I need more pressure???
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Road Master
Joined: Nov 2009
Posts: 997
Likes: 3
From: Charlotte, N.C.
I need more pressure???
How do I go from 9.2:1 to 10:1 compression on a stock 96 inched motor. I am thinking thinner head gaskets but wondering what are the options for thickness and what compression will that get me. I see that HD sells .030" shorter and longer push rods, but cant find where they have thinner gaskets, not sure if this is even possible, looking for the easiest way or a set of good inexpensive bolt on heads that will get me there. I am planning to use the SE204 cams and I want to match the compression with the overlap.
Road Warrior
Joined: Mar 2009
Posts: 1,485
Likes: 232
From: Ohio
On my 2008 FLHTC, I used cometic 0.030" thick head gaskets and had a local machine shop take off 0.040" from the heads. I think I am around 9.7:1 compression ratio. The bike does not hesitate when cranking with no compression releases. I guess I could have taken another 0.010" off the heads but I couldn't figure out if everyone is talking about static or dynamic compression ratio so I went conservatively and took off 0.040".
Thread Starter
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Road Master
Joined: Nov 2009
Posts: 997
Likes: 3
From: Charlotte, N.C.
On my 2008 FLHTC, I used cometic 0.030" thick head gaskets and had a local machine shop take off 0.040" from the heads. I think I am around 9.7:1 compression ratio. The bike does not hesitate when cranking with no compression releases. I guess I could have taken another 0.010" off the heads but I couldn't figure out if everyone is talking about static or dynamic compression ratio so I went conservatively and took off 0.040".
Tourer
Joined: Aug 2010
Posts: 320
Likes: 24
From: Hudson Valley
More pressure or more compression?
You think you wanna run 10:1 with SE 204s? I don't think you do, but I am a little conservative.
Without telling us more about your bike, its hard to know what you'll need to do, but I am guessing from your questions, you need a little help.
Here is a calculator that will help you
http://www.bigboyzheadporting.com/TwinCamComp.htm
9.6:1 is where many like to run the SE204, it still gives you a little wiggle room for bad gas. You might be able to get away with up to 9.8:1 with the right heads.
If it was me, I would call Kevin at ProTwin and get a set of cometic .027 head gaskets and call it good, if you wanted to be a little less conservative, you could run the cometic .018 head gaskets for 9.7:1 CR. You could grind a squish groove in if you think they make a difference.
On a stock 96" motor to get to 10:1, you will get your heads CC'd and millled to 80.5CCs and run a .030 head gasket. You will likely mill somewhere between .025 and .030 off your heads if they are 86CC heads.
I would personally use adjustable pushrods, but you could use the perfect fit if you wanted.
You think you wanna run 10:1 with SE 204s? I don't think you do, but I am a little conservative.
Without telling us more about your bike, its hard to know what you'll need to do, but I am guessing from your questions, you need a little help.
Here is a calculator that will help you
http://www.bigboyzheadporting.com/TwinCamComp.htm
9.6:1 is where many like to run the SE204, it still gives you a little wiggle room for bad gas. You might be able to get away with up to 9.8:1 with the right heads.
If it was me, I would call Kevin at ProTwin and get a set of cometic .027 head gaskets and call it good, if you wanted to be a little less conservative, you could run the cometic .018 head gaskets for 9.7:1 CR. You could grind a squish groove in if you think they make a difference.
On a stock 96" motor to get to 10:1, you will get your heads CC'd and millled to 80.5CCs and run a .030 head gasket. You will likely mill somewhere between .025 and .030 off your heads if they are 86CC heads.
I would personally use adjustable pushrods, but you could use the perfect fit if you wanted.
Thread Starter
|
Road Master
Joined: Nov 2009
Posts: 997
Likes: 3
From: Charlotte, N.C.
More pressure or more compression?
You think you wanna run 10:1 with SE 204s? I don't think you do, but I am a little conservative.
Without telling us more about your bike, its hard to know what you'll need to do, but I am guessing from your questions, you need a little help.
Here is a calculator that will help you
http://www.bigboyzheadporting.com/TwinCamComp.htm
9.6:1 is where many like to run the SE204, it still gives you a little wiggle room for bad gas. You might be able to get away with up to 9.8:1 with the right heads.
If it was me, I would call Kevin at ProTwin and get a set of cometic .027 head gaskets and call it good, if you wanted to be a little less conservative, you could run the cometic .018 head gaskets for 9.7:1 CR. You could grind a squish groove in if you think they make a difference.
On a stock 96" motor to get to 10:1, you will get your heads CC'd and millled to 80.5CCs and run a .030 head gasket. You will likely mill somewhere between .025 and .030 off your heads if they are 86CC heads.
I would personally use adjustable pushrods, but you could use the perfect fit if you wanted.
You think you wanna run 10:1 with SE 204s? I don't think you do, but I am a little conservative.
Without telling us more about your bike, its hard to know what you'll need to do, but I am guessing from your questions, you need a little help.
Here is a calculator that will help you
http://www.bigboyzheadporting.com/TwinCamComp.htm
9.6:1 is where many like to run the SE204, it still gives you a little wiggle room for bad gas. You might be able to get away with up to 9.8:1 with the right heads.
If it was me, I would call Kevin at ProTwin and get a set of cometic .027 head gaskets and call it good, if you wanted to be a little less conservative, you could run the cometic .018 head gaskets for 9.7:1 CR. You could grind a squish groove in if you think they make a difference.
