Ok,

So I've been doing some research on engine upgrades for my '07 FXDL. I'm looking at bumping to 103"-107", just because I don't feel like boring the cases right now. I'm also looking for 110/110 to 120/120 range from this build, which from what I have read, is very doable. I want good, reliable, long lasting power from this build. Plus I'm going to attempt to do the parts swap myself. I am an aircraft mechanic, so it's not like I can't turn wrenches.

From what I'm seeing, alot of you like Head Quarters, Hillside, and GMR. I've also checked with Zipper's since I have the tmax with a/t. I figured it would be easy since all the components are theirs. But, I'm finding the price tag a bit steeper than I expected. Especially for a 103". Plus the HP/TQ #'s are on the bottom side of the range I want.

I've already conceded to the fact that I'll be getting the fatcat, but what else do I need? Clutch upgrades? Driveline upgrades? Intake? It doesn't look like everyone uses a larger TB, is it needed? Injectors?

What am I missing? Anything to look for or out for?

Any and all advice and recommendations would be greatly appreciated! Including your preferred vendor. Thanks in advance!




Mike

 

You are on the right couse in dealing with a reputable company and going with a "kit build" rather than trying this and that to get what you expect out of the engine. I am partial to Headquarters as their components are top notch and their kits produce reliable results that are repeatable in each and every build. Plus, Doug and Kevin are great to deal with .

You can run your stock TB but may want to go with SE injectors to get the duty cycle down to a reasonable level. Clutch, the stock clutch may handle the power for some time but most likely will want to beef it up a bit eventually either with a VPC or by going with a SE spring, although the SE spring will increase lever effort. The FatCat is an excellent choice for exhaust. Dont worry about the stronger cylinder studs, not necessary. The driveline will handle the power without modifications. I always recommend new lifters when you change cams. Adjustable pushrods, dont go with the SE pushrods unless you get the new taper style, the original style have a habit of hitting the tubes, causing what appears to be lifter noise. Roller rockers - not necessary. I also recommend staying around 10.0:1 compression as above that you may have a bit of detonation depending on riding style and it is easier to tune. Nothing wrong with 10.5:1 but you will need to downshift a bit more often even though you have more power on tap. If that doesn't bother you, go for the max as there is a bit more as the compression goes up.

All in all, 103, 107 builds are a great way to pick up power at a reasonable cost. Plus on the 07s and up, the build is a piece of cake compared to earlier models, dont need to press the cams in the plate.

Good luck on your build.

 

I used an AIM tamachi lockup clutch for my 95 ci HQ build, I havent had any clutch issues yet. there about 250$, easy to install.

I called alot of guys before I dropped coin on a kit, there are alot of real good guys out there, but after I called HQ, Doug put all my concerns to ease.

HQ dose all there own in house work, plus they design there own cams and provide tech support with free tunuing maps. Everything designed to work together!

a 103-107 engine with the HQ .575 cams will give you 120+ lbs of torque, broad fat powerband. very reliable and good fuel economy.

 

I am going to try one of those lock ups for my 107 build. You have anymore info you can share about it?

 

Thanks for the replies guys. I was thinking of going with the VPC clutch booster. Zipper's recommended it too. And a definite yes to the lifters.

I'll probably let whoever I decide to buy the kit from "guide" me in the right direction when it comes to injectors vs. TB and such.

With the Tmax, I'll have to mess with the timing tables anyway, so I'll be able to tweak in or out whatever I need, wherever I need it.




Mike

 

You have no location listed. Just remember (and I hope the kit Co tell you) If you live where it is hot or plan on riding in some serous heat, don't go crazy with cylinder pressures.

 

I live in KS, so it can get good and warm in the summer. Not crazy hot like TX and AZ, but warm enough for me. I'd planned on staying around 10-1. That should run ok on 91 octane, without creating too much heat I'd think.




Mike

 

All great info! But, can anyone tell me if you need to replace or re-work the crank when you bump up the CI' s on the '07/'08 motors?

m.a.c.

 

A lot of 103s and 107s running around on the stock cranks, some have failed but by far there are more running without any issues. You go any bigger, then definitely have the crank work done - timken conversion, truing, balancing and pinning or welding. Anytime you mod an engine you are stressing components beyond their design, I know of a few crank failures on some healthy 95" engines also. It is up to you if the chance is worth it. Before I built this to 120", I had it at 103" and 112hp/118 tq with no issues but only ran it for 10k miles before I went up in size.

 

I wonder how many crank failures were legit and how many were caused by rider mistakes like lugging and over-run