PDA

View Full Version : RV antifreeze or just drain a Corvette LT1


mgs96ps
09-06-2013, 04:51 PM
I have heard that you should not fill an LT1 with antifreeze because of the aluminum heads. Can other LT1 owners and/or knowledgeable TT'ers pipe in on the subject? This will be my first year winterizing my boat with said powerplant.

Thanks

jakethebt
09-06-2013, 05:26 PM
http://www.mastercraft.com/teamtalk/showthread.php?t=51183&highlight=LT-1+winterization

Try this link. I think all your questions will be answered. I plan a small update to the checklist when I get closer to doing it this fall.

CantRepeat
09-07-2013, 07:37 AM
I think if you live in an area that gets into single digit or teens for more then a couple of days during the winter you should always use anti freeze.

Legolamb
09-07-2013, 07:49 PM
Dry blocked my 96 LT1 last year, no problems at all.

Ben
09-07-2013, 07:55 PM
I have been draining only for at least nine years. After draining, I do also drive around and hit some bumps and ramps prior to closing the drains for the winter. Not sure if this does anything, but it makes me feel better....

mgs96ps
09-08-2013, 09:08 AM
Based on what I am reading and learning, I think that I will dry block engine for the winter. I may still fill manifolds with antifreeze though.

Jakethebt, thanks for posting the link with the checklists....they will come in handy.

CantRepeat
09-09-2013, 12:53 PM
The problem I had with just draining, which I did that for 8 or 9 years, was that these motors sit on an angle and if you just drain you do not get all the water out of the motor. If you look at the location of the drain on the starboard side of the motor, in a direct drive, it sits up pretty high on the block.

What happened to me was that the remaining water froze and push out the freeze plug behind the starter one winter. I didn't notice it and ended up burning up a muffler and exhaust hose. I'm in the southeast and we normally don't get long hard freezes here. I had been lucky for a long time but my luck finally ran out.

Now I always use anti freeze and on the nights that it gets below 10 degrees I always but a drop light in the bilge.

bsloop
09-09-2013, 03:58 PM
As jake's list details; drain, fill, drain.
Use an A/F that has corrosion inhibitors. Most of the newer formulations will say "safe for aluminum" or "protects all metal components"

jakethebt
09-09-2013, 10:12 PM
I did a lot of research on this last fall. As detailed in the other thread are my comments as I learned them. I refined them into the checklist. This included calls to indmar, local mc dealers and numerous people's input here. So it is drain, fill drain for me from here on out. After doing it, it is pretty simple. It is easier than changing the oil which requires you to either get the engine really warm or wait forever while it drains.

CantRepeat
09-10-2013, 04:57 AM
What is the reasoning behind draining the anti freeze out? If it's to prevent corrosion on the heads isn't there a better type of AF to use?

bsloop
09-10-2013, 08:22 AM
What is the reasoning behind draining the anti freeze out? If it's to prevent corrosion on the heads isn't there a better type of AF to use?

It is discussed in jake's thread linked above and again here............
http://www.mastercraft.com/teamtalk/showthread.php?t=51183&highlight=LT-1+winterization

CantRepeat
09-10-2013, 09:48 AM
It is discussed in jake's thread linked above and again here............
http://www.mastercraft.com/teamtalk/showthread.php?t=51183&highlight=LT-1+winterization

Both ethanol and propylene glycol are safe for aluminum. I guess the RV stuff is said to have been reformulated to be safe as well, or so I have read.

Surely normal automotive AF are find for aluminum. How else would all those imports being running it?

mgs96ps
09-10-2013, 11:41 AM
What is the reasoning behind draining the anti freeze out? If it's to prevent corrosion on the heads isn't there a better type of AF to use?

If I am reading thread correctly...1.) dump lake water. 2.) flush with clean tap water to clear out residual lake water and open t stats. 3.) drain tap water 4.) fill with rv antifreeze to mix with residual tap water that may or may not drain from lower engine passages. 5.) drain again

Correct me if I am wrong.

CantRepeat
09-10-2013, 02:16 PM
If I am reading thread correctly...1.) dump lake water. 2.) flush with clean tap water to clear out residual lake water and open t stats. 3.) drain tap water 4.) fill with rv antifreeze to mix with residual tap water that may or may not drain from lower engine passages. 5.) drain again

Correct me if I am wrong.

JimN has posted that you should not use RV anti freeze in LT1 motors. During his training they said not to use RV AF. I have since read that RV anti freeze has been reformulated to not cause harm in LT1 motors; the issue being aluminum heads. Everything I've read about using normal automotive AF is fine for LT1s.

