ATC
New Member
I was blowing some steam out my my starboard engine driving over to my haul out (both engines reading little over 1000 hours). We pulled the manifolds and found a lot of rust in the center chambers. Performed a compression test with the following: 1-97, 3-73, 5-56, 7-93; 2-89, 4-71, 6-85, 8-89. Pulled one head to find the head gasket blown out between several cylinders. Rusted head bolts prevented pulling the other head (will grind and pull this weekend).
As a precaution, performed a compression test on the port side, with the following: 1-135, 3-139, 5-100, 7-125; 2-121,4-107, 6-107, 8-120. Pulled the heads and found some blowout but not nearly as bad as the starboard.
** FYI- post-test I read that the throttle (carbs) should be locked WFO while perfroming- we did not do this- don't know the effect this would have had, but the variance between cylinders is what was alarming.
Purchased the boat a year ago July, so I don't have history on the engines. My first boat, so yes I was dumb and should have paid for a compression test then.
What I can say, is that the bottom ends look super clean; cylinder walls look fine, lifters slide right out of the bore and show no signs of wear, and neither engine burns a drop of oil. Oil pressure is spot on.
My guess is that they were overheated at some point popping the gaskets.
My dilemma is do I do heads and save some $$, or bite the bullet and long block them. I'm also doing dripless seals this winter, so I'd like to save some money if possible, but don't want to do so foolishly.
Look forward to your recommendations.
-Al
As a precaution, performed a compression test on the port side, with the following: 1-135, 3-139, 5-100, 7-125; 2-121,4-107, 6-107, 8-120. Pulled the heads and found some blowout but not nearly as bad as the starboard.
** FYI- post-test I read that the throttle (carbs) should be locked WFO while perfroming- we did not do this- don't know the effect this would have had, but the variance between cylinders is what was alarming.
Purchased the boat a year ago July, so I don't have history on the engines. My first boat, so yes I was dumb and should have paid for a compression test then.
What I can say, is that the bottom ends look super clean; cylinder walls look fine, lifters slide right out of the bore and show no signs of wear, and neither engine burns a drop of oil. Oil pressure is spot on.
My guess is that they were overheated at some point popping the gaskets.
My dilemma is do I do heads and save some $$, or bite the bullet and long block them. I'm also doing dripless seals this winter, so I'd like to save some money if possible, but don't want to do so foolishly.
Look forward to your recommendations.
-Al
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