VETDRMS

As the title implies I finished up my week long project of rounding up parts and getting everything back together.

First off I"ll say that this setup was a very noticeable improvement over the prior hydraulic roller and unmodified AFR 195's. Simply awesome. :reddevil:

The bad part is that the same day I got it back from the exhaust shop it had a mishap. First the exhaust. I had a tubular crossmember fabricated for the transmission as mine was bent and there was no way to run a straight 3" exhaust with it. The tubular setup turned out great, and I had a driveshaft loop fabricated at the same time. Pictures of the exhaust and crossmember to follow.

Anyways I had just come back from the shop and reset the timing and got the carb dialed in when I went to take it for a test run.
Drove a ways to get it warmed up and decided to get on it a little.
3/4 throttle from a 5mph roll and the tires went up in smoke, just about at 5000rpm in 1st I hear a loud BANG, and no power, a few pops and i hit the kill switch i installed that shuts down the ignition and the fuel pump without locking the steering wheel (pics to follow).

I rolled to the side of the road (luckily at my friends shop), and tried to diagnose the problem. I noticed my fuel pressure regulator was not working and was flooding the carb with 14psi. I thought this could be my problem and it was just loading up. There were no leaks or holes(thank God).
I turned it over a few times and it turned over fine, but was laboring on one compession stroke...not good.

I pulled the passenger side valve cover to check the lash and everything checked out (thinking it was a poly lock that had backed off).
I had an appointment and had to leave so I pushed the car into my friends shop and decided to come back and check it out later that night.

Wow, this is long winded (sorry). I came back and pulled the driver side valve cover to find the problem: a broken rocker stud.



This was the least of my problems. From what I can figure out the poly lock that broke off fell between the springs on the #3 cylinder and bound up the intake rocker. I noticed the intake rocker was off a bit and was bound up.
After taking it off I noticed it had chewed up the top of the valve, and in the process it chewed up the roller rocker:



After pulling that I noticed the pushrod was bent:



Just as soon as that was noticed I saw this in the lifter valley:




I pulled it home last night and pulled the motor. Upon tear down I was able to confirm nothing else had been damaged and the screens I had installed in the oil returns caught the chunk missing from my lifter (cheap insurance!)

I took the head to my machinist today to have the valve replaced/fixed.
I also picked up a new lifter, some ARP pro series studs and have a rocker arm and pushrod on order.

With any luck I will have it running this coming weekend. :)

The moral of this very long story: ADJUST YOUR LASH CORRECTLY.
After talking with my machinist I made a common mistake when trying to "lock" the poly lock.

I set the lash with the hex, tightened the lock, backed it off ~1/4 turn, retightened the lock and used the hex to crimp down the lock in the stud.
This ends up twisting the stud and weakening it.

lesson learned

:cheers:

69 N.O.X. RATT

First, that sucks !!

Second, Just to be sure you may want to pull the pan and check the bearings. I am over **** about this stuff and would pull the head and give the piston a check, or at least do a compression check. Could have easily bent a valve.

CFI-EFI

Damn sure does. He said the head was at the machine shop.

I have always tightened poly locks, that way. Maybe you over did it? I have zero confidence in a set screw, jam nut, or whatever you prefer to call it, tightened, only, with an Allen wrench. Someone over on the C4 Tech performance section had a similar problem, recently. Do you think it was the stud that "let loose" first? Did you notice how far down the stud the poly lock screwed on? The guy on the C4 section, didn't have enough thread engagement between the stud and the nut.

A "new" engine *I* bought only had 1/4" of stud into the poly lock. The valves were adjusted on this set up and is was supposed to be ready to fire. I tore the whole engine down "just to check". I corrected a few other things, but that was the most glaring problem *I* found. To me, a stud diameters worth of thread engagement, is the absolute minimum. NHRA requires, one and one half, a studs diameter thread engagement into the HEX portion of a wheel nut. Good luck, and...

