01-12-2023, 11:55 PM
(This post was last modified: 03-05-2023, 04:22 AM by Terry Bentley.)
Chapter 124
During the week I had to make some very important decisions. I spent this morning talking to Mr Sadeskey about a couple of the issues that were plaguing me. The most difficult problem was deciding on what to do about the pistons and filling the empty ring grooves with something.
Mr Sadeskey rubbed his chin several times, then a couple more times. That is an interesting problem and an unusual solution. I have no idea about filling the ring grooves with some type of epoxy.
I dont see this as a long term fix. But in your case, it might do just fine. With all of the space rockets these days, I am sure there is some new technology already out there that should do the job. But I am not up to date for things like this.
The is nothing I can recollect reading anything of this nature in Popular Science or Popular Mechanics either. New fangled high temp epoxies would be something notable to cover in a article. But it escapes me as I try to remember.
Have you thought to inquire about this to Coach Rhimes? He does teach Physical Science and Biology. But I dont recall him actually having a specific degree in either field. Let me do some checking and see what I can find out.
There is one other thing with deciding to use the stock piston with both thick rings or attempt to fill the lower one like on the E-65 pistons. Again this is does depend on what he finds out about the epoxy.
For now the three of our engine blocks are ported exactly the same. I still plan to build up the modified engine originally on the Cates kart as a back up. But this will only happen if time allows.
I am satisfied with the original intake manifolds that have been modified to use the Go-Power six petal pyramid reed assembly. Steve did good when he bought the three cages. We finally get to find out just how well they work.
Only my engine will be used for testing the waters, like filling the ring grooves and the lightened flywheel at first. I also planned to advance the ignition timing a whole bunch on my one engine. From an article I read, it may be possible to really bump it up a lot. I figured with the compression so low, there should be a big buffer zone to work with.
Since we absolutely can not spin the guts out of a bushing engine like Frank tries to do with his deluxe model Westbend 580, I thought about a totally different direction to go. My plans are to use the lightened cast iron flywheel with most of the cooling fins machined off. Cut the shroud back roughly the amount of fins removed from flywheel. From my guesstimate that is somewhere around 1/2 inch to be sliced off of shroud.
This had already been done on the Cates engine. But I found out later after talking to Mr Cates something that he had not been aware of at the time. Mr Cates told me his stock cast iron flywheel had been sent to California to a big wig kart shop. They claimed massive gains with a lightened flywheel. This is right before the newer style aluminum flywheels were available.
He sent in the old flywheel and they shipped a lightened one right back to him. They already had these cut down ready to unload, I mean sell. But I found out over the summer there were several different weights of the cast iron flywheels. After a lot of cutting and weighing, I ended up with a light weight flywheel that still weighed more than the stock one.
It took some head scratching to figure out the cut flywheel was an older model and the fins were a lot thicker. It was very noticeable only after cutting down and comparing to the newer flywheel after it was also machined and sitting side by side. So Mr Cates only gained the loss of drag from cooling fins removed without any advantage to less rotating weight. This is the only reason why he had decided to lighten the flywheel in the first place. Just to lose the weight.
Mr Cates told me he did not bother to weigh the old flywheel before sending it off. But it still seemed to be just as heavy when the special cut down flywheel arrived a week later.
The one thing Mr Cates did attempt to explain to me is how well the port tuned exhaust worked. It was weather sensitive, but usually could be worked out by slight adjustments. So far I have not put aside the time to study up on his tuned exhaust. It looked just like a plain old rusty muffler to me by the time we found it.
There was an article in an older issue of some kart magazine. I dont even remember if it was Karting World, Racing Karts, KART or another issue. But after doing the calculations this article claimed the optimum pipe length for a Clinton engine would likely be close to 32 inches. This I laughed about before figuring things out. Where would you put that much pipe on a kart anyway? Maybe run it thru a frame rail or something?
