piston ring question
Thread Starter
|
Cruiser
Joined: May 2007
Posts: 198
Likes: 0
From: Colorado Sprgs, CO
piston ring question
Here is the scenario. 95" motor with only 4000 miles on it. SE211 cams.
Indy says motor losing compression because of the HD cookie cutter build. He says rings are gaped too wide. Wants to replace the rings with some 5 over for 1550 motor. No mention of honing the cylinders.
1. Would you replace rings without honing the cylinders?
2. Would you replace rings when the engine hasn't been opened and someone only thinks the ring gap is too big because the the HD did it thing?
3. Can it be determined what might cause a low compression without opening it up?
4. Would you go to another mechanic before proceeding?
Thanks for any insight. I hate hindsight.
Indy says motor losing compression because of the HD cookie cutter build. He says rings are gaped too wide. Wants to replace the rings with some 5 over for 1550 motor. No mention of honing the cylinders.
1. Would you replace rings without honing the cylinders?
2. Would you replace rings when the engine hasn't been opened and someone only thinks the ring gap is too big because the the HD did it thing?
3. Can it be determined what might cause a low compression without opening it up?
4. Would you go to another mechanic before proceeding?
Thanks for any insight. I hate hindsight.
Road Captain
Joined: May 2006
Posts: 720
Likes: 2
From: Kansas
1. absolutely not
2. no
3. yes, with a proper leak down test, done correctly.
4. yes
211 cams have a 45deg. intake closing and 40deg. overlap.... you will loose some ccp unless it has 10.5 or 11:1 mechanical comp ratio.
2. no
3. yes, with a proper leak down test, done correctly.
4. yes
211 cams have a 45deg. intake closing and 40deg. overlap.... you will loose some ccp unless it has 10.5 or 11:1 mechanical comp ratio.
Outstanding HDF Member
Joined: May 2008
Posts: 2,009
Likes: 0
From: South Jersey
Let's see. SE 95 with a 211 should make about 170 CCP at sea level. Subtract for 6000 feet of elevation in CO Springs and you should have 140 with a 6% margin so if your compression is in the 130 range there shouldn't be a problem.
What is strange is Chazmanian posted the exact same build with CCP of 130 also living in Colorado. My personal opinion is there is nothing wrong with the bike. Swap out the cam with a intake closing of 30-36* SE 203 or 204, Andrews 21 or 26 or a crane 1-3000 or 1-3001 and be happy. The SE builds are built all the time and the ring gaps are probably within specifications.
What is strange is Chazmanian posted the exact same build with CCP of 130 also living in Colorado. My personal opinion is there is nothing wrong with the bike. Swap out the cam with a intake closing of 30-36* SE 203 or 204, Andrews 21 or 26 or a crane 1-3000 or 1-3001 and be happy. The SE builds are built all the time and the ring gaps are probably within specifications.
Ultimate HDF Member
Joined: Feb 2007
Posts: 7,663
Likes: 7
From: Northeast Ohio
Here is the scenario. 95" motor with only 4000 miles on it. SE211 cams.
Indy says motor losing compression because of the HD cookie cutter build. He says rings are gaped too wide. Wants to replace the rings with some 5 over for 1550 motor. No mention of honing the cylinders.
1. Would you replace rings without honing the cylinders? .005 over rings are designed to work in cylinders that are bored .005 over. No, I would not do this.
2. Would you replace rings when the engine hasn't been opened and someone only thinks the ring gap is too big because the the HD did it thing? Without doing a compression and leakdown test, to arbitrarily make this statement the ring gap is too big is wrong. No, until I knew exactly what , and if there was an isue I would not replace the rings.
3. Can it be determined what might cause a low compression without opening it up? See answer to question two.
4. Would you go to another mechanic before proceeding?
Absolutely if you have told us the whole story, these shot in the dark, shoot from the hip diagnosis will do nothing but cost you money and may not fix your problem.
Thanks for any insight. I hate hindsight.
Indy says motor losing compression because of the HD cookie cutter build. He says rings are gaped too wide. Wants to replace the rings with some 5 over for 1550 motor. No mention of honing the cylinders.
1. Would you replace rings without honing the cylinders? .005 over rings are designed to work in cylinders that are bored .005 over. No, I would not do this.