RACE ON!!!

VETDRMS

69 N.O.X. RATT It was an unpleasant suprise, but i'm just thankful the residule effects are minimum. I did pull the head and there was no piston to valve contact. Everything looks fine. The valve will be checked at the machine shop. :yesnod:

CFI-EFI I think I may have been a little over-zealous in my attempts to secure the lock. Would there be any downside to using a little red locktite on the set screw?

The poly lock had at least 3/8" of thread engagement, I will make sure to double check, but I think that was what it was. I was trying to find a longer stud with a taller shoulder as the rocker rides on some of the lower threads, but ARP does not make a suitable stud in the pro-series, at least not in 3/8".
I will make sure there is plenty of thread engagement upon reassembly.

Thanks!

:cheers:

CFI-EFI

"Over-zealous", might be the right term. After I posted, I was thinking a 1/4 turn was a lot. I don't think a little locktite will hurt. I use so little of that stuff, I get my colors mixed up. Red? Blue? I would use the least permanent of the two. While I don't think it will hurt, you really don't need either, and you WILL want to adjust your valves someday. I never considered you might have 3/8ths" studs. Your 3/8ths" thread engagement, is what I would consider the absolute minimum. My engine came with what appears to be stock, big block studs. My first clue to the problem, was how deeply set, the set screws were. Where are you looking at ARPs offerings? Summit? Jeg's? ARP may offer studs the resellers neglect to catalog. You can also look at Crane, Comp Cams, and other sources. You may find a better selection, or at least choice for your application, elsewhere. Good luck, and...

RACE ON!!!

VETDRMS

I think its a combination of user-error and quality. The blue is the lesser of the two. I will most likely just take a more conservative approach this time and run the pro series studs with a gridle.

As far as thread engagement i have .523".
I was looking for a stud with a little more shoulder, but cannot get one in ARP's catalog. All the tall shouldered studs are in 7/16". The rocker arm union does ride on "some" threads. ~4.

CFI-EFI

That ought to do it. The 1/2"++ thread engagement, should be plenty.

RACE ON!!!

427Hotrod

Sorry to hear of bad news, but at least it wasn't too bad.....

You want as much thread engagement as possible. Much better if rocker rides down in the shank area. My first thought here is that you really need to check rocker geometry. it sounds like pushrods might be too long. Pretty common with roller cams, block/head milling etc....

If all checks Ok there, you can do some searching in the ARP catalog. I couldn't find exactly waht I needed or liked listed for a big block Chevy, so I got a set of extended ones for 351C Ford ( :eek: ) that used the old tall valve covers where the studs came out the top and used the cover as a stud girdle. Actually a pretty slick concept! I had to shorten them a little to work, but they are great and I have tons of thread engagement and the rocker is down where it belongs.


JIM

VETDRMS

427hotrod

I checked the pushrod using a plastic length checker and everything was right on with +.100" pushrods. The roller sits just behind the valve tip centerline and sweeps an equal distance past it over the stroke of the lift.

Thanks, I actually went digging through the catalog and found a stud for a...ford...that is .200+ tall and has .100+ shoulder. The only issue was they don't offer it in the pro series. I got a stud girdle tonight so I may just get the standard series and use the girdle.

LD85

Man sorry to hear this, I guess having 7/16 studs gives a little more beef, but I need to recheck the tightening method, I think I did them the way that you did.

CFI-EFI

I don't think the method was the problem. In my opinion, that is the way it has to be done. I don't think tightening the set screw with the minimal force you can get with an Allen wrench is sufficient. I also think, a quarter turn was likely, excessive.

RACE ON!!!

clem zahrobsky

never run a solid roller cam without a rev kit to keep the roller in contact with the cam lobe at all times and use a stud girdle to hold the peices together if something breaks. solid roller lifter have a habit of lifting off the cam because of the weight and then smacking back into cam lobe and the extra spring on the lifter helps to prevent this.