After Steve found the old rusted exhaust out at the track several months later, it was not very impressive to look at. But I finally investigated the exhaust thing a lot closer. The larger diameter pipe bolted to the engine is about 11 to 12 inches long. Originally I thought this long of a pipe must be very restrictive. There is still so much about all of this I have absolutely no clue or understanding about.
This long pipe curves around and down under the engine then slides into the exhaust looking thingy. The muffler is about 4 inches in diameter and 10 inches long. The entry pipe I later realized travels the full length to a back compartment. What this does is now adds the overall length to almost 22 inches give or take an inch.
The next big surprise is discovering the exiting pipe extends around half the length of exhaust and sticks out a couple of inches. Now the overall length works out to right at that magic 32 inch number. Another unexpected surprise is the exiting pipe is even adjustable. I can lengthen or shorten almost two inches. One thing I could never get past is how small the exit pipe was. The outside diameter is right at one inch. One small inch does not seem like is big enough for any size engine.
So while I have been wrapping my brain cells around the engines to squeeze more horsepower out of them, all this time overlooking something that can be bolted over the exhaust ports and make more power without doing anything else. Is this Voodoo magic or what? Maybe just some good sales pitch.
There was also a major article in Karting World magazine covering mufflers for the engines. All of them based the findings against an open header. It made the most power. Some of the mufflers did kill the engine completely with dyno tests showing the drop in horsepower. So why would this big old rusty muffler make more power than an open header? Once again call me skeptical.
This exhaust is one thing I have been wanting to test out. But so far is the last thing on my mind every time. Suppose I quit bothering with all of these minor details. Just leave the engines mostly stock and put some attention to the tuned exhaust. What could it hurt? The Cates was originally running right up with David Watkins when I first drove the kart. It sure wasnt my driving that made me able to stay up with him that one time. He was the fastest driver out there that night in the junior bushing class too.
So should I spend some serious time on the exhaust or forget about it for now? There is no way I can copy it and have another one or two ready for this weekend to try out. I dont really see any chance of getting this one even set to try for myself. I gotta stay focused on putting the engines together. Thats all, nothing else.
Back to other concerns. At first I was sure that bumping the timing up a whole lot would help out great. But now finding out the stock timing is already set at 35 degrees advanced. Comparing that to around 26 degrees on other small engines is a big big difference.
Could I go a lot more on the timing? Would it be harder to start or cause problems like pre-ignition on regular gas? I keep thinking that without the extra drag of the cooling fins, engine should rev up quicker. Still with a lot of weight from the cast iron flywheel I am hoping it will be strong running out of the turns and even taking advantage of using a smaller axle gear.
Remembering back about some of our tried and failed attempts over the years, a lighter weight flywheel has a tendency of shearing the key if timing is too advanced. Usually caused when it sometimes backfires, but the heavier cast iron flywheels would carry over the crankshaft almost eliminating any chance of backfiring to shear the key.
I always thought this sounded backwards, but a heavier flywheel helps keep engine from a possible backfire, lessening the likelihood of a sheared key. Sounds simple enough. Or is it? This is mostly when trying to crank over a cold engine when the flywheel shears the key. May not be an issue on the kart tho.
Another reason for keeping with the heavier flywheel for now is the bored out carburetor. I want to make sure there is enough momentum maintained if pulling a lot smaller axle gear. Will it stall out in a really tight turn when under a heavy load? For now this is my plan. Then start changing things over once we get some more track time to do back to back comparisons.
Since Chris is a featherweight driver, his engine will be the least altered. For now I want to keep with most of his original parts. Well mainly with the two thick ring piston. He is a great driver from what I remember at our first race. Considering how bad his kart was jacked up and now fixed, he should be a rocket. Especially with a much faster engine.
Using the new Go-Power intake manifold and pyramid reed cage and bored out carburetor, his engine doesnt need any experiments to start with. The internal modifications are the same as the other blocks. Ports, slipper cut piston, E-65 side cover and cleaned up intake passage are matching.
