Shovel Top End
#11
You should have your cylinders rough bored, but not finish honed. Then, order the pistons, and finish to size. For a 74 inch motor, the Andrews AB or A2 now, is a nice performer with about 9-1 CR. I wouldn't waste my time with porting stock heads for a 74" motor. If you want more power, srtoke it. Then it will really run good. I never could see sinking over a grand in a 74, after all, it is still only 74 inches.
#12
#13
Im running KB 9.5:1 pistons, 3 angle valve job done by me, with new guides and seals, electronic ign, andrews A/B grind cam, cycle shack single piece 2 into 2 exhaust, S&S super E carb--.295 idle jet and 72 main, and after dialing it in, had some ping..... adjusted the ign to get the ping out and had a stutter, so wound up having to put the final drive gear ratio back to stock (it was geared for highway speeds) once i did that and timed it right on the money with a light, runs like a bat outa hell! but if you use KB pistons, break it in nice and easy.......and it'll last you forever!
#14
These need some kind of dommed piston because they are a Hemi design, I had dropped compression to 7-1/2 :1 but it never would burn clean, just re-doing it now and went with Wiseco 9:1, my Indy that did the machine work recommended it, he's been doing H-D motors for thirty years and races Nitro's on the side, so I trust his call.... billy g
#16
For instance, S$S builds some of the fastest and quickest race bikes in the world, and they apply the technology to street motors and provide us with parts that have a high degree of reliability. We break the parts (racers and streeters), and in some cases send them back so they can make them better. In the end, we the consumer, get a better product. It's a big circle.
The key to any performance upgrade is parts compatability/reliability, and your builder knowing what he is doing, ie getting the air/fuel in the carb and out the exhaust as fast as possible. Is your builder guessing at what might work, or is he using sound principals in your build. You are the one paying the bill.
As far as the shovelhead, you will not get the performance out of it that you will get out of an EVO with similar upgrades, just due to basic design. That doesn't mean that you can't get a shovel to run good. With the products available on the market today, it's nothing to get a 80" shovel to roll 100 HP on the rear wheel, and have a very high degree of reliability, though you aren't going to get that kind of performance out of stock cases, cylinders and heads. (notice I didn't say STOCK 80" shovel) Now apply those principals to the 74. Performance is tied directly to your pocketbook.
Last edited by AlCherry; 04-30-2010 at 07:06 AM.
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