Rocker Arm Studs

[R Walter]

The West Coast is running at Button Willow this weekend and I'm feeling a little
uncomfortable. It started with an "isolated" rocker arm stud break on Brian's car. Now
at Road Atlanta Paul Arnold, Rafe Baskin, and John George all broke rocker arm studs.
From the information supplied on the heads they came with ARP rocker arm studs...where
do you go from there?
Well I guess this weekend I'll find out if I will also have the same problem.
Robert
West Coast Challenge car #3

[Jim Schenck]

Robert,

We have sent Johns studs back to Trickflow and they are looking into the cause. I expect to hear from them very soon with the results and what needs to be done to stop it from happening anymore. I will update everyone as soon as we hear from them. For the time being I would back the shift points down to 6000 to be on the safe side, we were banging the limiter at 6250 several places in Atlanta and I think that was making the problem more pronounced.

[mhoward1]

Jim,
I will volunteer my car as a test subject for TF if needed. They just need to put the parts on and I will test them.

Seriously, I can probably drop the car off there if needed.

[Snake Eyes]

I have had 4 lifters come apart at VIR with the new top end. Max RPM on the tach is 6250. Anyone else have this problem? The second set that came apart were hi-po comp cams lifters made for higher RPM. Ford engineer at Superfest thinks it may come from floating the valves but we all should have TF's best double springs. Right? Its getting frustrating.

[Bob Cowan]

Historically, TFS has a reputation for one of the best castings on the market - making excellent power for the money.

Unfortunately, they also have a reputation for using cheap parts during assembly. If you're floating valves and breaking lifters at 6,200 rpm's, and breaking rocker studs, they're still doing the same thing. I remember not long ago that every pro builder on the Roadster boards recommended buying bare castings and adding your won parts.

Before I bolted on a pair of TFS heads, I would replace all the studs, valves, and springs. I would also check installed heights very carefully.

[johngeorge]

Bob, we have run the TFS package for 3 years on the Ed's 25hr enduro car, no issues whatsoever with any TFS parts.

The kit we all installed is excellent making great power which has made the cars great to drive. TFS is aware of the stud braking issue and they will give us a fix soon (I believe it is new 7/16 studs and rockers.)

[Scott McKay]

When I used to drag race, the crowd also told me that Trick Flow had great castings and garbage hardware. Unfortunately, I don't think its legal to swap valves and springs, and it certainly gets expensive. I haven't broken anything, yet (well, I guess I haven't hooked the intake yet after the car died), but would sure like a fix before I do break something. PS I was wailing on the rev limiter coming down the RA backstretch many times. VIR and Daytona will have the same issue, for sure.

[Scott McKay]

I also think people are putting on too much preload which is killing the lifters at high rpm. Thin oil will also contribute to this when it gets hot.

[mhoward1]

Scott,
When are going to look at things from RA? Do you know what killed the power on Sunday?

[Snake Eyes]

Going to Charlotte in 2 weeks. Long back stretch and same high-hanging RPMs. I will be using 5th gear and shifting early. Hope things stay together. These valve springs we got are the double ones with the small spring inside that looks more flat than round. Right?

[FFRSpec72]

Have not had issues yet, before we installed the heads we did check the springs (no binding) and the valve height and no issues (close on the height) but all within specs. Hopefully we will get the word on the stems soon. I have not gone beyond 5900 rpms according to my tach memory (speedhut guage)

[johngeorge]

Dont think its valve spring issues, they seem stout. Aren't we at .510 lift anyway, no where close to the .600 max? Mine are the double ones, part# here:

Valve Springs, Optional: (TFS-16315)
1.460" o.d. double with damper
125 lbs. @ 1.800" installed height
376 lbs. @ 1.180" open
420 lbs. per inch rate
.600" maximum valve lift

[mhoward1]

Talking to a friend who is an engine builder. He suggested we may want to look at lobe ramp up. A standard ramp up on a cam is fine for short higher rpm burst, but for entended runs you want a milder ramp up. Considering how much time everyone spent bouncing off the limiters we may want to consider that advice.

[johngeorge]

I talked to Eddi Pinegar @ Trickflow (330-630-1555) yesterday regarding our 3/8 rocker stud braking issue and the news was good. TFS will send us new 7/16 studs, 7/16 rockers, and lock nuts to all who purchased the kit. First items shipped yesterday to racers racing this weekend at MidOhio, and the rest will get shipped out Monday 7/2/12 (there was a delay in procuring the new parts as they didnt have them all in stock.)

