The machine shop just called... :(

[Dante04SRT]

The head has a 2" crack in it. Unfixable.



I have seen this head here:

http://cgi.ebay.com/ebaymotors/Merc...ryZ33617QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

However, it seems to be FROM a 2.5 motor. I understand the heads are similar, but are they the SAME? My head seems to have bigger valves than the one on eBay.

I'm almost at my wits end with the boat already... but... can't give up hope just yet.

 

[Don S]

Re: The machine shop just called...

Where is the crack located? Are you sure there isn't a like crack in the block.
Find out NOW before you buy another head.

 

[Dante04SRT]

Re: The machine shop just called...

Where is the crack located? Are you sure there isn't a like crack in the block.

What is the best way of checking when the block is still in the boat? Just crank it over to see if the cylinder walls look ok?

 

[Don S]

Re: The machine shop just called...

Where was the crack on the head?

 

[Dante04SRT]

Re: The machine shop just called...

Not sure. I've gotta talk to the shop again tomorrow...

First glance, when turning it over, all cyl walls look/feel fine.

When turning the motor over by hand tonight I noticed my #1 piston looks SHOT... I hadn't seen it up close before because it was sitting deeper in the cyl and it was dark.

Let me get someone's opinion... pics:

I poured water in it while it was in the cylinder and there was no sign of any leaking by the ring, but man.... this can't be good..... ideas?????

Did the previous owner pull the head, see the damage and put it back together or what?? What I can't figure out is the valves all looked good, also, the plugs were intact and had been on a WHILE, considering the fact the boots feel apart in my hands when trying to remove them)... What destroyed this piston and where did it go?

 

[Bt Doctur]

Re: The machine shop just called...

gasket area on the bottom looks blown/cooked.rust on the valve would indicate water intrusion from someplace.
may have been vaporizing the piston

 

[wncrjb]

Re: The machine shop just called...

The way the piston is chewed up, my guess would be either a bad case of detonation, or something small and hard found its way into the cylinder.

I had a motor in a drag car years ago that had a case of detonation and that is how a few pistons looked.

just my $.02

 

[Don S]

Re: The machine shop just called...

You need an engine, not a head.
Over a third of the #1 piston edge is gone, the ring is showing, the gap between 1 and 2 cylinders is gone, from your other post and pictures the gap between 2 and 3 is gone also. Both head and block. Can't see everything, but I sure wouldn't put it back together with that block.

 

[Dante04SRT]

Re: The machine shop just called...

[insert curse words here]

 

[KaGee]

Re: The machine shop just called...

Look up RapidoMarine dot com. Excellent prices on re-manned engines. Call Raul and see if he has any 2.5L longblocks.

Maybe you can upgrade to a 3.0 without a lot of hassle?? Don or Bondo would know for sure. I believe 3.0's are more plentiful than 2.5's.
Good luck!

 

[95yj]

Re: The machine shop just called...

When you go about replacing the motor, take a good close look at your exhaust. That may be where all your problems came from. It'd be a shame to repower just to gernade the new motor if the exhaust was leaking.

 

[Dante04SRT]

Re: The machine shop just called...

The manifold is being pressure tested to see if it too was bad.

 

[Don S]

Re: The machine shop just called...

A leaky manifold or riser connection may put some water on a piston, but don't even think it will cause the oil level to rise by any noticable amount.

 

[dvan1901]

Re: The machine shop just called...

I agree with Don S; get a new long block. You may replace the heads, but then you may only be fixing a symptom of a problem. If you can do it yourself, you can save yourself $1000 - $2000. A long block may run you about $2k or so. Most places, the long block kit is only a hundred bucks more or so and, in my opinion, it's better to get the long block so you can ensure that all the parts are in "harmony". In your case, your pistons are toast so I don't think you have another choice. There are a few good sources for these engines too for a good price.

 

[EricR]

Re: The machine shop just called...

You could also look around for salvage auctions- I have seen boats damaged by storms where a tree fell on them when they were on the trailer- so the engine was not under water.

A guy I worked with bought an old Wellcraft Airslot with a 165 in it, the manifold was shot and had put water in the engine. There was a place near my work that was re powering an old 25' Bertram from twin 165's to new Volvos or something, one engine ran when pulled, so he got the whole thing with carb and all for $250. Tore it down, re ringed and re bearinged it, though it really was ok.

Or you could find a boat with a running 120 in it that has a case of the terminal stringer rot or a broken drive that someone wants rid of. Always keep looking.

 

[scott9398]

Re: The machine shop just called...

When I worked in a buddies machine shop I have made that phone call. It's like telling some guys that a loved one has died. I once made the call on a 1969 orginal numbers maching 302DZ block out of a '69 Camaro Vert.. It was cracked across the #2 web couldn't be fixed. I like Erics idea find a 3.0 motor and refit from a damaged boat.