Engine Compartment heat--help

[pra100]

This has been a battle for me ever since I have had this boat.Long post to explain.History.The boat 1991 Mariah 4.3 Cobra ho.Holley 4bbl.Spitfire ignition ( no distributor).<br />Starts fine cold on muffs,starts fin when unloading,runs great,never misses runs great wot.Engine temp never goes over 180.Has new thermostate,new impelier.New fuel pump.Carb has been rebuilt.Has new ignition sensor.Has a new coil.Once I stop and sit for 1/2 hour or more it will not start,will crank for ever till engine compartment cools down.I can open engine compartment and leave open then it will start and runs great again till I let it sit.The blower will not effect it.So I am thinking,extreme messures.Mount a electric radiator fan in the compartment to draw cool air into it.I know this is extreme mesures but I need some help or ideas on this.

 

[Scaaty]

Re: Engine Compartment heat--help

You could nave a bad starter (heat sinking) if it won't turn over, or you are vapor locking. When it does this, pop the flame arrester and pump the throttle...you should see a squirt of gas in the carb. Or if it smells like gas to begin with, you are boiling fuel out the bowl and into the carb. Either way, you need to reduce the heat.

 

[pra100]

Re: Engine Compartment heat--help

Thanks for the reply Roby6950 but I have had this problem for a long time and have done all the ovious.To clarify, it is not a starter problem,starter turns over fine.I have checked carb for fuel flow,there is fuel flow,although I did try spraying berremans b12 in it several times when it did this and it started once but I feel this was just exception due to the fact I had had the cover off for sometime.I even got some cans of electronic instant cool and started spraying fuel line down,fuel filter and carb down then sprayed the ignition module down.then it started again.By the way this ignition module (OMC Splitfire)is a,not avalible item.Again this engine is running 150 degrees at idle and will not go over 180 at wot.I verified this with a electronic temp gun I borrowed.This Mariah has a very closed in engine compartment,vent on either side of boat and one bildge blower on port isde.

 

[Don S]

Re: Engine Compartment heat--help

You may need more blowers and bigger vents to cool it down, but don't use automotive fans. They are not ignition protected like engine room blowers are. You probably only have a small 3" blower in the boat already, changing to a 4" or possibley 2 of the 4" bilge blowers will circulate the air more and allow the engine to cool quicker.<br />But, if the ignition module is the problem, it may have to be replaced with a complete system if you can't find a module that can stand the heat.

 

[Uncle Dave]

Re: Engine Compartment heat--help

I would bet my entire .o2 cents it is your module.<br />Electronics are often heat senstive. Get it nice and hot where it wont start and apply an ice pack . Even water will often do the trick. It s an old auto mechanic tip. I have started them back up with a rag and a little ice water.<br />But it will eventually leave you paddling one day soon.<br /><br />Uncle Dave

 

[pra100]

Re: Engine Compartment heat--help

Yes Uncle Dave I figure that is the case.I did spray module down with cool spray but had no effect.I figure I will eventually have to put a distributor in it and coil.Now that is another problem all together.It is hard to find a 4.3 distributor that does not require a external module.I was told that you can use a 350 gm hei distributor with some changes but haven't been able to find any info on how to do that.

 

[bolo789]

Re: Engine Compartment heat--help

i am having the same problem right now with my 5.7 merc, when you fix yours, please post the cure.

 

[pra100]

Re: Engine Compartment heat--help

Well I haven't fixed yet but found a cure.My engine cover is 2 piece.I took the top half off and left it home,I know dangerous with spinning belts but had to try.Anyway temp. outside was 102 degress engine ran at 160 or so degrees.I shut engine down and sat for 45 mins or so and it started right up everytime.I notice that before with engine cover on after running then sitting for awhile the carb bowls,lines, fuel filter etc in engine compartment was near to hot to touch.With cover off today bearly could fill any heat at all on carb bowls or anything else.So now all I have to do is figure some way to cool inside of engine compartment.Think I will try a couple 4 inch blowers and put a couple vents in front of engine compartment.

 

[trebor0301]

Re: Engine Compartment heat--help

i had the same problem.Every time I ran thru a no wake zone the motor would act up when I tried to get back up to speed.If it stalled out(almost every time)I could not get it to start back up for a little while.I suspected it was because of being too hot inside the compartment as well.opening the compartment while idleing helped greatly.I could not understand why my blower didnt help until I found there had been a mouse nest inside the vent hose.Now when I idle for any amount of time I just run the blower.Problem compleatly solved!

 

[waterone1@aol.com]

Re: Engine Compartment heat--help

Getting more airflow into an engine compartment can never be a bad thing. As Don suggested make sure that you use marine grade, ignition protected blowers. Secondly, make sure that all of your blowers work as a system. Having one blower, blowing inward two inches away from another blowing out will do nothing to solve your problem, plan this for airflow, while still getting bilge fumes out of the engine compartment.