my v4, How to make oil scraper ring?

[sition]

My V4 is 3.5cc. How can I make a scraper ring? Smoking is really annoying.

Sorry I can't publish piston pictures.

 

[sition]

I'm making a V4 engine. It works at 90 degrees.

 

[sition]

I made an oil pump and sprayed the lubricant onto the crankshaft for splash lubrication.

 

[Cogsy]

What are the dimensions of your piston? I'm building a ~10cc V4 and I thought that was getting pretty small, 3.5cc sounds very tiny. How many rings per cylinder do you have at the moment?

 

[sition]

What are the dimensions of your piston? I'm building a ~10cc V4 and I thought that was getting pretty small, 3.5cc sounds very tiny. How many rings per cylinder do you have at the moment?

Single cylinder 3.5cc total 3.5*4

Two rings at present

 

[Cogsy]

Ahh, about the same size then. Maybe you could add a third ring below the gudgeon/wrist pin but possibly you are overwhelming your rings with oil. The V4 I'm building uses a dipper on the bottom of each conrod for simple splash lubrication. I can't say on my model as it's not finished, but I have not seen a smoking issue with other peoples' builds of the same engine. Maybe try reducing the amount of oil spraying onto the crank.

 

[Hopper]

As well as reducing oil supply, you could look at putting on a crankcase breather with reed valve so crankcase pressure can escape but air can not be sucked back in.

 

[sition]

Ahh, about the same size then. Maybe you could add a third ring below the gudgeon/wrist pin but possibly you are overwhelming your rings with oil. The V4 I'm building uses a dipper on the bottom of each conrod for simple splash lubrication. I can't say on my model as it's not finished, but I have not seen a smoking issue with other peoples' builds of the same engine. Maybe try reducing the amount of oil spraying onto the crank.

I tried to reduce it, but the cylinder on the left has almost no lubricant, and the cylinder on the right has normal lubricant. If a ring is added, will the resistance be greater? The displacement of 3.5CC is uncertain whether these resistance can be overcome well. Thank you very much

 

[sition]

As well as reducing oil supply, you could look at putting on a crankcase breather with reed valve so crankcase pressure can escape but air can not be sucked back in.

When there is no spark plug, turn the crankshaft and the ventilator has no gas. When there is a spark plug, the gas is blown out. Are these gases leaking from the piston? Is there no negative pressure in the ventilator? Thank you

 

[WOB]

When there is no spark plug, turn the crankshaft and the ventilator has no gas. When there is a spark plug, the gas is blown out. Are these gases leaking from the piston? Is there no negative pressure in the ventilator? Thank you

It sounds like excessive ring leakage to me. That will cause crankcase pressure as well as oil burning. I suspect your rings are not sealing well. I'm guessing your bore dia. is between 1 and 1.5 cm. Making rings that seal well at that small size is very difficult. I would suggest lapped pistons rather than rings as a cure.

WOB

 

[sition]

It sounds like excessive ring leakage to me. That will cause crankcase pressure as well as oil burning. I suspect your rings are not sealing well. I'm guessing your bore dia. is between 1 and 1.5 cm. Making rings that seal well at that small size is very difficult. I would suggest lapped pistons rather than rings as a cure.

WOB

O-ring Seal Is it suitable for high speed?

Thank you

 

[editor123]

O-ring Seal Is it suitable for high speed?

Thank you

No, they will melt.

 

[Cogsy]

I believe the Tiny inline 4 uses o-rings as piston rings successfully. Your bores are going to need to be super smooth though.

 

[sition]

I believe the Tiny inline 4 uses o-rings as piston rings successfully. Your bores are going to need to be super smooth though.

Nice, thank you. What is the maximum speed?

 

[Cogsy]

The Tiny inline 4 revs to very high RPM but I don't know the surface speed of the orings.

 

[necowboy]

Heavy oil consumption can also be caused by a lack of valve seals, particularly on the exhaust valve.
Exhaust gases rushing past the valve guide cause a low pressure around the valve guide.

 

[sition]

The Tiny inline 4 revs to very high RPM but I don't know the surface speed of the orings.

Are there any running videos? Thank you

 

[sition]

Heavy oil consumption can also be caused by a lack of valve seals, particularly on the exhaust valve.
Exhaust gases rushing past the valve guide cause a low pressure around the valve guide.

Yes, I didn't make valve oil seals. The valves are very small. What can you do to make such small valve seals?

 

[Cogsy]

I don't get what you mean - it is running in that video. If you search 'Tiny Inline 4' on Youtube you should get plenty of other videos.

 

[sition]

I don't get what you mean - it is running in that video. If you search 'Tiny Inline 4' on Youtube you should get plenty of other videos.

Good. Have you tried to run for a long time? Great L4