Go Back  Offshoreonly.com > Technical > General Q & A
HP 500 EFI head gasket failure >

HP 500 EFI head gasket failure

Notices

HP 500 EFI head gasket failure

Thread Tools
 
Old 07-14-2025 | 05:15 PM
  #11  
Registered
Community Builder
5 Year Member
 
Joined: Aug 2019
Posts: 1,247
Likes: 420
From: BC
Default

Aluminum heads on BBCs have many benefits...

Be grateful you have the room to do some surgery...I would have to pull the engine to pull the heads. Even get the exh manifolds off.

Glad you were able to get more data on how the stb head gasket failed.

As Brad said...worth just having a look at rhe rollers on the lifters and the cam lobes.
Tartilla is offline  
Reply
Old 07-14-2025 | 05:22 PM
  #12  
VIP Member
Community Builder
VIP Member
 
Joined: Jun 2021
Posts: 3,533
Likes: 2,137
From: SW Ohio
Default

Originally Posted by Tartilla
Aluminum heads on BBCs have many benefits...

Be grateful you have the room to do some surgery...I would have to pull the engine to pull the heads. Even get the exh manifolds off.

Glad you were able to get more data on how the stb head gasket failed.

As Brad said...worth just having a look at rhe rollers on the lifters and the cam lobes.
Tartilla,

I’d love to take credit, but that was JayTee.

But I do stand my my Cometic recommendation.

Thanks. Brad.
Brad Christy is offline  
Reply
Old 07-14-2025 | 07:34 PM
  #13  
Thread Starter
Registered
5 Year Member
 
Joined: Jun 2016
Posts: 197
Likes: 259
From: park hill OK
Default

Originally Posted by Tartilla
Aluminum heads on BBCs have many benefits...

Be grateful you have the room to do some surgery...I would have to pull the engine to pull the heads. Even get the exh manifolds off.

Glad you were able to get more data on how the stb head gasket failed.

As Brad said...worth just having a look at rhe rollers on the lifters and the cam lobes.
I did peek at the rollers. The main reason I bought this boat was the HUGE engine room, but I never planned on pulling the heads in there. I have extension boxes so I dont even need to pull the drives to get the engines out. Im gonna try to remember to fix the float switch before I put the exhaust back on. I dropped 2 bolts(stainless of course) and was able to simply reach down and retrieve them. I sure hope this works out, I really do prefer being on the lake rather than being in this engine room.
Shotgunn is offline  
Reply
Old 07-14-2025 | 09:25 PM
  #14  
Registered
Community Builder
5 Year Member
 
Joined: Aug 2019
Posts: 1,247
Likes: 420
From: BC
Default

I bought a telescoping magnetic pick-up tool to keep on the boat....but .ost of my hardware is stainless....lol...so it mostly gets used for the odd socket that migrates to the bilge.
Tartilla is offline  
Reply
Old 07-15-2025 | 02:11 AM
  #15  
SB
Registered
20 Year Member
 
Joined: Nov 2004
Posts: 14,140
Likes: 3,708
From: On A Dirt Floor
Default

I have two of these.(they fo make a much longer one too ) . Super soft aluminium. Will bend into any shape.
I broke off the magnet off one. I bend the end into a U. Size depending on objectvtrying to get. It lets me pull things forward on floor of boat
Amazon Amazon
under engine without getting stuck on other metal things .



SB is offline  
Reply
Old 07-15-2025 | 05:31 AM
  #16  
VIP Member
20 Year Member
VIP Member
 
Joined: Nov 2002
Posts: 4,180
Likes: 333
From: ankeny,ia.
Default

Originally Posted by Shotgunn
Glad I did the other side! Thanks


Now that you’ve schooled in doing these, you should probably plan on doing
its neighbor to the right….. I’ll bet they’re in the same condition as the head you last removed
JaayTeee is offline  
Reply
Old 07-15-2025 | 07:35 AM
  #17  
Thread Starter
Registered
5 Year Member
 
Joined: Jun 2016
Posts: 197
Likes: 259
From: park hill OK
Default

Originally Posted by JaayTeee
Now that you’ve schooled in doing these, you should probably plan on doing
its neighbor to the right….. I’ll bet they’re in the same condition as the head you last removed
Next time they are getting pulled lol. The other one had a top end done before I got it. The little wire lock through the intake bolt is missing and the head gasket looks different. I am unsure exactly when but was told it was recent(by the salesman, so you know its true). I am planning to yank them this winter and turn them into 509s. The boat runs plenty good so maybe just a bit of head and intake work and a better tune, and hopefully all set for another 600hrs. Maybe my next life I'll get my staggered Top Gun with some serious power, but this go round I'm a Baja baby. I really do like these HP500EFIs, the boat is pretty solid with all the luxuries you could ever want, a pretty good starter boat into a realm I wish I'd gotten into years ago.
Shotgunn is offline  
Reply
Old 07-15-2025 | 10:42 AM
  #18  
Registered
15 Year Member
 
Joined: May 2009
Posts: 630
Likes: 408
From: Indiana
Default

How’s the block deck under that really bad gasket?
liberator221 is offline  
Reply
Old 07-15-2025 | 10:55 AM
  #19  
Thread Starter
Registered
5 Year Member
 
Joined: Jun 2016
Posts: 197
Likes: 259
From: park hill OK
Default

Originally Posted by liberator221
How’s the block deck under that really bad gasket?
it was fine, cleaned it up and put a straight edge on it. I will work on it in the evenings and hopefully find out by this weekend.
Shotgunn is offline  
Reply
Old 07-15-2025 | 12:21 PM
  #20  
Registered
5 Year Member
 
Joined: Jan 2021
Posts: 919
Likes: 428
From: Gothenburg, Sweden
Default

2 down. 2 to go.
Markus is offline  
Reply


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

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.