How do you do a leak-down test?

[pastorbud]

#2 cylinder

 

[pastorbud]

#3 cylinder

 

[pastorbud]

#4, problem child. The rust is all at the very top of the cylinder, above where the rings seal. The rust further down the walls was just drip-down from the top. It wiped right off with a rag and WD40. The white powder on top of the piston was just corrosion debris from when I removed the head. It cleaned right up.

 

[pastorbud]

I hope I haven't ruined this head. This is cylinder one area. Note where I caught the mating area with a pickle fork and made a nick and a bump on the outside near the bolt hole. Doesn't affect the cylinder wall mating area, but it does affect the water jacket mating area. It also made a corresponding, but much smaller, gouge in the block, but again, not near the cylinder. It should not keep the head from seating on the cylinder, but I'm not sure what it means for the water jacket. But look how clean #4 is, LOL! It's been through the car wash, due to almost no compression.

 

[flyingscott]

It will be fine. If it is raised a bit file it down flatish then finish when you resurface the head.

 

[jerryjerry05]

There's nothing there that can't be fixed.
The gouges in aluminum, some people try to fix with methods other than welding?
Most patches fall out fairly soon.
Any deep gouges get welded or the head cut down. Weldings prefered.
I'm lucky I have a guy who does all my machining and welding close by..

 

[pastorbud]

It will be fine. If it is raised a bit file it down flatish then finish when you resurface the head.

How do you resurface a head? Never done this on anything bigger than a 18.5 hp lawnmower engine. I just wire brushed that one!

 

[racerone]

The head is warped.--------Use a flat surface ( glass plate ) some valve grinding compound and some work to make the head flat again.----Process is called lapping.

 

[pastorbud]

Thanks. There’s an outboard shop a few miles down the road from us. Maybe I’ll get a quote.

 

[pastorbud]

Ya know what? I found a new one (old stock) on eBay.

 

[pastorbud]

Trying to get this back in the water for Labor Day. I’ll probably re-surface the old head over the winter.

Any advice on cleaning up the block and cylinders?

And can I re-use the old head bolts?

 

[jerryjerry05]

Yes reuse the old bolts.
They only had 18# of torque and probably not streched.

I use a wire wheel on a dremel/air tool to remove the old glue.
You can use a green/white/burgundy scrub pads.

 

[pastorbud]

Roger, thanks

 

[pastorbud]

Well, I don’t know. My new head came in. It was old stock, but never installed, from a marina in Florida.

It looks pretty good but there is a small pit at about 10 o’clock on the number two mating surface.

I wonder if it’s useable or not.

 

[pastorbud]

Try summa this?

 

[pastorbud]

That Permatex stuff gets good reviews.

 

[Nordin]

I think that very small notch would not affect the head gasket to seal properly.
But the Permatex gasket stuff will not hurt but probably have neither or nor affect.
I use Permatex gasket sealant at other gasket surface when I rebuild or repair OBs.
Good stuff and the one with an built in pencil in the cap are really easy to use.

If you feel more comfortable with using this product to you head then use it.
But I think it is not necessary.

 

[jerryjerry05]

It "might" work for a while but it's a spot that's gonna cause trouble.
How bad's the old one?

The trouble with a filler(silicone), it's gonna get hot and come loose/melt.
Get it welded and cut down.

 

[racerone]

Post a picture with the new gasket in place.-------I think it will seal just fine.----Too much overthinking here.

 

[pastorbud]

It "might" work for a while but it's a spot that's gonna cause trouble.
How bad's the old one?

The trouble with a filler(silicone), it's gonna get hot and come loose/melt.
Get it welded and cut down.

Heh. I only need it to last a little while, it’s the end of the season!

I’m gonna see how it does, but get the old one resurfaced for a backup.