Blown Head Gasket
Thread Starter
|
Novice
Joined: Apr 2013
Posts: 16
Likes: 0
From: Washington State
Blown Head Gasket
Hey All I just pulled the heads and discovered that not only the front head gasket was blown but also the rear.
Also please look at the condition of the heads and provide any insight or thoughts.
This top end was brand new 900 miles ago! New Pistons and reworked heads!
I am not sure why they blew nothing obvious so far.
I am not sure what the torque was but I know it did not take that much to break and only about a 1/2 turn to become loose!
Any thoughts or things I should check and especially anything I should do when I re assemble would be appreciated.
As mentioned previously this is my firast EVO (aluminum motor)
Also please look at the condition of the heads and provide any insight or thoughts.
This top end was brand new 900 miles ago! New Pistons and reworked heads!
I am not sure why they blew nothing obvious so far.
I am not sure what the torque was but I know it did not take that much to break and only about a 1/2 turn to become loose!
Any thoughts or things I should check and especially anything I should do when I re assemble would be appreciated.
As mentioned previously this is my firast EVO (aluminum motor)
Tourer
Joined: Apr 2013
Posts: 313
Likes: 84
From: Central KY
I don't have access to the pictures for some reason. The fact that your headbolts were loose speaks volumes. The question is why. I've built a number of engines and never had more than a small amount of movement when checking torque after a few miles. Did you ever check the headbolt torque after the top end rebuild?
Road Warrior
Joined: Apr 2010
Posts: 1,648
Likes: 37
From: Monroe, Louisiana
If heads weren't tightened down evenly before final torquing that would account for the problem. They should be tightened like 10 lbs. first round then half way to final number second round then all the way on final round. Also good idea to re torque after couple of heat cycles. Keeps from cocking the head. Better make sure the heads or cylinder aren't warped also.
Outstanding HDF Member
Joined: Dec 2008
Posts: 2,007
Likes: 353
From: Ohio
If heads weren't tightened down evenly before final torquing that would account for the problem. They should be tightened like 10 lbs. first round then half way to final number second round then all the way on final round. Also good idea to re torque after couple of heat cycles. Keeps from cocking the head. Better make sure the heads or cylinder aren't warped also.
Trending Topics
Thread Starter
|
Novice
Joined: Apr 2013
Posts: 16
Likes: 0
From: Washington State
Bingee, All,
As for the retorque I agree, I have not seen that in any of the manuals and as you mention pretty big job to accomplish. I am getting a truing bar to check heads and jugs and I will check the case bolts as well. My guess is that the retorque was not accomplished correctly.
Any ideas about an additional sealant? Copper spray or ???.
I am also going to replace the base gaskets as long as I am here. Any addtional sealant there?
Appreciate any info.
As for the condition of the heads valves and pistons??Is that kind of carbo build up normal? Only 900 Miles since rebuild.
Thanks All
VZ
As for the retorque I agree, I have not seen that in any of the manuals and as you mention pretty big job to accomplish. I am getting a truing bar to check heads and jugs and I will check the case bolts as well. My guess is that the retorque was not accomplished correctly.
Any ideas about an additional sealant? Copper spray or ???.
I am also going to replace the base gaskets as long as I am here. Any addtional sealant there?
Appreciate any info.
As for the condition of the heads valves and pistons??Is that kind of carbo build up normal? Only 900 Miles since rebuild.
Thanks All
VZ
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Times Harley-Davidson Chucked Tradition Out the Window
Verdad Gallardo
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
Outstanding HDF Member
Joined: Dec 2008
Posts: 2,007
Likes: 353
From: Ohio
If it were me I wouldn't use any sealants. The newer gasket materials and designs work very well without any. There are some exceptions to that like the older Evo rocker box cover oil leaks. Coating the gaskets with a little Halomar (Permatex Universal Blue) seems to help. But for heads, cylinders, rocker boxes, no. That doesn't mean it's wrong to use sealant. It's just that I don't know the result, so I don't use them. And I never see them recommended in the manuals.
Hard to say what the carbon buildup is all about. Usually it's caused by running too rich. That's probably the problem. Also possible that the head leaks had something to do with it.
Hard to say what the carbon buildup is all about. Usually it's caused by running too rich. That's probably the problem. Also possible that the head leaks had something to do with it.
