04-29-2023, 12:07 PM
(This post was last modified: 05-10-2023, 12:52 PM by Terry Bentley.)
Chapter 133
Shortly after returning from 7-11, we filled up on the M&M's and one soda each. It seemed like no time at all had passed before mom called us in for dinner. I didnt realize it was getting so late. So far not all that much had been accomplished, but some things were going back together.
Tonight mom had cleaned out the fridge and made soup from a mix of leftovers from the week. I could just taste the individual flavors from previous nights dinners. But now all mixed together was just about as good.
Chris was not at all shy about asking for seconds. I was surprised he had managed to go so long without talking. He must know it is not polite talking with your mouth full. Mom made corn bread muffins to go with the soup. The thick cakey ones this time that are so sweet. I love these, especially after layering on with lots of butter.
We went back outside and working on things again. OK really just now getting started working on things. While I didnt get an engine assembled yet, most of my time ended up explaining to Chris everything that had been done on them. His hands were all over the engine parts. He was careful handling them and making sure not to accidentally drop anything.
His questions were flying just a little faster than I was explaining everything. Chris finally realized he just needed to hold out for a few seconds before asking every question and most of them would be answered. He lifted up his engine block to the light and looking all over trying to figure out some things for himself.
Terry, what is the difference between two and four stroke engines? Paul acts like our kart engines are all complicated and scared to even touch one. He freaks out when pouring gas in the tank too. He has to think about which gas can to use. Just in case he grabbed the wrong one without oil mixed in.
How in the world does my engine keep from locking up with the oil mixed so thin with gas? I dont understand how that works. I mean Paul is always checking his equipment making sure it is not low on oil. He complains about none of his customers bother to do that when they rent the equipment.
He says they let the oil get low and engine locks up or rod seizes on crankshaft. How does a two stroke engine stay oiled if it is mixed like water thin? This makes no sense to me. Terry, I can not figure this out. What am I missing? Is there that much difference in two and four stroke engines?
Chris that is a mystery to me too. I have messed around with small engines for a long time, and I dont get it either. Me and Steve have destroyed plenty of them letting the crankcase get too low on oil. I mean there is still an oil film on everything, but usually only one part is all messed up. Like Paul told you when the rod seizes.
I know there are special oils for like boat motors, but those can also use plain old motor oil too. So the same oil in a car mixes with gas and runs in a two stroke engine without anything trashing out. Hmmm.
Chris had walked over to the shelf against the wall and grabbed a gas can then shaking it. He remove the cap and taking a sniff. Is there oil mixed in here?
Yea Chris, that is what I have to use when messing around with some of my junk. Hey, Terry, you got any unmixed gas in a can? Sure, its that other one sitting there, the plain looking can without an X.
What is the big X for?
What is the middle letter in miXed?
Oh, never mind.
Chris opened up the first gas can after shaking and looked in there. Then picked up the unmixed gas, doing the same thing again. Hey, what kind of oil are you guys running?
Either Steens or outboard motor oil from Shell. The blue looking stuff. That gas there just has regular 30W motor oil mixed in.
Its hard to tell by the color which one is which here. But when I shake the mixed gas it stays all foamed up. This other can doesnt do that. So is this a good way to make sure of which one you want to use? Or am I missing something?
I was not sure what Chris was talking about, so went over and repeated what he just did with the two gas cans. Sure enough there was a big difference when the mixed gas foamed up and the other did almost nothing. Wow Chris, I did not realize that. I am going to keep an eye on this to make sure it is the same way for different mixed oils.
Chris had a big gleam on his face. Seems he had discovered something I didnt know about. Hey Terry, where is your racing gas? Do you have any of it mixed up? Over there by the karts, the two cans sitting side by side. Both of them should have some left in there.
Chris repeated the same thing and noticed this mixed gas did the same and foamed up for a few seconds. Well this gas does the same thing too. But since it has blue oil mixed in, I guess makes things very obvious. Not at all like regular motor oil. OK I am satisfied for now. So whats the difference?
One has oil mixed in and the other one doesnt. I thought you figured that out already. No, not that. What the difference in the engines? Why is one two and the other one four? It cant just be oil in the gas. That doesnt make any sense to me.
Oh sorry Chris, yea there is a big difference in them. Have you not seen a four stroke engine torn apart before? You did tell me the intake manifold was removed from your engine. So you saw what that looks like inside.
