waddisme

I got over 21 track days on the stock TFS valve springs before one broke (#8 exhaust). After repl them with the Brian Tooley springs, my plan was to change them every 10 - 12 track days which is about what I do a year. I didn't even get 5 track days out of these before the #5 intake broke both springs. Now my rocker arm looks like this:




My MS3 (237/242 .603"/.609") cam from Texas Speed is pretty aggressive, but it seems to have done fine for the first 5 years. Seeing I am going to have to remove heads to assess damage, should I just go ahead and change to different cam? I don't mind doing the spings once a year, but not getting even 5 track days is not good. Are there better springs than the BTR ones? Is that the route to go? Just don't want to have to be worrying about this everytime I do a track day. BTW, car was kicking *** before I felt it break.

FASTFATBOY

MS3/4 have no business in a road course car. Those cams have very aggressive lobes....of course you can see that now.

Too many other choices out there, call Bret Bauer at Bauer racing engine in New York.

willyfastz

If you need a little help with your valve train issues shoot me a pm. I'm in NC as well. Trick flow heads with Ms cam and average springs can cause issues.

rfn026

You need to think of the whole valve train as a system.

When it comes to springs the industry standard is Performance Springs Inc. in Michigan. Just get ready to write a very large check.

Here's an article I wrote with all the details.

Richard Newton

waddisme

I wish you were closer to help with the tear down. That whole alt bracket/ps pump this is tough to get off. The valve springs are the ones recommended by Brian Tooley himself. He knew what it was going into and what I did with the car. Just disappointing that they only lasted less than 5 track days.

If I thought their springs could handle this cam, I would rather go that route than replacing cam. Repl cam means tearing front of motor off, plus $250 for a retune etc.

All that become irrelevant if there is piston damage. Pulled spark plug last night and it is beat up pretty bad - not a good sign. Hopefully will get head off tonite and get a look at all that. All is removed except for the 15 bolts holding the head down. Fingers are crossed but not looking good.

Thanks for the inputs

0Anthony @ LGMotorsports

Could be the ramp of the cam, could be a spring issue...could be the entire valve train.

Hard to tell exactly by the picture, but those rocker arms I am going to say are a bit heavier than what a stock rocker is going to be, which leads to more weight to throw around....probably going to need to look at the entire valve train together and get something matched.

FYI...we ran stock rocker arms on the World Challenge Vette and could spin it to 7600 without issue.


Let me know if you want any help with any of it.

waddisme

Seems like I had to change to them when I went to the Trickflows. Can't exactly remember why now.

mrr23

Not seeing the rockers as an issue as he made 21 events on the initial setup. Changed springs only and now has an issue.

0Anthony @ LGMotorsports

Might not have been an issue with the first setup, but it might be an issue with the new springs.

With the Challenge cars we did spring changes every 20-25 hrs of run time on them. The endurance cars every 35-40 hrs.

If the driver over rev'd the engine, springs were changed after that session.

SStrokerAce

As everyone with experience so far has said.... The rockers are not helping this at all.

In terms of the springs.... The TFS spring is a better piece, hence why it lasted longer. Still not up to the job obviously, but that is most likely due too the added mass from the aftermarket rockers, a stiffness issue and too little spring load for that combination of parts.

The PSI suggestion is a good idea, and mine would be the proper PAC RPM dual for the combination along with fixing the other issues. (Rockers!)

You can control that cam and have longevity for what you are doing... I have done it with that cam lobe family. The problem is you can't expect high end results from cheap *** parts. Not to mention a valve train is a system.... Even though LS motors are "LEGO" motors you still should science out the parts... And not just take the word of a salesman.

For as many times as I've seen claimed "our springs have NEVER had a failure" I've seen cases like yours and fixed them.

Good luck with the fix.

Bret Bauer

FASTFATBOY

These cars really don't need aftermarket rockers, it's been proven time and time again.

The factory piece is damn good.

hungryhippo

Also a possibility that the car is being driven harder now if you were just starting out when the setup was new.

waddisme

I will check my emails, but I am sure I was told I had to have upgraded rockers to go with the trickflows. As far as the springs, I talked to Brian Tooley personally, so he knew what my motor specs were and what I did with my car. Those springs were good to .650" lift - go figure.

Here is a typical lap for me at VIR (before repaving). 9 times out of 10 I shift to 5th gear on the backstretch to get to my 155ish. This particular lap, I didn't get out of Oak Tree very well, so I didn't shift:

SStrokerAce

Exactly you talked to a SALESMAN.... just ask those springs NEVER break

SStrokerAce

BTW the cam is a 3729 / 3731 XE-R Comp grind...... yeah stock rockers, beehives put in right and the right pushrods and that deal will run all day long. Even with the heavier TFS valves. I've done that for YEARS.... mind blowing that the "best" springs on the market today (sarcasm) can't handle that?

Last C5

Yes, supposedly the Farrea springs are better. Expensive, but better.
"Is that the route to go?" Ask me after about 10 track days.

mrr23

Im sure they are. I bought my car from a used car lot. Did some research to find out the previous owner did road racing in north florida. Stock motor only external mods. Figure i would swap springs out as car had 110k miles. This is what i found.

http://www.corvetteflorida.com/forum...d.php?t=102574

A stock rocker twisted on the stand.



I'll stand by what i said. The rockers aren't the issue. Brian tooley knew the rockers were in there. Maybe there's an installed height issue here. Was that checked? Why did the tfs springs last over twice as long?

mrr23

Tfs wants you to use aftermarket rockers due to the valve angle change from 15* to 13.5* and so you don't wear the bronze guides.

64drvr

Get an endurance cam like eps/cam motion, world challenge, asa, etc....
Id also recommend stock rockers, with che bushings, and for valve springs- PSI's as one of the best, but the btr duals should work.

FASTFATBOY

Put a LS6 cam in and forget it.

Was that rocker that's twisted, the bolt loose? Almost has to be.

I have seen cars with valve float issues put stock rockers back on, fix the valve float and pick up .5 at the dragstrip. Seen this numerous times.