SonexBuilders.net

Over the past few days, I've been working on trying to get Aerovee #631 up and running now that I have that darn "screw" service bulletin finished, but I seem to be having some difficulty. Long story short, I have everything ( to my knowledge) finished and the starter spinning the engine just fine. For some reason, however, the engine doesn't want to fire.

I know I have the following done:
-Fuel to the carb (maybe too much as I tried to really prime the engine tonight and some fuel started seeping out of the air filter. Also, I pulled a lower plug and it seemed wet with fuel.
-Secondary ignition (the coils) are timed and we confirmed that they are in fact sparking. Using the stock Aerovee self made plug wires, I should add. They seem to work even though the spark wasn't very intense.
-Valve gap set per the book.
-compression seems fine.

There's more, but as far as I can tell the engine should fire right up. Has anyone else had any issues or things they may have overlooked? I guess I could be flooding out the engine but I would think it should give at least some indication of starting.

Did anyone else have any issues? I'd consider it a wonderful Christmas present if I could get this thing running :D

If not, Merry Christmas to everyone!!

Hi Mike and Merry Christmas to you.As to your starting problems I checked over at http://groups.yahoo.com/group/aerovee/
and when I looked for engine start problems I got over 150 hits.I spend a wee bit of time lurking in the background there and they seem a helpful bunch.Good luck and I hope Santa starts your engine. :D
Mike

Hello Mike,

Thanks for the response. I've actually read just about every post I can over there in relation to starting problems and have a few ideas to check. The main reason for my post over here was to see if anyone has any first hand stories of issues they had.

I'll figure it put though! Thankfully I'm on a nice long holiday weekend starting this afternoon so I should have plenty of time to troubleshoot!

Thanks again.

Kind of figured you would have checked over there first.
On the whole how are you feeling about your Aerovee choice ?(Not concerning your start problem.Everyone will have those no matter the engine choice.)

Well Mike, right now I feel like my engine is a very nice $8000 paperweight :lol: Maybe once the darn thing runs I will hopefully change my opinion!

Seriously, overall I've been happy with things. If you look at my previous thread about my engine I talked about some of the trials I faced while building. If I were to do things again I think it would be easier and I do appreciate how Sonex tried to make a lot of the build "idiot proof" by having things only fit one way. The build itself really isn't too bad and as soon as I figure out why it won't start I think I'll be pretty happy with it.

I certainly wouldn't hesitate to put one in your Onex. In my Waiex I would still install the Jab 3300 if I could but I just couldn't swing the cost.

I'm hoping to dig back in to my engine tomorrow so wish me luck!!

Figuring things out is what makes life good. :? :arrow: :idea: :arrow: :D
Cheers.

Well, I think I figured out what my problem is...


Hello All,

I've been investigating why my engine won't start so I did a compression check
today. Turns out I have no compression at all, but out of curiosity I spun my
prop the wrong direction and sure enough, got compression.

I removed the valve covers and spun the engine the correct direction only to
find that on each cylinder the exhaust valve opens first, followed by the intake
valve. When spun the opposite direction the valves worked normally (intake
open, then exhaust opens), thus telling me that my ACV-P01-72 camshaft was
milled for a right turning engine as opposed to the Aerovee's left turning one.

Unfortunately Sonex is closed until after the first of the year so I can't talk
to anyone at the factory, but even if I'm wrong on this I would rather everyone
here hold off before closing your case halves, just in case a batch of reversed
camshafts were sent out.



So much for flying soon...

Yikes ,I hope everything works out all right Mike.I'll wait to see how you resolve this but it makes me think a prebuilt and tested from Great plains or Revmaster might be the way to go for me. For now I'll still be sitting on the fence.
Good luck,
Mike

Could it be that your cam was installed 180 degrees off? Are there any right turning VW conversions out there? I know there would be no use in the auto world.
Either way, the timing (no pun intended) really sucks. And its clear you will need to split the case to remedy it.

If shared pain makes you feel any better, my son and I pulled the engine out of my 72 Karmann Ghia last weekend to replace the clutch. Took all of 45 minutes. Threw it back in, hooked up the wires and no joy. Wouldn't pop. I plugged the 12v into the wrong post on the coil. Did you know that the $150 electronic ignition module doesn't make any sound or smoke when you fry it? Local bug shop said they sell tons of them to people like me. They stock plenty.

I spent some time this evening looking things over again and thankfully it seems the camshaft is moving valves in the correct sequence, so my fault for raising that flag.

I've checked my camshaft to crankshaft timing and all is fine there, so I still can't determine why I don't have any compression (unless the engine turns the wrong direction). I'm still hoping it's something simple but we'll see...

Stay tuned...