update/closed cooling sytem issue merc350 alpha1

[freeone]

my initial problem.
was loosing coolant didnt know where. in the prosess of compression test #6 cyl had coolant. some of the ideas were head gasket, riser to manifold gasket. got the heads back from machine shop no cracks but "minor" warp(corrected) waiting for gasket set and ss block off plate for the riser coming in on monday to put her back together. anything else i should check or do while in the prossess?

 

[freeone]

Re: update/closed cooling sytem issue merc350 alpha1

maybe i need to give more info? its a 83 i/o merc 350 w/alpha one.

 

[Apollo75]

Re: update/closed cooling sytem issue merc350 alpha1

Since you can get to all those big holes --- I would wipe them all out and apply some engine oil on the cylinder walls --- also, take a flash light and put #6 piston all the way down in the bore and double check it for anything that looks like a crack. Use you finger nail if you find something to rule it out as just a mark.


Good Luck


OFM

 

[freeone]

Re: update/closed cooling sytem issue merc350 alpha1

decided to start a new thred some posts were getting off track. again thanx for all the input. cyliner wall crack came to mind when all this was unvailing. wouldn't that cause coolant to get into the crank case?

 

[TowRoper]

Re: update/closed cooling sytem issue merc350 alpha1

that would depend on where the crack was, if it was low in the bore it could but if it was up high and not below the rings it wouldn't.

 

[freeone]

Re: update/closed cooling sytem issue merc350 alpha1

so that would be about the top 1" of the cylinder wall? if i cant visually see a crack could there be one? reminds me of the saying "if a tree falls in the forest....." could i use the acetone test?(that would be a lot of acetone) i just dont want to think about removing the engine agin. last time around needed a forklift to get it high enough to clear the top of the transom.

 

[freeone]

Re: update/closed cooling sytem issue merc350 alpha1

i got my gasket set, does the head gasket go with stamped ridges up or down? also th manual 3 states if using ss gasket use perfect seal. is that correct? as far as i know ive never used any sealant on head gasket, also ive never seen a gasket like this.

 

[zbnutcase]

Re: update/closed cooling sytem issue merc350 alpha1

Yes that is correct if you are using steel shim type head gasket and ridges go up. However I much prefer composition type gaskets in marine engines as they tend to seal better. 'nutcase

 

[freeone]

Re: update/closed cooling sytem issue merc350 alpha1

the gaskets came out of a marine app head set. so do i need to use sealant on that? or should i look for another gasket?

 

[freeone]

Re: update/closed cooling sytem issue merc350 alpha1

anyone?

 

[TowRoper]

Re: update/closed cooling sytem issue merc350 alpha1

you should use sealant on that style gasket it is marine so it wont corrode in salt water the gasket nut case is talking about is automotive and will work if its used in a closed cooling system

 

[freeone]

Re: update/closed cooling sytem issue merc350 alpha1

thank you. i do have a closed cooling system. i have rebuilt a few of these engines but all on cars and trucks so this is new territory for me. so i should stick with that gasket. what type and how much sealant gets used on head gasket?

 

[Apollo75]

Re: update/closed cooling sytem issue merc350 alpha1

I like a good composition gasket ---- they seem to seal longer around coolant holes and do not leak or blow as easily as a thin metal gasket when an over heat condition happens.

Added : Sounds like you have SS gaskets already --- there is nothing wrong with those gaskets.

If you decide to put a composition gasket on read the instructions as some have a gasket sealer already applied. Either way use a gasket sealer you can get on evenly like a spray ---> I like coper coat.

There are many brands, I cannot recommend one over the other --- Fel-Pro are usually quality gaskets.


Good Luck

OFM

 

[TowRoper]

Re: update/closed cooling sytem issue merc350 alpha1

I like a good composition gasket ---- they seem to seal longer around coolant holes and do not leak or blow as easily as a thin metal gasket when an over heat condition happens.

If you decide to put a composition gasket on read the instructions as some have a gasket sealer already applied. Either way use a gasket sealer you can get on evenly like a spray ---> I like coper coat.

There are many brands, I cannot recommend one over the other --- Fel-Pro are usually quality gaskets.


Good Luck

OFM

i agree with that BUT i prefer silver coat it has a higher heat resistance, not that it will ever reach 1200 degrees and if it does you have a whole other set of worries lol
BTW copper coat and silver coat are not really sealants but are anti seize

 

[Apollo75]

Re: update/closed cooling sytem issue merc350 alpha1

i agree with that BUT i prefer silver coat it has a higher heat resistance, not that it will ever reach 1200 degrees and if it does you have a whole other set of worries lol
BTW copper coat and silver coat are not really sealants but are anti seize

I have never used Silver Coat --- it does not stick like Aluminum Paint does it Worst experience I ever had was sanding the Aluminum paint from the block and head surfaces of a 350-4 bolt main I bought.


OFM

-----------------------------------------------------------
If the boat is not sinking or on fire, Relax

 

[TowRoper]

Re: update/closed cooling sytem issue merc350 alpha1

lol no it works just the same as copper coat its just for higher heat

 

[Apollo75]

Re: update/closed cooling sytem issue merc350 alpha1

Great --- I will give some a try.


Thank You.


OFM

-----------------------------------------------------------
If the boat is not sinking or on fire, Relax

 

[freeone]

Re: update/closed cooling sytem issue merc350 alpha1

don't know if you can tell from the pic but this set looks like it has something already sprayed on there, its silver. i will use the perfect seal as outlined in the manual. off subject a bit but when i used to buy head sets they came with some instruction on paper or stamped on the gasket. ie; this side up, forward.... use sealant dont use sealant. last two sets i bought there was nothing in the box not even a parts list.

 

[TowRoper]

Re: update/closed cooling sytem issue merc350 alpha1

i cant tell from the pic but its a good idea to do what the book said to do

 

[Apollo75]

Re: update/closed cooling sytem issue merc350 alpha1

Well, as long as there not made out of old tuna cans --- should be okay

Yeah, perfect seal is good stuff too.

I like a little information when I buy something too --- it is not like a suppository that you know what to do with

Keep the faith.

OFM

-----------------------------------------------------------
If the boat is not sinking or on fire, Relax