So after reading all the posts about big bore upgrades and going back and forth on several different builders, I finally settled on Automotive Machine in Ft Worth, TX. I wanted a kit that would deliver good rideability and reliability without breaking the bank and this one pretty much fit the bill.

I was heading to Dallas for the Arkansas – Texas A&M game at the new Jerrydome anyway, so I just left a little early and dropped all my parts off at the shop instead of dicking around with packing and shipping all the parts. I spent over an hour with the guys at the shop talking about the build and checking out all their equipment. It was really nice to be able to meet and talk face to face with the guys that were cutting on the motor. Let me go ahead and say that they have always taken the time to talk on the phone as long as I needed, and they took more than enough time to show me around and go over everything in detail while I was there.

Their cylinder and piston kit is a 105” (96” if you have an 88” motor to start with) where they bore your cylinders to match a set of forged pistons. The ones I got were CP pistons, but they are working on some with Wiseco IIRC. They also mill the cylinders to get the correct deck height for a good quench. I got mine back together with the pistons .005 in the hole. Combine that with the .030 head gasket and you get a .035 quench which should help reduce the chances of spark knock.

The head package consists of CNC porting on the intake, a 1.900 intake valve, new guides (only on the intake unless the exhaust needs to be replaced) and seals, a multi-angle valve job, milling the head to achieve the desired cc in the combustion chamber, and ceramic coating the exhaust ports. They don’t really mess with the exhaust port much since it is supposedly pretty good straight from the factory. I had them go ahead and install manual compression releases since I was bumping to 10:1 static and have to deal with 100+ degrees in the summer. Figured an extra $100 now would probably save more $$ and time in the future.

On their recommendation, I went with the Andrews 54H cam and stuck with the stock chain drive since it doesn’t seem to have any of the issues of the previous spring loaded tensioner setup (yet).

Assembly was about as uneventful as could be, except for me letting a wrist pin locking clip fly across the garage, then dropping it down in the engine case. ****!!! Didn’t have the rags stuffed in there quite good enough I guess…. No luck fishing it out with the magnet, but it somehow stuck to the left side flywheel and I was able to grab it when I rotated the engine over. I was thinking if I wound up having to crack the case to get the stupid clip out, I might as well bore the cases and go big. Project for a later day thank goodness….

Once all the pieces were buttoned back up (no leftover bolts/nuts/screws), I hit the starter. Fired up on the first crank and idled like a champ. I have just over 600 miles on it now and decided to do a compression test. Rear cylinder came up at about 188, and the front was dead on 190 which equates to a perfect 10:1 on the BigBoyz calculator.

I have the FatCat quiet baffle and love the new sound. It is actually a bit quieter than the 96” with the Andrews 26 cams which I wasn’t expecting but is a nice change. I also am running the T-Max with autotune, but I’m going to head back down to Dallas this spring and get a custom tune from Ed @ The Dyno Difference on PhilM’s and Ultrakla$$ic’s recommendation. It runs really good and pulls hard with the current setup, but I’m sure that I’m leaving some performance on the table by not doing a custom tune. Be on the lookout for a lightly used T-Max later….lol.

First riding impressions…. There is a noticeable difference over the 96” with the Andrews 26 cam. It rips through the gears, but where I really notice a difference is on the highway in 6th. Keep in mind that I have the Evo 49 tooth clutch sprocket installed as well, but the engine just doesn’t sound like it’s working very hard anymore. Pulling a incline in 6th with the 96” would be a chore. The engine really sounded like it was having to labor to get up the hill (not mountain, just a typical highway hill). Now it just motors along like nothing is going on. This is with my detachable fairing loaded with an amp and 6x9 speakers and my 250 lb **** on board. Like I said, it runs good with the T-Max, but I can’t wait to get an actual custom tune done.

I’ll attach a few pics of the pieces before they were assembled. Most of us have seen pictures of other teardowns/builds, so I’ll skip most of the repetitive stuff…..

Newly bored, honed, and milled jug




Closeup of crosshatch




Top of CP piston with AMS laser etched logo



Side of piston with rings installed



Bottom of piston



Cleaned up topside of the head with compression release and new seals visible



Intake port with new guide and valve seat. You can see marks where they hand smoothed after the cnc job. They look rough, but are smooth to the touch.



Exhaust port



Combustion chamber with new 1.900 intake valve



I wanted to post this review since I really couldn’t find much about these guys on the forum except from people that had gotten their FatCat from them. I’m really pleased with the build and wouldn’t hesitate to go with their build again in the future. I’ll follow up after I get my dyno tune done. If anyone has any questions, I’ll be glad to answer as best I can.

 

Great post, very informative, and appreciate the pics. Sounds like you hit a homerun, and with the final tune back in Dallas you should be right on the money. Well done, and thanks for sharing with us.

 

Congrats on your build and thanks for the pics. So this is a 3.90 bore on a 4.375 stroke?

Zach

 

Yep. 3.914 depending on the exact measurement of the piston. Just a hair over 105".

 

Nice build,so what was your total cost???

 

Let it rip tater chip!!!!!! Sweet headwork! I guess I'm gonna have to tear mine off now.

You are gonna be surprised how much is being left on the table with that Tmax.

Excellent writeup!

 

Let me think. I try not to keep track too much or these things might never get done.... lol. The machine work was about $1200 (including compression releases and shipping back to me), $250 for the cams, set of lifters from LSHD, gaskets, orings.... I'd say about $1700 total maybe. That's before a day at the dyno, so I'd guess a little over $2k by the time it's said and done.

 

Yeah, after talking to you, Phil, and Ed, I can't wait to get it down there. If I can ever quit going to Houston every 2 weeks I might get a chance to do that. Hopefully right after New Years...

 

I talked at length a couple of times with the guys at Automotive Machine about the 105 kit. Was about to pull the trigger when my local HD dealer offered to do the 103 upgrade and dyno tune at a very good price about this time last year, so I did that instead. Glad to see the write up on the 105, it was exactly where I was headed. I am very pleased with my set up I have now, but the future may bring another 96ci bike that is in need of an upgrade. Next time it could very well be a 105 from Automotive Machine in Ft. Worth.

 

Thanks for the write up. I am just down the street from these guys, and was wanting to hear from someone with their 105". I am trying to decide between the Head Quarters 107 and the AMS 105. I can't wait to hear more from you.