piston fit

[dwilfong]

"The BS stops when the prop hits the water".

 

[steve wood]

Oh ok so we are talking about two different motors or were we?????? Now that I got Your attention Steve did i understand you to say that in your motor (Nova or rossi) which ? you saw significant increases in your rpm and hp with the simple change of a head button you sell? I also asked have you confirmed these improvements of performance on a dyno?

by going with the brass,we are running higher compression ratio and a shorter pipe=higher rpm(in the nova).there are only 2 dynos in the usa that i know of,and i don't have one

gotta remember,everythings a combination,and all the parts have to work together.sometimes if you change 1 part you have to change something else to get the combination to work right

every one that i know of thats running brass won't go back to alumminum

 

[dwilfong]

there are only 2 dynos in the usa that i know of,and i don't have one

I know who has one for a nitro eng.

Now if I could just have the privilege of running a eng on it after he blows the cobwebs off it.

 

[hugh hargett]

I know somebody too JIM ALLEN more than one right up the road from me literally. Steve is a higher compression ratio meaning a thicker button? Could you not also achieve the same compression with the appropriate aluminum button thickness ? At what point are you over compressing inducing detonation???

Hugh

David when I get out to falls lake to test with Jim if he allows ill get some video of his eagles flying!!!

 

[steve wood]

I know somebody too JIM ALLEN more than one. Steve Im assuming a higher compression ratio means a thicker button. Could you not also achieve the same compression with the appropriate aluminum ? At what point are you over compressing inducing detonation???

no. .19 cc aluminum detonates.factory is about .22.my brass is .17.runs like stink

why would higher comp mean thicker.just shallower bowl

 

[hugh hargett]

Steve, Im asking you I dont know. So you are running a shallower bowl with the brass than the aluminum button. Thats what I was trying to ask sorry. I didnt see why there would be an increase in compression/rpm/hp with just a material change.

 

[RodneyPierce]

yes, less bowl volume or tighter clearance to up the compression. Either or will get the job done. I have not tried to run really high compression. The most compression I have ran was 11.2:1 and it was very very picky, and hard on plugs if the needle, pipe length, and load wernt just perfect. I wont run that high again.

 

[John Beardslee]

Oh ok so we are talking about two different motors or were we?????? Now that I got Your attention Steve did i understand you to say that in your motor (Nova or rossi) which ? you saw significant increases in your rpm and hp with the simple change of a head button you sell? I also asked have you confirmed these improvements of performance on a dyno?

by going with the brass,we are running higher compression ratio and a shorter pipe=higher rpm(in the nova).there are only 2 dynos in the usa that i know of,and i don't have one

gotta remember,everythings a combination,and all the parts have to work together.sometimes if you change 1 part you have to change something else to get the combination to work right

every one that i know of thats running brass won't go back to alumminum

Hi Steve,

The first dyno I was aware of was an eddycurrent dyno that Tom Hyner built (late 70's - early 80's) and used, it was sweet and probably the best setup I've ever seen. Of course his years in the dyno room at Ford gave him a great resource to call on. Wonder what ever happened to it when he passed. Joe Weibelhouse and I were just talking about it at the Burton race. I know that the guys from Indy have a dyno, I think its a brake dyno isn't it Marty, but who has another one? There were lots of torque reaction/spring reaction dynos built but they may not count as a true scientific tool.

Thanks, John

Thanks, John

 

[John Beardslee]

yes, less bowl volume or tighter clearance to up the compression. Either or will get the job done. I have not tried to run really high compression. The most compression I have ran was 11.2:1 and it was very very picky, and hard on plugs if the needle, pipe length, and load wernt just perfect. I wont run that high again.

Hi Rodney,

Years ago we had alot of problems trying to heat race with 50-60% nitro in our twins (67's-80's) and we found that if we upped the compression ratio and lowered the nitro and ran hotter plugs we could run more consistant and not chase a needle settings. You needed a good starter and new belts because is was noticeably more difficult to turn over. I think Jerry Devay never ran over 35% SIG fuel - ha there's a name from the past!

John

 

[dwilfong]

I just want to thank every one for there contributions to this post.

It is amazing how one thing leads to another.

