1988 3.0 blown head gasket

[thumpar]

Re: 1988 3.0 blown head gasket

http://forums.iboats.com/mercruiser...n-mc-1-thru-alpha-i-gen-ii-drives-586050.html

The 470 and 4.3 are usually around 1.84 ratio and the 305 is usually 1.62/1.64 or 1.5/1.47. You may get away with your drive on a low powered 305.

 

[aerobat]

Re: 1988 3.0 blown head gasket

Does anyone know by chance, does a late 80's 470 and a late 80's 305 have the same outdrive ratio from what I understand it does just wondering if anyone knew for sure.

no. you should have 1.84 , the 305 V8 runs 1.5

Seiler Marine - Mercruiser Gear Ratio Chart

 

[hadaveha]

Re: 1988 3.0 blown head gasket

well crap its looking like a 4.3 or bust, I love the 4.3 had one in a s10 when I was younger couldn't kill the motor. They seem to be the hardest to find in donor boat around here anyway's. Ill just have to widen the search and see what I can find. unless I found a V8 with a good outdrive then the work starts adding up

 

[aerobat]

Re: 1988 3.0 blown head gasket

yes aerobat the donor will be just to steal the motor from or motor and outdrive if need be, for my crestliner

ok now i understand it fully. from a technical point of view like stated above a 470 will not bring you anywhere where a 3.0 cannot get - and there are several reports of succesful repowering with the 3.0. so when you want to keep performance and just have a troublefree season the 3.0 is a solid way to go.

on the other hand - when you have one engine with a cracked block , the other with a suspicious head gasket etc i would be careful if you do not run into another nightmare. you can try to ask to remove the head of the blown gasket one to verify its really the gasket.

i,m not sure if you can get away with 300-500 bucks for a good solid repowering.

 

[hadaveha]

Re: 1988 3.0 blown head gasket

aerobat I know but it seems crazy you have your 300 to 500 donors then it skips to your 2000.00 donors maybe Im just hitting CL at the wrong time but Im going to keep digging until I work it out. I will be on the water this spring, if its with just the kicker motor

 

[aerobat]

Re: 1988 3.0 blown head gasket

I will be on the water this spring, if its with just the kicker motor

thats a sentence i believe you will make it ! look for a 3.0 or a 4.3 and look for a complete engine. manifolds, exhausts etc will not fit from your 470 so you want to have them attached. the 3.0 is sufficient if you are happy with 30 mph and the cheapest way to go. be aware that the engine mounts will not fit.

maybe go straight forward and buy the 300 bucks 1987 3.0 blown head gasket. its worth a try .

 

[hadaveha]

Re: 1988 3.0 blown head gasket

yes I have thought that also surley I could sell the trailer and a few other pieces and get my 300 back if it doesn't workout

 

[hadaveha]

Re: 1988 3.0 blown head gasket

from what I understand if a engine any engine has a blown gasket, its been hot, I quess how hot and what did the heat take with it besides the head gasket, and how long was it run hot, that the gable.

 

[aerobat]

Re: 1988 3.0 blown head gasket

from what I understand if a engine any engine has a blown gasket, its been hot, I quess how hot and what did the heat take with it besides the head gasket, and how long was it run hot, that the gable.

hot, wrong ignition timing, ran hard when not warmed up...

 

[oldjeep]

Re: 1988 3.0 blown head gasket

hot, wrong ignition timing, ran hard when not warmed up...

Or in the case of a 3.0L - there is just so little space between the cylinders that sometimes they eat the gasket. On mine it was right between 2 and 3

 

[hadaveha]

Re: 1988 3.0 blown head gasket

I quess there is only 1 way to find out. there is no way to get a compression check with a bad head gasket is there. seller said we could fire it up and let it run on the hose a bit so I could hear that there is no knocks or any other noices

 

[oldjeep]

Re: 1988 3.0 blown head gasket

I quess there is only 1 way to find out. there is no way to get a compression check with a bad head gasket is there. seller said we could fire it up and let it run on the hose a bit so I could hear that there is no knocks or any other noices

The only thing a compression check might tell you is which cylinder(s) might be victims of the head gasket. Luckily it is pretty quick and easy to pull the head off a 3.0L

 

[alldodge]

Re: 1988 3.0 blown head gasket

^^+1, and with it running you can get a quick see of other things. Back out the drain plug on the out drive just enough to see the color of the gear lube. Hope there will be no water, milk or discoloration

 

[hadaveha]

Re: 1988 3.0 blown head gasket

are the 3.0L engines bad to warp if they are run hot,I think while I have the head off Ill drop it off at the machine shop and have it checked out, also since Im going to have the head off should I replace the timming chain, are their any seals or any items to be checked since Im atleast that far into the engine.

 

[aerobat]

Re: 1988 3.0 blown head gasket

they are not especially sensitive to this - of course it at any engine depends how severe it was overheated. when you have the head off just surface the head - it should be not expensive. there is no timing chain on this engine - the camshaft is driven by gearwheels .

check the exhaust riser and manifold for leaks, and also check the valves for corrosion ( water ) . you will need a headgasket, a manifold gasket and maybe a valve cover gasket.

 

[fishrdan]

Re: 1988 3.0 blown head gasket

So, are you going for the blown head gasket 3.0L?


Check the head and block for flatness, see Merc manual for specs, and if they are within tolerance you should be good to install a new gasket. Though, if it blew a head gasket, something with their surfaces could very well be out of tolerance. Check the blown-out gasket area really good for surface damage, pitting....

Not a bad idea checking manifold and riser for cracks while they are off, fill then with acetone. Don't use white/green manifold and riser gaskets as they are poor quality, use the silver/gray metalized (graphite coated I think) gaskets.

Also, follow the Merc manual to a "T". You'll need to chase all the head bolt holes in the block, wire brush the bolts, and use sealant on the head bolts during assembly, Permetex Aviation sealant works well.

 

[redneck joe]

Re: 1988 3.0 blown head gasket

hey hava - you found your engine yet? If not I 'know a guy' in the Guntersville area that has probably 100 boats in his graveyard - and he doesn't advertise on CL its all word of mouth. Two seasons ago when I bought my Carver he bought an old trihull abandoned in dry storage (same as mine was) with a brand new (maybe 10 hours per marina owner) 302 in it. He'll probably have something you can use and he's an honest guy - no BS. PM me if you still are looking.