Thank you Sam! The new motor stays together as is.
Sam LeBanco:
Thank you for your insight. The only reason I will disassemble and re-assemble this factory replacement block is to deal with porting work for other anomolys that may not mean anything to a stock engine but to racing one does and re-assemble it with its new OMC pistons. For the Future I will sure watch for the wear limits you are describing to later act on. Why spend a whole extra wack of extra money for other aftermarket pistons where you have a new set to count on from the original purchase price to work with first time around at least.
Any advice on breaking the rings in while on petroleum based oils and when switched over to synthetic and advise what synthetic is best for these 3 Holers overall.
Again thanks. :)
Ring Flutter, Coatings & Lubrications
Sam LeBanco:
My aircraft pilot neighbour who go me involved in all this in the mid 1960s when doing his rebuilds on his C-Racing, C-Service and then his racing KG9 Merc would spray all his rings with some kind of graphite spray on each side that would dry and harden before he would flip them to do the other sides for installation. This he claimed would help with a slowing of the break in of those real wide rings he used. He also used some kind of graphite additive in his fuel mixes as well that left a grey residue streaming down outside his exhaust ports. He never talked about things such as ring flutter and if he did I was too young to understand that, he kept me to basics as a protege. One thing he did mention was wanting some kinds of rings that fitted ring groves as standard but tapered outward to half the ring grove width at the cylinder wall as being a better racing ring. That was still greek to me too! I never saw rings like that until the later 1990s for Mercs running Turner pistons. Just last year I made up a D-Mod gas engine with NOS Turner ultralight 2 ring gasser pistons where I installed these type of NOS tapered to the outside half width rings that looked they were a kind of chrome high tension ring material. I have yet to test the engine. I take it that narrower rings of suitable material took out ring flutter at these higher rpms? I suppose that these modern day teflon and ceramic coatings and sprays also help prevent ring problems at high rpms?
Its entirely new to me about metal transfers from one side of the rings groves to another. I saw some weird stuff on the Turner piston ring groves on scortched, scored, melted and fried pistons from Alky deflector engines but never on the stock or mod Mercs I have worked on. Is that what you mean by metal transferance? I would not have recognized what I was seeing other than thinking that the piston maker made things that way?
There is so much to think about in your post I have to go into Jennings material to get further out of what your saying. For anyone else to read I do believe there is a thread on BRF with links to download his, Jenning's book.
Thanks for the break in proceedure advice, slower means better or even more long lasting parts wise hopefully. I notice you did not mention Red Line synthetic 2 stroke oil for gasoline fuels. With sitting on about 6 gallons of it, I must ask if it has fallen out of favor these days??
A few years ago I had the misfortune about not knowing anything about Amsoil and that Amsoil synthetic was just that being synthetic and could not figure out why the Merc 55H just would not break in its rings no matter what I did. When I found out the whole experience soured on me thinking it was a weird engine of no use and there it was the synthetic oil screwing up the rings breaking in all along. What a horrible lesson to learn about not knowing oil brands and using them thinking in that case thinking Amsoil was petroleum based with no can or specs to read and find out any different at the time.
I am defintely going to use the new OMC pistons already loaded into the replacement complete block and be mindful of all your pointers.
Thanks for all that info. :)
Graphite lube and OMC's running fast and hot.
Sam LeBanco:
The graphite spray that Ted Coates used on the piston rings was different and he got it from mechanics at his commercial airport repair depot. The small can of graphite lube mix that was sold for fuel mixes specifically and different from the rings sprays was from "Wynnes" products, who also made a lot of other specialty lubricants to general sale to the public as well. He told me it was good for the OMC bushings still in the engine as well. He was also in the midst of converting his engines to more modern bearings and seals. After conversion he kept on using the Wynnes graphite lube in his fuel.
I thought the sparkplugs would foul on graphite being what it is but he always changed sparkplugs on the Elto and Johnson every heat anyway with clean ones so he never saw a problem by using his practices of changing plugs religiously to get excellent starting and running. For some reason he only changed sparkplugs on the Merc KG9 (Champion J4J) on the next race date but not at any other times between heats or even on a 2 day race weekend. He had no problems there either.
I was under the impression that the OMC 3 Holers being loop charged that they would run inherently cooler than their older deflector engines by virtue of the new technology but I am being informed that in either case that is just not so, be it a 35HP deflector or a 3 Holer looper. That for a ski/fishing based market that they are oversquare engines with way larger piston bores than crankshaft stroke making them high revers by their nature. Is there no way to make them transfer heat faster and tuned to run cooler? When it came to Merc/Mariner 3 Holer direct charged engines I thought my burn them to bits days were over and OMC a lot lot better?
People I know that are working on OMC 35 - 2 cylinder class C Modifieds are going to be very interested in your posts as there are 3 versions ports wise of these deflectors being constructed during their same years of production that from examining their innards as they put it have "racing written all over them"! They seriously want to boot some Yamato butt and are concerned about anything that can be done to make these engines heat managed, powerful and reliable given engines spec'd limitations for the class?
The nice thing about all the OMCs of yesteryear is that they are so so plentiful and so inexpensive to buy used albiet that they are all so heavy mainly from flywheel weight. Do these OMCs have to have such heavy flywheel systems to keep the whole motor stable or can they be made way smaller and lighter and still keep stock ignition parts going?
Sounds like asking for a lot of advice, yes but there are a lot out there who want to race and see racing spread through economies of scale, so OMC it is and just like Mercs here everything from the similar eras are so inexpensive for our sports use.