Steves engine has been strong since our very first practice. Odd since it was also completely stock with exception to chainsaw reeds and small Tillotson carburetor. I think nothing more than the modified intake manifold with Six petal reed cage and bored out carburetor it should be very competitive. His engine will match mine mostly with exception to using all three rings on the E-65 piston. I dont want to take any chances with this engine until I have proven reliability in the other modifications.
Now it comes down to what is different on my engine. I have no problems using high temp epoxy to fill the empty ring grooves on piston. Instead of using the high mileage Bradfield connecting rod, I am considering two or even three different possibilities.
I could stay mostly like the other two engines, except for no bottom rings. Or I could also consider using the E-65 engine block over the A-490. I could swap out the cranks or machine a special full floating bushing for the steel rod.
By swapping in the A-490 crankshaft, will be nearly a direct fit. Not much to worry about. But I would prefer to have the extra counterweight on the E-65 crankshaft.
Another option still is swapping out the A-490 crank with an E-65 in my A-490 engine. This still requires a full floating bushing for the rod. I think it can be done easily enough. Just dont know if there is enough time before the weekend. I would need to make sure the backup engine was ready to go if I went this route.
One other thing needing to work out is cutting back the pto side of engine block for shorter crankshaft from E-65. I checked everything over and think it should work. But a lot of material has to be machined off to fit the shorter length. Just more things to do and running out of time to get it all done. But this has been the story all along.
Without all of these problems that need to be worked out, this journal would really be boring. If I could send my engine out to a real professional, then all of the work needing to be done is just setting up the chassis. That is no fun at all. With a really fast engine almost any idiot could go run out in front. What fun is that? Even if we get our butts kicked at first, I will have learned so much from trying things out. So after a while, not so much guess work getting to the front. I want to be that idiot that figured out everything for himself and can make a decision based on proven testing. Not what someone wrote down on a piece of paper that cost a small fortune in box after someones magic hand waved over the engine.
During the week I had to make some very important decisions. I spent this morning talking to Mr Sadeskey about a couple of the issues that were plaguing me. The most difficult problem was deciding on what to do about the pistons and filling the empty ring grooves with something.
Mr Sadeskey rubbed his chin several times, then a couple more times. That is an interesting problem and an unusual solution. I have no idea about filling the ring grooves with some type of epoxy.
I dont see this as a long term fix. But in your case, it might do just fine. With all of the space rockets these days, I am sure there is some new technology already out there that should do the job. But I am not up to date for things like this.
The is nothing I can recollect reading anything of this nature in Popular Science or Popular Mechanics either. New fangled high temp epoxies would be something notable to cover in a article. But it escapes me as I try to remember.
Have you thought to inquire about this to Coach Rhimes? He does teach Physical Science and Biology. But I dont recall him actually having a specific degree in either field. Let me do some checking and see what I can find out.
There is one other thing with deciding to use the stock piston with both thick rings or attempt to fill the lower one like on the E-65 pistons. Again this is does depend on what he finds out about the epoxy.
For now the three of our engine blocks are ported exactly the same. I still plan to build up the modified engine originally on the Cates kart as a back up. But this will only happen if time allows.
I am satisfied with the original intake manifolds that have been modified to use the Go-Power six petal pyramid reed assembly. Steve did good when he bought the three cages. We finally get to find out just how well they work.
Only my engine will be used for testing the waters, like filling the ring grooves and the lightened flywheel at first. I also planned to advance the ignition timing a whole bunch on my one engine. From an article I read, it may be possible to really bump it up a lot. I figured with the compression so low, there should be a big buffer zone to work with.
Since we absolutely can not spin the guts out of a bushing engine like Frank tries to do with his deluxe model Westbend 580, I thought about a totally different direction to go. My plans are to use the lightened cast iron flywheel with most of the cooling fins machined off. Cut the shroud back roughly the amount of fins removed from flywheel. From my guesstimate that is somewhere around 1/2 inch to be sliced off of shroud.
