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Old 20-07-2006, 12:08 AM   #21
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Originally posted by Tony Davis
Yeh, as used by Gary Glitter.
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Old 20-07-2006, 12:30 AM   #22
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I recall that in the early days, mobil were the only 1 offering a "true" synthetic. I'm not really going down the synthetic vs mineral route - I'm happy with what I've got as far as general usage goes, I just want to understand the "why" if there is any fact behind the mineral to breakin story.

A number of manfr's offer cam lube for the 1st start - but I've got some nice clean molybdenum disulphide grease that'll do.

Quote:
Originally posted by jw.
I'd never heard of it either. I always used gear oil when building the engine and then, like Jon, kept the revs up for a while to provide plenty of splash.


Edit. I just remembered a conversation I had with a lady Techie at Castrol a few years ago. She reckoned mineral oil was still (then) a better lubricant than a synthetic oil but the synthetic's benefit was it's ability to stand high temperatures. Things may have changed nowadays. But maybe it's not just a myth.

Second edit. Piper used to sell a special lube for coating their cam lobes during initial build.
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Old 20-07-2006, 12:39 AM   #23
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Quote:
Originally posted by Matt
I recall that in the early days, mobil were the only 1 offering a "true" synthetic.
Yeh, I remember using that. It was pish thin and the motor rattled like a bag of bolts. It wasn't in there for long. Back to the Duckhams.
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Old 20-07-2006, 12:44 AM   #24
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Good old Duckams Q eh.
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Old 20-07-2006, 12:54 AM   #25
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If you are talking about flat tappet inboard engines....
(if talking about outboard, I can't comment for lack of knowledge)

Here is the states, we tend to add General Motors EOS additive at break-in, or some use any of the cam company's break in lube. Run a break-in routine of at least 1/2 hour at between 2000 and 2500 rpm, varying the rpm often. Then drain the oil and lines, and the filter, and add new oil. It is imperative the engine be ready to start when first cranked. The valve lash, timing, and carb settings need to be completed before and after the break-in period - NOT during. You want that cam and those lifters spinning at around 1000 rpm (2000 crank rpm) from the very first rotation through 1/2 hour. Do not worry about running a little rich or a little lean at this time, or timing being off. Just get the engine spinning lubricated. Before actually firing the engine up for the first time, pull the distributor and prelube the engine. And not just until you read oil presure. Pull the valve covers off and make sure you have oil coming out each pushrod. On a virgin Big Block Chevy, this could take a few minutes. You want the engine to start and have oil immediately at the lifters. If you have to crank the engine any more than a few turns without firing and getting it up to at least 2000 rpm, your lifters/cam will fail. End of story. Detailed preparation for break-in is the most important thing you can do.

This especially applies to solid lifter cams. In the USA, the EPA has had the oil companies remove most of the ZDDP (essentially zink) in additive packages in the last year or so because it is claimed the zink. Zinc is what protects the cams and flat lifters. Many cams/lifters have been ruined in the last year or so because of this.

Also, all cam manufacturers, and a lubrication engineer I know, do not recomend synthetic oil in a racing engine or a marine engine because of the loads incurred. I guess the additive package for extreme loads is not there. Automotive synthetics are design for modern low rpm engines. In fact, it is now recommended that either, and only, "off-road racing oil" or diesel engine oil (such as Shell Rotella T , Delvac, etc) be used. Not sure how things are labelled over there, but over here, racing oil and off-raod racing oil are two different things. I am sure somebody will eventually develop an off-road racing synthetic. That would be the ultimate answer.
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Old 20-07-2006, 11:45 AM   #26
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Quote:
Originally posted by Matt
Ere you go:
http://www.compcams.com/Technical/In.../Files/145.pdf
http://www.cranecams.com/pdf/214e.pdf

Both say don't use synthetic - but I can't find any credible reason why.
I think its because synthetic oils don't allow things to wear like mineral oils so it would take alot longer to bed in.
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Old 20-07-2006, 12:09 PM   #27
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CarCraft have a nice article about Synth Vs Natural oil on URL below lifted from that article

"Because a synthetic oil’s molecules are much more consistent in size and shape, they are better able to withstand extreme engine temperatures. By contrast, the unstable molecules in conventional oil can easily vaporize or oxidize in extreme heat. Mobil 1 synthetic is said to be capable of protecting engines "at well over 400 degrees F"; in the real world, most racers have no problem running synthetics up to 290 degrees F under prolonged use, but they get really jumpy when a conventional exceeds 270 degrees F."

http://www.carcraft.com/techarticles/15378/

I have run a fully Synth oil Castrol R4 Superbike for the last 4 seasons offroad with no problem or noticeable wear I have continued to use it over the Castrol Off Road which is only a part synth oil. The wet plate plates have really held up well & still have plenty of life in them which is a really good indicator as it does take a lot of stick!!

I'm a synth fan in fact a fan of all the modern man stuff, give me kevlar, carbon fibre, gor-tex and all that other stuff anyday.
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Old 20-07-2006, 12:35 PM   #28
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Right. So there's still no hard and fast evidence as to why you shouldn't use a synthetic to break in a cam.
It has better film strength, better temperature resistance, better low temp viscosity.

Some oil's generally don't have a sulphur additive package which reduces their ultimate "last chance" strength - but this applies equally to mineral & synths.
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Old 20-07-2006, 12:53 PM   #29
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Might me a half assed fool but treat you engine like a person, watch the "Diet" changes.
I have always used good old Mineral/cooking oil whatever to run in on as thats what you want to do, bed things down to operating / working tolerances, then gone to a part synth for a short time after the break in and finally for the fully systh there after. I have found less wear with the fully synth. Opinions vary widely & many points are valid it's whatever works for you. Frequent changes the most important.
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Old 20-07-2006, 01:56 PM   #30
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Not sure about the reason with new cams, but a guy near me who builds serious race and rally cossie motors said that on a freshly built engine synthetics are just too good a libricant and stop the rings etc bedding in properly.

Piper still make the cam lube so no doubt recommend that you buy that!
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Old 20-07-2006, 05:32 PM   #31
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Mobil's response:

Synthetic motor oils can be used without any issue when it comes to break-in however,if you have a flat-tappet cam you may need to utilize a motor oil with higher anit-wear additive levels. Mobil1 0W40 or 15W50, Mobil1 Turbo Diesel Truck 5W40, Mobil1 MX4T 10W40 and Mobil1 V-TWIN 20W50 motor oils would be the best choices. If your cam manufacturer recommends conventional motor oil for break-in, Mobil respects their wishes and suggest that you follow the guidelines, but switch to Mobil1 as soon as you feel comfortable for maximum protection and performance.
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