For me, I warm the motor to operating temp and then just put the through hull water pick up into the big bucket of AF. I run it until the bucket is empty and then verify that AF is coming out of the exhaust. Some folks then drain the motor of the AF. For me, I leave it in for the anti corrosion properties of the AF; rather then leaving air water passages that can condensate water.

mgs96ps
09-16-2013, 09:23 AM
Ok, I know that you should not own a mastercraft if you can't afford to take care on all things maintenance; and I have no problems spending money to insure that my prostar will continue to perform year in and year out....but that doesn't mean that I don't have "maverick" tendencies. So here is what I am thinking....wait for it....

If I am going to pump RV antifreeze into the LT1 just to dump it 5 minutes later, (with the idea the any residual water will be mixed on not freeze over the winter), why not just use windshield wiper fluid instead? Half the price. I keep my boat in a non-insulated garage over the winter.

Rockman
09-16-2013, 09:44 AM
Before storage last year, we changed the oil and filter, ran marine antifreeze thru the motor until it reached a certain level on the little glass meter, fogged motor and that was it.

CruisinGA
09-16-2013, 09:52 AM
For me, I warm the motor to operating temp and then just put the through hull water pick up into the big bucket of AF. I run it until the bucket is empty and then verify that AF is coming out of the exhaust. Some folks then drain the motor of the AF. For me, I leave it in for the anti corrosion properties of the AF; rather then leaving air water passages that can condensate water.

I know a lot of people do it the way you described, but seeing antifreeze come out of the exhaust doesn't confirm that any A/F made it in the block since water always passes through the manifolds regardless of thermostat position.

This bothers me, hence the reason I pull the t-stat every year and pour a/f in there with the engine drain plugs removed so I can see the a/f come out of the block.

xbot50000
09-17-2013, 08:29 AM
I brought my MCX up to operating temp and ran antifreeze through it on the weekend. Pulled a drain plug as a sanity check, and saw only water coming out. I drained all the water again. My question is, do I need to get to operating temp to fill with antifreeze, or can i do it cold?

CruisinGA
09-17-2013, 08:31 AM
The thermostat needs to be open in order for you do be able to fill with antifreeze.

At operating temperature, you have a reasonable chance that the thermostat is open.

My problem is that it is only a chance, and you waste a lot of AF out the exhaust. Hence the reason I pull the thermostat housing every year. It's two bolts and a $2 gasket for peace of mind.

CantRepeat
09-17-2013, 02:06 PM
I know a lot of people do it the way you described, but seeing antifreeze come out of the exhaust doesn't confirm that any A/F made it in the block since water always passes through the manifolds regardless of thermostat position.

This bothers me, hence the reason I pull the t-stat every year and pour a/f in there with the engine drain plugs removed so I can see the a/f come out of the block.

You are correct, if you don't run the motor up to temp the thermostat would not be open you wouldn't get AF into the motor. Hence, the bring the motor to temp and then put your big bucket of AF in the motor.

I am fully confident in the fact the heat in the motor will keep the thermostat open and AF will get into the motor. It's how the dealers do it and we all know they aren't pulling thermostats out on every job. Likewise, I'd rather have the anti corrosion properties of the AF in the engine rather then air.

At operating temperature you have a better then reasonable chance the thermostat is open.

But I agree, do what makes you sleep better through out the winter!!

GoneBoatN
09-17-2013, 02:28 PM
Ok, I know that you should not own a mastercraft if you can't afford to take care on all things maintenance; and I have no problems spending money to insure that my prostar will continue to perform year in and year out....but that doesn't mean that I don't have "maverick" tendencies. So here is what I am thinking....wait for it....

If I am going to pump RV antifreeze into the LT1 just to dump it 5 minutes later, (with the idea the any residual water will be mixed on not freeze over the winter), why not just use windshield wiper fluid instead? Half the price. I keep my boat in a non-insulated garage over the winter.

I got RV Antifreeze on sale at Walmart a couple of weeks ago for $1.30/gal. Actually my wife seen it and picked it up for me. :) So at that rate it would not make sense. Around here it is hard to get any wiper fluid that is rated that low.

mikeg205
09-17-2013, 02:31 PM
I got RV Antifreeze on sale at Walmart a couple of weeks ago for $1.30/gal. Actually my wife seen it and picked it up for me. :) So at that rate it would not make sense. Around here it is hard to get any wiper fluid that is rated that low.

was it the RV AF with corrosion protection? Usually that is on sale at $2.69 or so... ;)