimMueller ]</small>

 

Jim,

I'll be bringing extra springs, valvespring compressor, pen magnet, metric hand tools, 24MM for the crank bolt. I'm sure I'll think of more.

The springs have 500 miles on them. The engine is a little more than a week old.

Carter,

The heads are on the vehicle as of last week with a new engine. My last busted piston misadventure split the sleeve as well. I'll get a few miles on the engine and head to the track.. see what the new parts gave me. The goal is- 11s on 20s !!

 

Spring "surge" is the likely culprit. The valvetrain has different vibratory frequencies throughout the rpm range. When the natural frequency of the valve spring is at or near the the frequency that the rest of the valvetrain is operating at, the spring is sent into surge - bascially a standing wave pattern that will destroy the valvespring. I went with the Isky 295-D's as they have an internal damper to help "absorb" (basically changes the natural frequency of the spring) certain frequencies. I have 1000 or so miles on a TR224/.561"lift with the springs - including a 350 mile road trip. No probs so far. Isky makes good stuff - I use their springs in my 410 sprint car that turns 8300rpm! They have a great grasp on the metalurgical composition of their springs. Good to see that there are other guys out there that like putting road trips on their cars <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

I have the Thunder Racing modified 295-D's. They removed the inner spring and modify the damper by removing a small bit of material from the bottom. The come with spring shim/seat that sits right in the stock spring pocket. They also include new valve seals that don't have the under spring extension on them - the stock valve springs hold the stock valve seals in place as the stock seals function as both a seal and a spring seat - I know you know that after replacing springs so many times. <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />
I love the fact that the Isky's are strong springs and did not require pulling the heads to machine the pockets. At the time I bought them from TR, I didn't have to pay extra because the titanium retainers for the Isky's are cheaper than the Comp retainers - extra Isky spring price washed even. I would have liked to have dual springs - but this is the most robust set-up that I have come across without pulling the heads. Glad I can help out an F-car bro <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" />

 

Checkout the thread on the REV 1116 dual spring that's bouncing around. Looks like a lot of positive feedback on those and no machining the spring pocket.