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[Tom149]

I have been asked why I chose a 107CI build on my 06' FLHTCUSE (103CI) using TC 88 heads instead of my SE 103 stock heads, and why I didn't change out my exhaust (from TD's to 2:1) instead of increasing my displacement to 107CI. Here is my reasoning:

1. Quite a few reputable head porters recommend TC 88 or 96 heads over CVO 103 stock heads for porting and polishing as a result of the size and shape of the combustion chamber on the CVO 103 heads (too big & hemi shaped) and the huge valves that they incorporate. The roughly 85cc, bathtub shaped, TC 88 head will provide more efficient combustion and higher compression than the 95cc - 98cc SE 103 stock hemi-shaped head. I needed 10.1 - 10.2:1 compression to run the Andrews 54N cams efficiently and was able to get that in part by cc'ing the TC 88 heads to 87cc. To get 87cc's out of SE 103 stock heads would require welding up and CNC cutting the combustion chambers and/or severely milling them. I believe that Don Dorfman (Dewey's Heads) and Scott (Hillside Cycles) prefer the TC 88 heads for performance builds and some head porters I contacted would not even work on the CVO 103 heads.

2. While the heads were off, it was relatively easy and inexpensive (about $450.00) to bore my existing jugs and add the oversize (3.938") cp pistons increasing my displacement to 107CI. $450.00 is considerably less than a D&D Fatcat 2 into 1 exhaust system. Also, displacement = power and "there is no replacement for displacement", to coin a phrase. The 96CI or 103CI to 107CI conversion is a very popular build and almost all of the Independent Performance Shops are recommending/offering it. As long as you have a 4.375" stroker, the 3.938 bore will get you to 107CI (actually about 106.5CI  ).

3. My thinking was go with the build that I planned (107CI), have it Dyno-SERT tuned, and see what the HP, TRQ, and and Curve look like. Then, if I believed that those elements could be improved upon, I could always modify/change my exhaust setup at a later date. I was unaware of just how poor a performer the Rinehart True Duals would prove to be, especially with the "performance baffles" when it comes to torque and where that torque comes in.

However, overall the bike really runs great now with plenty of HP and TRQ, but shifting the torque curve left a bit might be a little more in line with where I'd like my torque to come in with a heavy bagger thus increasing the "seat of your pants dyno".

Here is a very similar build by GMR Performance producing very similar peak numbers but by using the Fatcat 2 into 1. Check the difference in the overall torque curve and at what rpm the 100 ft/lb mark is reached. The build is a 107CI conversion from a 96CI (bored to 3.938") with Andrews 54s, reworked heads set to 9.8:1.

http://www.gmrperformance.com/index.php?option=com_docman&task=doc_download&gid=34&Itemid=60    105ft/lb at 2250 rpm

Here is the very same build/motor with Rinehart TD's with "quiet baffles", quite a difference in where the 100 ft/lb mark is reached.

http://www.gmrperformance.com/index.php?option=com_docman&task=doc_download&gid=33&Itemid=60    100 ft/lb at 2750 rpm

With my "performance baffles" (least restrictive), I don't reach 100 ft/lb until about 3200 rpm. After speaking with Rinehart Tech Dept., they believe that the "quiet baffle" will get me 100 ft/lb at about 2600 rpm. I think that is a nice compromise and quite acceptable and probably the direction I'm headed! It will cost me $94.00 (baffle) and tweaking my current tune (hopefully 1 - 1 1/2 hours dyno time = $90.00 - $135.00).

Tom

[timtoolman]

hi  tom  ijust did a build similiar to yours,  stock heads but i changed to 1.900 intake valves and 1.72 se. rocker arms.  with 54h cams,  i had a pcv but swithched to tts (ts on its way) i have reinhart slip ons to loud  i put 2.00 fulsacs on  havent dynoed it but wow.  i used s&s 106, with 10:1 comp.  it has the torque!!!!

[timtoolman]

the performance shops that do the heads all say use 88 or 96 cuin heads for performance work,steve at fulsac's says the 09 ,2010 heads flow very well and dont really need much  work at all,

[HD Street Performance]

Believe it or not those big heads drop CCs in a hurry when milled and they flow very well. Not saying the other choice is wrong or bad that would depend on how effective the changes to the stock heads are. I have done them both ways with success.
I am sure it will run fine.

[Tom149]

hi  tom  ijust did a build similiar to yours,  stock heads but i changed to 1.900 intake valves and 1.72 se. rocker arms.  with 54h cams,  i had a pcv but swithched to tts (ts on its way) i have reinhart slip ons to loud  i put 2.00 fulsacs on  havent dynoed it but wow.  i used s&s 106, with 10:1 comp.  it has the torque!!!!

