MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

[Don S]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

Does anyone know why the #4 cylinder is the problem child of the 470? And is it possible to blow a head gasket without ever overheating the engine?

With the open deck design of the aluminum block, it always surprised me that they don't blow more often than they do.

 

[natemoore]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

Both were surfaced. Can't remember what the machine shop did, although I know I mentioned it to them. I vaguely recall the owner doing one, but saying that it wasn't necessary to do the other, or he had other means to check it.

Keep in mind that I've been on the water a lot in the past two years and this just started happening recently. Not saying a crack couldn't have formed, but I would think that this problem would have been there from the get-go.

 

[natemoore]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

With the open deck design of the aluminum block, it always surprised me that they don't blow more often than they do.

"open deck design" meaning that right below the head gasket are coolant passages?

I read that water getting into the cylinders would make the spark plugs white or very clean. #3 and #4 were carbon fouled. Does that mean anything, or can you have carbon fouling with a blown head gasket?

Incidentally, can over revving blow a head gasket? I've since gotten a higher pitch prop, but with the 19 pitch that was on it, I would be at WOT rpm at about 75% forward of the stick. One day while getting out of the hole (is that the proper term) I over revved it for a 10 or 15 seconds to about 5500+ rpm before backing off the throttle.

 

[natemoore]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

I've run the engine with the reservoir cap off recently. I didn't notice any oil in the coolant or any bubbles coming up. From what I saw on youtube , I would certainly have noticed the bubbles!

Almost got my manifold pressure tester put together. I'll post some pictures of that.

 

[natemoore]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

Here's my pressure tester. Got all the hoses, plugs, and fittings at Lowes.






No bubbles, except for a tiny one coming from the gasket every 60 seconds or so. Got visual ID on that one. It's held 15 psi for almost two hours now. The needle hasn't move a bit.

 

[natemoore]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

On thing I noticed about the gasket mating surface of the exhaust manifold is that it's not perfectly flat. I took a large file and started to clean up the surface when I noticed a sunken spot indicated by the grey area. Wonder if you can get this surface machined flat, or would some sanding with sand paper glued to a metal or glass plate be good enough, or I this not a concern.

This could very well be what's allowing a few drops of coolant to enter the exhaust manifold.

 

[natemoore]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

I wouldn't rule it out. Put the elbow back on, fill the cooling system and leave the cap off. Then retest #4 for leak down. Don't worry about the numbers, just watch for bubbles in the coolant reservoir.

Did it. Leakage in the low range. No bubbles in the reservoir. So, now can I call it a good head gasket?

I surfaced the gasket mating surface of the exhaust manifold with a diamond sharpening stone, which is the flattest thing I could find. Got it all leveled and shiny. Putting it back together now.

 

[joewithaboat]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

From the looks of that picture id say you might have found your leak.

 

[Don S]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

Put it back together and try it. If it still does gets the steam around #4. You may have fixed it.
If it still steams, don't start ripping stuff apart before asking about further testing.

 

[natemoore]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

Put it back together and try it. If it still does gets the steam around #4. You may have fixed it.
If it still steams, don't start ripping stuff apart before asking about further testing.

Too late...already have the engine on a stand Just kidding. It's all back together. I'll test tomorrow morning (glad I'm self-employed). I'm just relieved that the head gasket isn't blown. I need to redo that compression test with the engine at operating temperature.

All the valves clearances are good and all push rods are straight, btw.

 

[natemoore]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

Fixed it, I think. Runs great. No steam!

 

[joewithaboat]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

Great job! Success feels good doesnt it?

 

[natemoore]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

Great job! Success feels good doesnt it?

Yes! Now I've got to get back on that shift cable adjustment problem. All this stuff was just a distraction.

 

[natemoore]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

View attachment 118186

Even though the bungee cord slipped off the prop and hit me in the forehead, I'm still smiling because not only did I get the upper shift cable replaced and get the shifting working perfectly, my baby jumped to life after sitting for a week, no coolant smell, no steam, purred like a juvenile feline.

Taking it out tomorrow with my new 23 pitch prop. I'm hoping to hit 45 mph at WOT (but only in short bursts)

 

[mikesearay270]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

(Does anyone know why the #4 cylinder is the problem child of the 470? And is it possible to blow a head gasket without ever overheating the engine? I would bet my life that the temperature has never gone above about 160. One eye is always on the temperature gauge.)

I talked with Kevin at Breezeworks.net, he told me EXACTLY why the #4 cylinder on the 470 fails. It would be worth a call to him or to join his 470 forum to hear it straight from the horse's mouth. He been rebuilding and working on the 470 engine most of his life and knows it every which way.
Breezeworks Services, Inc.
Clearwater, Florida 33756
Phone: 727-422-1269
Email: brzwrking@yahoo.com
http://www.breezeworks.net

 

[natemoore]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

(Does anyone know why the #4 cylinder is the problem child of the 470? And is it possible to blow a head gasket without ever overheating the engine? I would bet my life that the temperature has never gone above about 160. One eye is always on the temperature gauge.)

I talked with Kevin at Breezeworks.net, he told me EXACTLY why the #4 cylinder on the 470 fails. It would be worth a call to him or to join his 470 forum to hear it straight from the horse's mouth. He been rebuilding and working on the 470 engine most of his life and knows it every which way.
Breezeworks Services, Inc.
Clearwater, Florida 33756
Phone: 727-422-1269
Email: brzwrking@yahoo.com
http://www.breezeworks.net

Thanks. I've visited that site before. It doesn't seem as active as this forum.

Mind sharing what he told you?

 

[natemoore]

Re: MCM 165/3.7L/470 steaming near #4 cylinder upon cold start up (video)

Well, I didn't get the 45 mph at WOT I wanted after the prop change, but I did get an extra 15 mph to 35 mph. That's still pretty fast for out on the water in a 17 ft boat.