Why Massive amounts of methanol getting into crankcase?

[Scarface5029]

I changed cams a couple a weeks ago to a bigger lift and duration cam and ever since I did that I started having a lot of methanol getting into crankcase, so much so that fresh oil will turn almost white after one warm up run on the stand, what is going on here? The motor runs great but having to change the oil after every time I start it and shut it off it is getting expensive. I didn’t have a problem with methanol getting into the oil (it would some but not much and not enough to change the color of the oil) with the old cam but I don’t see how changing the cam could cause this. Almost Everything is the same with the engine, the only components I changed was the cam, push rods and valve springs. Any ideas? I know worn rings or blown head gasket can cause this but shouldn’t it have been doing the same thing with the old cam if either one or both of these are the problem?

 

[One Fast Kat]

Just a Thought, Changing the cam can change the pulse signal in your carb.

 

[racinnut15xm]

I changed cams a couple a weeks ago to a bigger lift and duration cam and ever since I did that I started having a lot of methanol getting into crankcase, so much so that fresh oil will turn almost white after one warm up run on the stand, what is going on here? The motor runs great but having to change the oil after every time I start it and shut it off it is getting expensive. I didn’t have a problem with methanol getting into the oil (it would some but not much and not enough to change the color of the oil) with the old cam but I don’t see how changing the cam could cause this. Almost Everything is the same with the engine, the only components I changed was the cam, push rods and valve springs. Any ideas? I know worn rings or blown head gasket can cause this but shouldn’t it have been doing the same thing with the old cam if either one or both of these are the problem?

Quit starting it in the shop and not getting it up to temp, it will burn it off/evaporate when run hard and the oil is up to temp. Methanol is rough on cylinder walls, once you are done with it start it on 2 stroke gas mix and run all the methanol out. Also when you make any changes on an engine you change the demand for fuel and maybe timing

 

[spincycle]

Trying to think it thru logically, if you went to more duration and lift, obviously that's more time for the piston to draw more fuel into the cylinder...maybe you need more timing advance to allow for more time to burn all that excess fuel? Or maybe need to close up the mixture needles a bit? Or maybe valve guides need to be replaced? Or maybe need to have a cylinder leak down test (excess fuel getting past rings)? Not an engine guru by any means, but maybe some things to take a closer look at....

 

[spincycle]

Also you'll want to check the gasket that sits underneath the plate that the valve springs sit on...

 

[Scarface5029]

Trying to think it thru logically, if you went to more duration and lift, obviously that's more time for the piston to draw more fuel into the cylinder...maybe you need more timing advance to allow for more time to burn all that excess fuel? Or maybe need to close up the mixture needles a bit? Or maybe valve guides need to be replaced? Or maybe need to have a cylinder leak down test (excess fuel getting past rings)? Not an engine guru by any means, but maybe some things to take a closer look

Just a Thought, Changing the cam can change the pulse signal in your carb.

 

[Scarface5029]

I’m pretty sure it’s coming from the intake valve guide and worn rings also, I had planned on putting in bronze guides anyways so now is as good a time as any. Thanks for the responses everyone.

 

[Skidude]

What carb are you running? If a Tillotson, you’re going to get excessive cylinder wash at low RPM. They need to idle little run hard a lot. If a Mikuni or Walbro, you need to check your carb. And as for your oil turning white, that doesn’t sound right. What oil are you using. You should be using an oil that is compatible with alcohol such as FHS or Cool Power.

 

[Scarface5029]

What carb are you running? If a Tillotson, you’re going to get excessive cylinder wash at low RPM. They need to idle little run hard a lot. If a Mikuni or Walbro, you need to check your carb. And as for your oil turning white, that doesn’t sound right. What oil are you using. You should be using an oil that is compatible with alcohol such as FHS or Cool Power.

It’s a chikuni 22mm and running vr1 oil and is made for engines running on alcohols. It’s just weird to me how I’ve been running it the last couple months whether on the stand or on the track with no issues with the oil turning white and as soon as I change the cam is when the problem started, even if the new cam is causing more pulsing form the carb or letting more fuel in I wouldn’t think it would make that much of a difference but apparently it does, as I mentioned above I’m going to go ahead and put new rings in and probably get the cylinder honed by a professional shop and then put new guides in and that should help imo.

 

[flattop1]

Have you measured what you put in vs what comes out ?
If you put in 14 and 16 comes out that's a concern . If it's 14 in and thirteen out then it's a oil issue .

 

[mike97760]

Dont discount the fact even a little 22mm carb is quite a bit bigger than the stock carb right off the bat

 

[Bodydropped]

Vr1 is car oil not karting. Most car oil won’t mix with alky. Karting oils will mix and some time flash off the alky out ofnit

 

[Scarface5029]

Have you measured what you put in vs what comes out ?
If you put in 14 and 16 comes out that's a concern . If it's 14 in and thirteen out then it's a oil issue .

I have not checked it but I will the next oil change. Again though I’m using the same oil with this cam as I have been the last two months with the dyno cm cam and the oil always looked more or less clean after a race day, it wasn’t grey and definitely not white lol.

 

[Scarface5029]

Vr1 is car oil not karting. Most car oil won’t mix with alky. Karting oils will mix and some time flash off the alky out ofnit

I know it isn’t for karts but it is formulated for engines running on alcohol’s and I have been running it almost two months with the cm cam on methanol with no issues turning white or grey, unfortunately I do not have anywhere nearby to get kart specific oil so I stop by napa and pick up the vr1 anytime I come through the nearby town.

 

[Scarface5029]

Dont discount the fact even a little 22mm carb is quite a bit bigger than the stock carb right off the bat

I’ve been running the 22mm chikuni the last month or so with the dyno cm cam without any oil issue though, as I said in my first post everything except the cam, springs, and push rods are the same as they were with the cm cam. I did have to clearance the cam and deepen the piston valve reliefs but doubt that would be the problem. I have to say I do like the 22 chikuni, I see many people talking negative about it but It has worked great with my engine and was simple to tune to run on methanol and making good power from it.