Our Sister Sites:

Bikernet Trikes Bikernet Baggers Bikernet Blog
Ride Forever - Bikernet.com
Friday Edition


Bennett’s Performance 2004 Dyna Build 106-Incher

Giving a Twin Cam the Best of All Worlds

By Bandit with photos by Wrench
7/23/2013


Share this story:



Eric, are you building an engine or what?
Eric, are you building an engine or what?



Eric Bennett grabbed the shop door chain and hoisted the roll up door for the first time, in 2000. He started his mechanical career as a certified diesel mechanic with 60-weight always flowing through his blood stream. Finally, he gave into his entrepreneurial spirit and his desire to make motorcycles his life—he opened his own shop on Signal Hill. The rest is motorcycle history, much of it spent at the Bonneville Salt Flats with his dad, Bob.



He recently owned a modified twin cam FLH, but a customer made him a deal he couldn’t refuse, so he let it go. Then a deal on a Dyna surfaced and he made a quick move to snatch it. This time, he decided he would take it to the concrete and rebuild every aspect of the bike to be moderately fast, ultimately reliable, precise, and built with absolutely all the best mechanical intentions and components in mind. You get to see the 106-inch project unfold before your very eyes right here.



One of the benefits of running a service center in the largest city in Los Angeles County includes encountering every possible mechanical malady and the ability to research whatever solution might be necessary. Since LA is also the motorcycle media hub, he has constant opportunities to test anything new on the market. After working on Twin Cams since their introduction into the market in 1998, Eric has watched every configuration, modification, performance recipe, and model roll in and out of his shop.

This JIMS tool serves several purposes. It aligns the Timken insert  and hold the case securely.
This JIMS tool serves several purposes. It aligns the Timken insert and hold the case securely.



This is the JIMS Timken insert kit.
This is the JIMS Timken insert kit.



With this build he could pour every lesson and improvement into his own ride. It started as a bone stock 2004, 88 cubic inch TwinCam. Eric could choose from any hot rod configuration in the world, but he chose to roll with a 106-inch kit from S&S and Branch re-tuned heads. He started the process by installing a JIMS Timken conversion into his left case and welding his crankpin into the S&S lower end after it was balanced.



“With superior S&S flywheels, I didn’t need to monkey with the cases,” Eric said.

Eric used this combination to press in the insert, but the JIMS tool will do the job.
Eric used this combination to press in the insert, but the JIMS tool will do the job.

 
 
 He bored the stock barrels from 3 ¾ to 3 7/8 inches and increased his stroke from 4 inches to 4.5. With JIMS tools he pressed in the JIMS race (using green Loctite) (9-59-1) while keeping his fixture perfectly flat and the hole in the race at 12 o’clock.



Eric drilling the oil splash feed hole.
Eric drilling the oil splash feed hole.



Using a JIMS fixture tool, he was able to drill guide holes in the case for Timken bearing and race oiling. The JIMS tool holds the drill and guides it. The drills are set to indicate the depth. Otherwise, he would need to use transfer punches and a milling machine. Then he used another JIMS tool to drill for the race fastener holes, and used tap guides to prevent misalignment.

This shows how to align he bit up so he doesn't over-drill or under drill.
This shows how to align he bit up so he doesn't over-drill or under drill.



A transfer punch used for alignment.
A transfer punch used for alignment.



“I’ve made tap guides for every size tap,” Eric said.



Eric made a thicker tap guide for more accurate starting.
Eric made a thicker tap guide for more accurate starting.



One of the benefits of the higher quality Timken lower end bearings is their ability to lock the lower-end into place.


“I have never seen a Timken bearing fail,” Eric said. Until recently Timken’s were used since 1957. “I’ve seen dozens of roller bearing failures!”



The cost saving shift to roller bearings started in 2003 during the 100th anniversary season. “The best Twin Cams were built in 2002,” Eric confirmed. “Better engines, still carbureted and with 1-inch axles for strength and stability.”





Eric used red Loctite on the race screws. He uses a tool for installing both Timken races at the same time. Kelly McKernnan, an amazing machinist out of Portland, Oregon, manufactured it.





The next phase included welding the S&S flywheels. Anytime Eric has a twin cam lower end out of a customer’s bike, he welds the crankpin in place with stainless TIG rod. It doesn’t create much heat and is not a structural weld; it just cements alignment and prevents shifting. He always checks the true after welding.



