Do I need to pull the motor now?
 

So I'm checking the timing this morning on my 468ci while on the hose. I increase the RPM to 2000 and feel a vibration that I had not felt yesterday. I notice the vibration is between ~1800 - 2400 RPM and then settles smooth. I go back down to idle, 900 RPM, and hear an abnormal noise out of the exhaust, I get out of the boat and listen closer and it sounds like a slight "clanging" out of the port side exhaust. My engine is up to temp so I rule out the hypereutectic pistions that are .001 under the bore. I shut down the motor and begin to pull the riser. Water! :poopoo: Come to find out one of the internal runners on my Gil manifolds cracked a hole in the jacket about an 1/8", thus leaking water into #5 exhaust valve.

What is the probability I bent a rod? What should be my next step? Aside form being sick to my stomach...

BTW, the oil(RP 15-40) is milky.

Thanks in advance!

with the vibration sounds like it...now engine vibration vs miss right ? doubt bent the rod while running unless hydro locked when starting....but water in the oil can do damage...

the milky oil may be reversion from the leaking manifold,do a leakdown and go from their,you might get by with just replacing the manifold,good luck.

Do a compression check too. In the unlikely event that it bent a rod, it probably won't show up in just a leakdown test.

Did you by chance have the drive up while revving engine and checking timing? may have damaged a u-joint.

it,

No matter what you decide to do, pull all of the plugs and the manifolds and then crank the engine over to get all of the water out of the cylinders. Then shoot all eight cylinders with a good long blast of fogging oil through the plug holes and crank it over some more. You cannot believe how quickly raw water will start to eat up a cylinder wall :(

I have a couple of blocks, I mean anchors, at the shop right now that "only had water in them for a few days" :poopoo:

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

Thanks for the replies Gent!

This engine has got me sick! It's my fault for going to the engine shop that I did in the first place, but I digress...

I had the outdrive a little past half way down, Snap, so I hope not. And I do plan on doing a compression test first thing when I wake up tomorrow. (I work nights 6p-6a)

I will not be able to fog it tonight considering I'm at work, I will pull the plugs in the morning and shoot the cylinders before I go to sleep Bill, thx.

I was also thinking of a miss as well ez, but that doesn't answer the question of the sound coming from out of the exhaust would it? Like the pistons were not heated up, mainly on the port side. And I had the oil heated up.

I think I had a total run time this afternoon of a half hour, however, I am not sure when the oil turned milky. It was clear on the lake yesterday. The manifold cracking had to have happened today during heat up.

I'm positive the ex. valve was sucking the water in. I have had 6 hours of run time and producing excellent oil readings. New manifolds will more than likely be on order tomorrow regardless what else I find, thx.

Pull all the plugs and squirt some marvel mystery oil in the cylinders, to prevent any furthur rusting!

i don't think you bent a rod. i did once hydrolocking a small block. starter was spinning full speed. WHAM! stopped motor cold. pulled plugs blew out water. loud rap! bottom of piston was hitting crank throws. you know it when something bad enough to bend a rod happens.

Done...going to sleep now, then will do compression test.

I'm surprised Auto Zone carried Marvel!