Yes, it got loose so I wanted to see what was inside of my engine. I had no idea of what is was supposed to look like or what the parts were. I dont have a clue about a four stroke engine. Are they like completely different from each other?
Well they share a lot of the same components. But there is a ton more parts on a four stroke. Hey let me show you what one looks like. I have plenty of them torn down in here.
A quick detour around the other side on the Model A, I reached down to grab something sitting in a box full of parts. Then retrieved an engine that had a lot of the bolt on stuff already removed.
Look here Chris, the cylinder head, carburetor and shroud have been taken off this edger engine. Does it look anything like the insides of your kart engine?
Heck no, not really. But the head does not come off of my engine either. So I have not seen what it looks like up there. Oh, wait a minute, I was looking at my parts a while ago. Yes sort of looks the same, but some big differences. Like the piston is flat on this engine here. Mine has that crown deflector thing you were showing me the difference between the two pistons on our engines. How one has a little bit more compression than the other.
What are these other things next to the piston?
Those are valves. The bigger one is intake and the other is exhaust. So for the next 30 minutes I explained the differences and similarities between the types of engines. Chris seemed to absorb most of the things I explained to him. Not so many questions this time.
So how does gas get in the engine? The carburetor sort of sits lower than the valves.
Instead of an explanation, I grabbed his hand and layed it flat on top of engine covering over the piston. Then rotated the flywheel over enough for the palm of his hand to get sucked down tight on of the block. You get it now Chris?
Chris pulled his hand away quickly and turning it over to see a big red ring in center of his palm. That sort of smarts a little bit. Now my hand is all red. I bet that can pull the blood right thru my skin if I kept doing that.
Before you ask about the exhaust, it works just the opposite. Instead of suction, when piston is going back up, the pressure pushes burnt gases out when the other valve opens. Everything make sense now? Simple enough dont you think?
Yes sort of, I think. But now I am even more puzzled about how my kart engine works. There is no crankcase full of oil, no valves, or that other shaft thingy that turns the valves. The caming shaft, or something you called it. One more thing I dont get. My kart engine has fuel going in from the bottom and gas is all over the crankshaft. Nothing like that on this other engine. Everything is separate.
After reading about how a 4 stroke engine works in the school library and now seeing the real parts, I am starting to figure things out more. But also more confused. So first the piston goes down and sucks air in mixed with gas. OK next you gotta explain to me how a carburetor works.
How does the piston know when to go down first? This gets complicated.
OK the piston goes down and sucks air and gas in when the intake valve opens. So that is the intake stroke. Then piston comes back up but now both valves are closed. This is the compression stroke. When the piston gets to the top, then spark plug ignites the mixture. This causes the piston to go down a lot faster, so it is the power stroke.
Starting to make sense now. The exhaust valve opens up and piston pushes out the burnt gasses. Everything starts all over again. Do you have an engine torn apart I can look at the insides?
After some more digging I found one project with the side cover already removed. Inside the crankcase Chris was able to see the camshaft in action and how the lobes open and closed the valves controlled by the gear on crankshaft.
Hey Chris, why dont you play around with those engines for a while. I need to get back working on some things before our engines can be put back together.
I am sorry Terry, but this is something that has been bugging me like crazy. And nobody so far has been able to tell me anything. Now that I see the inside parts, everything is making more sense. After all that reading, I was not expecting this to be so complicated. But it really isnt so much. Well it is on some things, but now other stuff is more clear.
No problem, I can answer some questions while getting these engines ready to bolt back together. You have everything right there to see the differences now. Give me a few minutes to make sure I have all the bugs worked out here. I dont see much chance our engines will be put back together tonight anyway. I almost forgot about this here. But do need to machine a piston on the lathe.
While Chris was mesmorized rotating the partially torn apart engine over, I got back focused on the E-65 piston. The one I filled the two lower grooves in with the dummy rings and epoxy. I removed the hose clamp and layer of wax paper. Then noticed the epoxy had dried good and hard. And very grey.
To machine the piston diameter and removing the excess material, I first chucked up the fixture plate made for boring out the carburetors. But did not need the adjustable top plate that carburetor bolted directly to.
The piston just needed a flat surface to push against on the skirt. There was already a small center drilled indention in top of the piston. This must be similar to how these pistons were originally machined.
