DIY Engine Mods

With winter coming on and decent riding days fewer and farther between I'm think about putting a H-D/Screamin' Eagle big bore stage II kit on my '06 Softail myself.

I know, I know... "You'll void the warranty!" But I'm not worried about that.

Even though I've never been that deep into a Harley engine, I'm pretty confident in my mechanical skills to do this myself and I have a decent if not complete shop in my garage. I know there are some specialized tools I might need buy or borrow. Plus I'm already going to be taking the bike apart to put on chrome engine covers, braided ss clutch, throttle and idle cables, etc. I have all ready put on a SE stage 1 air cleaner, Rinehart staggered exhaust, and a PowerCommander IIIUSB with the appropriate program (no factory ECM upgrade though).

What I'm looking for are any tips or considerations from those of you who have done this sort of thing (other than "don't do it" ). My biggest reservations are replacing the cams and whether to stick with my stock heads or get the SE HTCC CNC ported and polished heads (recommended by the parts guys at the dealership)

Thanks for any help in advance.

95" kit

In this month's issue of American Iron Magazine Donny Peterson talks about achieving 1+ hp per cubic inch from the 88 cu in Twin Cam motor just by getting the heads ported and polished. That's more hp than what you would gain from installing just the 95" kit without the head work. Imagine what could be gained by doing both???? Plus even more gains if you installed the Kuryakyn cams that's being talked about. Good luck and keep us posted. I would like to do the same to my 06 Road Glide but I don't have the shop and limited mechanical skills.

I just read that article the other day. I guess I need to go back and read it again because it apparently went in one ear and out the other (so to speak)! Thanks for the input. I will definitely keep you posted.

I'm thinking I may just port and polish the heads and add cams for now and forego the 95" kit. Then again, if I'm going that far I might as well go big! I'm also looking at heads on e-Bay that were taken from the same bike as mine; that way I'll have minimal downtime in case of a surprisingly nice day like today was (we were supposed to have thunderstorms).

Engine Mods

STRAN,
I would go for the whole package(IMO).True,A displacement change only probably would not produce BIG H-P,But combined with more cam lift & duration-
I think you're scooter will surprise you with it's hidden power potential.Note:The
special tools needed for this job will be in the price range of $$$350.00(all worth
it).One thing I would recommend is make sure before you bolt down the lower
rocker cover;You check for clearance between the exhaust valve spring retainers & the inside corners of the lower rocker cover.(applies only if new heads or larger valves used).With some common mechanical sense & PATIENCE you should have no problems.

Cams, Heads and Tools... AARGH!

Ok. I'm stuck for two reasons.

1. This is getting more expensive than I anticipated.

2. Can't Decide on heads and cams.

I can't decide if I should port and polish my heads or I'm looking at the Screamin' Eagle Pro Head. Without decking my heads and using flathead 95" pistons I'll get 9.4:1 compression. Using the SE heads I'll get 10:1.

Then I can't decide on cams. I'm looking at S&S 570G's or SE-257's they have similar characteristics. With either of these sets, I'll probably want the higher compression, but I'm not crazy about decking my heads. I found a deal on new in the box SE pro heads for $550 on e-bay, so I may go with those. Also with the S&S cams I'll need to do some grinding for clearance, but I get more accurate timing and I think longer life than a chain with that high lift.

Then if I get a high lift cam I need roller rocker arms for longer life of my valve stems. Which means modifying my rocker boxes for clearance. The SE heads already accomodate .575" lift cams, but I would have to put new springs and valves in my heads.

Also to buy my own tools to replace the cams and remove/install the pistons I'm looking at around $500.00 for a one shot deal. Still beats the $70.00 an hour labor though.

I could go on forever. I'm thinking now to save money and still have decent performance that I will just put the 95" kit, leave my heads alone and put in a mild cam like the SE-204. But I'd really like to see if I can get that 1+ HP/ft-lbs torque per cubic inch without going overboard.


Any suggestions or advice is appreciated. Like I said, this is my first time out on a project like this and I want to do it right the first time myself. I'll keep y'all up to date on my progress.

Very simple formula really.

Take on part TC88A engine
Mix with two jugs bored to 95" specs.
Add flat top 95" pistons.
Add TW37 cams
Add appropriate fuel control i.e. Power Commander or carb kit with adjustable ignition.
Add good exhaust.

Viola! should be at least 90+ ft lbs torque.

I am pulling 95+ ft lbs of torque but my HP is lower than it could be because I did not modify the heads.