This thread is as dynamic as the engs we work on.

thanks again

David

 

[RodneyPierce]

yes, less bowl volume or tighter clearance to up the compression. Either or will get the job done. I have not tried to run really high compression. The most compression I have ran was 11.2:1 and it was very very picky, and hard on plugs if the needle, pipe length, and load wernt just perfect. I wont run that high again.

Hi Rodney,

Years ago we had alot of problems trying to heat race with 50-60% nitro in our twins (67's-80's) and we found that if we upped the compression ratio and lowered the nitro and ran hotter plugs we could run more consistant and not chase a needle settings. You needed a good starter and new belts because is was noticeably more difficult to turn over. I think Jerry Devay never ran over 35% SIG fuel - ha there's a name from the past!

John

John, good info! Im currently running 66% nitro, but I only run .21 engines (for now anyhow). Seems the little guys love the nitro. Like I said, Im not even sure what the current compression is. I have never checked. I will have to do that here someday.

David, where have you found to be the most success in the compression area? I know you have been all over the place with nearly every size motor.

 

[hugh hargett]

If people would stop looking down there nose they may see whats right beneath it

https://www.intlwaters.com/gallery/thumbnails.php?album=338

 

[Marty Davis]

Oh ok so we are talking about two different motors or were we?????? Now that I got Your attention Steve did i understand you to say that in your motor (Nova or rossi) which ? you saw significant increases in your rpm and hp with the simple change of a head button you sell? I also asked have you confirmed these improvements of performance on a dyno?

by going with the brass,we are running higher compression ratio and a shorter pipe=higher rpm(in the nova).there are only 2 dynos in the usa that i know of,and i don't have one

gotta remember,everythings a combination,and all the parts have to work together.sometimes if you change 1 part you have to change something else to get the combination to work right

every one that i know of thats running brass won't go back to alumminum

Hi Steve,

The first dyno I was aware of was an eddycurrent dyno that Tom Hyner built (late 70's - early 80's) and used, it was sweet and probably the best setup I've ever seen. Of course his years in the dyno room at Ford gave him a great resource to call on. Wonder what ever happened to it when he passed. Joe Weibelhouse and I were just talking about it at the Burton race. I know that the guys from Indy have a dyno, I think its a brake dyno isn't it Marty, but who has another one? There were lots of torque reaction/spring reaction dynos built but they may not count as a true scientific tool.

Thanks, John

Thanks, John

Inertial Dyno

 

[Norm Doerr]

Oh ok so we are talking about two different motors or were we?????? Now that I got Your attention Steve did i understand you to say that in your motor (Nova or rossi) which ? you saw significant increases in your rpm and hp with the simple change of a head button you sell? I also asked have you confirmed these improvements of performance on a dyno?

by going with the brass,we are running higher compression ratio and a shorter pipe=higher rpm(in the nova).there are only 2 dynos in the usa that i know of,and i don't have one

gotta remember,everythings a combination,and all the parts have to work together.sometimes if you change 1 part you have to change something else to get the combination to work right

every one that i know of thats running brass won't go back to alumminum

Hi Steve,

The first dyno I was aware of was an eddycurrent dyno that Tom Hyner built (late 70's - early 80's) and used, it was sweet and probably the best setup I've ever seen. Of course his years in the dyno room at Ford gave him a great resource to call on. Wonder what ever happened to it when he passed. Joe Weibelhouse and I were just talking about it at the Burton race. I know that the guys from Indy have a dyno, I think its a brake dyno isn't it Marty, but who has another one? There were lots of torque reaction/spring reaction dynos built but they may not count as a true scientific tool.

Thanks, John

Thanks, John

Oh ok so we are talking about two different motors or were we?????? Now that I got Your attention Steve did i understand you to say that in your motor (Nova or rossi) which ? you saw significant increases in your rpm and hp with the simple change of a head button you sell? I also asked have you confirmed these improvements of performance on a dyno?

by going with the brass,we are running higher compression ratio and a shorter pipe=higher rpm(in the nova).there are only 2 dynos in the usa that i know of,and i don't have one

gotta remember,everythings a combination,and all the parts have to work together.sometimes if you change 1 part you have to change something else to get the combination to work right

every one that i know of thats running brass won't go back to alumminum

Hi Steve,

The first dyno I was aware of was an eddycurrent dyno that Tom Hyner built (late 70's - early 80's) and used, it was sweet and probably the best setup I've ever seen. Of course his years in the dyno room at Ford gave him a great resource to call on. Wonder what ever happened to it when he passed. Joe Weibelhouse and I were just talking about it at the Burton race. I know that the guys from Indy have a dyno, I think its a brake dyno isn't it Marty, but who has another one? There were lots of torque reaction/spring reaction dynos built but they may not count as a true scientific tool.