Tim,

Sounds like it will be a fun ride! Mine dynoed at 104PWR and 112TRQ, its a blast. I also went with 1.90 intake valve and 1.615 exhaust valve and welded up the intake and exhaust ports and reshaped them for better flow.

I just need to tweak (quiet baffles) or replace my Rinehart TD's to eliminate the torque dip and move the curve left a bit!

Tom

[Unbalanced]

Tom149,

The only thing I am curious on is the thickness of the spigots and the worry of cracking using a stock cylinder bored out that extra bit to go from 103 to 107.  Yes I know there are some out there and it is becoming more and more popular and that some say it is fine, but was told of one the other day that was .032 thickness and had cracked.   I don't know if this is a one off issue or whether it would be common, guess time will tell.

I have not tried to find the information yet, but wondering what Axtell's thickness  for their 107 cylinders vs. cut stock 96 or 103 cylinders.

[Twolanerider]

I have not tried to find the information yet, but wondering what Axtell's thickness  for their 107 cylinders vs. cut stock 96 or 103 cylinders.

I mic'd them when using Axtell jugs for my 107" build.  Not a spec I immediately remember though.  Will look this evening and see if I still have those notes.

[Tom149]

Tom149,

The only thing I am curious on is the thickness of the spicket and the worry of cracking using a stock cylinder bored out that extra bit to go from 103 to 107.  Yes I know there are some out there and it is becoming more and more popular and that some say it is fine, but was told of one the other day that was .032 thickness and had cracked.   I don't know if this is a one off issue or whether it would be common, guess time will tell.

I have not tried to find the information yet, but wondering what Axtell's thickness  for their 107 cylinders vs. cut stock 96 or 103 cylinders.

The Spigot thickness is a concern, but I was assured that the stock Harley Cylinders should hold up. As you say, "time will tell". There are quite a few after-market 107 cylinders out there that have gotten great reviews, and I inquired about them, but again, I was "assured" I shouldn't have any problems (keeping my fingers crossed).

Tom

[Unbalanced]

I mic'd them when using Axtell jugs for my 107" build.  Not a spec I immediately remember though.  Will look this evening and see if I still have those notes.

Thanks Don

[Tom149]

Believe it or not those big heads drop CCs in a hurry when milled and they flow very well. Not saying the other choice is wrong or bad that would depend on how effective the changes to the stock heads are. I have done them both ways with success.
I am sure it will run fine.

Thanks Don,

I have heard that the SE 103 stock heads can be reworked to achieve positive performance levels as well. There is a fellow here in Colorado (Ken Weber - 10 Litre Performance) that has had success reworking them.

Tom

[Twolanerider]

Thanks Don

Got back here a few minutes ago.  Haven't immediately found those sidebar notes from the build.  If I do later will post them.

[johnsachs]

With a little fluffing,decent valve job,including os intakes,the 103" CVO heads can work REAL good.There's several dynos on the board in the 103" CVO models section.
John

Don't want to be a naysayer,but you could never have me build a stock cylinder with a 3.938" bore.It just ain't worth it.............
I've seen them crack,and out of round from getting too hot.

[Tom149]

With a little fluffing,decent valve job,including os intakes,the 103" CVO heads can work REAL good.There's several dynos on the board in the 103" CVO models section.
John

Don't want to be a naysayer,but you could never have me build a stock cylinder with a 3.938" bore.It just ain't worth it.............
I've seen them crack,and out of round from getting too hot.

Ut Oh ....... ...... John, I hope I am lucky!

Tom

[HD Street Performance]

Axtell pistons (Wosserman) are for a 3.932 bore and set up with .002 clearance

[Tom149]

Axtell pistons (Wosserman) are for a 3.932 bore and set up with .002 clearance

Don,

I think that these are the pistons you are referring to, fairly new product for Axtell:


Squeeze is good:
Axtell Sales has just released 2 new pro-street piston kits for twin cam engines. These 3.932 bore pistons bump a 88 up to 97ci and a 96 to 107ci and can use stock cylinder castings. This 10.25-1 piston utilizes a perimeter dome combined with a re-machined shelf in the combustion chamber to improve mixture burn and airflow. This configuration has proven on our 117 & 124 engines packages to be easily tuned and a big power producer. Axtell will modify your cylinders and heads and can assist you in the design and modification of your engine. Use kit # 800-997 for 4 inch stroke engines and part # 800-115 for 4 3/8 inch stroke late model engines.  