2. Would you replace rings when the engine hasn't been opened and someone only thinks the ring gap is too big because the the HD did it thing? Without doing a compression and leakdown test, to arbitrarily make this statement the ring gap is too big is wrong. No, until I knew exactly what , and if there was an isue I would not replace the rings.
3. Can it be determined what might cause a low compression without opening it up? See answer to question two.
4. Would you go to another mechanic before proceeding?
Absolutely if you have told us the whole story, these shot in the dark, shoot from the hip diagnosis will do nothing but cost you money and may not fix your problem.
Thanks for any insight. I hate hindsight.
Last edited by Dalton; Jan 18, 2009 at 10:45 AM.
Thread Starter
|
Cruiser
Joined: May 2007
Posts: 198
Likes: 0
From: Colorado Sprgs, CO
Thanks for the info.
Seems to be some confusion about whether it is losing compression (large ring gap story) or just insufficient compression to begin with.
I think a leak down test somewhere else that know nothing about what the situation and see what comes of that.
BTW, it is not my bike.
Seems to be some confusion about whether it is losing compression (large ring gap story) or just insufficient compression to begin with.
I think a leak down test somewhere else that know nothing about what the situation and see what comes of that.
BTW, it is not my bike.
Outstanding HDF Member
Joined: May 2008
Posts: 2,009
Likes: 0
From: South Jersey
Trending Topics
Tourer
Joined: Apr 2006
Posts: 252
Likes: 0
From: Oceanside CA
Hi Newhawk,
FWIW, I agree with the advice you are getting here. However you may want to have a look for yourself. I can't vouch for the quality, the price is right, probably Okay: http://www.harborfreight.com/cpi/cta...emnumber=94190 . Learn to use it and have some fun figuring things out for yourself, I'm sure that there are many members here and on other boards that will be happy to help you gain the knowledge you need.
FWIW, I agree with the advice you are getting here. However you may want to have a look for yourself. I can't vouch for the quality, the price is right, probably Okay: http://www.harborfreight.com/cpi/cta...emnumber=94190 . Learn to use it and have some fun figuring things out for yourself, I'm sure that there are many members here and on other boards that will be happy to help you gain the knowledge you need.
HD Forum Stories
The Best of Harley-Davidson for Lifelong Riders
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Verdad Gallardo
8 Best Harley-Davidson Motorcycles Ever
Pouria Savadkouei
10 Worst Harley-Davidson Motorcycles Ever
Pouria Savadkouei
Killer Custom's Jail Break Is The Breakout That Refused to Blend In
Verdad Gallardo
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Verdad Gallardo
Harley-Davidson Reveals Super Cool Cafe Racer Concept
Verdad Gallardo
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Verdad Gallardo
10 Motorcycles You Should Never Buy
Joe Kucinski
10 Things Harley-Davidson Needs to Fix in 2026
Verdad Gallardo
Sponsor
Joined: Dec 2007
Posts: 12,084
Likes: 829
Here is the scenario. 95" motor with only 4000 miles on it. SE211 cams.
Indy says motor losing compression because of the HD cookie cutter build. He says rings are gaped too wide. Wants to replace the rings with some 5 over for 1550 motor. No mention of honing the cylinders.
1. Would you replace rings without honing the cylinders?
2. Would you replace rings when the engine hasn't been opened and someone only thinks the ring gap is too big because the the HD did it thing?
3. Can it be determined what might cause a low compression without opening it up?
4. Would you go to another mechanic before proceeding?
Thanks for any insight. I hate hindsight.
Indy says motor losing compression because of the HD cookie cutter build. He says rings are gaped too wide. Wants to replace the rings with some 5 over for 1550 motor. No mention of honing the cylinders.
1. Would you replace rings without honing the cylinders?
2. Would you replace rings when the engine hasn't been opened and someone only thinks the ring gap is too big because the the HD did it thing?
3. Can it be determined what might cause a low compression without opening it up?
4. Would you go to another mechanic before proceeding?
Thanks for any insight. I hate hindsight.
Your mechanic must be the second coming of Houdini, to be able to alert you to all that info without testing procedures.
I want to get a pair of those goggles he has!
Cheers,
Scott