SonexBuilders.net

Slightly off topic but what problems are people seeing with the mofoco heads? (i.e. what should I watch for when I assemble my August 2016 edition aerovee turbo ;-) )

A common problem was the one I had, the spark plug holes were tapped incorrectly, reportedly due to the use of worn tooling. When I installed the spark plugs the fist time I spun the lower right hole. Sonex took care of the problem and replaced both heads with new heads that had Timeserts in each spark plug hole. Check your heads and make sure the Timeserts are present, if not contact Sonex or MOFOCO directly. When I had my problems Sonex said they were having Timeserts installed in all MOFOCO heads they sell. You will also need to use a spacer under the intake manifold to raise the intake elbows to clear the rear upper spark plugs.

markschaible wrote:

to then pass customer quality issues off to your supplier is just unconscionable.

Unconscionable? Not at-all. It's just the fastest-most efficient way for you to receive service for your heads when it comes to MOFOCO. When we began the relationship with MOFOCO, they were insistent that they wanted their logo to remain on the heads because they were very proud to be a supplier for the AeroVee. With that voluntary identification by the vendor comes the customer's ability to go to them directly for service, and the vendor's responsibility to provide that service. If you're more comfortable bringing MOFOCO head service issues to Sonex tech support first, then by all means do so!

So, as a turbo owner, I have to assume this policy extends to other engine parts. Like the turbo.

Should we contact the turbo manufacturer directly Mark?

markschaible wrote:...
Keep in-mind that, although an aluminum case build-up of the AeroVee may still fit within the Sonex’s 200 lb FWF weight limit, it is dead weight that is not doing anything for you in-terms of providing additional power.
...

I agree it does not do anything in terms of power, however I would not call it dead weight either.

Magnesium alloy work-hardens over time, that is a fact.
The magnesium cases will therefore eventually develop cracks.
I don't believe we're talking instant catastrophic failure cracks, they start off very small often around the case savers and you'll notice little oil leaks long before it becomes a potentially dangerous situation.

Most data on how long it takes before cracks occur comes from the old RevMasters as they've been around the longest, and it seems to suggest that it can start to occur somewhere around the 500 hour mark on those engines. Just have a look on the Revmaster & VW conversion forums.
There isn't much info available on how long it takes before this happens in case of the AeroVee but it should be similar, I've found one AeroVee example that had 490 hours on it when a crack developed. (see http://www.sonerai.net/smf/index.php?topic=3553.0).

All this said, 500 hours is a lot and given the price of these cases, it's not that big a drama to have to replace it after 500 hours.

Jeeeeeeez.........all I wanted to know is if 10 extra pounds on the nose of a Waiex was detrimental.

Don't get me started on the fuel tank again. I couldn't even give that misshapen piece of plastic waste away .

Enjoying the build with both eyes WIDE open here @ Area 51%