Tom

[skyhook]

i did something similar...put ported 96" heads on my 110" for the same reasons as you stated

[HD Street Performance]

Just got a report back from a guy that I did the 103 heads for, just a street port with flow work and he made 109 and 121 with a pancake torque curve. Still not condemning the OEM head but this one had SE103 heads and a Wood TW408-44 and stock 103" cylinders SE HC pistons

edit:
Made a mistake this one was stock bore and SE HC pistons, been real busy with several of these

[Tom149]

Just got a report back from a guy that I did the 103 heads for, just a street port with flow work and he made 109 and 121 with a pancake torque curve. Still not condeming the OEM head but this one had SE103 heads and a Wood TW408-44 and Axtell 107" stock bored barrels. 10/1.

 
Great Numbers ..... Don, do you know what exhaust he is using?

Tom

[HILLSIDECYCLE.COM]

Tom149,

The only thing I am curious on is the thickness of the spigots and the worry of cracking using a stock cylinder bored out that extra bit to go from 103 to 107.  Yes I know there are some out there and it is becoming more and more popular and that some say it is fine, but was told of one the other day that was .032 thickness and had cracked.   I don't know if this is a one off issue or whether it would be common, guess time will tell.

I have not tried to find the information yet, but wondering what Axtell's thickness  for their 107 cylinders vs. cut stock 96 or 103 cylinders.

We have been boring those since early 2007. 88-98", 96-107", with our private label Wiseco kits. NOT 1 problem.
Only at clients request do we bore to the 95", or the 103".
The .032" info is totally wrong. .060" if not mistaken, and there is not load in that area anyway.
BTW, we bore the 124" S&S's to 128.5" as well, and it maintains the clamping force that the 131" do not have, causing the inherent leaks on those.
Scott

[Tom149]

We have been boring those since early 2007. 88-98", 96-107", with our private label Wiseco kits. NOT 1 problem.
Only at clients request do we bore to the 95", or the 103".
The .032" info is totally wrong. .060" if not mistaken, and there is not load in that area anyway.
BTW, we bore the 124" S&S's to 128.5" as well, and it maintains the clamping force that the 131" do not have, causing the inherent leaks on those.
Scott

Scott,

Great information, makes me feel alot better!

Tom

[mcdonaldroadcapt]

Tom,

My CVO is triked out and I would like to move the torque down lower for the additional weight. Where can I obtain the Rinehart quiet baffles for $94.00?   Keep seeing $124.00 for True Duals,


Jim

[Tom149]

Tom,

My CVO is triked out and I would like to move the torque down lower for the additional weight. Where can I obtain the Rinehart quiet baffles for $94.00?   Keep seeing $124.00 for True Duals,


Jim

Jim,

Here ya go:

http://www.denniskirk.com/jsp/product_catalog/Product.jsp;jsessionid=UKLZSQ2RHWHIBLA0WTKSM4VMDK0NCIV0?skuId=4401995&store=Main&catId=&productId=p4401995&leafCatId=&mmyId=

Tom

[Unbalanced]

We have been boring those since early 2007. 88-98", 96-107", with our private label Wiseco kits. NOT 1 problem.
Only at clients request do we bore to the 95", or the 103".
The .032" info is totally wrong. .060" if not mistaken, and there is not load in that area anyway.
BTW, we bore the 124" S&S's to 128.5" as well, and it maintains the clamping force that the 131" do not have, causing the inherent leaks on those.
Scott

Scott,  Is that .060 your number (Hillside's value / spec) or Axtell's number or someone elses number?   

[Tom149]

i did something similar...put ported 96" heads on my 110" for the same reasons as you stated

Skyhook,

I am very satisfied with the head swap and I hear those 96" castings are a real good starting point as well!

Tom

[HD Street Performance]

Great Numbers ..... Don, do you know what exhaust he is using?

Tom

Here is the dyno. He used V&H Big Radius. Not a real strong performer. There is more in there, but rather than focussing on the numbers notice the torque curve even with that sketchy pipe.

I am beginning to grow fonder of the TW408-44 and would really like to use it with high ratio rockers, bypassing the TW7, so the TW5-6 as a torque monster and then the TW408-44 or the TW8-6 for somebody that wants some more punch but still very good low end torque.

[skyhook]

yeah it works great...just got back from a backroad blast and it's amazing how quick it hits the rev limiter in 1st and 2nd gear!

[Tom149]

Here is the dyno. He used V&H Big Radius. Not a real strong performer. There is more in there, but rather than focussing on the numbers notice the torque curve even with that sketchy pipe.

