HarleyTechTalk

Anyone have an idea of how much power the S&S 89cc Super Stock heads are good for out of the box? I am trying to hit around 135-140hp out of my 126 with 4.125bore x 4.75stroke...

Running a 45mm Mukini, Im at 122hp/137tq. I realize this carb is pretty small so I just got in a S&S G modified by dan davinci, venturi is bored to 49.5mm.. With the new carb Im hoping it will get some more air in the top end, but I am wonder if these heads will not flow enough out of the box?

Running a D&D boarzille exhaust. Don't know CR or cam unfortunately.

Thanks

I don't have a lot of experience with S&S heads, but those heads will flow around 260/270 cfm at a .550 lift, more info on the heads will get you a more accurate answere, intake port size? valve size? cam info also?
That small carb is holding it back.
...Bake...

2.000 inch intake and 1.605 inch exhaust valves

I am not sure what cam is in this engine

None of the head porting guys have any feed back on these heads???

Quote from: Merc63 on December 23, 2011, 09:29:40 PM
None of the head porting guys have any feed back on these heads???

Out of the box, I'm not too sure how well they work.  I know Hillside has had good results from porting them, and so has Kendall Johnson.  Maybe make a couple calls to some head porters about them. 

Also... I just looked at Tman's website and he offers both a Stage-3 & Stage-4 port on those heads.  I'm sure he would have some information of out-of-the-box #'s. http://tmanperformance.com/heads.htm


K.

http://harleytechtalk.com/htt/index.php?topic=7971.0
This one made 147/147 SAE with just a little buff and fluff

I have seen the box stock crate 124 make 140-150 hp with an S&S man,S&S carb w/thunder jet, and good flowing stepped head pipes. If I remember correctly it made about 142 with the 48 Mik and wood large air filter. The heads should not hold you up.

Quote from: Deweysheads on December 24, 2011, 07:16:29 AM
http://harleytechtalk.com/htt/index.php?topic=7971.0
This one made 147/147 SAE with just a little buff and fluff

Who was it that got all in my face the other day for suggesting it's better to attach images to the forum instead of providing links to off-site locations...?

Quote from: 1FSTRK on December 24, 2011, 07:52:16 AM
I have seen the box stock crate 124 make 140-150 hp with an S&S man,S&S carb w/thunder jet, and good flowing stepped head pipes. If I remember correctly it made about 142 with the 48 Mik and wood large air filter. The heads should not hold you up.

Don't feed folk's that bull"Potty mouth" about 150 hp from a crate 124"ers.
THEY DON'T.

  Who needs Oprah!

Quote from: Hillsidecyclecom on December 24, 2011, 11:16:42 AM

Quote from: 1FSTRK on December 24, 2011, 07:52:16 AM
I have seen the box stock crate 124 make 140-150 hp with an S&S man,S&S carb w/thunder jet, and good flowing stepped head pipes. If I remember correctly it made about 142 with the 48 Mik and wood large air filter. The heads should not hold you up.

Don't feed folk's that bull"Potty mouth" about 150 hp from a crate 124"er, because it is a LIE.
THEY DON'T.

So what are these heads good for out of the box? I have a 4.75inch stroke so I think this engine needs a lot of air at higher rpm.  I'll attach a dyno sheet when I get home, the torque blasts up quick and low but starts to almost instantly fall on its face.

My Friends 124" S&S was hitting 145/150 but his was built, Leineweber cams and a lot of compression.. you can feel the rumble when riding beside it.

Quote from: Barrett on December 24, 2011, 12:17:53 PM
My Friends 124" S&S was hitting 145/150 but his was built, Leineweber cams and a lot of compression.. you can feel the rumble when riding beside it.

Yep.

Quote from: Merc63 on December 24, 2011, 11:54:06 AM

So what are these heads good for out of the box? I have a 4.75inch stroke so I think this engine needs a lot of air at higher rpm.  I'll attach a dyno sheet when I get home, the torque blasts up quick and low but starts to almost instantly fall on its face.

