SBC Emergency Engine Problem

[nitetrain4590]

I hope someone with some building experience in diagnosing problems with sbc's...... I just finished the build of this SBC a few months ago, hydraulic roller cam, roller lifters, 1.6/1.52 roller rockers, hooker super comps with Super 44s. The engine was running fine during warmup and EFI setup, took it around the parking lot to run through a few gears, and something audibly "blew", nothing metallic, but it sounded like an air pump was pushing air out of my right bank. No noticeable loss of power, no fluid leakage, just the horrible sound. Here is a video of what is sounded like after....there was a little valve chatter from improperly adjusted rockers(I found some lash when I pulled the valve covers), but the valve train still looks fine, all getting oil. I can't see any damage to my exhaust gasket at the head, or at the collector.

https://skydrive.live.com/redir.aspx...G9FX4fbl2grsL4

Any ideas on this would be great.

[MrQuick]

Almost sounds like the flywheel cover is touching. What are the 1.6'ers on? did you check clearance during assembly? It might have kissed a couple pistons. I would not run it again till you check your piston to valve clearance.

[FlyDoc]

I would not run it again!
looking at you build picks... what was your piston to deck high? it looked like a 0 or +(piston poking out of the block)
if I had to guess I would say that you had some valves get a little to friendly with some of your pistons!

[TheJDMan]

I agree with MrQuick. Remove the flywheel cover and see if the noise goes away. I have had that problem in the past myself.

[nitetrain4590]

The 1.6ers are on the intake (7/16) stud mount with poly locks, 1/2 turn past zero lash. I've got a ton of valve to piston clearance, the heads were rebuilt to have a lot of clearance with the Probe pistons. Plus, the first few runs, I didn't have any of this noise, if it was a valve to piston issue, wouldn't I have heard it right away? This is my first build, so I'm not sure about anything. Now that some one mentioned the flywheel, I did have an issue with my throw out bearing being installed incorrectly and partially gauging the clutch springs on my tko 600. I had to pull the tranny and reinstall a new throw out bearing after sanding the clutch spring surface smooth. Could this have caused an issue with my flywheel? When you mean flywheel cover, do you mean scattershield? I'm about to pull the heads, but don't want to if this isn't a valve/piston problem. Thanks again, and keep the comments coming.

[nitetrain4590]

I think I answered my own question, my keisler kit has their aluminum bell housing with a black/18 ga sheet metal
Flywheel cover. What would cause the flywheel to interfere with the cover?

[MrQuick]

at least pull your plugs, loosen your rockers and rotate the engine by hand to see if you hear any scraping. I would not run it anymore just in case it is an internal engine issue.

[nitetrain4590]

Sounds good. Safer is better. I'll let you know how it pans out . I appreciate it.

[Vegas69]

Header or collector gasket?

[David Pozzi]

I'd turn the engine over slowly with plugs out, or pull the ign wire and turn it with the starter while listening underneath. If it isn't the flywheel cover (check that first) it might be something like a rod bolt or nut backing off and hitting the oil pan or windage tray. Keep an eye on the pan for dents pushing outward or discolored areas.

[TheJDMan]

Might not hurt to pull all the plugs and run a quick compression test.

[nitetrain4590]

So it definitely was the flywheel cover.....I have no idea how that happened(nor would I have ever thought that was the issue). I guess that it had been rubbing the whole time, and for whatever reason, when I drove it, the flywheel pulled the cover into itself and bent if toward the flywheel face. I'm going to pull the cover, and still pull the plugs and take the serpentine off and rotate the engine over just to make sure. I've got to go through my valve adjustments again, for anyone who has experience with Comp Cams stuff, the Magnum Rollers with an extreme energy hydraulic roller cam: do you guys go 1/4, 1/2 or full turn past zero lash on the base circle? I'm reading conflicting info on this. I'm going to run a compression test also just to make sure.

With the flywheel scraping against the cover for that one or two minutes: what are the chances that the billet flywheel may be out of balance with the rotating assembly? I don't want to pull the bell housing cover off, but if I'm going to do all of this now, I want to do it the right way.



Thanks guys....

[TheJDMan]

It won't hurt the flywheel but it doesn't do the cover any good. As for adjusting hydraulic lifter vavle lash, you back the rocker nut off till you can rotate the push rod easily with your fingers. Slowly tighten the nut till you feel the push rod start to drag as you rotate it. From that point tighten the nut an additional 1/2 to 1 full turn. I normally do 3/4 turn. You should never have to readjust them which is the whole point of the hydraulic lifters. If you are still in doubt read your installation instructions for the manufacturer's recommendations.

[MrQuick]

With the flywheel scraping against the cover for that one or two minutes: what are the chances that the billet flywheel may be out of balance with the rotating assembly? I don't want to pull the bell housing cover off, but if I'm going to do all of this now, I want to do it the right way.

Thanks guys....

only if the weights got knocked off. lol 1/2 turn is fine. I go half turn then an additional 1/4 while rotating the allen set screw and nut in unison.

[MonzaRacer]

only if the weights got knocked off. Lol 1/2 turn is fine. I go half turn then an additional 1/4 while rotating the allen set screw and nut in unison.

ditto

[tlillard23]

did you figure this out?

[nitetrain4590]

Yeah, figured it out with the help of the guys here on the forum...





It was my own fault, I didn't locate the positive retention tabs behind the oil pan flange, and with the crankshaft end play and engaging the clutch, the crank flange hit the cover. No damage to the crank, but I replaced the cover for GP.