better acceleration

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Jun 12, 2017 | 07:46 PM

#11

1997bagger

Seasoned HDF Member

Joined: Aug 2008

Posts: 5,080

Likes: 2,153

From: Ohio

Going off a fellow members 3.34 lead here on that bike, changed my 3.15 to 3.34 and then added a 30 tooth trans drive sprocket along with a 89". Yes the accelleration was good but 65 mph on a interstate wasn't for the weak with rpm's, only way out of accelleration gearing and interstate was a OD6 trans gear set so be careful on your direction.

I know SE makes a 21 tooth compensator chain and sprocket but dam you are going to be geared low, I'm not to sure they make other sprockets to split the gearing but never persued that too deep. A 30 tooth trans sprocket will work but the belt adjustment will be out to the end, Andrews makes a 31 tooth sprocket but alot of work to change out trans sprockets.

Another member mentioned the W6 cam, sounds like your not interested in a cam swap BUT at 9.25-1 compression the SE54's 48 intake closing with the 250/260 duration the engine is going to need a pusher vehicle to get it moving. Something with a 40 or lower intake closing is a good direction, the big cam and low gear ratio doesn't work with a Harley like the old school car hot rods, just speaking from experience, not trying to tell you what to do.

If you allow us to spend your money you will keep the 3.34 and install a S&S 111/124 or Ultima 127, any direction you go, it is going to cost some coin to get just be a little quicker, we are way ahead of you in doing crazy stuff for power so you cannot ask a stupid question on here. Some Evo section power addicts have sold a kidney for 3 hp and one guy hid a 127" from his wife in a garbage can so you can trust us

Last edited by 1997bagger; Jun 12, 2017 at 08:00 PM.

Jun 12, 2017 | 08:01 PM

#12

Beemervet

Ultimate HDF Member

Joined: May 2006

Posts: 6,590

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From: Ohio

SE heads should give you 9.5 compression.

lol97

Jun 12, 2017 | 08:05 PM

#13

98hotrodfatboy

Seasoned HDF Member

Joined: Mar 2010

Posts: 21,093

Likes: 7,622

From: Poolville

Quote:

Originally Posted by bentparts

Thanks for the input guys, appreciate the suggestions. I feel the gearing is so tall that I can't use 5th gear on most back road cruising. I'll keep my Mikuni, I've trie other carbs and nothing, imo, is as smooth all through the power band as the Mikuni. Compression is estimated at 9.25/1 BTW, I worked at an HD dealership for a couple years and that's how I was able to build the bike. Gonna look into the fewer tooth engine sprocket.

At that compression I would go with an EV27 and if you have not already a .030" head gasket to bring it up to 9.45 static which would bring your ccp to 180 psi........... the 36*ivc will do your motor a little more justice..... easy bolt on.....

Jun 12, 2017 | 08:07 PM

#14

1997bagger

Seasoned HDF Member

Joined: Aug 2008

Posts: 5,080

Likes: 2,153

From: Ohio

Quote:

Originally Posted by Beemervet

SE heads should give you 9.5 compression.

lol97

That's what I was thinking with 72 cc heads and 8.5-1 compression unless the older engine is at 8.25-1

Jun 12, 2017 | 09:41 PM

#15

Tommy C

Seasoned HDF Member

Joined: Oct 2015

Posts: 13,491

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From: Pine Flat Dam/South Bay Area, CA

SE heads, W6 cam, stock pistons & .030 head gasket will give you 185 ccp. That's the setup I'm running in my 80in FXLR.

Jun 12, 2017 | 10:18 PM

#16

Owtlaw

Road Warrior

Joined: Oct 2011

Posts: 1,376

Likes: 36

From: Round Rock, TX

Baker drive train should have a compensator sprocket to do what you need. I think you can go a tooth with the same chain, but check with Baker to be sure.

Jun 13, 2017 | 04:56 AM

#17

grbrown

Club Member

Joined: Jun 2007

Posts: 45,429

Likes: 2,898

From: Bedford UK

I fitted a 21T to my Dyna and transformed the darned thing - much better bike. There used to be a SE kit of comp plus chain for a street-based drag class IIRC. Riding with lower overall gearing is no problem at all - especially if we wear ear plugs on longer rides, as we all should. The bike will be fine!

As for your gearing feeling tall I'm a bit mystified by that. Either your bike has modified gearing or the tune of your engine is working agin you. Being a jonny foreigner my FLHS was originally International spec when new and had a 61T rear pulley, instead of the US spec 70T (which it now has). Which do you have on your bike?

Jun 13, 2017 | 04:26 PM

#18

bentparts

Thread Starter

Road Captain

Joined: Apr 2009

Posts: 501

Likes: 150

From: Jersey

Quote:

Originally Posted by Beemervet

SE heads should give you 9.5 compression.

lol97

I'm going by what my machinist told me ( A 35 year Harley engine building specialist ) He did all the machine work, I did all the assembly. It does require a certain technique to start it and labors a tad on the compression stroke, but once running is a very nice engine. Rip snortin midrange to redline with a classic lopey cammed up idle.