I held piston against the flat piece chucked up and ran the tailstock up to center drilled spot of piston deflector. After rolling the chuck over by hand I saw the piston was running perfectly true.
Flipping the power-on switch, my little lathe was spinning the piston and ready to make a cut then clean up the ring area. A few light passes later, there was two thick shiny circles around the piston that now blended in nicely with the sides.
I noticed Chris was still heavily involved with the partially disassembled edger engine and the other one with the guts hanging out. Guess that is why he was not over here watching what was going on. Hey Chris, wanna check this out before I remove it from the lathe?
HUH? Oh yea, hold on. So what did you do? He stared down trying to figure out why I was machining the piston. Are you going to cut more ring grooves there where its all shiny?
Nope, just the opposite. Those are filled in with blanks and epoxy so they dont come loose. I am trying this out on my engine, so you guys dont loose yours if it dont work so well. No reason to buy a new high dollar racing piston if this works just as good.
Do you think it is going to work?
Heck if I know. Right now your guess is as good as mine.
Terry you have a lot more guessing knowledge about this stuff than I ever will. Mine would be useless. But sure will be cool if it does work out. So why are you doing it?
Well there is no reason to have three rings on a piston for racing. If the ring is sealing like supposed to, then should be no less compression with just one of them. If the engine is built for only reliability to run a long time, then having more rings makes perfect sense.
The piston you showed me out of my engine only has two rings. Does that help any? Or not so much yet?
Did you notice how thick those rings are? Your two piston rings are 3/32" of an inch thick. This E-65 piston has three rings and only 1/16" each. But that works out as the same amount of surface area pushing against the cylinder. I thought about doing the same thing with the stock piston at first. But this E-65 piston also ups the compression a little bit more. Then getting rid of these two rings, and wallah, instant racing piston. Well more or less, something like that, if it works.
This is just one more thing that saves money doing the work myself. But if it doesnt work, I am not out anything. I also found out something that most people could not care any less about. Guess it is too much trouble for most people if they can just buy a particular racing part for not so much money. If you cant find parts to make an engine faster, that leaves two choices. Make your own parts or change engines.
If these Clintons could produce some better horsepower, there would be a lot more racing parts available for them. But since it has a bushing on the rod, there are limits to how much you can do without them blowing up. Besides who wants to spend a lot of money on an engine to make it a little bit faster when you could just buy one already a whole lot faster right out of the box?
Its makes more sense bolting racing parts on an engine that is capable of making a lot more power and not turning to shrapnel. I also think its cool trying to make our Clintons run a little bit faster without them blowing up. At least for a while anyway.
Do you see in the kart mags how many different companies making all kinds of racing parts? McCullochs are super strong and can really be modified a bunch. You can buy so many racing parts for them, the Power Products, and Westbends.
Are you finished with this piston Terry? Can I compare it to the one going in my engine? Chris put a lot of torque on his brain cells trying to understand everything we were talking about. Shaking his head like satisfied, but still had a puzzled look on his face.
There is another thing I still dont get. Its about the four stroke engine needing thick oil or it locks up. My engine has gas going all over the same looking parts, and you cant even tell there is any oil mixed in. Well maybe after the gas evaporates, you can sort of feel something slippery. But even then, it doesnt seem to be enough to do any good.
When Chris mentioned about the gas evaporating, something clicked in my head. Hey Chris, I think you might have it. The gas is evaporating, well sort of, but the oil ends up sticking on the moving parts. This is making some sense to me.
Me and Steve had blown up a lawn mower engine a while back. There was a big hole in side of the block. The oil was almost like a mist or fog when engine was running. It covered over everything inside and outside of engine. So until that oil film was gone, that engine didnt blow up.
On our kart engines, the gas vapor carrying oil is coating every moving part. That gas vapor is sort of being carried along mixed with air. The oil is heavy and separates quick enough when passing over the moving parts. Most of the oil is lubricating the internal parts. As more fuel passes thru it sort of washes the old oil away while leaving fresh in its place. OK that might not be exactly how it all works. But you get the idea.
So the gas vaporizing is also cooling the internal parts as engine heats up from spark plug igniting the mix under a lot of pressure. Oil film is left while the gas burns away. So long as heat is controlled, then less chance of engine failure. A few things have to be right for all of this to work, but this might be close to the reason why a two stroke survives.
