motor id

[rickfromoz]

hey all ! i,m trying to find out if the motor in my boat is out of a car and if so what car it,s a 120 hp mercruiser 4 cyl around 1970 in a 17ft bellboy i think it,s gmc but i,m not sure the intake and exsuarst mainfolds are on the same side if that helps it,s my first boat with an inboard with a separate leg. i,m in austraila and i,m pretty sure i,ve never seen this type of motor in any cars we get here so i,m assuming its out of an american chev any help would be cool.also it,s over heating in a big way when its in the water even at idle speeds in gear but i can run it at home with muffs on even in gear for hours without a problem i,ve installed a new inpellor in the leg and when you discernect the hose that brings water from the leg to the thermosate housing it floods out so i,m assuming thats fine it has,nt got a thrmosate in it at all is it suppose to? also if the legs pumping water into the motor and the motors running with the thormosate cover off its shooting water about a foot in the air does that mean the water pump on the motor is working fine? how much water should comeing out with the exsuarst with the muffs on cause it seems to me like a lot more waters being sucked in than blown out does that indicate a blockage in the mainafold or maybe the curved pipe that comes from the top of the mainafold at the rear and connects to the exsuarst i dont know! again any help would be great thanks. the novice

 

[BMDODGE]

Re: motor id

it's a 3.0l mercruiser - didn't come in a car - just marine applications.... just a guess but i would think that your overheating is due to not having a thermostat in it - welcome to the board and you'll get lots of help here , bruce

 

[fireship1]

Re: motor id

Hello, The only other place you might find that motor in industrial applications. It was also used on forklifts, generators, and hydraulic power units on man lifts. All industrial stuff. However even if you find one from industry it is still not considered marinized. It needs to have marine components to be safe and reliable. Do a few searches on here and you will see the differences between marine VS auto engines and the dangers associated between the two. I agree with Bruce, put a thermostat in it. This type of engine needs to have a t stat installed to cool properly. If you still overheat I would pull the exhaust elbow and the manifold to check for clogging. BTW: the exhaust manifolds and intake are all one unit on this engine. If this does not help pull the engine circulating pump on the front of the block. Someone might have replaced it in the past with an automotive unit. This would have caused the impeller to rot away when used in salt water. The result would be no cooling! (see where marine Vs auto starts to make a difference)! Hope this helps! Good luck and keep posting!

 

[rickfromoz]

Re: motor id

hey hows it going no worries i was thinking that if it came out as a car engine as well i could get cheaper gaskets and such but what was said made perfect sence i had,nt even thought of that no point risking your life over a few dollars anywayn thanks a lot guys i went and got a thormosate. Problem solved (i,m as happy as a pig in ****) i took it out this afernoon about thirty mile. bloody brillant!!i love it lots of big fish and the peace of the ocean do you get big red snapper there in the states? also here,s my next issue the boats got the old type mercruiser forward controls you know the ones that click into gear and then the same stick becomes the throttle as well instead of clicking straight into gear like it should it doesnt engage until you push it all the way forward which of course makes the engine peak.i,ve got the thottle working through the smaller lever on the side but would like to know what would cause this and how do i fix it? thanks again all

 

[BMDODGE]

Re: motor id

sound like the remote cables could be out of adjustment .. way out - glad to here she's not overheating. have fun in the water - here in the states (in mass anyway) it's -10 f degress with wind chill's in the -30's. i won't see the water till spring - thanks , bruce

 

[Buttanic]

Re: motor id

If it's a 1970 120 horsepower Mercruiser I don't think it is a 3.0 (180 ci in). 3.0s were 140 HP. The 120 HP was a car engine. Chevrolet put it in the Chevy II in the mid 60's. It is 153 cubic inches (2.5L)and used a lot of parts out of the 307 cubic inch V8.<br /><br />Buttanic

 

[rickfromoz]

Re: motor id

sorry to hear that bmdodge the weather can suck alright here its bloody been over a hundred f(way over)44c for over a week too hot thanks for the tip same parts as a v8 ah cooli,ll give that a try thanks