Milkshake would be the least of your problems if it was reversion.....

-beerjet-

To get milkshake through a cylinder is an enormous amount of water.

-beerjet-

ahhhh - gotcha

here is a pic of #7 that had zero compression (valve guides so loose you could bang the two valves together, see the nicks on them?)

anyhow - this is hole that had zero compression - def water getting in, look at the exhaust valve (on the right) with rust from water droplets....  this hole wasnt burning it back off at all...

hence my post in the first place - my worry about just putting new heads on the same config and going back out....

How are the bearings after running with that milk shake.  Known to be pretty tough on the bearings.

Milk shake, in my opinion, is coming from somewhere else.
The rust could be from the oil making its way down the valve and puddling on top of the piston if it ever sat at the top of the hole.
I just don't feel like reversion caused it.
Now if you ask my wife, I'm always wrong so take it for what it's worth.

-beerjet-

Any pictures of the mating surface on the heads?
I originally thought my milkshake was caused by reversion... Until I ran my headers dry and still brought the boys to the yard.... Ended up being a poor machined surface between the block and heads...


Sent with my Fingers

sadly cant find any other info than is what shown in the pics..... engine assembler is anonymous and specs are lost.  heads appear true to the shop and gaskets dont show leakage...

#57 & 58 on the pics you posted the link to show strange signs to me. Corrosion beyond the seal on the heads/intake manifold mating surface... Water is getting past the seal...

Omar, correct me if I'm wrong... Thanks bud!


Sent with my Fingers

He mentioned the seals were bad.

-beerjet-

Since the boating season is winding down, if it was me, I'd pull the engine and go through the whole thing looking for tell tale signs of any possibility where water is entering the engine. Have the block and heads magnafluxed or pressure checked because the eye can't see everything. Another thing to be sure of is that you're not running too much internal water pressure through the engine pushing a gasket. I run a -8 ball valve from the pump to the water inlet of the engine and a mechanical water pressure gauge and have it dialed in so water pressure and engine temp are happy. I have 5lbs pressure at idle and dead in it I have 15lbs and temp at idle is about 150 and 125-30 at cruise. As far as water reversion, I have a cam that has a fair amount of overlap and wet headers and never have had water in the oil. I use a Bassett T with one more restriction in my lines. The feed line is -8 and I use a -8 male union that I have tapped for a -4 pipe plug inside with a .100 hole in the middle. My headers are dry at idle and have a nice fog at mid rpm and at WOT are dry again. I have seen many other jet boats with wet headers that are pouring water out the collectors at all rpm and this is too much. You will find the problem, and as with most, it's something simple or stupid...Best of luck.

Since the boating season is winding down, if it was me, I'd pull the engine and go through the whole thing looking for tell tale signs of any possibility where water is entering the engine.

I believe it is getting in past the rings... Sorry Omar.

Have the block and heads magnafluxed or pressure checked because the eye can't see everything.

Good call.

Another thing to be sure of is that you're not running too much internal water pressure through the engine pushing a gasket.

Another one, but I can expand on this momentarily.

I run a -8 ball valve from the pump to the water inlet of the engine and a mechanical water pressure gauge and have it dialed in so water pressure and engine temp are happy.

I have 5lbs pressure at idle and dead in it I have 15lbs and temp at idle is about 150 and 125-30 at cruise. As far as water reversion, I have a cam that has a fair amount of overlap and wet headers and never have had water in the oil. I use a Bassett T with one more restriction in my lines.

You simply cannot cut the water off of jacketed thru hulls...

The feed line is -8 and I use a -8 male union that I have tapped for a -4 pipe plug inside with a .100 hole in the middle.

 

 

My headers are dry at idle and have a nice fog at mid rpm and at WOT are dry again.

Again... The boat would sink in about three minutes... (burned hoses)

I have seen many other jet boats with wet headers that are pouring water out the collectors at all rpm and this is too much.

Wrong again.

You will find the problem, and as with most, it's something simple or stupid...Best of luck.

Ain't that the damn truth...

GT

This is the timeline that maybe will shed some light on where i am now looking.....

502 Engine Timeline - need help finding a cause before re-assembly

Noticed milky oil - engine sounded good on trailer

Took out and did half lap on water - started steaming through valve covers

Unsure if would just steam it all off, went home for oil change

Did compression check while draining oil  - ZERO on # 7

Disassembled and head gasket looks ok except soot across water jacket outlines on HG

#5 and #7 were getting wet as pistons (especially 7) were steam cleaned

Took heads to machine shop - found cracks only in #1 near spark plug hole and stud @ #1

Valve guide in #7 shot - valves so loose the can touch each other and wiggle when pulled out a ways

GEN VI 502 - blind head bolt holes - no chance water came from there

Headers are wet style lightning - could be reversion?  Rust water drops on #7 exhaust valve

Unknown cam specs to determine overlap (thinking reversion again)

Putting fresh aluminum heads on (old ones were iron WP Merlins)

Pictures of tear down -

https://www.dropbox.com/sh/ec7dcnx5cp417hq/AACmw1fhqAnM08EEeb3ueT6va?dl=0

Questions, I like 'em as much as pictures...

What RPM does this deal idle?

What do you have controlling water flow?

Is there a dump line anywhere?

Even a remote wild ass guess as to what the running block pressure is?

What temperature does it run (may have missed that)?

Where does your ignition timing run at idle and above 2,500RPM?


The potatoes.

Without precise control of the water volume going through the headers, you can very easily flood the exhaust with too much water. This will cause some pretty severe and constant reversion. Do you have flapper valves? You should.

I would be willing to bet your camshaft has a silly big overlap or a simply nutty exhaust duration, this will cause so many issues with a flooded exhaust. Even extending the internal collector tube will not help IMHO. To give you an idea, my '64 Chevelle when it had a 410" small block in it could suck a red rag right out of your hand and into the tail pipe at idle... 

Lightnings are tricky. I personally can't stand them, but they can be made to work, and work very well.

With the engine running, the exhaust outlet (where the exhaust gasses mix with the water) really needs to be hotter than you would think. I have heard numbers anywhere from 160°F all the way to 230°F. Too cold indicates way too much water to exhaust ratio.


You can check the lobe centers with a degree wheel or a timing tape and a dial indicator. Once the exhaust valve closes (as indicated by the dial indicator on the lifter or the rocker arm), move the dial indicator to the intake valve lifter/rocker and note the degree wheel/tape reading, slowly move the crank until the intake makes even the slightest move. Bam...
There is your number. For that system to work, 108° will work with a very small duration, but if the cam is as gnarly as I am betting it is, you really need to be at 112°..  There are not very many "off the shelf" camshafts with those specifications.

If the engine temperature is low (at all times) you can really cut the amount of water to the engine down. Shoot for a WOT temp in the 120-130°F range, it should idle around 150°F tops. The idle in the water should be about 1,000-1,100. This sounds high, but it is not if the cam is large.

My marathon motors typically idles at about 1,200 and were unhappy about it. (lumpy)

Some more ignition timing at idle can help if the problem is not too severe... I suspect that this one is pretty bad.

I need to look at your pictures a little closer and I will respond again if I see something suspect.

Good luck bud.

GT

One more question.... Where the hell is your header water coming from? The water should be hot (over 120°), from the engine. I can't see how that would be the case... What am i missing?

GT