Marvel Mystery Oil

[Kelliots]

So does anyone use Marvel oil in their engine? From what I understand, it is a light solvent oil that helps with valve sticking, carbon buildup, etc. I was thinking of using it during my ring/cylinder break in flights now that I am up to about 10 hours, but wasn't sure. Any opinions on this stuff? Thanks......

[flying bee]

I use it religiously in my engine oil and fuel. I have a high time engine with good compression and no valve sticking issues. Not sure if Marvel is the reason but I'm not stopping now!!

[Gilbert Pierce]

Marvel is as you say a light petroleum solvent. It evaporates very quickly when hot. It does nothing to prevent varnish build up/ring sticking which is caused by unburned fuel molecules blowing past the rings. These molecules are highly reactive, combining with oxygen and CO2 in the exhaust gasses to form a sticky varnish. Marvel will dissolve this sticky varnish in the ring grooves when you first put it in and free up the rings. However it gets used up quickly and then more sticky varnish forms.

If you really want to prevent sticky varnish and carbon buildup you will be much better off using CamGuard. http://aslcamguard.com/aircraft/ I have been using CamGuard for about 4 years and have noticed many benefits, not the least of which is no more carbon chunks in my oil filter and no more weeping oil around my prop/crankshaft seal and push tube seals. Anti-oxidant additives in the CamGuard neutralize the reactive components in the blowby preventing the sticky varnish from forming. If you use Aeroshell 15W-50 it is 50% synthetic oil which slightly shrinks seals and gaskets per a conversation I had with an Aeroshell Engineer. CamGuard contains an additive that causes seals to slightly swell. I use Phillips 20W-50XC and 5% CamGuard. It also contains a rust inhibiter.

Aeroshell straight weight oils and Phillips 20W-50XC contains no synthetic oil which is a very poor at holding the lead particles in the oil in suspension. That is why Mobil 1 aircraft oil failed, it was 100% synthetic and the lead promptly formed a sludge and screwed up a lot of high dollar engines before it was pulled from the market.

Steve's daughter Taylor did a school science project in which she bead blasted a number of piston pins. She dipped them in straight oil and various aircraft engine oils with and without the CamGuard additive and then placed these pins in a homemade humidity chamber using salt water. The pins dipped in oil without the CamGuard promptly started rusting. The pins with CamGuard additive in the oil lasted much much longer before rust started appearing.

Lastly, CamGuard is FAA Approved.

[Pacerfgoe]

Very informative Gilbert.....Thanks

[moe2goe]

Gilbert, great explanation I will be sharing with others. thanks

[cgfyl]

I'm using camguard now too.

[bobbynick@msn.com]

How much Marvel Mystery oil should be added to engine oil if I were to decide to use it?

[Steve Pierce]

I always used it per the instructions on the bottle. Can't remember the ratio.

[P.o.P.]

Last week a cherokee had a reading of 42/80 by on 1 cylinder.

Air would exit the Breather that indivates Rings.

Piston was dry (normal) , no cylinder scoring per scope, & no metal in the

screen or filter.

Several flights did not affect the reading.


Removing the top Plug with the Piston bfore TDC & then filled the Combustion Chamber with MMO.

Reinstalled Top Plug & applied some weight to the prop to squeeze the solvent & allowed to sit overnight.

Next day oil was drained via lower Plug & engine rotated to assure no Liquid Lock.

Post Flight Comp is now 72/80.

This is NOT a one-timer.

I don't know if Comp would have improve without the MMO but it's worth

a try if there are no confirming defects.

[cgfyl]

Sounds to me like a recent problem I had. My engine guy said it's new additived I 100ll, in the last two years he has seen excessive buildup in carbon on the valves. Do a compression test, if the compression is low, strike the cylinder, see if it changes. If it changes go fly for a few hours. If the compression difference exceeds 10% or 8 psi, its carbon build up. If its less, rings or valves, etc.

I learned the hard way and removed two cylinders that i didnt need to.