Thanks, John

Thanks, John

OOPS beat me to it.. yeah what Marty said.. LOL

 

[dwilfong]

So to get back to the piston fit.

I have ordered a custom 29mm hone from Brush research.

It is a 800 grit Levigated Alumina compound. there specks for the surface finish are RA 3-10 (.05-.2 micrometer)

My intent is to polish the cylinder. Don't know how it will work till I give it a whirl. for $32 have nothing to lose testing it on old liners.

Will give it a try this weekend.

David

 

[Jeff Lutz]

As additional information, the following metals are listed in order according to their thermal conductivity amounts. It can be easily seen that brass & steel would not be the most desireable metals to use for a head. All numbers are BTU/in/hr/ft squared/deg F. All the numbers can be found on any available metal's specification sheet from Google.

1018 cold rolled steel - 360 BTU....

#360 brass - 804 BTU....

2024 aluminum - 840 BTU....

2017 aluminum - 930 BTU....

It doesn't take a rocket scientist to figure this out.

"Andy, I guess where the peppering can be seen should be expected since the brass has a thermal conductivity 1/2 of aluminum."

Jim, The truth of your statement above is not reflected in your list of Thermal conductivity.

I will say that when comparing brass to aluminum it is far from correct to make statements like, "Brass and aluminum expansion is close." ~ Jeff L. or "brass has a thermal conductivity 1/2 of aluminum." ~ Jim A.

Aluminum alloys will expand as much a 50% more or 50% less than many brass alloys. While the Thermal conductivity of many Aluminum alloys are within + or - 20% of each other, Copper alloys (brass) swing very widely, Some are in fact 1/2 of aluminum, but other copper alloys are more than double that of aluminum.

Therefore I think it would be proper to specfy the particular alloy one is refering to when making these claims.

If you go back and read before I said aluminum and brass expansion is close, specifics were covered. Marty and Jim had already said they used 2024 aluminum. Marty said he was trying 360 brass (yellow brass). 360 brass is 11.3, 2024 aluminum is 12.9, close, not the same. Those 2 materials were being compared. 5052 upto 7075 aluminum are all in the 13.1-13.2 range. 360 brass does not conduct heat nearly as much as the mentioned aluminum alloys.Do some research and you will see Jim is close to being correct saying about 1/2 on conductivity of 360 brass versus any of the above mentioned aluminums.

From Matweb dot com 360 brass 798 BTU... 2024 alu. 840 BTU.... I did the reseach. Jim also mentioned 2017 alu. 930 BTU... Somewhere Jim mentioned 544 bronze 604 BTU... No body said we were specificly refering to 360 and 2024 in this thread. Others have mention BeCu heads 720 BTU... At one point Steve Wood was making heads from 2011 alu. 1180 BTU. ...and I use an alloy different then all of those.

Lots of variety going on here.

Jeff, Where did you get these numbers? "Coefficient of thermal conduction (btu/hr-ft-*F) of aluminum is 104, when brass is 67" ~Jeff L.

For 360 brass I find 798 BTU-in/hr-ft2-*F. For 2024 alu. I find 840 BTU... This reflects a 5% difference, not 1/2. Now if you compare 544 bronze (an alloy Jim mentioned) it's TC is 604 BTU to 2011 alu. 1180 BTU... the difference is in fact 51%, about 1/2 and reflects somewhat the difference in your 104 and 67, but that difference does not match your two alloys of 360 and 2024, which is only about 5% difference according to the source on Matweb.

This is why I suggest specifics.