This had already been done on the Cates engine. But I found out later after talking to Mr Cates something that he had not been aware of at the time. Mr Cates told me his stock cast iron flywheel had been sent to California to a big wig kart shop. They claimed massive gains with a lightened flywheel. This is right before the newer style aluminum flywheels were available.
He sent in the old flywheel and they shipped a lightened one right back to him. They already had these cut down ready to unload, I mean sell. But I found out over the summer there were several different weights of the cast iron flywheels. After a lot of cutting and weighing, I ended up with a light weight flywheel that still weighed more than the stock one.
It took some head scratching to figure out the cut flywheel was an older model and the fins were a lot thicker. It was very noticeable only after cutting down and comparing to the newer flywheel after it was also machined and sitting side by side. So Mr Cates only gained the loss of drag from cooling fins removed without any advantage to less rotating weight. This is the only reason why he had decided to lighten the flywheel in the first place. Just to lose the weight.
Mr Cates told me he did not bother to weigh the old flywheel before sending it off. But it still seemed to be just as heavy when the special cut down flywheel arrived a week later.
The one thing Mr Cates did attempt to explain to me is how well the port tuned exhaust worked. It was weather sensitive, but usually could be worked out by slight adjustments. So far I have not put aside the time to study up on his tuned exhaust. It looked just like a plain old rusty muffler to me by the time we found it.
There was an article in an older issue of some kart magazine. I dont even remember if it was Karting World, Racing Karts, KART or another issue. But after doing the calculations this article claimed the optimum pipe length for a Clinton engine would likely be close to 32 inches. This I laughed about before figuring things out. Where would you put that much pipe on a kart anyway? Maybe run it thru a frame rail or something?
After Steve found the old rusted exhaust out at the track several months later, it was not very impressive to look at. But I finally investigated the exhaust thing a lot closer. The larger diameter pipe bolted to the engine is about 11 to 12 inches long. Originally I thought this long of a pipe must be very restrictive. There is still so much about all of this I have absolutely no clue or understanding about.
This long pipe curves around and down under the engine then slides into the exhaust looking thingy. The muffler is about 4 inches in diameter and 10 inches long. The entry pipe I later realized travels the full length to a back compartment. What this does is now adds the overall length to almost 22 inches give or take an inch.
The next big surprise is discovering the exiting pipe extends around half the length of exhaust and sticks out a couple of inches. Now the overall length works out to right at that magic 32 inch number. Another unexpected surprise is the exiting pipe is even adjustable. I can lengthen or shorten almost two inches. One thing I could never get past is how small the exit pipe was. The outside diameter is right at one inch. One small inch does not seem like is big enough for any size engine.
So while I have been wrapping my brain cells around the engines to squeeze more horsepower out of them, all this time overlooking something that can be bolted over the exhaust ports and make more power without doing anything else. Is this Voodoo magic or what? Maybe just some good sales pitch.
There was also a major article in Karting World magazine covering mufflers for the engines. All of them based the findings against an open header. It made the most power. Some of the mufflers did kill the engine completely with dyno tests showing the drop in horsepower. So why would this big old rusty muffler make more power than an open header? Once again call me skeptical.
This exhaust is one thing I have been wanting to test out. But so far is the last thing on my mind every time. Suppose I quit bothering with all of these minor details. Just leave the engines mostly stock and put some attention to the tuned exhaust. What could it hurt? The Cates was originally running right up with David Watkins when I first drove the kart. It sure wasnt my driving that made me able to stay up with him that one time. He was the fastest driver out there that night in the junior bushing class too.
So should I spend some serious time on the exhaust or forget about it for now? There is no way I can copy it and have another one or two ready for this weekend to try out. I dont really see any chance of getting this one even set to try for myself. I gotta stay focused on putting the engines together. Thats all, nothing else.
