CAP1....take a wild guess!

[Strip]

Went to test the new car tonight....

We made a few passes and on the fourth we had a little excitement at the end of the burnout. The motor goes pop-pop-pop-tink-tink and shuts off before the wheels stop spinning.

 

Care to guess what is was?

Strip

[CAP1]

Went to test the new car tonight....

We made a few passes and on the fourth we had a little excitement at the end of the burnout. The motor goes pop-pop-pop-tink-tink and shuts off before the wheels stop spinning.

 

Care to guess what is was?

Strip

yikes!



pop pop pop is never good. almost sounds like she swallowed a valve?

[Strip]

I would have sworn the same thing, and would have bet money on it!

Come to find out it looks like it bent a pushrod and broke a rocker arm right at the adjuster.

We arent out of the woods totally yet but this is about as good as could have hoped for under those circumstances.

The unfortunate part is the first night of points is less that 18 hours away.....oh well I guess, could have been a LOT worse.

 

(Going to check that cylinder for piston to valve clearance though, both problems were on number two cylinder.)

Strip

[CAP1]

I would have sworn the same thing, and would have bet money on it!

Come to find out it looks like it bent a pushrod and broke a rocker arm right at the adjuster.

We arent out of the woods totally yet but this is about as good as could have hoped for under those circumstances.

The unfortunate part is the first night of points is less that 18 hours away.....oh well I guess, could have been a LOT worse.

 

(Going to check that cylinder for piston to valve clearance though, both problems were on number two cylinder.)

Strip

bent pushrod is bad too. was the valve lash too tight? somethign had to bend it...........

ya...it could've been something deep inside the engine.....or that swallowed valve, puncturing the piston, and chewing up the combustion chamber....

[Strip]

All the valve heads are still on, the rocker arms are still adjusted to normal clearances. At the very least that precludes a piston-valve munching incident I hope. A bent pushrod is bad, a sign that the valves have been kissing the piston perhaps. We shall see, would love to bore scope the top of the pistons and look for witness marks.

FYI....The exhaust rocker arm broke and intake pushrod bent, very intriguing to say the least!

Strip

[CAP1]

All the valve heads are still on, the rocker arms are still adjusted to normal clearances. At the very least that precludes a piston-valve munching incident I hope. A bent pushrod is bad, a sign that the valves have been kissing the piston perhaps. We shall see, would love to bore scope the top of the pistons and look for witness marks.

FYI....The exhaust rocker arm broke and intake pushrod bent, very intriguing to say the least!

Strip

yikes! i don't know what to make of that....i thought the same rocker/pushrod bent/broke. definitly a good idea to get a look inside before ya run it.

[Strip]

We found a new rocker arm and swapped a pushrod to check everything out. I appears we did not get as lucky as we first thought last night. The valve with a bent pushrod is not going up and down the full rated lift. I will post our findings after we get the intake off but I fully expect to see a broken lifter/lobe.

 

Ryan Norton

[Shuffler]

lol I would have guessed as valve too..... but instead of dropping... burnoff then turn horizontal burying itself in the piston dome then hitting the head.

[CAP1]

We found a new rocker arm and swapped a pushrod to check everything out. I appears we did not get as lucky as we first thought last night. The valve with a bent pushrod is not going up and down the full rated lift. I will post our findings after we get the intake off but I fully expect to see a broken lifter/lobe.

 

Ryan Norton

was the swapped in pushrod the same length as the one that bent?

 a couple of possibilities.......first off, what cylinder # is it? didn't chevys tend to wipe out cam lobes on # 7 and/or 8?

 if it's not going to full lift, but is returning the valve to a fully seated position, then you may have a wiped out cam. bad news, as the metal had to go somewhere.....namely all through the engine.
 if it's not going to full lift, and the pushrod isn't going all the way down by itself, when you know you've got the cam on the base of the lobe, try pushing it down. if it goes, then the lifter is moving ok in its bore, and you've probably got a bent valve.
 now, of course, this brings up the question of how the valve got bent. lash could've been too tight, if the pistons had to be machined for valve clearance, they could've been slightly off.......


 i'm really interested to see what happened now.

 good luck sir!

john

[Strip]

Boy am I whipped!

We broke the Jesel rocker at the pushrod cup, or so we thought, I never get that lucky. Well we found the opposing valve for that cylinder was not going up and down. Pull the intake and found the roller lifter on the intake bound up and the roller exploded. The lifter was riding on the pin supports and eating the outside of the cam away. This caused a burr on the lifter and bound it within the bore. Very little damage was done to the cam where the roller rides so we bought a set of lifters. Managed to also find a pushrod but was close to racetrack and a two hour drive away so we had a friend bring it out.

Car fired up for the first time as I was putting the belts on for second (my only) time run. Which I promtly manage to go too easy on the motor and do a weak burn out leading to an aborted run. Mean while we have zero full throttle passes on this motor so I have no idea what to dial. Car ran a 5.11 turning only 133mph even though I took the long way down the track. Left okay but rattled the tires after the shift and it started skating so I let off about 580-600 feet. When I let off the car started bouncing so I said the heck with this and pulled the laundry, car settles right down. Didnt manage to focus on the light so I was asleep at the starting line with a .045 light (1.110 delay) .

First round .011 light (1.095 delay felt late) and car lays over due to low fuel pressure, still no clue what to really dial.

Second round, .003 light (1.100 delay felt good) and run .002 under (5.05 dial) on the brakes killing 4-5 mph taking .022

At least it stayed together though, 3 hours before we got to the track the motor had no intake, no roller lifters, no rocker arms and no pushrods installed.

Fired like a champ once we phased the distributor right...

Oh well, this is why I love this sport!

[Strip]

Tore the valve covers off today and checked the lash, everything appears to be running good now.

 

Will post some pictures of the carnage tomorrow...

Strip

[CAP1]

Tore the valve covers off today and checked the lash, everything appears to be running good now.

 

Will post some pictures of the carnage tomorrow...

Strip

i read the post about the lifter......

does/did it just look like a defective lifter?

 i'd be worried(i'm paranoid, remember?) about what caused that to happen.

i am, however, glad you got to run her.

 workin your bellybutton off to make those runs makes it all that much more rewarding in the end, even though we all prefer to just go, race, and relax.

 

john

[Strip]

To be honest it just looked old and worn out, we bought this motor with supposedly 30+ passes on it, more like 300+ if you ask me.

I am going to upgrade the cam after tax return comes back, its about the only thing that worries me now.

Maybe that intake valve too, its only got an 7mm stem!

 

Strip

[CAP1]

To be honest it just looked old and worn out, we bought this motor with supposedly 30+ passes on it, more like 300+ if you ask me.

I am going to upgrade the cam after tax return comes back, its about the only thing that worries me now.

Maybe that intake valve too, its only got an 7mm stem!

 

Strip

wasn't off of craigslist, was it? 

[Strip]

No, not much better though, RacingJunk.com....

Pulled the valve covers off today to check lash, get to the last one and I see something very alarming. The rocker arm is cracked on on the valve end near the pin support on the top side. Its cracked from the upper left pin all the way through to the top side of the rocker arm. This would indicate a trend, not a one time broke rocker arm, not relishing buying a set of these or a cam.

Ryan Norton