Is this a problem or what?

[64 inboard]

This summer the 170 in my 64 Correct Craft has been a little tempermental.

First off I fried the two year old points and condenser, for no apparent reason. Im running what are probably the originals right now. Just got the replacements and hope to get them in this weekend.


Then Ive been having problems with eratic oil pressure readings. I added about 1/2 qt of Marvel Mystery oil, and now its running in the 30-40 lb area.

This week, the boat is occasionally falling flat on its face when I give it gas from a slow/no wake area. It has also acted like its loading up when idling, again in a no wake area. When I loaded the boat on the trailer the exhaust smelled pretty rich.

Tonight while looking things over, I noticed what appears to be a crack in the intake, just below the carb mounting base. Here are a couple of pics of the area in question...






Have you guys ever seen this situation? Wouldnt it make it run lean, not rich? Its hard to see, but in the second pic, the line looks like it actually extends up to the mating surface of the carb mounting base.


Any other ideas?

 

[BIGREDRASA]

Looks like somebody already tried JB Weld or a weld. That will screw you up big time. It's not going to run right until you fix that major vacuum leak. It might be worth cleaning thoroughly and liberally applying some JB Weld.

 

[Asa]

i don't think i've ever heard of a head cracking there... if it's in the intake log, it's most likely throughout the head

what does the oil or coolant look like?
wait, this is in a boat, i hope you're not using lake water for coolant, if you do have a crack throughout you might have the EPA breakin down your door soonish

 

[64 inboard]

Oil is fine... no water in it. When I run the engine in the drive, I hook a garden hose up to it. There are no signs of anything but water coming out of the exhaust. No "oil slicks" when boat is in the water, like some outboards Ive seen.

Do the stock intakes have a hole located there, maybe for vacuum,or was this added? The line connected to this comes from the flame arrestor. With the Carter side-draft carb, any "flooded" gas is supposed to enter back into the intake thru it.

 

[BIGREDRASA]

That's the normal source for manifold vacuum.

 

[ludwig]

That is the standard vacuum port for the I6. The cars have a brass block there with 3 nipples for spark advance, power brakes and what ever else.

It looks to me as if that crack is going up to the carb base and around the side of the log. If there is no contamination in the oil, you probably can fill it one way or another since that is not a high pressure area. I'm thinking more, and more recent JB, high temp epoxy, brazing or similar.

 

[Asa]

if i were going to fill it, i'd grind it down, and probably cut into it to create a groove to make sure the filler material got into the crack

if you can find the ends of it, you should be able to stop it from spreading by drilling through the ends of the cracks

 

[64 inboard]

This is all leading more and more towards a 200 transplant this winter.. The head had been replaced somewhere before my ownership. Its dated 73. Theres been a question on wether its even the right CC head for the 170? ........ hmmmmm.

 

['68falconohio]

I had a C8 head that was cracked on the 'log' in that area too. This same head was cracked from pushrod hole to exhaust valve guide for #3 or #4, can't remember. I remember it was one of the siamesed exhaust valves, but not which one. Then another crack through one of the flanges the exhaust mounts too.

Ya never know how these things were treated by the previous owners, the oil pan on that motor had 3/4 of an inch of black 'putty' in the bottom. Eww.