O-320-H2AD Diamond Like Lifters

[zwages]

A few weeks ago my engine broke a rocker arm stud. Initially I thought it to be freak thing. Maybe not so much now. I have removed all of the lifters. The camshaft is damaged and seven of the lifters are shot.

The engine was built by a reputable builder in Florida and has around 300 hours. Seven regrinds were used and one "Diamond Like Coating"(DLC) lifter was used. It's part number is 15B28093. It can be seen that the only lifter that is any good is the DLC lifter.

There is a lot of conjecture as to what is the right thing to do with these engines. This includes the additive that lycoming decrees you must use. This picture speaks for itself. Use DLC lifters in these engines. Dont forget that this DLC lifter was likely eating trash from it's brothers and it still looks perfect.

I will call the builder this week to have a chat. Hopefully he accepts that he shouldn't use regrinds in a H model again.

 

[blaplante]

What does the cam lobe look like that had the DLC lifter?

I think we can make really tough lifters... but if they just chew the cam instead, there's not a net gain. Maybe that's the cynic in me...

 

[zwages]

Cam

I'll get the borescope out and take a picture soon. But I'm betting the cam looks fine as some of the chewed up lifters had lobes that looked okay.

 

[avrojockey]

I feel your pain brother, though those tappet bodies are the worst I've ever seen. I opted for the Lycoming cam kit in my overhaul...which come with the DLC lifters. FYI, the Superior lifter do not have the DLC coating.