What size and manufacture of methanol nozzle did you use?

 

SMC kit, version 1 rev 5. I'd have to look, should be a 7 though it seems to spray like a 10.

 

So your thinking that just recently your crankcase venting system malfunctioned so adding alc to it resulted in that?

Or do you think the problem was more chronic and happened over time?

Did you have excessive oil consumption? - A sticking PVC check valve will cause that (oil in intake track - not plenum)

 

I'm not decided on it. Haven't nailed down the initial cause of the problem nor the chain of events. Once I can measure the pistons and bore I will know more. I don't want to make any judgements yet. Only 2 things I know is extreme detonation and the meth/oil mix seems to be the root it.

But I did confirm meth has that problem before posting on here, don't want to spread bad info.

FWIW afr was around 10.8 and timing was around 8 at 24-25 psi.

Didn't consume any oil, blew it out the dipstick tube.

 

Well sorry to hear the problem, thanks for the info and keep us updated

 

Just an update, got the pistons pulled and everything measured. Everything is close to spec, cylinder 1 was the loosest. It must have just sucked oil in through the intake track. Live and learn. The engine is all ready for a new set of pistons and bearings.

Think I'm going Arias pistons this go around, as long as they are in stock.

 

You need to get get one of these PCV catch can systems.

 

you got the pistons hot from a lean condition, which probably started some det that blew those edges off. i would look into the tune. oil isn't gonna get into the combustion chamber from blow by. poor ring seal will, caused by det. beating up the ring lands not allowing the ring to stay perpindicular with the bore. not to mention all the debri that chews up your cylinder walls. the motor has slowly been eating itself up from some point in it's life. that excess oil however is gonna cause some serious preignition/detonation issues though. the feeler guage is not the proper tool to be used in determining piston/wall clearance, and .026 clearance is way too big! meth is known for keeping motors together and keeping the chamber cool, not melting down pistons.

 

Do you mean that the excess oil on top the engine will cause extreem cyl pressure?

I still don't buy the theory of "methyl alcohol explodes spontaneously on motor oil", I need to see some facts first. At some point it will "detonate" but the presence of oil wont determin it, and it would be beyond the temp and pressure pump gas does -I bet.

 

Hey Ivan

Would you mine explaining the krank vent valves(dejon tool)?

 

A few posts up I mentioned I got the motor apart and everything measured good(correct measurement devices, bore gauge and such).

It was explained by people/tuners much smarted then me about the meth/oil problem. These are people that deal with methanol drag cars and their tuning/maintenance. One looked at the pictures and said if he is running methanol that would cause the detonation. This is without it ever being mentioned to him I was. The other is Justin Humphres crew chief, he confirmed it and also said they lost a cylinder in the drag car, just from dropping a valve guide and oil getting in the chamber.

I'm just relaying information that was given to me from people I trust.

Ivan

 

i run an RX7 and spray 100% methanol thru two M10 (1200 cc/minute) nozzles.

i add 1/2 oz of 2 cycle oil per gallon to my pump 93 at fillup... lubricates the apex seals.

i do not know if your problem comes from having alot more oil in your combustion chamber than my situation or whether you may not have reached the proper diagnosis.....

BUT

i have NO knock, 1190-1200 egts preturbo at 19 psi boost and am making above 500 rwhp w my custom made twin TO4 turbo setup. all w oil in my combustion chamber.

i run the Alkycontrol system and love it. good luck in straightening things out.

howard coleman

 

I think most agree that seeping oil from PVCC into intake combined with methanol will not influence detonation. All it does is raise the pressure of detonation and cools, so it does the opposite, oil or no oil

 

Methanol doesn't spontaneously combust when it comes in contact with engine oil any more than it does with gas. I will explain what probably happened if oil was a factor in the engine failure below.

When that oil mixes with the fuel in the combustion chamber you get a combustible fuel/oil mixture with a lower octane rating than the fuel by itself. When you're tuned for a given octane fuel and that octane rating drops you will have detonation. The fuel you're running could be gas, methanol, e85, etc. and it doesn't matter. What matters is you're putting a lower octane mixture in your combustion chamber than you're tuned for. Think of throwing 87 octane fuel in your tank and drag racing on your race gas or methanol tune.

The other issue that can come into play is if the oil gets on the plug more spark energy than usual is required to burn the fuel/oil mixture, just like when a plug gets fouled with gas. If you're running methanol you already need more spark energy than if you were running gas and perhaps adding the oil puts you over the edge and causes misfiring, but oil causing misfires is an issue in gas and methanol burning engines alike.

 

I was going to leave this along, but I'll bite. Let's see if we can agree on some things first. Methanol will pre-ignite on hot spots in the cylinder, agreed?
Ok, so we know it can and does violently pre-ignite on hot spots.

So how does the oil come into play. Well oil has a problem of leaving ash deposits when burnt. These ash deposits can form hot spots in the combustion chamber.
You can say I took items out of context, but how many people put detergent free oil in their engine. Last time I used deterget free oil was in an air compressor, I had to go and find it.

So we have hot spots generated from excess oil in the combustion chamber being burnt with the fuel. Thus providing methanol the opportunity to pre-ignite and distroy the piston.

Ivan