Airflow Performance FM-200 Adapter on Sump - Is this normal?
 

Yesterday I got my engine hung :D - much easier than I thought it would be.

As I was admiring all the shiny bits, I noticed the fit of the Airflow Performance adapter plate to the sump. There is quite a mismatch in the diameter of the bore of the adapter plate and the inlet bore in the sump. The adapter plate measures approx. 2.375 and the bore in the sump is approx. 1.95. So, I'm questioning if this is normal. It sure goes against all my hotroding instincts, but maybe it's OK. The engine is a TMX-IO-360 and the injector servo is a FM-200.

Here's a couple of pictures:



Close up:



Any thoughts??

Thanks - Chris

Not Normal
 

First check the servo to make sure it doesn't have an extension that mates to the pipe going through the sump (unlikely!). If not, I agree with your hot-rodder instincts. A full radius transition even though beautifully made is not going to do the airflow any good if it does not transition to the pipe ID going through the sump. Talk to the manufacturer, but I wouldn't accept it as is.

Chris,

I am not familiar with the TMX sump but thought I would show you the difference with my ECI IO-360 sump.



You can see that the sump opening is larger and mates perfectly with my AFP bracket.

I have an ECI vertical sump with AFP adapter and don't recall having any mismatch like what you show.

Hi all,

Bit different, but I just fixed my rough running O-320 by inserting an insert that smoothed the transition from carb to sump - long story and not very applicable - but I can tell you that the turbulence in the updraft/riser from a step like the one in the picture here was enough to make her sound and feel like an old tractor.

Probably won't make an enormous difference on this IO engine, however it is a bit lazy not to have a smooth induction system.

Of course you could have an O-320 straight riser sump in which case the bore of the hole will leave that step...

Interesting
 

Check out post #30 in this thread!

http://www.vansairforce.com/communit...ad.php?t=63262

Sump Part Number?
 

Thanks for the responses so far.

I emailed Don at Airflow Performance the picture and his response was that he thinks I have a sump for a 320. I went out and got the part number off the sump, it's H LW13787 CFI E03-1. Can anyone verify that it's a 320 sump with that part number.

Thanks,

Chris

Here are your 360 sump #'s standard deck.

My O-320 sump.....
 

....is part # lw-10828 for what that's worth
but, it also has right at a 2" bore (didn't have my calipers handy, measured with a ruler)

Wrong Sump!
 

Well, after sending the picture to Mahlon at Mattituck and taking a measurement of the bore on the sump, it appears that it is either a 320 sump or a mis-machined 360 sump. Disappointed? - YES!! But, Mahlon assured me that it would be taken care of.

Now the question. Mahlon has given me the option of sending the engine back to them or having the parts sent to me so I or a mechanic I hire can do the swap. Having never worked on a Lycoming but with lots of experience working on cars, is there anything I should be concerned about before saying I'll swap it myself? Should I hire someone to swap it or look over my shoulder while I swap it? Or, should I bite the bullet and send the engine back and have Mattituck do it?

Expert advice much appreciated!

Thanks,

Chris