Andy,That was a chart I was glancing at. Ive attached a sheet out of the machinery handbook that shows the numbers very close to those numbers. I did not do the math it just looked like close to half was about right.This one shows a difference of about 38%. As far as Martys question about expansion, it looks like 360 brass is his best bet for staying with brass.Conductivity of brass versus aluminum I felt did need to be considered in the discussion of how it might help detonation,of course there is countless things to consider. Your comments about the melting point of brass making it not show the peppering was very valid and I was not arguing that at all.Thermal Properties.pdf

 

[dwilfong]

As additional information, the following metals are listed in order according to their thermal conductivity amounts. It can be easily seen that brass & steel would not be the most desireable metals to use for a head. All numbers are BTU/in/hr/ft squared/deg F. All the numbers can be found on any available metal's specification sheet from Google.

1018 cold rolled steel - 360 BTU....

#360 brass - 804 BTU....

2024 aluminum - 840 BTU....

2017 aluminum - 930 BTU....

It doesn't take a rocket scientist to figure this out.

"Andy, I guess where the peppering can be seen should be expected since the brass has a thermal conductivity 1/2 of aluminum."

Jim, The truth of your statement above is not reflected in your list of Thermal conductivity.

I will say that when comparing brass to aluminum it is far from correct to make statements like, "Brass and aluminum expansion is close." ~ Jeff L. or "brass has a thermal conductivity 1/2 of aluminum." ~ Jim A.

Aluminum alloys will expand as much a 50% more or 50% less than many brass alloys. While the Thermal conductivity of many Aluminum alloys are within + or - 20% of each other, Copper alloys (brass) swing very widely, Some are in fact 1/2 of aluminum, but other copper alloys are more than double that of aluminum.

Therefore I think it would be proper to specfy the particular alloy one is refering to when making these claims.

If you go back and read before I said aluminum and brass expansion is close, specifics were covered. Marty and Jim had already said they used 2024 aluminum. Marty said he was trying 360 brass (yellow brass). 360 brass is 11.3, 2024 aluminum is 12.9, close, not the same. Those 2 materials were being compared. 5052 upto 7075 aluminum are all in the 13.1-13.2 range. 360 brass does not conduct heat nearly as much as the mentioned aluminum alloys.Do some research and you will see Jim is close to being correct saying about 1/2 on conductivity of 360 brass versus any of the above mentioned aluminums.

From Matweb dot com 360 brass 798 BTU... 2024 alu. 840 BTU.... I did the reseach. Jim also mentioned 2017 alu. 930 BTU... Somewhere Jim mentioned 544 bronze 604 BTU... No body said we were specificly refering to 360 and 2024 in this thread. Others have mention BeCu heads 720 BTU... At one point Steve Wood was making heads from 2011 alu. 1180 BTU. ...and I use an alloy different then all of those.

Lots of variety going on here.

Jeff, Where did you get these numbers? "Coefficient of thermal conduction (btu/hr-ft-*F) of aluminum is 104, when brass is 67" ~Jeff L.

For 360 brass I find 798 BTU-in/hr-ft2-*F. For 2024 alu. I find 840 BTU... This reflects a 5% difference, not 1/2. Now if you compare 544 bronze (an alloy Jim mentioned) it's TC is 604 BTU to 2011 alu. 1180 BTU... the difference is in fact 51%, about 1/2 and reflects somewhat the difference in your 104 and 67, but that difference does not match your two alloys of 360 and 2024, which is only about 5% difference according to the source on Matweb.

This is why I suggest specifics.

Andy,That was a chart I was glancing at. Ive attached a sheet out of the machinery handbook that shows the numbers very close to those numbers. I did not do the math it just looked like close to half was about right.This one shows a difference of about 38%. As far as Martys question about expansion, it looks like 360 brass is his best bet for staying with brass.Conductivity of brass versus aluminum I felt did need to be considered in the discussion of how it might help detonation,of course there is countless things to consider. Your comments about the melting point of brass making it not show the peppering was very valid and I was not arguing that at all.

Jeff can you post the page with the iron alloys on it.