On a stock 96" motor to get to 10:1, you will get your heads CC'd and millled to 80.5CCs and run a .030 head gasket. You will likely mill somewhere between .025 and .030 off your heads if they are 86CC heads.
I would personally use adjustable pushrods, but you could use the perfect fit if you wanted.
Tourer
Joined: Aug 2010
Posts: 320
Likes: 24
From: Hudson Valley
I guess I should have asked that first, I am looking for the best compression for the 204 cams. My bike is a 2009 Road Kind with a stock 96 inched motor. It looks like your saying 9.6:1 is where I want to be with these cams. I will look up those head gaskets. I am wondering if the valvetrain geometry with the .027 gaskets will allow me to run the stock pushrods, if not which perfect fit ones do I need. I do not want the adjustable ones just a preference. They are heavier and may come loose at the higher rpms, I also notice that everyone that has them have problems getting the correct adjustment
Anyone that is having problems with adjustable pushrods is not installing them correctly.
The moderate weight difference is irrelevant, they will not back off if installed correctly and I agree, it seems a lot of people on this forum are having problems installing them correctly for whatever reason. I suspect after reading a couple of the threads, they don't know what they are doing. If you need help, I'm about an 1.5 hours away from you.
The "perfect fit" pushrods are not a perfect fit for either one of my suggestions above. You could probably use the -.030" pushrods with the .018 head gasket.
If you are determined to use the perfect fit pushrods for the SE-204, get a .030 head gasket and have .015 milled off your heads. Should give you about 9.7:1 and 190 lbs compression.
Road Master
Joined: Jun 2006
Posts: 1,220
Likes: 2
From: iowa
I have to agree with Inverse as far as the adjustable pushrods go. I did a lot of research on them and when I put in my TW-6-6 cams I chose the SE adjustables and have not had a single issue with them. I say "fear not the adjustables".
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Road Master
Joined: Nov 2009
Posts: 997
Likes: 3
From: Charlotte, N.C.
I understand your preference and I am going to give you my $.02.
Anyone that is having problems with adjustable pushrods is not installing them correctly.
The moderate weight difference is irrelevant, they will not back off if installed correctly and I agree, it seems a lot of people on this forum are having problems installing them correctly for whatever reason. I suspect after reading a couple of the threads, they don't know what they are doing. If you need help, I'm about an 1.5 hours away from you.
The "perfect fit" pushrods are not a perfect fit for either one of my suggestions above. You could probably use the -.030" pushrods with the .018 head gasket.
If you are determined to use the perfect fit pushrods for the SE-204, get a .030 head gasket and have .015 milled off your heads. Should give you about 9.7:1 and 190 lbs compression.
Anyone that is having problems with adjustable pushrods is not installing them correctly.
The moderate weight difference is irrelevant, they will not back off if installed correctly and I agree, it seems a lot of people on this forum are having problems installing them correctly for whatever reason. I suspect after reading a couple of the threads, they don't know what they are doing. If you need help, I'm about an 1.5 hours away from you.
The "perfect fit" pushrods are not a perfect fit for either one of my suggestions above. You could probably use the -.030" pushrods with the .018 head gasket.
If you are determined to use the perfect fit pushrods for the SE-204, get a .030 head gasket and have .015 milled off your heads. Should give you about 9.7:1 and 190 lbs compression.
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Cruiser
Joined: Oct 2007
Posts: 145
Likes: 0
From:
I have a 2011 FLHX with the 103" Power Pack option. Considering a set of cams and a .030
cometic gasket. Please let me know what you think about this idea.
Thanks
cometic gasket. Please let me know what you think about this idea.
Thanks
More pressure or more compression?
You think you wanna run 10:1 with SE 204s? I don't think you do, but I am a little conservative.
Without telling us more about your bike, its hard to know what you'll need to do, but I am guessing from your questions, you need a little help.
Here is a calculator that will help you
http://www.bigboyzheadporting.com/TwinCamComp.htm
9.6:1 is where many like to run the SE204, it still gives you a little wiggle room for bad gas. You might be able to get away with up to 9.8:1 with the right heads.
If it was me, I would call Kevin at ProTwin and get a set of cometic .027 head gaskets and call it good, if you wanted to be a little less conservative, you could run the cometic .018 head gaskets for 9.7:1 CR. You could grind a squish groove in if you think they make a difference.
On a stock 96" motor to get to 10:1, you will get your heads CC'd and millled to 80.5CCs and run a .030 head gasket. You will likely mill somewhere between .025 and .030 off your heads if they are 86CC heads.
I would personally use adjustable pushrods, but you could use the perfect fit if you wanted.
You think you wanna run 10:1 with SE 204s? I don't think you do, but I am a little conservative.
Without telling us more about your bike, its hard to know what you'll need to do, but I am guessing from your questions, you need a little help.
Here is a calculator that will help you
http://www.bigboyzheadporting.com/TwinCamComp.htm
9.6:1 is where many like to run the SE204, it still gives you a little wiggle room for bad gas. You might be able to get away with up to 9.8:1 with the right heads.
If it was me, I would call Kevin at ProTwin and get a set of cometic .027 head gaskets and call it good, if you wanted to be a little less conservative, you could run the cometic .018 head gaskets for 9.7:1 CR. You could grind a squish groove in if you think they make a difference.
On a stock 96" motor to get to 10:1, you will get your heads CC'd and millled to 80.5CCs and run a .030 head gasket. You will likely mill somewhere between .025 and .030 off your heads if they are 86CC heads.
I would personally use adjustable pushrods, but you could use the perfect fit if you wanted.
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