Go Back  Offshoreonly.com > Technical > General Q & A
Aluminum heads >

Aluminum heads

Notices

Aluminum heads

Old 09-12-2011, 08:05 PM
  #21  
Platinum Member
Platinum Member
 
mcollinstn's Avatar
 
Join Date: Sep 2001
Location: tn
Posts: 5,752
Received 133 Likes on 82 Posts
Default

Aluminum castings can be anodized after all machining operations have been performed. Used heads can be anodized, but must be stripped and cleaned first.

Properly done, anodizing completely prevents subsequent corrosion, but it the anodizing is scratched thru - it opens a "wound" that can infect the surrounding areas.

Many anodized castings are improperly "gasket matched" or deburred by engine builders as a result of "habit" and this gives entry to a path of corrosion. Once anodized, the coated surface must be preserved.

As a side note, anodizing is a form of corrosion. The electrical current ATTACKS the aluminum and changes the upper surface into a form of mineral (aluminum oxide). Once changed, this surface will NOT conduct current or react to the normal range of antagonists that would normally continue to attack aluminum.

MC
mcollinstn is offline  
Old 09-12-2011, 08:28 PM
  #22  
Platinum Member
Platinum Member
 
Join Date: Dec 2002
Location: Dallas, TX
Posts: 2,195
Likes: 0
Received 2 Likes on 2 Posts
Default

Would you buy BBC iron heads if the pricing, HP/TQ results and acceleration were the same as as CNC aluminum? Say 800+ HP N/A? Jim Valako has made us 3 sets. The relativety small increase in boat weight won't likely show on the GPS and they should last indefinitely.
Ben
BenPerfected is offline  
Old 09-12-2011, 08:42 PM
  #23  
Registered
iTrader: (1)
 
offthefront's Avatar
 
Join Date: Feb 2004
Location: Northeast,Fla
Posts: 4,909
Received 9 Likes on 8 Posts
Default

Originally Posted by Mr. Demeanor
Flushing with water and vinegar will definitely prolong your aluminums life.

Before

http://www.flickr.com/photos/65811281@N07/6133149278/

After

http://www.flickr.com/photos/65811281@N07/6132602179/

Ok ..you got my attention .....how to you inject the Vinegar? Hose end sprayer? ....If you look at the salt away type injector the hole the water has to flow thru is ridiculous ....I would sat 1/4" or smaller ...m
offthefront is offline  
Old 09-02-2019, 10:38 PM
  #24  
Registered
 
Join Date: May 2016
Posts: 209
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by mcollinstn
Aluminum castings can be anodized after all machining operations have been performed. Used heads can be anodized, but must be stripped and cleaned first.

Properly done, anodizing completely prevents subsequent corrosion, but it the anodizing is scratched thru - it opens a "wound" that can infect the surrounding areas.

Many anodized castings are improperly "gasket matched" or deburred by engine builders as a result of "habit" and this gives entry to a path of corrosion. Once anodized, the coated surface must be preserved.

As a side note, anodizing is a form of corrosion. The electrical current ATTACKS the aluminum and changes the upper surface into a form of mineral (aluminum oxide). Once changed, this surface will NOT conduct current or react to the normal range of antagonists that would normally continue to attack aluminum.

MC
Who does this for heads?
GrannySShifting is offline  
Old 09-03-2019, 05:23 PM
  #25  
Registered
iTrader: (1)
 
Join Date: Apr 2014
Location: North Florida
Posts: 649
Received 121 Likes on 58 Posts
Default

Why not just plumb in a heat exchanger. It’s much easier than buying heads and intakes. I bought a used mercury heat exchanger for $200 and a new puke tank for $50. Hoses and clamps were another $50. My heads and intake are anodized as well but it probably wasn’t necessary. If you boat in salt, flushing is a must, even with outboards, but nothing beats not having salt water in the water jackets at all.
ph1971 is offline  
Old 09-03-2019, 08:11 PM
  #26  
Registered
 
Tinkerer's Avatar
 
Join Date: Jan 2002
Location: ALTO, MI
Posts: 4,612
Received 7 Likes on 6 Posts
Default

From experience - find a 351 and do some work to that engine. That 302 will need a lot of exotic parts to make it produce a noticeable HP increase.
I went from a merc. 188 ( 302) at 188 HP stock to over 500 HP with more money spent than you can imagine.
I had a SMALL engine bay and the engine cover was hitting the exhaust. Glastron Carlson CVX 18.
I wish I could have gone to a 351.
everything should bolt up the same. the engine will be a little bit taller and wider.
Your exhaust will move but if you are running rubber hose connectors they should give that much.
Tinkerer is offline  
Old 09-04-2019, 12:37 PM
  #27  
Registered
Platinum Member
 
Join Date: Sep 2012
Location: new baltimore mi
Posts: 523
Received 38 Likes on 32 Posts
Talking

closed coolant system .

just changed my motors to closed coolant system.

Last edited by flashgordon; 09-04-2019 at 12:38 PM. Reason: spelling
flashgordon is offline  
Old 09-04-2019, 01:09 PM
  #28  
SB
Registered
iTrader: (1)
 
Join Date: Nov 2004
Location: On A Dirt Floor
Posts: 13,516
Received 3,088 Likes on 1,390 Posts
Default

This thread was started ages ago by the guy with the 302.

Besides that, I vote for closed cooling too, however, there was a guy on here recently that had his heads rotted from outside. Salt air/water attacked areas near exhaust ports/header flanges.

If you gets heads hard anodized, make sure they are done after machining, not before. As mentioned, any areas with anodizing that have been machined off, well, defeats all purposes of anodizing. Canfield used to anodize after. I'm not sure about Dart and Brodix - must ask ! I know AFR machines after anodizing.

If getting heads and/or intake hard anodized after machining, make sure they keep atleast threaded head accessory holes (for ground cables) and spark plug holes non anodized. You need plugs grounded ! I grounded coolant temp sensors on their exterior, since the t-stat housing will be electrically dead, or unless you ground the housings with a separate ground wire. T-stat housing normally grounds thru intake which grounds thru......
SB is offline  
Old 09-04-2019, 07:04 PM
  #29  
Registered
 
Join Date: Jan 2006
Location: taxachusetts
Posts: 3,075
Received 670 Likes on 340 Posts
Default

Originally Posted by GrannySShifting
Who does this for heads?
absolute plating in Norwood,Ma.located on Bridge st.
they did our 1075 merc heads to a mil spec coating and then some.these were brand new heads,they have to be,also had to remove guides and all the helicoils.
hope this helps a little.
sutphen 30 is offline  
Old 09-06-2019, 07:15 PM
  #30  
Registered
 
Join Date: Aug 2016
Location: Melbourne,Australia
Posts: 139
Received 3 Likes on 3 Posts
Default

Originally Posted by sutphen 30
absolute plating in Norwood,Ma.located on Bridge st.
they did our 1075 merc heads to a mil spec coating and then some.these were brand new heads,they have to be,also had to remove guides and all the helicoils.
hope this helps a little.
Did you put plugs in the spark plug holes
AusScarab29 is offline  

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.