Need A4 help and guidance in Bellingham WA

[junaido]

The main hole is not deformed just one of the holes for the flange bolt.

[ILikeRust]

The guy told us to tighten the pieces together using as much force as we could use.

I would suggest you DON'T do that. There is no need to gorilla on the thing. Tight, yes. "As much force as you can use" almost certainly will be more than is necessary to get a perfectly and satisfactorily tight, leak-free connection.

[hanleyclifford]

Couple of things

Definitely get a new flange with the extra port for checking back pressure later. I don't like the check valve which is likely to become your next problem when it gets stuck and causes back pressure. I don't like the union either since it does not serve a useful purpose. It also represents a restriction. As you can see, you are replacing it and everything else back to the manifold and that is just the way it is: the hot section should always be replaced in it's entirety. The advice about tightening is not sound either; just a snug fit will suffice. Carbon and rust will seal things up nicely. It is not necessary to use any thread sealer. One thing not yet mentioned; this is a lot of weight hanging on your manifold with plenty of angular momentum - is there any support aft of the engine?

[junaido]

There is a support bracket for the pipe that is bolted to the engine itself. The pipe is secured to this bracket with a couple of hose clamps.

So I am getting the message that I need to tighten the pieces more than hand-tight but no need to torque the crap out of it, no joint compound needed. Do we need a vice and pipe wrench or is it sufficient with just two guys trying to tighten it manually ?

It seems like having a threaded flange is only convenient in that it can be threaded onto the new pipe, but its not really reusable. Oh well, another $70 bucks sacrificed at the altar of the A4 gods.


Junaid

[ILikeRust]

I would use a pipe wrench to get it good and snug, but you don't need to break your arm hanging off the end of it.

[hanleyclifford]

One guy with a pair of pipe wrenches can do the job nicely. The flange is threaded for convenience and versatility of design. I have re-used them in the past but I have the pipe tap. In fact, I open them up to 1 1/2" NPT when doing my own engine.

[edwardc]

The main hole is not deformed just one of the holes for the flange bolt.

But this almost certainly means that the face of the flange is no longer perfectly flat, and will not seal properly on the manifold. When the Home Depot guy pried on those two bolts they put a twisting force on the flange ears. If he used enough force to stretch the holes he probably twisted the ears too.

[junaido]

Success at last!

Finally put in the new exhaust (including new flange) this weekend. It was sweet vindication to finally see water gushing out of the transom. Next step is to replace the exhaust hose which is also showing some signs of age. Then hopefully we can put this A4 through its paces. One thing I was wondering about is whether we should put the heat wrap back on before the galvanization bakes off or wait till after ?

Thanks to all the members on this forum who have provided so much valuable advice.

Junaid

[Marian Claire]

FWIW. I have always wrapped my pipe before running. I had a flange with a piece of copper pipe stuck in it. I cut the pipe about a inch from the flange and then used my sawsall to carefully cut down the length of the pipe in two places about a 1/4" apart. Then popped/banged out the pieces. It buggered up the flange threads a bit but turning the new pipe in and out a few times cleaned them up enough to use. Dan S/V Marian Claire

[DDO]

Bellingham Atomic-4 folks...

I just noticed this discussion around the Bellingham boat. I am in Bellingham on Gate 9 and an avid DIY boater. I know many local others like myself that care for an Atomic 4 and I even know a great mechanic who sometimes will come to Bellingham for the love of A-4's and do some work while instructing. So let's chat Atomic-4, auction boats, etc., if you wish... email to commodore@cycbellingham.org will get to me. There are plenty of A-4's around here, especially Gates 8 and 9. I love mine!

[lat 64]

DDO,
I know Puget Sound is a big place, but a few guys(and one grandma) have asked about where to find a good mechanic around your area. I can't find the old posts—I'm terrible at the search features here.

Welcome for sure, and great to hear about more good guys,

russ

[romantic comedy]

I just typed a post telling how to get the pipe out of the flange.

where did it go??

[Lyric]

I'm having some problems with my exhaust. Two years ago I replaced all the rusted black pipe and installed new fiberglass 'tape' around it to keep the heat down.
However, when I replaced the pipe, I didn't replace the flange on the exhaust manifold and I'm had a hard time getting the couplers to tighten down so last night while doing my spring commissioning, exhaust filled the engine compartment.
While I haven't looked at it since then (plan to check it out this weekend), I suspect either the flange or the coupler just aft of the flange is loose.
My question is this: in a Catalina 27, is the multi-part coupler that you see in the attached picture, just before the first 90 degree elbow, really necessary? Can you just run a straight piece of pipe from the flange to the first upward elbow? Seems simpler and easier.
Wade

[JOHN COOKSON]

Wade
A big welcome to the forum.
I'm a fellow Cat 27 owner. I've rebuilt the exhaust hot section twice.
The answer to your question is the union is not necessary. However, it is extremely handy to have. You will find when you make up the new hot section some of the angles between the various pieces will need to be adjusted. It's a three dimensional not a two dimensional project. You will soon realize that is is a lot easier to tighten the union finger tight, figure out what needs to be changed, let the union loose, and and tighten the piping in the cockpit. If you can get to the new hot section and tighten the various joins up with pipe wrenches with the new hot section in place under the cockpit on a Cat 27 you are my hero.
Try to get some part of the riser as near the centerline of the boat as possible. This will make the new hot section function equally well on both tacks.
I always say doing marine engine M&R (maintenance and repair) on a Catalina 27 is like working down a gun barrel.

TRUE GRIT
Hull #4446