Basically the same thing on a four stroke, except less chance of controlling the internal heat without the fuel vapor passing thru. The oil is doing the same until heating up too much then lubricating film breaks down. It only takes a split second then the rod gawls up and welds to crankshaft.
Maybe this is whats going on. That could explain why leaning down the carburetor too much causing the engine to overheat and oil film is lost. I dont know for sure, but figure it has to be something close to this. I will run this by the Power Mechanics shop teacher next week at school and find out what he can tell me. You got my curiosity up now.
Wow Terry, that almost makes sense. Chris then went into total think mode. He was now sitting on a stool with legs crossed. An elbow dug in just before his knee and chin cradled in open palm of hand. He also had that thinking type smirk on his face too.
OK I sort of understand how the two stroke engine works compared to the four stroke engine. It is still confusing how when the intake ports open and blast in all that pressurized air mixed with gas. How come it doesnt catch on fire since the burnt gasses are being pushed out at the same time.
When my engine is running, I see all of that fire shooting out the exhaust header. So how come the fire doesnt mess with that fresh gas coming in just after the exhaust starts leaving. It seems dangerous to me. If something is not just right could it blow up?
Hey Terry, one more thing I dont get. I dont understand between strokes and cycles. Does a four stroke engine actually have to turn four strokes. I mean there is intake, compression, power and exhaust. But arent those cycles? Does a stroke make a full circle?
A two stroke engine would have two cycles not strokes. Wouldnt that really be a single stroke two cycle engine? So that would also mean two stroke four cycle engine.
Well now you got me confused. Let me think on that. No, a stroke is the full length of the piston travel from top to bottom. So a stroke is only half of a full circle. So I guess you can use either stroke or cycle and is correct. A two stroke or two cycle is the same thing.
While Chris was still putting too much thought in all of this, my focus went to the mower engine on the work bench he had been playing with. Something got those gears working in my head. This is not good. Well it is but also distracts from where my brain should be concentrating.
Hey Chris, I gots me an idea! Something that might help figure out what we have been talking about. And something super cool to try out just because. Well because I have no idea if it will even work. But I so gotta try it now after thinking about all this stuff tonight.
Shortly after returning from 7-11, we filled up on the M&M's and one soda each. It seemed like no time at all had passed before mom called us in for dinner. I didnt realize it was getting so late. So far not all that much had been accomplished, but some things were going back together.
Tonight mom had cleaned out the fridge and made soup from a mix of leftovers from the week. I could just taste the individual flavors from previous nights dinners. But now all mixed together was just about as good.
Chris was not at all shy about asking for seconds. I was surprised he had managed to go so long without talking. He must know it is not polite talking with your mouth full. Mom made corn bread muffins to go with the soup. The thick cakey ones this time that are so sweet. I love these, especially after layering on with lots of butter.
We went back outside and working on things again. OK really just now getting started working on things. While I didnt get an engine assembled yet, most of my time ended up explaining to Chris everything that had been done on them. His hands were all over the engine parts. He was careful handling them and making sure not to accidentally drop anything.
His questions were flying just a little faster than I was explaining everything. Chris finally realized he just needed to hold out for a few seconds before asking every question and most of them would be answered. He lifted up his engine block to the light and looking all over trying to figure out some things for himself.
Terry, what is the difference between two and four stroke engines? Paul acts like our kart engines are all complicated and scared to even touch one. He freaks out when pouring gas in the tank too. He has to think about which gas can to use. Just in case he grabbed the wrong one without oil mixed in.
How in the world does my engine keep from locking up with the oil mixed so thin with gas? I dont understand how that works. I mean Paul is always checking his equipment making sure it is not low on oil. He complains about none of his customers bother to do that when they rent the equipment.
He says they let the oil get low and engine locks up or rod seizes on crankshaft. How does a two stroke engine stay oiled if it is mixed like water thin? This makes no sense to me. Terry, I can not figure this out. What am I missing? Is there that much difference in two and four stroke engines?
Chris that is a mystery to me too. I have messed around with small engines for a long time, and I dont get it either. Me and Steve have destroyed plenty of them letting the crankcase get too low on oil. I mean there is still an oil film on everything, but usually only one part is all messed up. Like Paul told you when the rod seizes.