Back to other concerns. At first I was sure that bumping the timing up a whole lot would help out great. But now finding out the stock timing is already set at 35 degrees advanced. Comparing that to around 26 degrees on other small engines is a big big difference.
Could I go a lot more on the timing? Would it be harder to start or cause problems like pre-ignition on regular gas? I keep thinking that without the extra drag of the cooling fins, engine should rev up quicker. Still with a lot of weight from the cast iron flywheel I am hoping it will be strong running out of the turns and even taking advantage of using a smaller axle gear.
Remembering back about some of our tried and failed attempts over the years, a lighter weight flywheel has a tendency of shearing the key if timing is too advanced. Usually caused when it sometimes backfires, but the heavier cast iron flywheels would carry over the crankshaft almost eliminating any chance of backfiring to shear the key.
I always thought this sounded backwards, but a heavier flywheel helps keep engine from a possible backfire, lessening the likelihood of a sheared key. Sounds simple enough. Or is it? This is mostly when trying to crank over a cold engine when the flywheel shears the key. May not be an issue on the kart tho.
Another reason for keeping with the heavier flywheel for now is the bored out carburetor. I want to make sure there is enough momentum maintained if pulling a lot smaller axle gear. Will it stall out in a really tight turn when under a heavy load? For now this is my plan. Then start changing things over once we get some more track time to do back to back comparisons.
Since Chris is a featherweight driver, his engine will be the least altered. For now I want to keep with most of his original parts. Well mainly with the two thick ring piston. He is a great driver from what I remember at our first race. Considering how bad his kart was jacked up and now fixed, he should be a rocket. Especially with a much faster engine.
Using the new Go-Power intake manifold and pyramid reed cage and bored out carburetor, his engine doesnt need any experiments to start with. The internal modifications are the same as the other blocks. Ports, slipper cut piston, E-65 side cover and cleaned up intake passage are matching.
Steves engine has been strong since our very first practice. Odd since it was also completely stock with exception to chainsaw reeds and small Tillotson carburetor. I think nothing more than the modified intake manifold with Six petal reed cage and bored out carburetor it should be very competitive. His engine will match mine mostly with exception to using all three rings on the E-65 piston. I dont want to take any chances with this engine until I have proven reliability in the other modifications.
Now it comes down to what is different on my engine. I have no problems using high temp epoxy to fill the empty ring grooves on piston. Instead of using the high mileage Bradfield connecting rod, I am considering two or even three different possibilities.
I could stay mostly like the other two engines, except for no bottom rings. Or I could also consider using the E-65 engine block over the A-490. I could swap out the cranks or machine a special full floating bushing for the steel rod.
By swapping in the A-490 crankshaft, will be nearly a direct fit. Not much to worry about. But I would prefer to have the extra counterweight on the E-65 crankshaft.
Another option still is swapping out the A-490 crank with an E-65 in my A-490 engine. This still requires a full floating bushing for the rod. I think it can be done easily enough. Just dont know if there is enough time before the weekend. I would need to make sure the backup engine was ready to go if I went this route.
One other thing needing to work out is cutting back the pto side of engine block for shorter crankshaft from E-65. I checked everything over and think it should work. But a lot of material has to be machined off to fit the shorter length. Just more things to do and running out of time to get it all done. But this has been the story all along.
Without all of these problems that need to be worked out, this journal would really be boring. If I could send my engine out to a real professional, then all of the work needing to be done is just setting up the chassis. That is no fun at all. With a really fast engine almost any idiot could go run out in front. What fun is that? Even if we get our butts kicked at first, I will have learned so much from trying things out. So after a while, not so much guess work getting to the front. I want to be that idiot that figured out everything for himself and can make a decision based on proven testing. Not what someone wrote down on a piece of paper that cost a small fortune in box after someones magic hand waved over the engine.