Cooling System Warning Alarm

[Roughasguts]

Okay fella's the no thermostat idea has some draw backs, some I can think off are.

Metal to metal wear will increase do to a colder temperature.

Fuel economy will will be worse as the engine is not at optimum temp.

The engine may smoke badly after a while, as the oil takes longer to burn when cold, so there fore may build up getting smokier, and fowling plugs often.

Also increased carbon build up in the heads and under the rings.

This along with looser tolerances between bore and piston, may cause a ring to catch in the ports and break. Ouch.

Not trying to put you off, you can run with out a thermostat for a day or so and all will be good.

But put them back, and let the small holes in the poppets take up the work load if needed to cool the engine down a bit not a lot.

Cheers fella's and good luck.

[Smelly]

Thanks GUTs - this is what I was waiting for..I knew there solid reasons for using thermostats but was not sure what they entailed...

Great stuff.

I was never intending to run permanently without the thermostats - just for my small 30min test today - hopefully..

Stay tuned..

[FNQCairns]

Smelly good to read you are doing the job properly with new head gaskets (thumbs up ). and no gasket goo????

Seeing as you already have holes at least somewhere now don't bother running without thermo's as any airlock will disipate and and the late cracking of the thermo's which is so well known on these engines will be held at bay by the water that pushes through the holes, you now have at best known good heads and gaskets -which takes some of the guess work out.

Your engine will take a little while longer with the holes to reach full warm so just add another 2 minutes to your warmup routine before gunning it each time, as these engines will constantly try to run quite cold due to raw water cooling (unlimited cool water supply) the thermos are always working closed to keep the temp 'up' enough - somewhat opposed to a car engine which because of it's closed system, high relative coolent temp and high engine operating temp.

So anyway the hole's are not a great idea IMHO (possibly a bit early)but all said and done some may have bee need anyway, if it was actually the old air lock problem causing all your drama's.

IMO this time do it once and do it properly, got the torque specs?

Your only two vice's now the engine going together with good gaskets will will be either impeller operation (think this will be fine -you confident it went together well?)and unknown flow blockage somewhere. Happy to hear your heads are in spec, your horn must work early enough .

If possible get it onto the plane for some higher water pressure through the system before you call it quit's.

O yeah! Stay away from seaweed!!!!!!!!!

good luck

Cheers fnq

[Fiji_fish_head]

we pull out all the thermostats on our engines coz eventually they all get stuck and are expensive to replace!!!

[Roughasguts]

So what you saying there Fiji man, you run lots of motors and find the thermostat useless so you remove them all ??

But the thermostat ain't that exspensive, Guess it is compared to a car, but the failure of a thermostat to open can be exspensive.

[Smelly]

Fuji Fish head - are u not then concerned about the following potential killers of engine life:

1) Metal to metal wear (increasing due to colder temperature).
2) Reduced fuel economy (engine not working at optimum temperature).
3) Increased smoke build up with fowling plugs (oil taking longer to burn when cold).
4) Increased carbon build up in heads/under rings.
5) Enlarged tolerances between bore and piston (causing a ring to catch in ports and break).

Are u confident of these five(5) major elements of engine wear (noted by Roughasguts) will not take place if u do not insert thermostats in your engines?

Smelly

[Roughasguts]

Smelly, them there thermostats on your motor have they a little vent on the top plate for the air to escape ??? Something with a little wobbly pin in it.

I couldn't tell from the exploded diagram, so I assumed they didn't. That's why the sugestion of the small holes in the poppets.

FNQ, I agree with you, any mod over and above what the manufacturer has done for there motor is not a great idea, I know nothing compared to them.

But I can't see any other safe way around it, other than remove the thermos, but that's not an option as it would increase to much water flow and way to much cooling.

But I would consider removing them if I could control the water flow Via other means EG a restrictor, valve/ tap type of arrangement.

But something like that would have to be monitored closely with temp, and pressure gauges and such, until you found a good setting.

[Smelly]

FNQ - I have been using brand new head gaskets since I first took the heads off three(3) weeks ago...Now I need to buy new gaskets again...

