A4 rebuild

[MartinD]

I am in the process of salvaging an A4 for my Seafarer Tripp 30. I have broken down the motor to just the block and getting ready to send it to a machine shop to have it hot tanked, new valve guides and re-decked. My question is... when I was cleaning the head, I discovered a hole in it due to corrosion. The block had a lot of corrosion in it too. I had to use a drill to open up some of the water ports that were closed up, but I did not run across any holes in the block from corrosion. The block has a lot more meat to it than the head. So, I am wondering will it be worth my time to send the block off for work or not? I am sure someone has run across an old A4 motor that appeared to be in bad shape, but was able to salvage it. Any advice will be greatly appreciated.

[Don Moyer]

Martin,

I hope you don't mind if I fantasize a bit. Brenda's and my first boat was a Bill Tripp Seafarer 30, and while we've had two other wonderful boats since then, none have generated anything like the magic of the 12 years we spent ravaging the Chesapeake Bay in our beloved "Water Music".

I had to remove our engine about a year after we bought "Water Music" because a water pump leak had destroyed the head of the lower bolt in its mounting flange and there was no access to drill it out with the engine on the boat. Since the engine had to be removed anyway, I decided to disassemble it for rebuilding, and I discovered (as you did) that the cooling passages between the block and head were almost completely clogged. Fortunately, however, the block seemed to otherwise be in rather good condition after I had it hot-tanked.

Having seen the insides of many other engines since that time, it's quite clear to me that the alloy used in Atomic 4 blocks seems to have been considerably more resistant to corrosion than that which was used in either heads or manifolds, so you have good reason to hope that your block will come through the cleaning process OK. Here's a note from the overhaul section of our service and overhaul manual:

"NOTE: One of the very best places to check for the condition of your block with respect to corrosion is to note the number of threads remaining in the manifold stud holes. I consider 3 threads to be minimum before I would install a threaded bushing or other equivalent thread replacement. Heli-coils are not too good to use when studs enter the cooling jacket (as all ours do) because they are a bit hard to seal and water will sometimes leak past the threads. As a point of reference, the newest block I ever saw had 6 threads in this location."

Sometimes the calcified crud around the inside of these holes can look a bit like real threads, so it would be good to use a small round wire brush (valve guide cleaning brushes work well) to clean the holes for inspection even before sending the block to the shop for professional cleaning.

Don

[MartinD]

Thanks for the Reply

I will look into the thread issue. Thanks for the guidence. I already ordered your manual on the motor and will be sending it to the machinist in the next week or two. I am excited about the Seafarer. I am new to sailing and was in the position to rescue this fine boat. It was in pretty bad shape, as for as cosmetics go, but the hull is in excellent shape. I do have another question I might put out for your expertise. The shaft for the rutter on the boat is corroded real bad. (only where it was in the water, about two inches of it) Since I have her out in dry dock at this time, I want to pull the rutter out and replace/repair the shaft that comes through the hull. Do you have any knowledge on this for the Seafarer rutter? It is actually a large rutter, but it is hollow with holes in the bottom to allow it to fill with water. I guess to make it more sturdy in rough water. It appears to have screws at the top that are glassed in. I am hoping to be able to grind them out and the shaft can be removed for replacement. Any help or suggestions with this repair would be great.

[Don Moyer]

Martin,

Regretfully, I have no recollection of the details of the design of the rudder or the rudder shaft on "Water Music". I guess I must not have had any problems in that regard. Hopefully, someone in the boat repairing business at your marina will be able to help.

Don

[MartinD]

Piston stuck

Don,
I finished breaking down my atomic 4 and found out why it was not started in a while. The number 4 piston is stuck. I was not able to break it from the cylinder. I will send it to the machine shop to see if they can get it out, but I am quite sure that the piston will not be saved. Do you sell pistons or better yet, a rebuild kit that includes new pistons, rings, bearing and the works?
thanks,
Marty D.
Seafarer tripp 30

[Don Moyer]

Marty,

A machine shop should be able to safely press out the stuck piston. We do it rather regularly. With only one piston stuck, my guess is that it will not be too difficult to press it out. We use a round steel dowel that is just a little smaller than the bore to press down on top of the piston. If the piston is stuck quite hard, we recommend supporting the base of the block around the bottom of the bore so as not to risk cracking the block; but this precaution is only necessary in rather rare cases.

You're correct to suspect that the piston can not be saved. We don't package a rebuild kit since we wouldn't know what parts you will need (or the sizes of the various parts) until the engine is disassembled. However, our online catalog at moyermarine.com lists any part that you will need to rebuild your engine.

Regards,

Don Moyer