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Discussion Starter · #1 · (Edited)
Lightened flywheel? Quicker reving but what else can be expected?

Stroking an older Ironhead? HP but lose reliabilty?

Port and polish? Race cams?

Is this just puttin a top hat on a pig?
 

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The lightened flywheels were for drag racing mostly. On a street bike they would really kill your low end torque and make the bike hard to live with in traffic and taking off from lights, ect. As for the other stuff, a little headwork, decent cams, ignition, pipes and carb will really wake up and old Ironhead. BUT (there's Always a But!) I all depends on what you are looking for. If you want a little more power out of the old Ironhead and can afford it, then go for it. If your looking at competing with the newer HD's out there, your wasting your money. Not to say it can't be done, It Can, but at a cost, Money$$ and Reliability.. Remember that A newer 1200 Sporty has a lot of factory R&D in it. The Sportster of today has already addressed all the shortcomings of the old Ironheads. If you get a chance, hop on a newer 1200 Sporty and you'll see what I mean. Would I buy a newer HD? Never!! I like my older Harleys and always will but I worked in the shops back in the AMF days and Harley has come a Very Very Long way since then. Hope this helps. Pony.
 

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Discussion Starter · #3 ·
PONY said:
The lightened flywheels were for drag racing mostly. On a street bike they would really kill your low end torque and make the bike hard to live with in traffic and taking off from lights, ect. As for the other stuff, a little headwork, decent cams, ignition, pipes and carb will really wake up and old Ironhead. BUT (there's Always a But!) I all depends on what you are looking for. If you want a little more power out of the old Ironhead and can afford it, then go for it. If your looking at competing with the newer HD's out there, your wasting your money. Not to say it can't be done, It Can, but at a cost, Money$$ and Reliability.. Remember that A newer 1200 Sporty has a lot of factory R&D in it. The Sportster of today has already addressed all the shortcomings of the old Ironheads. If you get a chance, hop on a newer 1200 Sporty and you'll see what I mean. Would I buy a newer HD? Never!! I like my older Harleys and always will but I worked in the shops back in the AMF days and Harley has come a Very Very Long way since then. Hope this helps. Pony.
THX...I'll get away from lighteneing the flywheel.

Pipes--Is back preasure the answer? Can I get more back preassure from making them longer or am I going to have to put baffles in? Seems when I put the pipes with baffles in it runs faster. Running drags now.

Carb--I could never get the S&S carb to cooperate with me so I picked up a ZB with adjustable mj. Seems like I lost a little top end but but I dont have the flat spots through the band like I used to. Was this a mistake in your opinion as far as overall performance?

I'm really looking for more pull off the lights but don't want to kill the sound.
 

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Do a plug chop to see what it's doing on the top end. A little richer jetting might help the top end. Have you tried turning the main jet out a 1/4 turn at a time and checking the results?? It will Never match the S&S on top end but does quite well. Pipes are a whole another thing. My bike sounds like s*it with baffels in the pipes, so I run streights. If your looking for out and out power, look at the Harley drag bikes, they run medium length pipes. The exact length ditcates what rpm the power cure ends. The formula would drive Einstine nuts! Back in the late 70's when everybody and their mother was halking snake oil pipe set ups that was going to give you xx% increse in power, Choppers Magizine did a Hot Pipe Shoot Out. They used a mild Shovlehead with Superglide pipes that had the rear baffel knocked out. (short drag pipes with the factord tapered mufflers). They dyno him and then put around 12 different sets of pipes/headers/stock/ect on it, dynoed each one and lastly his pipes and re-dynoed. The end result was that his set up out performed half of the others, was even with a lot more and a couple did slightly better.
 

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Is this just puttin a top hat on a pig?[/QUOTE] Exactly!!!!!
 

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when we put my motor back together this summer we polished the exhasut ports, put rowe valves in and an S&S on it - I dont like the S&S for this setup, it wont run without the enricher pulled out and then it fouls plugs very quickly, gonna put the ZB back on and see what that does.

The bike does run ALOT better than it did before, no way to tell if it has anything to do with the carb, polishing or just the fact that it is now in a much better state of tune.
Put in a new clutch (kevlar) and it seems to work well. I run drags and I really like the way they sound, dont think I would change for a few extra hp.
 

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A good friend/old crusty Harley tech. has raced forever and showed me a neat pipe tuning trick.

-Grind portion of good sized washer flat and weld to short bolt (think lollipop).
-Drill hole in each pipe to accomodate bolt size.
-One washer on inside of pipe on nut and one on outside, put nut on bolt.
-DO NOT OVER TIGHTEN!

You now have an adjustable baffle. By having maximum surface area exposed you get maximum back pressure. Less surface area, less back pressure.

He uses this technique/trick for tuning on the dyno and at the track.
 
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