Also Eddi is on vacation the rest of this week and will be back on Monday.

[FFRSpec72]

I talked to Eddi Pinegar @ Trickflow (330-630-1555) yesterday regarding our 3/8 rocker stud braking issue and the news was good. TFS will send us new 7/16 studs, 7/16 rockers, and lock nuts to all who purchased the kit. First items shipped yesterday to racers racing this weekend at MidOhio, and the rest will get shipped out Monday 7/2/12 (there was a delay in procuring the new parts as they didnt have them all in stock.)

Also Eddi is on vacation the rest of this week and will be back on Monday.

Let us know how the change over goes and if there are any issues. I hate taking the upper intake off with that nut in the middle, just hard to get to, and hope the upper/lower gasket is still good. I assume the studs were not breaking at the threads to the heads but somewhere in the middle?

Also hats off to Eddie and TF for providing a potential fix

[tcoon]

Good news there's a fix, bad news I now have to remove the top of the engine again...this will be the fourth time! My
luck with the upgrade has been dismal. I hope this fix is the light at the end of the tunnel!

[FFRSpec72]

John, any update on rocher arms? Install go OK? Any new issues?

[johngeorge]

John, any update on rocher arms? Install go OK? Any new issues?

Tony, my car is at Mark Dougherty's place and I had the new rockers shipped to his house. Maybe Mark will chime in on how the install went, seems straight forward enough.

[FFRSpec72]

Tony, my car is at Mark Dougherty's place and I had the new rockers shipped to his house. Maybe Mark will chime in on how the install went, seems straight forward enough.

Heading out on a triple race week this week, I have not seen the new studs and rocker arms show up yet, I would hate to have an issue.

[johngeorge]

Tony, best thing to do is to call Eddi @ Trickflow and get an update from him directly.

[Scott McKay]

My rockers came today. I haven't been able to figure out why my car died at Road Atlanta because its running again. New coil and distributor going in. Not too many things can be heat affected I wouldn't think.

[R Walter]

Scott ....in one of my street Mustangs I had the problem of the motor shutting down when it warmed up...sit for a while
and off it would go. The coil would open when hot, then as it cooled the coil would once again be fine. Drove me crazy.

[Mark Dougherty]

the new replacment parts from TF are great.
I have them on johns and pete Laroses car now, and Waynes soon after. good arp studs and new rockers all went on great
the lifters should be preloaded 1/2 - 3/4 turn
no more no less. I use 1/2.
john has had other issues with his car alot of broken and worn out things.
all fixed now.
both cars will be done and at the aug midohio race.
later
mark D

[vnmsss]

Thanks so much for the update Mark....

Karen

[mhoward1]

Looking to see how well they perform. With the new gears will there a lot of time spent on the rev limiter in 3rd at Mid Ohio?

[Mark Dougherty]

marty
I believe they are topping out 4th on the straight.
the trick is to when you hit the limiter lift alittle.
lol
yeah I know racers dont get that foriegn word

LIFT what is this word LIFT.

[johngeorge]

lift.. ok now that is funny.

[mhoward1]

Ha Mark...you are so funny...Lifting...yeah right.

[Someday I Suppose]

Flat Out.... its how John drives...

lift.. ok now that is funny.

[FFRSpec72]

So is this the method used to adjust the rocker arms?

1. Following the proper firing order for your engine, turn the crankshaft until the first cylinder listed in the firing order is at TDC on the compression stroke. Both valves will be in the closed position.

2) Adjust the valves (turn the rocker arm adjusting nuts 1/2 to 3/4 of a turn past zero lash) then rotate the crank exactly 1/4 turn and repeat for the next cylinder in the firing order.

3) After the valvetrain for all of the cylinders have been adjusted, leave the #1 piston at TDC on the compression stroke for the rest of the reassembly.

[Mark Dougherty]

perfect tony

[Bob Cowan]

- Adjust the exhaust valve with the intake valve half way to full open.

- adjust the intake valve with the exhaust valve half way to closing.

-- that ensures that the lifter you are adjusting is on the base circle.

- In the olden days, you could find zero lash by tightening the nut until you could not spin the push rod with your fingers. With modern materials, that usually puts you past zero lash, and the valve will not close all the way. Instead, tighten the nut by hand. When you can't tighten it any more with your fingers, that's zero lash.

- Turn the nut 1/2 turn past zero lash.

http://www.compcams.com/Technical/In.../Files/250.pdf