914 cylinder head accessory bolt dimensions

Hi Christopher

The attach point is exactly that, a point for you to attach something like perhaps an air baffle if it is needed.  Even given the engine is aluminium there are no aluminium bolts, only plated ones with for the most part silver cadmium coating or Dacromet coatings.  Personally I have never seen corrosion on any of the bolts from dissimilar metals on these areas including the crankcase bolts.  These are all plated hardware in some way.  

it is an M6 I believe.  not sure of the pitch but it is the same as all the other M6 on the engine. you should be able to check that easily. 

Cheers

Google Galvanic Corrosion Chart and you will see that aluminum and cadmium are right next to each other, so there is little chance of corrosion, whereas aluminum and stainless steel are far apart, setting up the potential for corrosion when moisture is present.

Mike

Thanks for that advice - just what I was considering. This engine will be exposed to water (including salt water) alas the reason it matters.

Appreciate the counsel.

Christopher

I would recommend you consider ACF 50 or some other type of treatment to reduce damage from salt water at the very minimum.  Marine engines are totally painted in, including bolts, after assembly.  Think about the ways you might reduce surface corrosion.  The type 914 is also bare metal, there is no paint on the block, cylinders and heads for example.  ACF 50 is also good to reduce any damage to electrical parts on the engine.  Be sure to use dielectric grease on all connections.

https://learchem.com/products/acf-50.html

Cheers

RW, really good point - and in our case, it's on a seaplane and high above the water, but still subject to spray. Your advice is particularly astute. Simple ways to reduce/avoid/eliminate corrosion are appreciated, and this is a good one.

Thanks & have a great weekend.