I am beginning to grow fonder of the TW408-44 and would really like to use it with high ratio rockers, bypassing the TW7, so the TW5-6 as a torque monster and then the TW408-44 or the TW8-6 for somebody that wants some more punch but still very good low end torque.

Don,

Now that curve is impressive especially with that pipe, and I like your cam plan. I'd be interested to see what the TW408-44 with high ratio rockers or maybe a +4 would do. I almost went with the TW-5-6-R with my build, but chose the Andrews 54N's instead.

Tom

[HD Street Performance]

Scott,  Is that .060 your number (Hillside's value / spec) or Axtell's number or someone elses number?   

Not either of their numbers just the math  
stock bore =3.750 spigot wall thickness =.153
3.938" Wiseco piston bore = .188 OS or .094 removed per side = .059 spigot
3.932 Axtell / Wossner piston bore = .182 OS or .091 removed per side = .062" spigot

[Unbalanced]

Tom149,

I wouldnt jump so fast into believing what you see there on that dyno sheet.  When you see the same bike run on a dyno that does their print outs in SAE / STD and prints the conditions then I would say you have a better basis to judge.

[Tom149]

Tom149,

I wouldnt jump so fast into believing what you see there on that dyno sheet.  When you see the same bike run on a dyno that does their print outs in SAE / STD and prints the conditions then I would say you have a better basis to judge.

I agree unbalanced, but shouldn't the shape of the curve remain?

Tom

[Unbalanced]

Tom,

It should be similiar I would just expect lower. 

[Tom149]

Tom,

It should be similiar I would just expect lower. 

Unbalanced,

I agree, LOWER!

Tom

[Unbalanced]

I can't see how the spigot is a non stressed area since the piston rides into the spigot area.  The piston then dwells at the bottom like it does at the top when the rod reverses direction.  

I know there are these builds out there, but I dont think that I will be using the stock cylinders if I end up going 106/107.  I have to believe that S&S has earned their credibility over the last 52 years, and has done the testing to be able to make statements like they do here in print.  

My biggest fear would be a cracked cylinder or an out of round condition which could be caused by over heating due to weather and traffic conditions.

I now leaning towards the the Axtell or S&S Jugs.  The money spent on the after market cylinders above what it would have cost to bore a set of stock cylinders seems to be good peace of mind.  Just like home owners insurance ... no one wants it, but sure glad you had it if you ever needed it.

[Tom149]

I can't see how the spigot is a non stressed area since the piston rides into the spigot area.  The piston then dwells at the bottom like it does at the top when the rod reverses direction.  

I know there are these builds out there, but I dont think that I will be using the stock cylinders if I end up going 106/107.  I have to believe that S&S has earned their credibility over the last 52 years, and has done the testing to be able to make statements like they do here in print.  

My biggest fear would be a cracked cylinder or an out of round condition which could be caused by over heating due to weather and traffic conditions.

I now leaning towards the the Axtell or S&S Jugs.  The money spent on the after market cylinders above what it would have cost to bore a set of stock cylinders seems to be good peace of mind.  Just like home owners insurance ... no one wants it, but sure glad you had it if you ever needed it.

Unbalanced,

I had read that S&S writeup and was ready to pull the trigger on overbore Axtell cylinders when I was doing my build, but again I was assured that the stock bored jugs would be reliable. I SURE HOPE SO. I have to agree, in hindsight, that the cost of new oversize jugs, once you substract the cost of the bore and hone on your stock cylinders maybe worth the peace of mind if nothing else, based on the small additional investment.

Tom

[HILLSIDECYCLE.COM]

I can't see how the spigot is a non stressed area since the piston rides into the spigot area.  The piston then dwells at the bottom like it does at the top when the rod reverses direction.  

I know there are these builds out there, but I dont think that I will be using the stock cylinders if I end up going 106/107.  I have to believe that S&S has earned their credibility over the last 52 years, and has done the testing to be able to make statements like they do here in print.  

My biggest fear would be a cracked cylinder or an out of round condition which could be caused by over heating due to weather and traffic conditions.

I now leaning towards the the Axtell or S&S Jugs.  The money spent on the after market cylinders above what it would have cost to bore a set of stock cylinders seems to be good peace of mind.  Just like home owners insurance ... no one wants it, but sure glad you had it if you ever needed it.

That spigot wall thickness, is NO different than if you bored your OE cylinders.
Scott

[Unbalanced]

Scott,

What about the liner thickness as well as the Spigot?   

[HD Street Performance]

What about the liner thickness as well as the Spigot? 

The math
Stock liner minor diameter (thinest point remember these are centrifugal spun-cast iron) = .200 - .094 per side = .106"

[HILLSIDECYCLE.COM]

What Don said.........
Scott