HarleyTechTalk

Looking for thoughts on build,  going to put together a 98 as soon as this last piece is done.  I have a 2000 RKC with MM injection.    this is going together with Hillside 98 piston with -2.3 cc and Big Boyz 05 heads street ported match cc at 84.  cam is Andrew 26G and 1.725 rockers.   SERT , Thunderheader 2:1 .     corrected compression is 9.05:1      Should I leave the Magnetti 38 alone or go to a 42mm from Gerolamy,  got a guy that want to sell me a 50 HPI.     in my head says to leave the 38 mm and raise the rail pressure with new regulator.   welcome all thoughts.    

Yes I know you will all ask what type of riding,  I am half and half with long rides and also get up and go right now.  

Bob(FLTRI) welcome your thoughts on this since you will be doing the tuning.

Use the red injectors, BC bored TB, and no additional fuel pressure, not needed. Done several that way and the tuners report they tune fine.

>Looking for thoughts on build<

You might as well leave it stock.

put a carb on it.   

Carb Mag Morelli=  pain in the Ass 

  I have no problem taking care of this MM and 4 other MM bikes.  they are a very simple injection system.  I will stick with the set-up... they just got a bad rap from the HD crowd, many other bike use them.

>Looking for thoughts on build<

You might as well leave it stock.
the mm will probably work fine... if it was working before as stock ..... no real power gains anyway with the MM and this set up........sorry.......I'm cranky and tired ..i do like the 26..but not the MM

Built many back several years ago and the 26 or cams with similar duration were about what the MM 95" motor wanted. After that due to the law of constraints the TB became a road block even bored, not injectors or the fuel pressure. If we wanted to jack the pressure a little we would just alter the stock regulator. Guys tried bigger cams just to give up low end torque for very puny power gains. Tried a carb swap on one and went up from 90 -100 with that one change. My prediction for this build 95/95 with a good tune. Redeeming factor is the pipe and that will need the baffles modified to get away from the TH dip more than likely.

Quote from: PanHeadRed on November 11, 2009, 03:17:01 PM
>Looking for thoughts on build<

You might as well leave it stock.

seems like a nice reliable build compared to stock. should be around 90/100 or there abouts. 

From my experience, the MM is good for 100hp before it becomes the choke.
If it were me I think I would see if I could find a NOS SE throttle body. They relocated the injectors to where they should have been in the production piece (directly spraying on the valve) but I guess Willy G didn't like the looks of the injectors from the left side of the bike.
IIRC the SE piece is 43mm. It worked very well and could support 110hp no problem.
As always, JMHO,
Bob

My same experience. The SE43 is a tough piece to find but works. The MM injectors stock shoot straight down, what were they thinking??

Anyone have a part # for the Screaming Eagle 43 mm throttle body,  I was checking out the Horsepower MM 48, it looks like the injectors were relocated on that unit. 

Threw in an Evo item for good measure.    

J02462    SE-43 HIGH-PERFORMANCE INDUCTION MODULE FOR 1340 EVO,   27941-00

J02361    SE-43 HIGH-PERFORMANCE INDUCTION MODULE REBUILD KIT,   27500-01

J01790    SE-43 HIGH-PERFORMANCE INDUCTION MODULE FOR TC88,   27615-00

Dewey,   you ain't kidding about trying to find that S.E. 43mm throttle body....   I have been trying to locate one.

I have seen in the dyno, GMR Steve used one of the HPI 48mm set up and worked out really well with basically the same set up I have other than the heads. 

One one with tw37 cams we saw a 10 hp jump with a HPInc 51 from a stocker 90-100 hp. Torque remained the same at 100. Too spendy though to do that change IMO, ~1k after parts and tuning. At that point I would be looking at a carb, same result.

Quote from: JohnCA58 on November 11, 2009, 10:10:55 PM
Anyone have a part # for the Screaming Eagle 43 mm throttle body,  I was checking out the Horsepower MM 48, it looks like the injectors were relocated on that unit.  

Check this out:
http://bikerbobsstore.com/index.php?main_page=advanced_search_result&search_in_description=1&keyword=27615-00
I don't know if they actually have stock but worth a call,
Bob

JMO
I'd opt for the HP Inc 48MM conversion to Delphi type single bore intake
you get the best of the delphi type single bore, better injector pattern
and a large enough TB at 48MM

I'm sure to start a flame war but it's been proven that going to a larger throttle body will
not hurt performance, ie if you can use a 43 and max out at 43 mm TB flow, a 48 won't
hurt performance. IE outside of putting a trash can sized tb on a smaller engine
it's better to have a bit more than not enough...

One thing you could do is flow the intake and then compare the MM TB flow,
a SE 43 if you can find one and the 48's flow numbers. You don't want to restrict flow.

I know you like the MM but I've helped with a few conversions to carb still not a bad idea
when you compare costs of upgrading to a larger TB

Also I've seen a Dakota Kid bore out a TB on a hopped up 80 with heads, cams, pistons etc
nothing even after tuning...

Plus the new intake looks cool

I did call Biker Bob HD,  they didnt have one  oh well told them to update thier website.  

After doing some reading,  I have notice that some say the 97 on up MM throttle body for the EVO will work on the TC up to 01, Is that true?  if I can find a EVO S.E. 43mm I can make that work.

John, give Harley Davidson Customer Service a call. I've had good luck with them locating a dealer that stocks a part I couldn't find locally. Sometimes the dealer has one sitting on a shelf, part of their inventory. Worth a try.

Quote from: Deye76 on November 13, 2009, 08:20:47 AM
John, give Harley Davidson Customer Service a call. I've had good luck with them locating a dealer that stocks a part I couldn't find locally. Sometimes the dealer has one sitting on a shelf, part of their inventory. Worth a try.

Also dealers can search the nation for stock at other dealers, if they are on the same system, which most are now,
Bob

Deyes, Bob,  just got off the phone with HD Customer.    we all knew it was a obsolete part, and NO ONE has that part in the system.   

I got a line on a HPI 48mm with red injectors and air cleaner for pretty good price,  I think I just finished my last piece and will start on the bike next week...   Thanx guys

OK, not the last piece, I need to start thinking about the clutch now.  it hasnt slipped with the 26 in there yet.  wonder how it will hold up with the 98 set-up.   I am hoping to be close to a 100/100 set-up

Consider the 48 or 51mm with delphi style injectors, not the Marelli. Read back on Bobs post about injector angles. Also stay clear of any of the early ~2003 vintage HPInc stuff. Call and talk to Eric and he will tell you the generations and the ins and outs

OK, good info there,  I thought the MM48 had the injectors realigned with the intakes,   so only the MMX48 has the Delphi injectors and lined up with intakes?    heck by the time I get home the mid east and east coast is shut down,  will need to talk to HPinc and get more info.  thanx Dewey.