Coolant flow, head cracking

F

Farmallgray

New member
Joined
Nov 4, 2009
Messages
110
Do you guys do anything to redirect coolant flow to get more cooling to the head to help minimize head cracking?
 
In my case, a 3 cylinder Kubota. But I have been told that 400 series (414, 436 and 466) IH engines have the same problems with cracking between the valve seats and from the seats to the injectors. I guess it isn't a problem with the Cummins engines in high HP pulling applications? I'm hoping to find a possible solution other than hard blocking the head. I have been told part of the problem is uneven cooling flow through the engine. I guess the front cylinder gets more cooling flow than the rear.
 
Cummins do crack just like the others. I've been told if you mill the area between the valves down close to the same height as the seat it helps stop the cracking. I have no experience with doing it but some say it works. You may also try different hole size in the gasket. Bigger as you go towards the back of the engine.
 
DISTURBED said:
Cummins do crack just like the others. I've been told if you mill the area between the valves down close to the same height as the seat it helps stop the cracking. I have no experience with doing it but some say it works. You may also try different hole size in the gasket. Bigger as you go towards the back of the engine.
Click to expand...

Woodruff did that to a few heads I've seen...I've only seen one back off the engine, and it had not cracked. I would think it would help at least, that is the smallest area that gets a lot of heat on the head, and milling it out should reduce the stress in the area as well as give it slightly more surface area (due to the rounding)

I'm not an engineer by any means, but that's what I can come up with on my own analysis;)
Chris
 
Hercules has done it 2 different ways. The first version was a football looking shape machined in between the valves, the later version had a roughly .060 wide radius bottom slot cut between the valves that everyone thinks is a crack. Both versions work well.
 
9724VF350 said:
Hercules has done it 2 different ways. The first version was a football looking shape machined in between the valves, the later version had a roughly .060 wide radius bottom slot cut between the valves that everyone thinks is a crack. Both versions work well.
Click to expand...

Forgot about that...first time we saw that bottom slot we thought we were screwed.

Chris
 
So basically where the crack is in this one, mill a slot?
 

Attachments

  • IMG_4921 [800x600].jpg
    IMG_4921 [800x600].jpg
    79.9 KB · Views: 0
Think about flow in more than one respect, 1-your cooling media flow-rate and the cooling media volume at any place within the cooling system. 2- your heat flow rate from the surfaces of the combustion chamber to the cooling system. Materials will change rates as well as structure parameters. Don't forget your cooling media itself if you feel like you want to think that deep.
 
You must log in or register to reply here.
Back
Top