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440 Exhaust Manifold and Riser Temps

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blue_arabian

New member
"I have a '71 440 (V-D

"I have a '71 440 (V-Drive) that I noticed steam coming from the Exhaust (more from the starboard than on the Port)Using a laser temp gun I read temps from 160-170, but on the underside of the manifold on the end right before the riser elbow and on top of the swivel riser it read 235---is this too hot??"
 
"Time for new manifolds and ri

"Time for new manifolds and risers my friend. They are clogged up with gunk and rust, The cooling water is not flowing through them and its getting boiled inside the manifolds, and exiting as steam. 235 deg. is way too hot. I had the same thing last year. I would replace all risers and manifolds, especially if they are over 5 yrs old"
 
"Its possible, but if they are

"Its possible, but if they are around 5 yrs or older they should be replaced regardless. The inside walls of the manifolds start to get very thin, until they start leaking water into the cylinders. If this happens, when you shut down, water leaks into the cylinders near the internal holes, then you'll hydro lock the motor. If you leave it sitting with water in there, the rings and cylinder walls will rust and pit causing BIG problems. Happened to me last year, but got lucky, the motor only sat for a day, so I was able to unlock it and get the water out. I went for new manifolds and risers and no problems now. I found this website called boatfix.com, cost me about 350$ a side for a 318, dont know what the 440 setup would be, but give em a try. Also get the stainless mounting kits, will save headaches down the road if you have to remove them."
 
"Manifolds should not run hott

"Manifolds should not run hotter than about 160-170 'F.

If one side is hotter than the other, it's not getting enough water (plugged).

Jeff"
 
I have had risers in my Hatter

I have had risers in my Hatteras with 440 for 20 years and keep them cleaned out of rust. Have them checked for thickness. Ports get plugged sometimes and need cleaning. may need new "o" rings and sleeves after cleaning.
 
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