 

[Jim Allen]

The first dyno for model engines was built built by Ed Kalfus in 1939. When Ed's company moved out of Brooklyn to Poughkeepsie , I would go to Ed's house to watch him run his .60 cu in & his .90 cu in engine during dyno pulls. This was 1967 & ED died in 1972. Dyno pulls typically lasted 3 to 4 minutes at wide open throttle. On 50% nitro, his engine could make 5 HP at 26,000 RPM. The engine used a hanger piston, steel roller rod with rollers at the top & bottom & a dynamically balanced 1/4" thick phenolic rotor. His water brake with infinitely variable load was given to me in 1968. I used this water brake to build my first hydraulic dyno in 1973. The water brake was rebuilt in 2001 & a torque cradle type dyno was built at the same time to test one against the other.

These tools were indispensable in building what Andy Brown has refered to in the past as the "$10,000.00 engine". I will begin testing again next season with this 7 HP 30,000 RPM 100% reliable engine in one of Andy's custom built 80 boats.

Jim Allen

https://www.intlwaters.com/gallery/index.php?cat=10141; page one; A picture is worth a thousand words!

 

[Andy Brown]

As additional information, the following metals are listed in order according to their thermal conductivity amounts. It can be easily seen that brass & steel would not be the most desireable metals to use for a head. All numbers are BTU/in/hr/ft squared/deg F. All the numbers can be found on any available metal's specification sheet from Google.

1018 cold rolled steel - 360 BTU....

#360 brass - 804 BTU....

2024 aluminum - 840 BTU....

2017 aluminum - 930 BTU....

It doesn't take a rocket scientist to figure this out.

"Andy, I guess where the peppering can be seen should be expected since the brass has a thermal conductivity 1/2 of aluminum."

Jim, The truth of your statement above is not reflected in your list of Thermal conductivity.

I will say that when comparing brass to aluminum it is far from correct to make statements like, "Brass and aluminum expansion is close." ~ Jeff L. or "brass has a thermal conductivity 1/2 of aluminum." ~ Jim A.

Aluminum alloys will expand as much a 50% more or 50% less than many brass alloys. While the Thermal conductivity of many Aluminum alloys are within + or - 20% of each other, Copper alloys (brass) swing very widely, Some are in fact 1/2 of aluminum, but other copper alloys are more than double that of aluminum.

Therefore I think it would be proper to specfy the particular alloy one is refering to when making these claims.

If you go back and read before I said aluminum and brass expansion is close, specifics were covered. Marty and Jim had already said they used 2024 aluminum. Marty said he was trying 360 brass (yellow brass). 360 brass is 11.3, 2024 aluminum is 12.9, close, not the same. Those 2 materials were being compared. 5052 upto 7075 aluminum are all in the 13.1-13.2 range. 360 brass does not conduct heat nearly as much as the mentioned aluminum alloys.Do some research and you will see Jim is close to being correct saying about 1/2 on conductivity of 360 brass versus any of the above mentioned aluminums.

From Matweb dot com 360 brass 798 BTU... 2024 alu. 840 BTU.... I did the reseach. Jim also mentioned 2017 alu. 930 BTU... Somewhere Jim mentioned 544 bronze 604 BTU... No body said we were specificly refering to 360 and 2024 in this thread. Others have mention BeCu heads 720 BTU... At one point Steve Wood was making heads from 2011 alu. 1180 BTU. ...and I use an alloy different then all of those.

Lots of variety going on here.

Jeff, Where did you get these numbers? "Coefficient of thermal conduction (btu/hr-ft-*F) of aluminum is 104, when brass is 67" ~Jeff L.

For 360 brass I find 798 BTU-in/hr-ft2-*F. For 2024 alu. I find 840 BTU... This reflects a 5% difference, not 1/2. Now if you compare 544 bronze (an alloy Jim mentioned) it's TC is 604 BTU to 2011 alu. 1180 BTU... the difference is in fact 51%, about 1/2 and reflects somewhat the difference in your 104 and 67, but that difference does not match your two alloys of 360 and 2024, which is only about 5% difference according to the source on Matweb.

This is why I suggest specifics.

Andy,That was a chart I was glancing at. Ive attached a sheet out of the machinery handbook that shows the numbers very close to those numbers. I did not do the math it just looked like close to half was about right.This one shows a difference of about 38%. As far as Martys question about expansion, it looks like 360 brass is his best bet for staying with brass.Conductivity of brass versus aluminum I felt did need to be considered in the discussion of how it might help detonation,of course there is countless things to consider. Your comments about the melting point of brass making it not show the peppering was very valid and I was not arguing that at all.

