Need the group's help - block heaters

[mstailey]

I currently have Cummins factory mechanics working on the boat and part of this process is to install block heaters - that being said, based on the Coast Guards experience it was thought to go with the Kim Hotstart circulating water heaters. The Cummins guys have basically informed me they do not think this is a good idea. They can't see based on the size of engine blocks that these heaters will do an efficient job. Normal elements that insert into the block won't work due to raw water pumps.

After a search of the forum I've read that Karl has done work in this area with pad heaters.

A quick check of the pad heater sites state an engine with 4-6 gallons of lube oil need a 500 watt pad per engine. That's a total of 1k watts -vs- 3k watts for the Kim Hotstarts. I've heard there is a potential of the pad dropping off the bottom of the oil pan and laying in the bilge while activated. Any truth to this? Also, what about thermostatic control? Pad sites claim if sized properly one is not needed.

So, what do you guys think?

Thanks for you help.
Mike.

 

[34Hatt]

I just put the Wolverine pad heaters on my cummins 15 quarts I put a 250W keeps them warm and toastie. Had them on my old motors also worked great. Just do a GOOD Install and you should not have a problem. Also you should check them once and while they will not just fall off they will start to peel off slowly so put it on the list of checks with all the others.

Also Karl has all the Info on adding a Thermostat if you want one, I just added 250 watt so I just leave them on.

Good time to add that I learned of them from this site and have been very pleased with them Thanks too all that told me about them .

 

[Genesis]

I have two 250W units on each of my 6V92s.

One on the side of the oil pan, and the other on the oil cooler housing.

Both are rigged so they can't fall into the bilge if they manage to detach - they'll hang there and burn up. I don't see how they can come off to be honest unless you screw up putting them on - you need to have BARE metal and it has to be level and clean.

Just install with care. I added thermostatic controls and also wired into the hobbs (required a new switch) so they shut off automatically when the engine is cranked.

 

[SeaEric]

Karl, do you think they are as effective mounted on the side of the oil pan as opposed to the bottom of the oil pan?

 

[Jaxfishgyd]

I put one 250w pad heater on the side of the oil pan of my 6-71N's a year ago and they did great. I too have them wired thru a themostate and they fire off no matter what the air temp is.

 

[Genesis]

Karl, do you think they are as effective mounted on the side of the oil pan as opposed to the bottom of the oil pan?

Absolutely - BUT - do not use too big of a pad! You'll burn the oil at the point where the pan metal is not "covered" by the oil.

The bottom is a major problem - most Detroit pans have a raised logo on the bottom and if you mount a pad heater on that it WILL burn up immediately. Guess how I know this? They warn in the installation instructions about this and they're not kidding..... there's nowhere you can fit a pad where it will be always covered with oil EXCEPT on the side of the 92 series, and you can't use anything bigger than a 250W.

The second one goes on the oil cooler vertically between the two cover bolts. It fits VERY nicely.

Be prepared to do a LOT of prep work - you have to get ALL the paint off the housings, and that means some fairly serious sanding. In my case it took me about an hour per engine to strip all the paint off and get a clean surface to bond the pads to.

With the setup I have I can get on the boat in 30F weather and hit the button - I get an INSTANT start with no smoke - like its 80F out. The blocks are slightly warm to the touch at the top.

I find this a FAR better system than any of the immersion or coolant heaters. It does the job fabulously and its energy consumption is tiny compared to the immersion or tank heater setups you see on many boats.

 

[jim rosenthal]

I concur. I put mine on the side of my CAT engines' oil pans. I just leave them on. No problems so far...if applied properly they will stick and stay on. The engines do stay warm. I think part of the benefit of these is that the rising heat keeps some of the condensation out of the engines.

 

[SeaEric]

I have CAT 3208 TA- 355HP engines, circa 1984. The side of the pan would be MUCH easier an install for sure. I'll have to do some measuring. I'd much prefer to have the smallest wattage units that will do the job. I had separate breakers installed on my new AC panel for port and stbd block heaters in anticipation of adding them. I guess I should get going and get them ordered and installed!

 

[mstailey]

Good information. Thank you all for jumping in. After talking with Wolverine and the Cummins guys we determined the 1k watt pads. I thought that was a bit much at first however, then engines hold 8 gals of oil and the oil pan is pretty thick cast iron. No raised markings on the bottom of the sump and there is 5 1/2 inches of clearance between boat and pan so access for a good clean is very doable. Bringing the boat down from norther Michigan starting this weekend and when at home dock I'm having thermostats installed just to be on the safe side. I'll really get a chance to check them out as weather forecast for begining of next week is calling for temps at night in the high 20's with daytime temps in the low 50's! Just for good measure they are throwing in some ice rain and snow!

We're going to get a chance to test out the legendary Hatteras handling...


Again, thanks for your input.
Mike.