carbuff

iTrader: (8)

I did not. The car had been sitting for about an hour before I took that picture though, and the oil was hot when it let go.

Darth_V8r

iTrader: (4)

I truly hope it is just a failed rocker. Then it's a simple fix. is the pushrod still nice and straight? That might be a good indicator of the valve. Also, if you remove the rocker pair and adjacent rocker pair, put a straight edge across, maybe you can tell the valve height is or is not right?

AndyTA

Is this not a clearance issue? Or my eyes are just deceiving me? Picture angle makes it tough sometimes.

carbuff

iTrader: (8)

Not a clearance issue... The broken one does appear to be touching, but that's because it's been elongated now I believe. The others do have plenty of clearance. They will move away from the rail as they go up not closer to it.

carbuff

iTrader: (8)

Haven't pulled the pushrod yet, may do so tonight. After I saw the brake I snapped the picture and put the valve cover back on to prep for the trailer ride home. After two days in the Texas heat over the weekend, I haven't had much energy to go dig into it quite yet...

G Atsma

I hope the adjustment screw, etc didn't stray too far. It could jam into something with undesirable results.

carbuff

iTrader: (8)

I pulled the valve cover back off and removed the rocker assembly. I found the broken chunk with the adjuster. The rocker is too beaten up to determine how much is 'missing' at this point, but I only found 1 other flake. Looking at the head, there aren't a lot of spots for the flakes to disappear to unless they fell down the pushrod hole.

Speaking of the pushrod, it looks good. Straight as best I can tell, just a little scuffing of the finish from touching the rocker and the opening in the head.

Leakdown test is next, then time to make some decisions...

Darth_V8r

iTrader: (4)

Not bent pushrod might be good news. Put it in a drill and spin the drill. If bent it will appear to wobble.

Hope the leak down checks out good

G Atsma

Or barring that, roll it on a pane of glass.
Yeah, I know, we all have one of those laying around.... lol

carbuff

iTrader: (8)

I can do that... I expect that the aluminum rocker arm would have let go before the pushrod would have bent if there were a piston/valve collision, but a better check that rolling it on a surface would be good.

Che70velle

iTrader: (6)

Hate to see this Bryan. This is the very first Gen3 YT breakage that I’ve personally seen. How did the car run before the issue?

bortous

Which yells terra model?
How old are they?
And what was your open spring pressure?

Darth_V8r

iTrader: (4)

Post one of this thread has the deets. Looks like tony himself set up the heads.

Tuskyz28

carbuff

iTrader: (8)

Correct, although my engine builder did double check everything during assembly as well.

I have spoken to Tony, and it seems that I'm the first person to have one of these new-generation YT rockers break. Lucky me... I was a bit surprised to learn that not that many of these are out in the wild. But when you think about it, most people are running hydraulic cam setups and don't need the adjusters, so perhaps that makes sense...

carbuff

iTrader: (8)

I've owned them for about 2 years. They have been running in the car for about a year. I've put perhaps 500 - 600 miles on them. I ran a 2-day HPDE in February, driven a good number of street miles for tuning and break in, chassis dynoed last week, and then the 2-day HPDE this weekend. So operationally, not that old...

carbuff

iTrader: (8)

Me too... On both statements. And turns out it's the first that Tony knows of as well.

The car was running great! TOW is a handful on the track compared to the Porsches, BMWs, McLarens, Ferraris, etc that typically run the COTA HPDE events. I bested my previous best lap by over 5 seconds, and I still had a good bit more in me/her. I have some in-car video that I haven't had time to process yet, including at least one camera running when the rocker broke. I'll try to post it when I get it ready.

Che70velle

iTrader: (6)

5 seconds is for real. Good to hear TOW was working well. Get this rocker mess figured out. I know Tony will go way out of his way to make this right. Keep us updated.

carbuff

iTrader: (8)

For anyone who's interested, I caught my fastest lap on video. Gives you an idea of how I use the car...

http://www.youtube.com/watch?v=IXrj2...ature=youtu.be

GC99TA

iTrader: (30)

I'm a drag race guy at heart....but damn if that dont look like a lot of fun! Very cool!

Any more updates on your motor?