Repowering

dvx216

Well-Known Member
SILVER Sponsor
Feb 1, 2012
2,692
Catawaba Island/Orrville,Oh.
Boat Info
340 Sundancer 2001
Engines
8.1s 370 v drv.
Looks like I've got to the bottom of my sync gauge problem. Turns out my port engine #5 cylinder has low compression. Considering the hours on my engines going to have engine pulled and get a short block and head work done.
 
Before you go to that expense.... How many hours are on the motor? Did you do a leak-down test? You may just have a blown head gasket. I would find the cause of the low compression. You may just need to get the heads done and replace the gaskets. If the hours are not too high, and more importantly, the oil was changed regularly, your block may be fine and there may be no reason to pull the motor or go for a new short block.

I think I would do a bit more investigating.
Shawn
 
In DVX216 case it's easier to pull the motor and then inspect as the go. He's hoping for head work but it's easier to pull the motor and work from there...
 
In DVX216 case it's easier to pull the motor and then inspect as the go. He's hoping for head work but it's easier to pull the motor and work from there...
Maybe....but until I knew why there was low compression in #5 I would not go to the expense and trouble to pull the engine. I know that model boat well and you're right, pulling the motors is not difficult assuming you have a place to do the job and a forklift or a high enough a-frame or some other way to lift the motors. And since both motors are the same age and hours, IF you do pull one you might as well pull the other and do the whole engine room at the same time.
 
This is only the second season I've had this boat it's hard to say right now what is causing the bad compression at this point the shop that is going to do the work has the ability to pull the motor and go from there. Either they pull the heads and the block checks out ok or they decide to go with a short block .At this point for the shop to pull the head with the motor on a stand would end up being about the same as them pulling the heads in the boat considering the labor it takes to do it in the boat.The shop said since I haven't owned the boat since it was new it's hard to tell what has happened to the motor.
 
After the price to do what the marina said they could do for around 5 grand has grown into $6,500 a second opinion is in order.The second gentleman I talked to thought that seems to be a little rash of a decision to do a rebuild on my motor for that kind of money when if you get a manufactured short block that will come with a warranty. So unlike the first marina the second gentleman will do a running compression test to find where the problem is.The funny thing is the second guy use to work for the first guy and he wasn't surprised that was what he recommended because that is what makes them the most profit.So Thursday he will do what the first guy should have done to figure out what is going on at half the price .
 
For 6500 bucks you can get a new small block crate motor.
 
Second mechanic checked out my motor and I have a bad intake valve or seal .So option number 2 will put up my boat in heated storage for the off season pull both heads have them gone through for about half the price of option #1 .The good thing about this come mid I will not say the W word I will be able to go sit in the boat and dream of spring plus waxing before the season.
 
I hate to say" "I told ya so...."

Earlier this year my 383 Stroker motor in my Cobalt developed a hard miss....like a plug wire was off. Early investigation indicated 0 psi compression in the #5 cylinder. Knowing I had just changed head gaskets about 4 hours ago I knew something was not right. Discovered the #5 exhaust valve had stuck in the guide and bent the pushrod. Further investigation showed all of the exhaust guides were too tight and all intake guides too loose. Heads were pulled and all was corrected without pulling the motor.

Happy you got the second opinion and you are saving some money.
Shawn
 

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