OK To Run Engine Without Sterndrive??

[milkyway]

I have mercuiser 5.0L with alpha 1 Gen II sterndrive that has seawater water pump located at the lower part of the outdrive. I removed the lower and upper parts of the outdrive drives for maintenance and will put it back in May next year. But I need to run the engine for antirust procedure and winterizing. Since the outdrive is on the floor and I could not therefore use garden hose with a muff, I bypassed the seawater hose to the thermostat by attaching a hose with a garden hose so as to have cooling water going to the engine. I know my temporary source of cooling water works --- BUT is it OK to run the engine without the outdrive attached to it? Will it do any harm to the engine coupler or what else you know about?

 

[achris]

Re: OK To Run Engine Without Sterndrive??

BUT is it OK to run the engine without the outdrive attached to it?

Yes, it's ok. Use to do it all the time.<br /><br />

Will it do any harm to the engine coupler or what else you know about?

No, it won't damage anything. Use to do it all the time.<br /><br />Chris.......

 

[waterone1@aol.com]

Re: OK To Run Engine Without Sterndrive??

I agree. If the whole outdrive is removed, and you have weter connected to the engine, no problem. Just do not rev the engine for any length of time.

 

[garycinn]

Re: OK To Run Engine Without Sterndrive??

Here's a pretty neat gadget for the job:<br /><br /> http://www.mercstuff.com/coolingtools.htm

 

[achris]

Re: OK To Run Engine Without Sterndrive??

$25!!!! I can make one for about $3!!!

 

[crazy charlie]

Re: OK To Run Engine Without Sterndrive??

If you get the attachment that garycinn has cited there is one thing that you must be sure to do when using it.Make sure that you turn off the water supply BEFORE you turn off the motor.The attachment works great but it forces thewater into the motor.If you leave the water supply on while the motor is not running you stand a very good chance of hydrolock.Take it from me,I learn things the hard way. Charlie

 

[ron7000]

Re: OK To Run Engine Without Sterndrive??

Originally posted by crazy charlie:<br /> Make sure that you turn off the water supply BEFORE you turn off the motor.The attachment works great but it forces thewater into the motor.If you leave the water supply on while the motor is not running you stand a very good chance of hydrolock.Take it from me,I learn things the hard way. Charlie

Can you explain how forcing water thru the motor, from the garden hose, is going to get water into a cylinder?<br /><br />A cut garden hose, with a little duct or electrical tape on the end, fits real nice into the water inlet hole on the gimbal.

 

[tommays]

Re: OK To Run Engine Without Sterndrive??

i would like to know myself because the systems that flush you motor with fresh water while its in the water work by hose<br /><br />tommays

 

[crazy charlie]

Re: OK To Run Engine Without Sterndrive??

If the motor has valve overlap which is a design mercruiser has used for a while for better combustion you will get water in the cylinders if you force water into the motor w/o it running.Maybe some of the wrenches here can give you a better description of what actually takes place.Charlie

 

[tommays]

Re: OK To Run Engine Without Sterndrive??

well i could see a problem if the boat was in the water and the flow rate was higher than could drain out through the drive but on the trailer with no drive i am haveing trouble seeing it happen??<br /><br />tommays

 

[crazy charlie]

Re: OK To Run Engine Without Sterndrive??

As I stated before,I learned that lesson the hard way.But if you truely dont see it happening then feel free to give it a try.I highly recommend it to those who seek hydrolock.Charlie

 

[achris]

Re: OK To Run Engine Without Sterndrive??

If you had water get into the cylinders just from the garden hose, you have a leaking elbow or manifold. I've done this a lot over the years by just stuffing the end of the hose into the water passage in the bellhousing, and holding it there with a cable tie or bit of rope, and never had water enter a cylinder. The water exit in the elbow is past the end of the manifold and cannot backflow into the engine. Charlie, you have another problem that's causing the water to run into the cylinder.<br /><br />Chris...........

 

[deputydawg]

Re: OK To Run Engine Without Sterndrive??

Isn't this possible: The water exits the engine, enters the exhaust manifold where it is mixed with the exhaust gasses. Now how does the exhaust gas and the used water mix? In the exhaust manifold right? So is it possible that without air pressure from the exhaust forcing out of the engine, the water could fill the manifold and backflow to the exhaust valves? And if the engine is off, it is possible that at least one exhaust valve will be slightly open? With no exhaust being forced out and a valve open, what would keep the water in the manifold? <br />Just a thought on how this might happen.

 

[achris]

Re: OK To Run Engine Without Sterndrive??

Now how does the exhaust gas and the used water mix? In the exhaust manifold right?

WRONG!!!! <br /><br />The used water and the exhaust gas 'mix' at the exit of the exhaust elbow, and it's job is to cool the exhaust gas so it doesn't burn anything further down the system. All things being equal, water cannot flow back into the engine when it's not running. <br /><br />As an aside, the Vortec headed Gen + engines on the flushers (at idle) WILL stuck water back into the engine because of the valve overlap.<br /><br />Chris.........

 

[Bondo]

Re: OK To Run Engine Without Sterndrive??

For a Smart Wrench, such as yourself Chris.....<br />I'm Surprized,+ Stunned........ <br />

exhaust gas 'mix' at the exit of the exhaust elbow

You,+ I Both Know........<br />That's the Riser .........<br />The Elbows are farther downstream... If used at all.... <br /><br />And,<br />I Agree Totally......<br />Water Can't be entering the cylinders by Water Pressure alone....<br />Unless Something Else is Wrong.......

 

[achris]

Re: OK To Run Engine Without Sterndrive??

Hi Bondo,<br /><br />Why is it called an 'Exhaust Elbow Assembly' on Mercs part listing? (Can post picture is you like)<br /><br />I've always known a 'riser' as a spacer (available in 3" or 6") that goes between the manifold and the 'elbow' to raise the elbow height.<br /><br />Chris.........

 

[deputydawg]

Re: OK To Run Engine Without Sterndrive??

See, again I learned something here. So tell me, does the water intake also warm the water a little before it hits the engine? The reason I wonder is I have a private well at my shop. The water from the tap is about 34 to 36 degrees. Does it have to warm the water slightly so that cold water hitting the warm engine doesn't do damage? I have seen a lot of irrigation engines that have been overheated and had all of the water boil out. The fafrmers will then dip water out of the irrigation pipe and pour it into the engine wrecking the engine. I have just been curious why this doesn't happen in a boat. Or is it just that the engine is running coll enough not to be a problem?

 

[achris]

Re: OK To Run Engine Without Sterndrive??

does the water intake also warm the water a little before it hits the engine?

No.<br /><br />

I have just been curious why this doesn't happen in a boat.

It's because of the way the water distibution block (Thermostat housing) is setup.<br /><br />Chris........

 

[Don S]

Re: OK To Run Engine Without Sterndrive??

If the motor has valve overlap which is a design mercruiser has used for a while for better combustion you will get water in the cylinders if you force water into the motor w/o it running.

Valve overlap is on all of the Chevy V8 and V6 engines, more so on the newer engines, and has nothing to do with using a hose. It is also not something Mercruiser does, all Chevy engines have it in order to increase HP<br />Read page 3 of this sevice bulletin.<br /> Service Bulletin 2001-13 <br /><br />Having the hose on shouldn't be a problem with the engine off unless the engine is way nose down.<br />The water comes out the back of the exhaust ELBOW and mixes with the exhaust gas.<br /><br />Here is what Mercruiser calls an ELBOW in their parts and service manual.<br />

 

[Bondo]

Re: OK To Run Engine Without Sterndrive??

Ok, I stand corrected...........