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« « Previous Post: Aerovee #5 (Cylinder Heads and Valve Rockers) | Next Post: » »

Aerovee #6 (Cylinder Head Issues)

Posted by on January 18, 2015

Total Build Time: 789 Hours.

“During assembly of my aerovee kit, I was inserting the top spark plugs into the cylinder heads.  I gapped and applied anti-seize, then fit and hand tightened all 4 top plugs. I set my torque wrench to the prescribed 12 ftlb, and torqued the first plug successfully. However on the second plug, well below the 12ftlb setting, the plug turned easy and I soon realized that it had already stripped the threads in the head. I removed the plug and confirmed this.

I was able to hand tighten all of the plugs about 95% of the way (including the stripped plug), so I don’t believe it could have been cross-threaded. My only thought is that something was wrong with the threads in the head itself.”

Response: “Hello Ryan,

Please return the cylinder head to us in a box marked RMA XXXX.  We will inspect the head and either repair or replace it as necessary.”

 

Above is the email I sent to Aeroconversions tech support and their response. They subsequently accepted my cylinder head as returned merchandise and shipped me a new head, which I installed. This was the LEFT head of my Aerovee.

 

Waiex-1911

Waiex-1912

 

Upon receipt of the replacement head for my LEFT side, I installed it. After completing installation of both cylinder heads, I then discovered another issue on the RIGHT side, which I will detail by posting my email to Aeroconversions below:

“I’ve encountered what I believe to be a defective head in my aerovee kit, with an intake valve that is not fully seating. I previously sent in a cylinder head in for replacement that quickly stripped out a spark plug hole, however this is the OTHER head in the kit.

I completed cylinder head/rocker/valve installation and installed my spark plugs. Then I decided to start turning the crank to see how everything worked and what the compression felt like. I quickly discovered that the intake valve on cylinder #3 was letting air easily escape on the compression stroke with the valve fully closed.

Here is a video I filmed of what I’m describing.

I removed the head and inspected the valve by shining a light on the piston-side of the valve, while looking in the intake port and this is what I saw:

Waiex-1922

I then compressed the valve spring to open the valve, verified that it was smooth and clean of debris, and when I put it back the light was still visible. I also rotated the valve and the light was still present in the same general area, so my hunch is that the valve seat is not centered with the valve guide.

I have since sent the second head back to Aeroconversions and am awaiting their response.

 

 

 

 

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