Jeff, Maybe we even need to do our own materials testing to really know. Go to Matweb dot com. Lots of good info there. I have a Machinery handbook too, but I think some of their data has not been updated in a 100 years or so, LOL . At Matweb some of the charts there even give specific temperaturs ranges where the alloy was tested, because they transfer heat differently a different temps.

 

[Andy Brown]

As additional information, the following metals are listed in order according to their thermal conductivity amounts. It can be easily seen that brass & steel would not be the most desireable metals to use for a head. All numbers are BTU/in/hr/ft squared/deg F. All the numbers can be found on any available metal's specification sheet from Google.

1018 cold rolled steel - 360 BTU....

#360 brass - 804 BTU....

2024 aluminum - 840 BTU....

2017 aluminum - 930 BTU....

It doesn't take a rocket scientist to figure this out.

"Andy, I guess where the peppering can be seen should be expected since the brass has a thermal conductivity 1/2 of aluminum."

Jim, The truth of your statement above is not reflected in your list of Thermal conductivity.

I will say that when comparing brass to aluminum it is far from correct to make statements like, "Brass and aluminum expansion is close." ~ Jeff L. or "brass has a thermal conductivity 1/2 of aluminum." ~ Jim A.

Aluminum alloys will expand as much a 50% more or 50% less than many brass alloys. While the Thermal conductivity of many Aluminum alloys are within + or - 20% of each other, Copper alloys (brass) swing very widely, Some are in fact 1/2 of aluminum, but other copper alloys are more than double that of aluminum.

Therefore I think it would be proper to specfy the particular alloy one is refering to when making these claims.

If you go back and read before I said aluminum and brass expansion is close, specifics were covered. Marty and Jim had already said they used 2024 aluminum. Marty said he was trying 360 brass (yellow brass). 360 brass is 11.3, 2024 aluminum is 12.9, close, not the same. Those 2 materials were being compared. 5052 upto 7075 aluminum are all in the 13.1-13.2 range. 360 brass does not conduct heat nearly as much as the mentioned aluminum alloys.Do some research and you will see Jim is close to being correct saying about 1/2 on conductivity of 360 brass versus any of the above mentioned aluminums.

From Matweb dot com 360 brass 798 BTU... 2024 alu. 840 BTU.... I did the reseach. Jim also mentioned 2017 alu. 930 BTU... Somewhere Jim mentioned 544 bronze 604 BTU... No body said we were specificly refering to 360 and 2024 in this thread. Others have mention BeCu heads 720 BTU... At one point Steve Wood was making heads from 2011 alu. 1180 BTU. ...and I use an alloy different then all of those.

Lots of variety going on here.

Jeff, Where did you get these numbers? "Coefficient of thermal conduction (btu/hr-ft-*F) of aluminum is 104, when brass is 67" ~Jeff L.

For 360 brass I find 798 BTU-in/hr-ft2-*F. For 2024 alu. I find 840 BTU... This reflects a 5% difference, not 1/2. Now if you compare 544 bronze (an alloy Jim mentioned) it's TC is 604 BTU to 2011 alu. 1180 BTU... the difference is in fact 51%, about 1/2 and reflects somewhat the difference in your 104 and 67, but that difference does not match your two alloys of 360 and 2024, which is only about 5% difference according to the source on Matweb.

This is why I suggest specifics.

Andy,That was a chart I was glancing at. Ive attached a sheet out of the machinery handbook that shows the numbers very close to those numbers. I did not do the math it just looked like close to half was about right.This one shows a difference of about 38%. As far as Martys question about expansion, it looks like 360 brass is his best bet for staying with brass.Conductivity of brass versus aluminum I felt did need to be considered in the discussion of how it might help detonation,of course there is countless things to consider. Your comments about the melting point of brass making it not show the peppering was very valid and I was not arguing that at all.

Jeff can you post the page with the iron alloys on it.

David, Just go to Matweb dot com. Enter the alloy you want to look at in the search box on the upper right. You'll find tons of great info there.