rocker are stopers will solve all your problems no?
i have hks 272 cams, tomei dual valve springs, oem lifters, and rocker arm stoppers. I bounce off the rev limit enough… and i haven’t had any problems. like most ppl said, i think rocker arm stoppers might help.
I think it’s the bit that keeps the timing chain from coming off the crank gear when you let the chain drop. I remember that the FSM says the timing chain doesn’t have room to come off, and I think it might be because of that.
It makes sense that the rocker could take that with it as it traveled down the case.
The previous owner advised against rocker arm stoppers, as his engine builder advised him against it. I believe the reasoning is that a broken rocker getting stuck underneath the stoppers could jam a valve open, contacting the piston, and so on and so forth. I think re-shimming may do the trick.
On a side note, I hit up the drag strip today.
After spending Friday afternoon getting the engine running again, I decided to re-install my fixed full race manifold on Saturday.
It was a battle, as it had originally went on the engine while on a stand, and came off broken in two pieces. It wasn’t fun to install on the car as one piece, and I had to get creative with removal and installation of various turbo and engine components to get it to fit.
Anyway I hit up the streetcar shootout and entered the 13.0 second class.
Last time out I ran a 13.1 at 112mph on my street tires with no traction.
This time I brought my track tires and opted for the burnout box.
During qualifying I was running 13.0 and 13.1 consistently…although I was getting an ignition break-up or misfire or something at higher rpm.
I logged a run, and the boost was spiking over 20psi, so I dropped the boost at higher rpm.
I kept running low 13’s in qualifying, but could only hit 104-106mph. I think the timing (CAS) was off, as I just set it without a timing light very late last night, so I wasn’t running as fast as I should have.
Long story short, on my first competition run I had some detonation or misfire / ignition breakup / etc. It didn’t sound like detonation, it just seemed like a bunch of misfiring, so not quite sure what it was.
On this shitty run, where I had to peddle the top of 3rd and all of 4th, I ended up breaking into the 12’s !!
That’s a personal best, and the fastest run ever for the car.
Anyway, because I broke the 13.0 second mark, I got disqualified.
Good I guess that I hit the 12’s, but shitty that I could have went much faster if the setup had been tuned better. As always, it’s a work in progress…but it’s coming along.
All I know, and im not an sr guy, but all the road racing guys who seriously kill on their SR get rocker arm stoppers as a safety item when revving the sr to hell constantly.
Research it a bit… not sure why your engine builder or your friend said otherwise. I mean I dont know how people do things locally but almost every abused SR user down south and in europe recommends them as the first safety item on an SR…
I hope you resolve your issue, best of luck.
That looks exactly like an aluminum piece that keeps the timing chain from falling off the crank sprocket when you release the tensioner, I would almost bet money that’s what it looks like, it’s molded to the oil pump cover which is made of aluminum. I circled it in red for ya.
When your shit blew up it probably flew down the timing chain opening considering its at the front of the motor and got caught in the chain and ta-daa.
Vlad for the win…yup…those are them.
Oh…and don’t for a second think RAS will stop you from exploding rockers. I had Greddy RAS and destroyed both the intake and exhaust rocker on #2 cyclinder on a previous motor.
x2 … its still a good investment though coz when they break the RAS keeps them from getting thrown around the head.
Nobody read the thread?
lol
Do you know if the lash pad heights of each rocker have been checked. They are supposed to be within .001" in height to each other.
I’ve been told this is critical to prevent uneven pressure on the rockers.
Check the FSM for this procedure. Does need a special fixture and dial indicator