Should I use goo or not?

What's this "late cracking of stats" you have referred to that are common in my engine type?

Talk to me more about air locks in these systems..

Yes, I have the torque spec (6.5 - 9.5Nm)..Should I torque to around 7.6Nm (middle of range)?

I am confident the impellor/water pump install went well however (as highlighted before) I am uncertain if the hard plastic hose in the leg married into the outlet on top of the water pump housing..? I need somone to tell me how this is ensured during bottom leg bolt on as one cannot see this coupling going together during this install...HELP?

If I re-insert stats into assy and back into motor, then nothing much has changed - excpet those two(2) holes in each poppet. Do u think these new poppet holes will stop the warning siren(from overheating) form coming on ultimately??


Smelly

[Smelly]

GUTS - I just checked the stats.

No little vent on the top plate for the air to escape exists..

Good decisison..
Smelly

[FNQCairns]

Hi smelly, I mentioned about this problem pages ago have a read back.

Smelly I don't think you would have seen water half way up your heads if the pipe was not connected properly, thats a lot of head and volume for one of these pumps considering you didn't go over idle rpm's, the pump would need to fill that leg cavity up first-that's a fairly tall ask.

Yes I think it will stop the horn coming on at idle rpms (the holes), so would getting the engine onto the plane like 4500rpm then back to idle this would have poped the popets and cleared the air, as long as there is no other contributing blockage decreasing overall water flow somewhere hidden.
Although overall it would be nice to know where your operating temp falls within the normal range assuming a good test because just under the horn is too hot overall if you get my drift, something to think about anyway for later.


But really if it still overheats at idle let it cool very well then in short order get it onto the as plane per my past explanations if you like it - will tell a story.

If your heads have not seen warpage after all these horns, i wouldn't be greatly conserned about hearing it, but I would instantly shut down.

Sorry I didn't know how far you went with the rebuilding like new stuff and torque settings, makes for a real wildcard as anything is possible if the engine is put back together rubbery.

When will yours be on the water?

If you are worried about the holes don't be, it's not a new engine just warm it up a bit more every time before you blast away.


Just about to start my new secondhand engine for the first time downstairs on the stand, parts finaly arrived, all new gearbox seals and new pump kit fitted the shed looks like a bombshell hit, hope I don't have any cooling probs, a person can never know - just like you - need to suck it and see .


good luck

cheers fnq

[Smelly]

Thanlks FNQ - always good to have re-assurance from you and the mob..

I suspect the following will happen when I commence my next journey:
1) start engine
2) Idle for 2 min
3) If no horn, throttle up (forward)
4) horn will sound

After 4), should i ramp up the RPM to clear muck out for about 1 min or shut down?

THe problem is, (as what happen yesterday morning), I will be off the ramp and meters away from ramp and then the horn will go on..

SHould I conitune or shut down and row back somehow?

I need a game plan..I know you have hinted at some steps but exact steps woudl be good..Thoughts?

Good luck with your re-build. I am sure you won't have any problems...

Smelly

[station-rat]

Hi Smelly
Is this motor a VRO model or are you pre mixing petrol and oil?
Station-rat

[Chimo]

Smelly

I've been reaading but not contributing as there are plenty on this now, however has it been suggested to leave the cover off the motor when you put the boat in at the ramp so you can have good access to feel the metal all round the motor as you test it.

I assume your taking someone with you to drive so you can feel the metal temps as you start and then as the revs are increased to do the various tests that have been suggested.

Doing it this way will give you a good handle on whats going on and take some of the vagueness out of it.

Hope things are close to final and fixed for you.

Chimo

[Smelly]

RAT - VRO V4 1989 110HP OMC.

Chimo - Yes thanks - I have been doing that (cover off and feel) - so far I have only travelled 5m in boat - so far from finished really....

While I await for my new Head gaskets (ETA tomorrow Friday), I am taking off the exhaust chamber for inspection - right now..without taking powerhead off! (cool hey!)

SMelly

[station-rat]

Smelly
I think that the over temp alarm and the VRO alarm are the same horn, have you checked what is triggering the alarm?
Station-rat