Next, he installed the Timken bearing by heating the race to expand it, and it slippped over the shaft easily. There is very little endplay in the shaft, just .001-.002-inch. Eric cinched down the top bearing with another JIMS tool, then pressed in the main seal and spacer with yet another JIMS tool.





This is the spacer supplied with the Timken bearing kit. It's generally on the money.
This is the spacer supplied with the Timken bearing kit. It's generally on the money.





The JIMS tool installing the final bearing against the spacer. This is where he checks the end play.
The JIMS tool installing the final bearing against the spacer. This is where he checks the end play.



JIMS tool installing the seal. The spacer just pushes into place.
JIMS tool installing the seal. The spacer just pushes into place.



The 1 7/8 socket is made out of two sockets welded together. It works with the Timken installation tool, the seal installer, and a transmission pulley nut.
The 1 7/8 socket is made out of two sockets welded together. It works with the Timken installation tool, the seal installer, and a transmission pulley nut.



Sprocket shaft seal and spacer installed.
Sprocket shaft seal and spacer installed.



At this point, we shifted to pressing the new S&S cam bearings into the new heavy-duty Screamin’ Eagle cam plate for hydraulic cam tensioners, but Eric chose to shift to an S&S gear drive system, so he blocked off the oil passages to the hydraulics.


Pressing in the cam bearing. The JIMS tool is under the Screamin' Eagle plate.
Pressing in the cam bearing. The JIMS tool is under the Screamin' Eagle plate.



The JIMS tool to hold the cam plate for installing the cam bearings. This tool is an absolute must have. It's home base for installing the bearings and the cams.
The JIMS tool to hold the cam plate for installing the cam bearings. This tool is an absolute must have. It's home base for installing the bearings and the cams.



The S&S supplied plate to plug off the hydraulic chain tensioner oil feed hole.
The S&S supplied plate to plug off the hydraulic chain tensioner oil feed hole.






He still ran the larger capacity oil pump with the .585 easy-start cams for midrange power. He could have used the stock plate or SE plate. He also installed S&S piston skirt squirters, which are offset to prevent damage from longer stroke pistons.
 
If you don't change out the piston squirters the piston will break off the stock squirter.
If you don't change out the piston squirters the piston will break off the stock squirter.

 
 




Part of the JIMS tool kit is this bracket to hold the cams aligned for pressing into place. He pressed them in at the same time, which isn't necessary with a gear drive kit.
Part of the JIMS tool kit is this bracket to hold the cams aligned for pressing into place. He pressed them in at the same time, which isn't necessary with a gear drive kit.





Eric times the cams with the S&S marks.
Eric times the cams with the S&S marks.



He installed Torrington cam bearings in the right case prior to installing the new cams. His plan called for installing a D&D Bob Cat exhaust system, which is 20 pounds lighter than a stock exhaust. D&D pipes come bolted together with all spring clips, flanges, and heat shields in place. “They take like two minutes to install,” Eric said.


JIMS installation tool for installing new, full-compliment Torrington cam bearings.
JIMS installation tool for installing new, full-compliment Torrington cam bearings.







Eric performened a dry run clearance fit with the cam plate, before we installed the pump.
Eric performened a dry run clearance fit with the cam plate, before we installed the pump.





“It’s the easiest system I have ever installed,” Eric said. “It comes with the all the components needed and the heat shields in place. No shimming is necessary or egg shaping holes.”
 
Page 1 of 3
Prev
[1]
2
3
Next

Share this story:



Back to Tech




Reader Comments


My Mother is already dead. Who else can I kill for you to have you do to my bike, what you've done to yours? All I can think of to say is "Lord, this is Eric. It is upon him that I shall build my church."

--Trash
C 2/16 "Rangers" 65 - 66

Trash
Kagel Canyon, CA
Sunday, December 01, 2013
Editor Response I'm sure the team at Bennett's Performance will answer your prayers.
--Bandit

Your thoughts on this article

Your Name
Email
City
Country
v
State/Province
v
Comments
Anti-Spam Question:
Please enter the words you see in the box, in order and separated by a space. Doing so helps prevent automated programs from abusing this service.
Submit
Clear