General Engine Information Needed (from anyone experienced in engines)

[Timmeh]

Ok, I am asking for some advice here from people who do know what they are talking about.

I have had the opportunity to play with some expensive toys at work, and threw my RS2000 engine parts in the X-ray machines and Magnaflux testers.

The first big suprise was a massive sub surface crack across the number 3 cylinder part of the spare head I bought, invisible to the naked eye but comes up glowing in Magnaflux testing. I hope to get a photo of it tomorrow for those who want to see what it looks like.

I have two questions about some other things we found.

First is a simple one, has anyone ever pulled valve guides out of a head before? Look at the picture below and see if you can answer my question (I don't know the answer so I am asking it for real!):



Have a look at where the arrows are. Where does the valve guide end, that is replaceable, and where does the non replaceable head part start?

ie) The green and purple arrows are part of the valve guide and the red is part of the head. <-- what I have listed here is what I can tell. The machining shop will tell me for sure as they will be the ones replacing them, but we found some minor radial cracking where the green arrow is pointing. If it gets replaced, no worries, if not, it wasn't anything major, but it would be peace of mind to know if they get chucked or not.

Might be impossible to tell from these photos, but have a look at the valve to the right of the one with the arrows. It shows more clearly that i think the green arrow is part of the valve guide and therefore will be replaced.

Next question:



A minor crack was found in the crank (when I say minor, you cant see it by eye and its only a millimetre deep max, but that will be a stressed point), in the location as shown in the photo / drawing. This part of the crank sits just to the side of the bearings in Main number four, as indicated. There are no forward to aft shims / adjusters here, is there any reason why I couldn't get some minor machining on that face to remove the crack and therefore the stress and potential to be a point of failure?

I'll be asking the machining shop who have built many high performance engines before, it would be a shame to waste an otherwise flawless crank. The people who do metal working on the Hornet fighters have advised me if the face can be machined, it will be fine, just like parts on the jets they work on, but I'm always after opinions from people with experience.


The aim of this game is to not build a hand grenade! We are building a high performance engine to last, hence the amount of trouble and expense we are going to, to ensure this engine lasts.

Anyone with any advice, please feel free...

PS I'll get pictures of the testing up so people can see what it all looks like tomorrow

Tim

[Timmeh]

Thanks for all the replies! :

For info, the flaw in the crank I will machine out and have re-balanced, and the valve guides will be replaced with integral ones.

Tim

[gtfpv]

at least you didn't get bullshit replies made up chum but the thread was an interesting read non the less

[Timmeh]

Originally Posted by gtfpv

at least you didn't get bullshit replies made up chum

Yeah it's true... cheers.

Tim