The thing to remember is that when it comes to performance, parts ain't parts. It is like a jig saw puzzle. Choose the wrong pieces and it will not go together. The first step is to decide the end goal and make sure that each piece will be up to the task.

Yepper, CD, should that simple formula be shaken or stirred? LOL.
Sounds like you’re a bartender/mechanic telling someone his secret simple formula for the properly mixed motor. Lol

On the serious side and as CD says, “parts ain’t parts”. You can spend a whole bunch of money and end-up with a motor with 10-15 more horse power, is a ping-master that’s hard to start and gets poor mileage. There are many people out there riding a ping-master, please don’t be another one. It is up to you.

You say the warranty is unimportant to you,,, Ummm, OK.

Some things to think about.

What is your riding style? Where does your motor spend most of its time? What kind of softail is it? 1up or 2up?
What are you after? A stop light to stop light hot rod or a highway torquer.
How much are you willing to spend?

From reading your post it seems like your interested in ported heads, high lift cams and chasing that 100/100, and then saving money with an milder build.

The biggest mistake take that folks make is too high of compression for their cams application. Ping. It is better to go with a ‘little’ to much cam than not enough, but, the right combo is the better idea. You don’t need an high lift cam to make horse power, there are hundreds of motors out there with cams .510 and under, that are breaking that 100/100 mark.

There are several head porters out there with proven combinations that work. So relax, spend some time and do your home work and get it right the first time, you will then save a whole bunch of money.

95"

Had a friend go to the Dealer (?) and do the 95 to his ST. Broke it in for 750 miles and took off for the Wall. Did not make it to Albuquerque before the balancers went out (unkown to him at the time) .. he spent many days trailering and riding and getting things welded and finally back to CA. The Dealer fixed it alright.. for another 3500 bucks. Seems the warranty on the work done had nothing to do with the balancers ....... Funny, Factory says that they do not reccommend 95 in the B motor unless the balancers are removed and no, the Dealership did not remove them. I have real bad tastes for the D word and loads of proof. Find a wrench from the old school and pay the bucks to get it done right the first time. Another note before you start smokin' down the road ..... the cam plate is a piece of garbage and always has been. Lost my (check valve stuck) motor on a 99 Dyna with 70k miles on it. Front to rear the cases were cracked. Funny, three service changes and Factory still puts pot metal with steal check valve. I'm no rocket scientist but two dissimilar metals expand at different temps... duh!
Go with the quality and buy the cam plate, also .. cheap insurance. Quick and dirty on the module inputs... disconnect the battery for 12 hours and when you hook it back up... ride it like you stole it. The computer senses this and adjusts to it. With what you have done already, you should notice quite a change with that. But power is all about power and money.
You get what you pay for when it is done right the first time and the way you want it.

Being that we are talking H-D's here...I'd say definetely shaken.

cstran,

Hotrod is totally correct about the SE heads.
SE Performance heads, (to me) are one of the best deals going right now. You can pick a brand new set off eBay for less then $600 and with a little clean up are great for moderate builds. You must be aware that the SE performance heads only measure out to around 76-78 CC’s though. (Think compression).

It seems what a lot of folks are doing, is buying an extra set of heads off eBay for around $200, and then having them ported/CC’ed to match to their intended build, (cams/compression/cubic inches).

Do you need to have your heads ported? No. Folks with lower budgets are just getting there heads a 15 minute ‘clean-up’ if anything… The stock heads are a good design and have been proven easily support 90 horsepower, and with/if your tuner knows his stuff the can make around 100 HP, but that’s about the limit with stock heads without more serious porting, (which is pretty darn good).

Do a little home work, think before you send $$$, and you will be fine and have the big-grin

88 B Motor

Got to tell you that the motor was stock and went to the D and after about 1k miles, it went south. Did you not go downstairs to do the work for the 116? This fellow went with reworked heads and 95 bore, SE cams (with the chains of course) and reprogram the box. And, like I said, the dealer fixed it after 4 to 5 weeks of downed prime time (plus the 3 plus weeks of travel) at owners cost to the lower end. You tell me who got the shaft. This is a 2003 ST Springer. Myself, I went to the Branch package and Dakota Kid with the Pro One+P V&H with S&S roller and pushers, Feuling Oil pump and lifters on my 00 FLHTC. This muther screams and is very dependable. Note to Feuling owners, 1/2 quart or more less on the oil change or you will be looking for your dip stick. Been there done that.
Ride Hard / Stay Hard
When yer able
w