Crossflow help

[LJL]

Found this "hole" from a OMC V6 crossflow's cylinder #1's exhaust port. The picture is taken from the crankcase side. What is it? A bad casting? What should I do with it? It doesn't seem to leak water or air. It's propably 1/2" long and 1/16" deep.

LJL

[Laker]

Could you shoot a pic that shows where on the motor that is? Its alittle hard to tell.

[LJL]

The arrow points to the exhaust port, where the hole is. The hole is on the roof of that port. I tried to take a better picture, where you could see the hole better and see where it really is, but it's too tight a place to get a picture. The first picture is taken from the crackcase thru the rod slot. Should and can the hole be welded or should it be left alone? What kind of effect on performance will it have, if and when it won't leak air or water to the exhaust chest?

LJL

[Laker]

Are you sure its a hole? or just a pocket where air was in the casting? If its a hole where does it lead?

[LJL]

Laker,

It may very well be a pocket of air in the casting. I'm haven't yet been able to determine if it leads somewhere or is it just an air pocket. Do you have any suggestions how the port could be pressure tested? I'd hate to assemble the whole motor back together and see it's leaking, and then disassemble the block once more to get it fixed. Or any other good testing methods?

LJL

[84exciter]

magnaflux makes a great aerosol penetrant for crack checking.

www.magnaflux-online.com (http://www.magnaflux-online.com)

[B.Leonard]

I've seen minor imperfections like that (although that is pretty big) on the outside exhaust ports while porting.

If there are no signs of water and/or exhaust around it, I doubt it leads to anywhere.

What year is that block? XP/GT? Looks like an '83.

-BL

[LJL]

B. Leonard & 84exciter,

There is no indication of water or exhaust. So, it's propably only an imperfection. How should it be fixed? Should I get it welded or is there a trick to repair it? I believe the port can't be raised anymore, so I can't cut material off much enough to get the imperfection out of there without messing the port timing.

I'm not sure about the hp or year. It's 2.6 liter and propably early 80's block. I should check the serial plate to be sure. The port timing is pretty much the same as 2.6XP, but the ports ain't square. I have a XP block, but it got demolished (see picture).

Thanks for the answers!

LJL

[B.Leonard]

Those ports looked square. Maybe you ported them? What is the # off the plug on the top of the block?

-BL

[LJL]

I'm porting them square right now. Maybe there's some power torque left there :D Found that imperfection right under the original port surface. The surface finish may seem bad, but I just got started on that port. So it didn't left from the factory looking like that. I don't have the block here and can't read the # even from the original picture, sorry.

LJL

[84exciter]

like bl said,or there 's a product called Belzona that will withstand the heat.but it's alot $$$$$;)

[LJL]

Would you happen to know which Belzona product can stand all that heat? I wouldn't have to try to convince some tech support guy that they have such a product, which can be used to repair an outboard's exhaust port :) They can be a real pain in the ___ sometimes. Thanks!

LJL

[B.Leonard]

You might be able to weld it unless it is deep into the port where it merges into the liner and becomes thin.

-BL

[84exciter]

i've used 1391 &1111 both for steam turbine repairs when the customer wants it back in service "yesterday"!lol


www.icstechnologies.com/Belzona%20Coatings.htm

[JanR]

We took it off of a 1983 Seadrive 2,6. Plug says IAAL, number CTH30781433 according to my notes (I'm not in the garage). Should be a 1983.

The damaged block is a '84 235 STL. Huge ports, plastic reeds and fillers in intake. Engine probably has a race history. Don't know much about it.

JanR

[racer]

The 2.6 block looks stock in the photo

[H2OPERF]

How far up did you go with the port? The water jacket isn't very far up,its been a long time since an x flow has been on my bench but i think the circular waterjacket area around the cylinder is only about .100 above the ex port.I cant tell from the pict if your defect is below the jacket or if its further down stream in the port,if so and its not below the jacket i wouldnt think it would hurt much.You definately wont see any significant performance loss form it . I would definately make some block off plates and pressure check the water jackets when your done, this might be some extra work but it will save you a bunch of time and money if you have a water leak.I have all the plates made up for loopers but not for x flow sorry. Dave

[LJL]

You are right, the porting is stock on that 2.6 block. It has some other modifications, which could indicate that the block has been used in racing like JanR said. The attached picture shows the porting and the bottom of the cylinder, where someone has cut some material. Thanks for your reply!

LJL

[LJL]

We (me and JanR) really didn't go upwards at all. The port timing is original. We are just trying to increase the port area by making the ports square. The original exhaust port shape in this block can be seen in the picture.

There is still a bit more material than .100" between the port and the water jacket. But the air pocket propably could thru that .100". I'm sure we are going to get the block welded, so it won't matter if the pocket leads to the water jacket or not.

Thanks for your answer!

LJL

[B.Leonard]

Can you post a pic of the top of that block?

That recess on the cyl wall under the cover is different from mine. I've seen the pre '83 blocks have a recess at the top and bottom of the wall but not the whole area.

Not that it matters :rolleyes: Just curious.

-BL

[LJL]

I don't have the block here, but I'll post the picture as soon as I get a chance to shoot the picture.

LJL

[racer]

The cut on the bottom of the cyl wall on the intake side is STOCK 2.6 XP/GT. All true 2.6XP blocks had this cut, it can be done easily by placing the block on its back in a mill and using a 1/2 inch cutter, the arc is natural because you are cutting on a round hole.

[B.Leonard]

I think racer is refering to the scallop.

I was refering to what looks like a recess between the scallop and the port openings but it was the corner of the area under the cover. Sorry :rolleyes:


-BL