Coolent Passages

[eburka2]

I am doing a Heat Transfer Project on cooling of outboard engines. I am using a 35hp 80's model for my testing. I was just wondering if anyone new how far away the cooling chanels are from the cylinder walls. If not, could you point me towards a web site with a blueprint of any motor, any size that might have this info. It doesn't matter if it is for the correct model, just approximating values anyway.<br /><br />Thanks,<br />Eric Burka<br /><br />LSU Tigers

 

[Dhadley]

Re: Coolent Passages

It depends on the motor. Some motors have a steel liner with aluminum around that next to the water passages. Some motors have the aluminum chromed. Some motors are made of boreable aluminum. The actual distance between the rings and the coolant varies from model to model. Some motors run hotter than others.<br /><br />Depending on which 35 you have, the distance between the inside of the sleeve and the outside of the aluminum is fairly common.

 

[BillP]

Re: Coolent Passages

I haven't looked at one in a long time but if I had to pick numbers without looking I'd say the thickness is between 1/8" & 3/16".

 

[Paul Moir]

Re: Coolent Passages

My old (60s) 28hp has .275" walls, .135" of which is cast aluminum, and the rest 'hard iron'. But that has an open cooling system (no thermostat).<br /><br />Well, the parts motor anyway.

 

[Jack Shellac]

Re: Coolent Passages

Don't know if you'll find prints giving this detail, but 3/16 " sounds about right to me. Good luck on your project.

 

[eburka2]

Re: Coolent Passages

thanks guys, I think I will use 3/16. Someone had said that the passages were aluminum lined? That definatly makes sense, but just want to make sure because that changes the heat transfer equation a little, although aluminum does transfer heat very quickly. Anymore notes would be helpful, if ya got um.<br /><br />Thanks again....<br /><br />LSU TIGERS

 

[eburka2]

Re: Coolent Passages

oh, i almost forgot, what about the diameter of the coolent lines in the block??<br /><br />thanks again....

 

[OBJ]

Re: Coolent Passages

No coolant lines inside the block eburka....just cast in passages which vary in size with each horsepower block.<br /><br />EDIT: What ya' might want to look at is the amount of flow through the block. Each block is designed to allow a certain amount of water through it from the water pump and maintain the disigned temp. at full throttle. The thermostat compensates for lower value rpm by restricting the flow.