I know there are special oils for like boat motors, but those can also use plain old motor oil too. So the same oil in a car mixes with gas and runs in a two stroke engine without anything trashing out. Hmmm.
Chris had walked over to the shelf against the wall and grabbed a gas can then shaking it. He remove the cap and taking a sniff. Is there oil mixed in here?
Yea Chris, that is what I have to use when messing around with some of my junk. Hey, Terry, you got any unmixed gas in a can? Sure, its that other one sitting there, the plain looking can without an X.
What is the big X for?
What is the middle letter in miXed?
Oh, never mind.
Chris opened up the first gas can after shaking and looked in there. Then picked up the unmixed gas, doing the same thing again. Hey, what kind of oil are you guys running?
Either Steens or outboard motor oil from Shell. The blue looking stuff. That gas there just has regular 30W motor oil mixed in.
Its hard to tell by the color which one is which here. But when I shake the mixed gas it stays all foamed up. This other can doesnt do that. So is this a good way to make sure of which one you want to use? Or am I missing something?
I was not sure what Chris was talking about, so went over and repeated what he just did with the two gas cans. Sure enough there was a big difference when the mixed gas foamed up and the other did almost nothing. Wow Chris, I did not realize that. I am going to keep an eye on this to make sure it is the same way for different mixed oils.
Chris had a big gleam on his face. Seems he had discovered something I didnt know about. Hey Terry, where is your racing gas? Do you have any of it mixed up? Over there by the karts, the two cans sitting side by side. Both of them should have some left in there.
Chris repeated the same thing and noticed this mixed gas did the same and foamed up for a few seconds. Well this gas does the same thing too. But since it has blue oil mixed in, I guess makes things very obvious. Not at all like regular motor oil. OK I am satisfied for now. So whats the difference?
One has oil mixed in and the other one doesnt. I thought you figured that out already. No, not that. What the difference in the engines? Why is one two and the other one four? It cant just be oil in the gas. That doesnt make any sense to me.
Oh sorry Chris, yea there is a big difference in them. Have you not seen a four stroke engine torn apart before? You did tell me the intake manifold was removed from your engine. So you saw what that looks like inside.
Yes, it got loose so I wanted to see what was inside of my engine. I had no idea of what is was supposed to look like or what the parts were. I dont have a clue about a four stroke engine. Are they like completely different from each other?
Well they share a lot of the same components. But there is a ton more parts on a four stroke. Hey let me show you what one looks like. I have plenty of them torn down in here.
A quick detour around the other side on the Model A, I reached down to grab something sitting in a box full of parts. Then retrieved an engine that had a lot of the bolt on stuff already removed.
Look here Chris, the cylinder head, carburetor and shroud have been taken off this edger engine. Does it look anything like the insides of your kart engine?
Heck no, not really. But the head does not come off of my engine either. So I have not seen what it looks like up there. Oh, wait a minute, I was looking at my parts a while ago. Yes sort of looks the same, but some big differences. Like the piston is flat on this engine here. Mine has that crown deflector thing you were showing me the difference between the two pistons on our engines. How one has a little bit more compression than the other.
What are these other things next to the piston?
Those are valves. The bigger one is intake and the other is exhaust. So for the next 30 minutes I explained the differences and similarities between the types of engines. Chris seemed to absorb most of the things I explained to him. Not so many questions this time.
So how does gas get in the engine? The carburetor sort of sits lower than the valves.
Instead of an explanation, I grabbed his hand and layed it flat on top of engine covering over the piston. Then rotated the flywheel over enough for the palm of his hand to get sucked down tight on of the block. You get it now Chris?
Chris pulled his hand away quickly and turning it over to see a big red ring in center of his palm. That sort of smarts a little bit. Now my hand is all red. I bet that can pull the blood right thru my skin if I kept doing that.
Before you ask about the exhaust, it works just the opposite. Instead of suction, when piston is going back up, the pressure pushes burnt gases out when the other valve opens. Everything make sense now? Simple enough dont you think?
Yes sort of, I think. But now I am even more puzzled about how my kart engine works. There is no crankcase full of oil, no valves, or that other shaft thingy that turns the valves. The caming shaft, or something you called it. One more thing I dont get. My kart engine has fuel going in from the bottom and gas is all over the crankshaft. Nothing like that on this other engine. Everything is separate.