You really need a bigger carb
Follow Deweys link in the post above and look at the specs. He did buff and fluff the heads as he put it but he made 10 more than your looking for. If you install the carb you may have to try a baffle change and some dyno tuning but you shuold be close to your goal. What ignition are you using? I've seen the bestresults with the DTT on carb bikes

Quote from: 1FSTRK on December 24, 2011, 02:39:40 PM

Quote from: Merc63 on December 24, 2011, 11:54:06 AM

So what are these heads good for out of the box? I have a 4.75inch stroke so I think this engine needs a lot of air at higher rpm.  I'll attach a dyno sheet when I get home, the torque blasts up quick and low but starts to almost instantly fall on its face.

You really need a bigger carb
Follow Deweys link in the post above and look at the specs. He did buff and fluff the heads as he put it but he made 10 more than your looking for. If you install the carb you may have to try a baffle change and some dyno tuning but you shuold be close to your goal. What ignition are you using? I've seen the bestresults with the DTT on carb bikes

How can I change the baffle on the boarzille? I thought it was welded in there? Is this Modified G carb going to be big enough? The venturi is bored to 49.5mm and it has a signal booster added to it, no Tjet though, the guy that built it said it wouldnt need it....

I believe the ignition is a Dyna 2000. This engine was built about 8 years ago.

Id like to see around 140hp from this engine if possible without cracking it open.. Possible cam change in the future and maybe some head work... But I want to know if doing that is worthless if my new carb cant support that flow or something else is restricting it.. ?

Thanks guys.

Quote from: Deweysheads on December 24, 2011, 07:16:29 AM
http://harleytechtalk.com/htt/index.php?topic=7971.0
This one made 147/147 SAE with just a little buff and fluff

I'd love to be putting out those numbers or at least very close to that. Could you PM me the cost of doing my heads up like that???

Quote from: Hillsidecyclecom on December 24, 2011, 11:16:42 AM

Quote from: 1FSTRK on December 24, 2011, 07:52:16 AM
I have seen the box stock crate 124 make 140-150 hp with an S&S man,S&S carb w/thunder jet, and good flowing stepped head pipes. If I remember correctly it made about 142 with the 48 Mik and wood large air filter. The heads should not hold you up.

Don't feed folk's that bull"Potty mouth" about 150 hp from a crate 124"ers.
THEY DON'T.

Scott do the 126 G2 engines pull 150/150 out of the box or do they need head work to get there.

Quote from: Hillsidecyclecom on December 24, 2011, 11:16:42 AM

Quote from: 1FSTRK on December 24, 2011, 07:52:16 AM
I have seen the box stock crate 124 make 140-150 hp with an S&S man,S&S carb w/thunder jet, and good flowing stepped head pipes. If I remember correctly it made about 142 with the 48 Mik and wood large air filter. The heads should not hold you up.

Don't feed folk's that bull"Potty mouth" about 150 hp from a crate 124"ers.
THEY DON'T.

I would like to correct my original post to say that it was not "box stock" but I stand by the fact the heads were.

[attachment removed after 60 days by system]

Is there a difference between the evo style heads and TC?

Quote from: Merc63 on January 08, 2012, 10:25:03 AM
Is there a difference between the evo style heads and TC?

I honestly don't know. I do know that this was a motor from Dragspecialties and maybe S&S can tell you what heads are installed on what motors.
Sorry for any confusion that my post may have caused you.

Quote from: Merc63 on January 08, 2012, 10:25:03 AM
Is there a difference between the evo style heads and TC?

The ports are basically the same. Cam geometry differs.
John

Is it better on the TW or on the Evo?

Evo tends to be more friendly with tdc lifts on high lift cams.   
John

How can you be chasing numbers and swapping parts when you don't even know what CR and cam is in it? How do you know the thing was ever put together right?

Zach

Quote from: biggzed on January 09, 2012, 04:04:13 PM
How can you be chasing numbers and swapping parts when you don't even know what CR and cam is in it? How do you know the thing was ever put together right?

Zach

I assume it was built right, but you are right we don't know the internals as this engine was built over 7-8years ago and the guy who did it no longer works at the harley shop where it was assembled.

I can tell by the dyno sheet that its having a hard time breathing in the higher RPM. Torque shoots up fast but quickly starts to fall on its face.  Just by changing the exhaust to a boarzilla gave us over 10+ hp and flattened out the torque curve. Obviously the 45mm Mukuini is too small for this size engine.. Once the new carb is on and we see the result from that, we can either dig into it more (cam, heads) or leave it alone.


I see no other way to reach my goals other then experimenting? Do you have any ideas?