A buffalo’s first bowtie

I guess give it 20 minute or so to warm up and break the cam in, usually that time is used up setting the carb, and timing and checking for leaks in the drive and varing the RPM some.

Thanks Joe, I don't have the experience with this that you guys do. If I had know it would hit that soon, I guess on the ramp would have been better...but I didn't know to run the rpm's that high at first either.

Warm it up a little or go straight to higher rpm's?

I guess immediately answers my question...

81nautique wrote: What about cam break in, I didn't read back through this whole thread but you're running a regular flat tappet cam right?

Yes

8122pbrainard wrote: Greg, I'm very happy to here the good news but where are the pictures??

I have pics, but I have some more to diagnose. I took it to the ramp and it wouldn't start. The only thing that changed was the depth finder install so I'm guessing I pulled a wire loose somewhere else under the dash. It's acting like it's not getting fire, but I'm to tired and too bent to figure it out now.

The good, the bad, and the ugly?!!?

I found the wire that pulled loose and it started right up and ran beautifully...

EXCEPT I think I have a rod knocking. The noise is solid sounding and seems to be low in the front...it's also rythmic and in perfect sync with rpm's. It is the original crank and rods, so all I can think is that I missed a rod bolt somewhere...not sure how though because I triple checked everything.

If anyone knows of something I'm missing, I'm all ears.

JoeinNY wrote: Tragedy perhaps, what rpm were you running at?

Trajedy is a bit mild I think! When I started it I was going to follow Alan's last post and ran it right up to 2000. I backed off when I heard the noise and have started it twice for a few seconds after. The noise is different each time, and I went around it with my crow bar looking for the knocking...can't really find it.

I was hoping it would be the valve covers, but I couldn't hear a solid rap there. So I cleaned up the garage and am about to pull the %$#$% again...it's a half day job getting the engine out with my tools.

If it is a rod and the noise has been changing-going from louder to softer and not as rythmic and almost nothing at idle before I shut it off; that means there is metal all in the low end and it's another rebuild?

Dont get all worst case on us yet, if it wasnt for the cam needing to be broken in I would say futz around with it pulling plug wires while its running. But in this case I say pull the valve covers and check for loose push rods or play in the rockers before you get all crazy pulling the engine. If you pull the engine and its just one rod end I would say you have nothing to loose by just fixing that and giving it a run, whats the worst that can happen you need to rebuild it again.. since you can pull the engine yourself I would take the risk...

I'm not all PO'd...more like someone shot my new puppy?!!?

It's already back in the garage cooling off and I'll do whatever I have to.

FWIW, it sounded great unless I was right in front of the engine...

Harmonic balancers can alse make a heck of a racket.

Buffalo,

I think I feel your pain, as most of the others following the threads on your boat & engine would be. Devastating but as Joe said dont accept defeat too easily and pull the engine prematurely.

Remove plug leads one at a time to identify which rod bearing it may be. Hopefully there is no change and it is a lifter or something less than a bigend bearing.

Just take those mufflers off & it will go away! Or at least you may not hear it. Just kidding- hope you get it figured out. Bout time to pick that pumpkin!

I might be up your way this weekend. I think I know the general area you are in. Can you still get to your dock, or is it in the mud already?

Well a rod would change with RPM but I would still be thinking valve train, it was first dyno run last year on my 408 that a collapsed lifter (actually two) did me in.

Greg, try firing it up without the covers on it. Just have plenty of rags on the carpet below your exhaust manifolds to catch the oil. It you still hear the noise shut it down. Then try to push down on the rockers (with hand) against the lifter spring pressure. Lifters should be pumped up and should NOT give easily. Should fewel almost solid. If any do give, they may be collapsed or just not pumped up yet. How long have you ran it?

could also be your base timings out and your getting a damper knock which alot of times will sound like a rod knock and transmit thru the engine, a dead plug, a bad wire, timing, anything to cause a miss will transmisst as if you do have a bad rod and ends up being torsionals, tread wisely, you could have fouled a plug from assembly lube and so on

Just drained a little over a quart of oil over magnets laying in the drain tub and found nothing but clean oil. The valve train is also very clean. Gonna keep looking before I pull it.

The oil pan doesn't have any kind magnet in it, so if it was a rod shouldn't I see metal flakes?