After reading about how a 4 stroke engine works in the school library and now seeing the real parts, I am starting to figure things out more. But also more confused. So first the piston goes down and sucks air in mixed with gas. OK next you gotta explain to me how a carburetor works.
How does the piston know when to go down first? This gets complicated.
OK the piston goes down and sucks air and gas in when the intake valve opens. So that is the intake stroke. Then piston comes back up but now both valves are closed. This is the compression stroke. When the piston gets to the top, then spark plug ignites the mixture. This causes the piston to go down a lot faster, so it is the power stroke.
Starting to make sense now. The exhaust valve opens up and piston pushes out the burnt gasses. Everything starts all over again. Do you have an engine torn apart I can look at the insides?
After some more digging I found one project with the side cover already removed. Inside the crankcase Chris was able to see the camshaft in action and how the lobes open and closed the valves controlled by the gear on crankshaft.
Hey Chris, why dont you play around with those engines for a while. I need to get back working on some things before our engines can be put back together.
I am sorry Terry, but this is something that has been bugging me like crazy. And nobody so far has been able to tell me anything. Now that I see the inside parts, everything is making more sense. After all that reading, I was not expecting this to be so complicated. But it really isnt so much. Well it is on some things, but now other stuff is more clear.
No problem, I can answer some questions while getting these engines ready to bolt back together. You have everything right there to see the differences now. Give me a few minutes to make sure I have all the bugs worked out here. I dont see much chance our engines will be put back together tonight anyway. I almost forgot about this here. But do need to machine a piston on the lathe.
While Chris was mesmorized rotating the partially torn apart engine over, I got back focused on the E-65 piston. The one I filled the two lower grooves in with the dummy rings and epoxy. I removed the hose clamp and layer of wax paper. Then noticed the epoxy had dried good and hard. And very grey.
To machine the piston diameter and removing the excess material, I first chucked up the fixture plate made for boring out the carburetors. But did not need the adjustable top plate that carburetor bolted directly to.
The piston just needed a flat surface to push against on the skirt. There was already a small center drilled indention in top of the piston. This must be similar to how these pistons were originally machined.
I held piston against the flat piece chucked up and ran the tailstock up to center drilled spot of piston deflector. After rolling the chuck over by hand I saw the piston was running perfectly true.
Flipping the power-on switch, my little lathe was spinning the piston and ready to make a cut then clean up the ring area. A few light passes later, there was two thick shiny circles around the piston that now blended in nicely with the sides.
I noticed Chris was still heavily involved with the partially disassembled edger engine and the other one with the guts hanging out. Guess that is why he was not over here watching what was going on. Hey Chris, wanna check this out before I remove it from the lathe?
HUH? Oh yea, hold on. So what did you do? He stared down trying to figure out why I was machining the piston. Are you going to cut more ring grooves there where its all shiny?
Nope, just the opposite. Those are filled in with blanks and epoxy so they dont come loose. I am trying this out on my engine, so you guys dont loose yours if it dont work so well. No reason to buy a new high dollar racing piston if this works just as good.
Do you think it is going to work?
Heck if I know. Right now your guess is as good as mine.
Terry you have a lot more guessing knowledge about this stuff than I ever will. Mine would be useless. But sure will be cool if it does work out. So why are you doing it?
Well there is no reason to have three rings on a piston for racing. If the ring is sealing like supposed to, then should be no less compression with just one of them. If the engine is built for only reliability to run a long time, then having more rings makes perfect sense.
The piston you showed me out of my engine only has two rings. Does that help any? Or not so much yet?
Did you notice how thick those rings are? Your two piston rings are 3/32" of an inch thick. This E-65 piston has three rings and only 1/16" each. But that works out as the same amount of surface area pushing against the cylinder. I thought about doing the same thing with the stock piston at first. But this E-65 piston also ups the compression a little bit more. Then getting rid of these two rings, and wallah, instant racing piston. Well more or less, something like that, if it works.
This is just one more thing that saves money doing the work myself. But if it doesnt work, I am not out anything. I also found out something that most people could not care any less about. Guess it is too much trouble for most people if they can just buy a particular racing part for not so much money. If you cant find parts to make an engine faster, that leaves two choices. Make your own parts or change engines.
