heads or big bore
 

Hi guys I am in England and amnew to the forum,we have very few experienced HD specialists over here.I know this subject has been coverd alot, but I'm more confused now. I need morepower out of my 1993 fatboy, current spec, Crane Hi 4 single fire, air cleaner, EV27 cam, CV carb Yost kit, 2-2 exhaust soon to be 2-1. I was reading the engine build on the nightrider site stage 3. SE heads 83 Hp 87 Tq, good results, heads are cheap, the more I look through the HDforum I get more confused, i can spend more money so always like to see whats out there, S&S super stock kit comes recommended but is $3-400 more and you need tochange pistons, S&S specs is 81Hp and 83Tq, lot more money and work for less HP if the nightrider site can be trusted.I have looked at RP big bore kits, getting my heads done. Not sure, I travelling to florida in sept, getting married thought I'd try and pick up parts while I was in the state. anyone recomend any good dealers. standard head work seams slow and unreliable, many claims out there.
I know S&S are quality but the SE heads are supposed to be good, also edlebrock are mentioned.I need advice from guys who have done these conversions, should I go the simple route with the SE heads or spend a little more money and get more bang!! I still want reliability, Any help please guys would be appreciated.
andy[8D]

RE: heads or big bore
 

Hello There,
I have a similar setup to yours presently on my FXR. I have collected all of my parts and intend to tear down the top end in the next week ot two. I am installing the R/P 85" cylinders/CP piston combo with ported SE heads, a V-Thunder EVL 5015 cam, V-Thunder lifters, TP roller rockers and S&S rocker boxes. I have a dual/single fire Dyna ignition system and will go over everything.

I am associated with a R/P dealer, so to be fair it can not be said that I do not run what I sell. I have spent alot of time and have spoken to alot of different people. This combination ought to run extremely well. When all said and done, I probably would have been better off financially purchasing a new engine and keeping the original.

Larry's Motorcycle and Machine in Oak Lawn Illinois, performed the head work on the SE heads. There are many competent folks in the business. Larry knows what to do to make the right type of improvements to the SE heads. He also does what he says, is honestand gets the work finished on time. The SE heads when portedlike to flow the best at higher lifts, hence my cam choice withoout loosing all of the bottom end. I hope this has been helpful and not more confusing for you. Visit us in Florida or on the web at WWW.choppersspirit.org.

RE: heads or big bore
 

Hi Andy,

It is easy to be confused with what can be done! I am also in England and have owned Harleys since the 1970s. My 1990 FLHS currently has a JIMS stroker kit, high comp pistons, ported heads, etc, but will shortly get a new S&S 107 engine. I have been down the EV27 route, similar to you. :)

There are actually limited choices available. You mention big-bore kits, but I think your crankcases suffer the same short-comings as mine, and are not suitable for boring out, as the castings are too thin, hence my stroker kit. Indeed if you tune the engine highly there is also the risk of stripping the cylinder studs, even shaking loose the drive-side main bearing! I reckon I have pushed mine about as far as is sensible, hence the new motor. :D

So unless you are willing to fit replacement cases be wary of tuning too highly. New or modified heads with new pistons are straight-forward, ditto cam and carb, but decide what you want to useyour bikefor before getting too enthusiastic! Most of us ride the bike below 4,000rpm, whereas many engine mods will only give real improvements above that. I have chosen my 107 because it is expressly tuned for touring, and has better low down torque than a 124! [8D]

As you havejust discovered HDF, spend some time browsing, as you will find plenty of info here! :eek:

RE: heads or big bore
 

thanks for the advice, do think i will probably go with SE heads and 85" RP kit.
andy

RE: heads or big bore
 

Hi guys, just been directed to cyclerama's website and they have some high horse power claims for evo's,113Hp from head work and cam, you guys have any experience of these guys, say they have been in buisness since 1976, seems to good to be true.

RE: heads or big bore
 

Not to rain warm yellow water on anyone's parade, but it really seems to boil down to what you want your bike to do.

I've got a 'stock' EVO (1993 FLHS), slight overbore (with the new top end), stock heads that have been street ported, EV27 cam, SE air cleaner, Dyna 2000 ignition,and SuperTrapp slipons with 18 discs. My bike does everything I want it to do, will do it day in, day out. And get 40+ mpg. Two-up, loaded (I pack a lot), 70mph, and in the wind.

Ya want to race 'light to light': Dump the Fatboy and get an FXR.

RE: heads or big bore
 

Yepper,
Won't disagree with Hackd's comments.There are alot of trade offs and personal choices with engine builds.After the kit is installed, we get some breakin time and minor jetting changes it will be off to the dyno. Then we'll see what this old FXR has got or doesn't have ;).

RE: heads or big bore
 

Lookin' forward to the dyno results ......... what will you be happy with ? Must be a figure in mind. Will you leave it alone then ?

RE: heads or big bore
 

The bottom line is how do you intend on riding your bike.Big grunt comes from big cubes.If you want to buzz the motor all the time do the head work.In all years and experimenting, the best bang for the buck comes with big cubes Period

RE: heads or big bore
 

I appreciate all your advice, I could not agree more with hackd, I do realise that your use of the bike is important I am just trying to see all my options.thanks