If these Clintons could produce some better horsepower, there would be a lot more racing parts available for them. But since it has a bushing on the rod, there are limits to how much you can do without them blowing up. Besides who wants to spend a lot of money on an engine to make it a little bit faster when you could just buy one already a whole lot faster right out of the box?
Its makes more sense bolting racing parts on an engine that is capable of making a lot more power and not turning to shrapnel. I also think its cool trying to make our Clintons run a little bit faster without them blowing up. At least for a while anyway.
Do you see in the kart mags how many different companies making all kinds of racing parts? McCullochs are super strong and can really be modified a bunch. You can buy so many racing parts for them, the Power Products, and Westbends.
Are you finished with this piston Terry? Can I compare it to the one going in my engine? Chris put a lot of torque on his brain cells trying to understand everything we were talking about. Shaking his head like satisfied, but still had a puzzled look on his face.
There is another thing I still dont get. Its about the four stroke engine needing thick oil or it locks up. My engine has gas going all over the same looking parts, and you cant even tell there is any oil mixed in. Well maybe after the gas evaporates, you can sort of feel something slippery. But even then, it doesnt seem to be enough to do any good.
When Chris mentioned about the gas evaporating, something clicked in my head. Hey Chris, I think you might have it. The gas is evaporating, well sort of, but the oil ends up sticking on the moving parts. This is making some sense to me.
Me and Steve had blown up a lawn mower engine a while back. There was a big hole in side of the block. The oil was almost like a mist or fog when engine was running. It covered over everything inside and outside of engine. So until that oil film was gone, that engine didnt blow up.
On our kart engines, the gas vapor carrying oil is coating every moving part. That gas vapor is sort of being carried along mixed with air. The oil is heavy and separates quick enough when passing over the moving parts. Most of the oil is lubricating the internal parts. As more fuel passes thru it sort of washes the old oil away while leaving fresh in its place. OK that might not be exactly how it all works. But you get the idea.
So the gas vaporizing is also cooling the internal parts as engine heats up from spark plug igniting the mix under a lot of pressure. Oil film is left while the gas burns away. So long as heat is controlled, then less chance of engine failure. A few things have to be right for all of this to work, but this might be close to the reason why a two stroke survives.
Basically the same thing on a four stroke, except less chance of controlling the internal heat without the fuel vapor passing thru. The oil is doing the same until heating up too much then lubricating film breaks down. It only takes a split second then the rod gawls up and welds to crankshaft.
Maybe this is whats going on. That could explain why leaning down the carburetor too much causing the engine to overheat and oil film is lost. I dont know for sure, but figure it has to be something close to this. I will run this by the Power Mechanics shop teacher next week at school and find out what he can tell me. You got my curiosity up now.
Wow Terry, that almost makes sense. Chris then went into total think mode. He was now sitting on a stool with legs crossed. An elbow dug in just before his knee and chin cradled in open palm of hand. He also had that thinking type smirk on his face too.
OK I sort of understand how the two stroke engine works compared to the four stroke engine. It is still confusing how when the intake ports open and blast in all that pressurized air mixed with gas. How come it doesnt catch on fire since the burnt gasses are being pushed out at the same time.
When my engine is running, I see all of that fire shooting out the exhaust header. So how come the fire doesnt mess with that fresh gas coming in just after the exhaust starts leaving. It seems dangerous to me. If something is not just right could it blow up?
Hey Terry, one more thing I dont get. I dont understand between strokes and cycles. Does a four stroke engine actually have to turn four strokes. I mean there is intake, compression, power and exhaust. But arent those cycles? Does a stroke make a full circle?
A two stroke engine would have two cycles not strokes. Wouldnt that really be a single stroke two cycle engine? So that would also mean two stroke four cycle engine.
Well now you got me confused. Let me think on that. No, a stroke is the full length of the piston travel from top to bottom. So a stroke is only half of a full circle. So I guess you can use either stroke or cycle and is correct. A two stroke or two cycle is the same thing.
While Chris was still putting too much thought in all of this, my focus went to the mower engine on the work bench he had been playing with. Something got those gears working in my head. This is not good. Well it is but also distracts from where my brain should be concentrating.
Hey Chris, I gots me an idea! Something that might help figure out what we have been talking about. And something super cool to try out just because. Well because I have no idea if it will even work. But I so gotta try it now after thinking about all this stuff tonight.