103 build

[mikeyh5000]

Mike,
I bought cnc htcc heads, forged flat top stroker pistons 22942-00, 211 cams. The screamin eagle catalog says the cr for that head / piston combo is 9.8. I went with the 211 cuz its similar to the profile of the screamin eagle bolt in I put in my 94 sporty and I was very pleased with the results.
I had screamin eagle heads on the sporty and I don't know what the cr was but I gotta think its in the ballpark of where I'm at with this combo. Would you stay with the flat tops or go with the high compression htcc domes? I ride in the NYC area and spend plenty of time in hot summer traffic ( I used to think the sporty was gonna melt sometimes and listening to the valves slappin is never fun). Bottom line is I rode that sporty for 6 trouble free years and countless revs to the redline. Sold it last year to a young guy I still see around my way and several times now the bartender has put the upside down shotglass in front of me and said your next ones on him, as I look across the bar and see the guy who has my old sporty.
This is what I'm lookin for from my new build. I never dynoed the sporty but after increasing the vacuum on the voes and tweakin the super e it ran like a champ. Seat of the pants dyno told all.
Keep in mind that I already bought the parts including perfect fit rods, billet cam plate, se tappets, tp rocker boxes and roller rockers, b-168 cam bearings. I'm not looking to set any dyno records just steady reliable power that can pull on the open road. My bike is an 07 fxstc and I'm waitin for the weather to warm up a little cuz under 30 degrees is too cold for the garage. Any experience with this combo? Would the 50mm tb bog me down in traffic (i don't really care if mpg is only downside)? In the screamin eagle catalog there's a dyno chart of a 103 with cnc htcc heads and 22942-00 flat tops and 260 cams putting out big numbers 120/120. I was afraid of going too big on the cam.
I enjoy reading your forum and I apologize for the long wind.

Thanks,
Mike

[Mike]

Long wind? Have you seen my replies!! Ha, Ha!!

Normally we would like to see 10.2-10.5 compression with the 211's to help low end tq. Also, just for the record, we like to see the 251 cams to take advantage of the lift available in the heads. The 251's are very similar, timing wise, to the 211's and with slightly less duration and more lift, tend to build low end tq much better and they are a bolt-in to the CNC heads.

You may want to try Cometic .030 head gaskets to help build a little more cylinder pressure.

The dyno chart I believe your referring to appeared in the 2006 SE Pro catalog and was VERY optimistic and was not reproducable in the field (I tried it at school with hi-comps and HDU's dyno and did not come close). The numbers on the chart are 118hp/111tq. You'll note that those charts do not appear in later catalogs and those that do show much more conservative numbers (though not exactly the same packages). We just want to be sure our expectations are realistic.

Your concerns regarding heat and the fact you've already made the investment would negate those choices. The heat should be controllable via tuning so this would not normally be an issue.

The 50 Se t-body would not bog you down. Much of the tq losses associated with bigger bore carbs is a function of signal loss to the float bowl and emulsion tube. EFI bikes do not suffer from this. Port velocities are more a function of the port volumes and shapes and this is already build into your heads. BUT, the rest of the combo, entended use and expressed "not looking to set any dyno records just steady reliable power" really does not warrant the bigger t-body and so I would not neccessarily recommend it. I would recommend it with the 251 high compression version. Another part of that decision woudl be the exhaust. If you have a somewhat restrictive exhaust for low end tq, the bigger t-body would not give any advantage (not really utilized).

Having said all that, your combo, although conservatvie, will be a substantial gain over stock. It will slightly softer across the board (lower cylinder pressures) than the above recommendations but again, in theory, the lower lift of the 211's should help valve train life and noise. So, in the end it should be a very reliable user freindly combo.

Keep us posted on how it turns out!

[mikeyh5000]

Mike,
I appreciate the input. Using BigBoyz cr calculator as a reference the cometic .030 hg with 84 cc htcc heads and the flat tops give a 10.24 cr and a corrected cr of 9.22 for the 211's. Now if we pretend that $ is no object just how much more power would I gain from the 251 and the 50mm tb? Do you think the added compression(10.5 cr according to SE) and the increase in fuel/air going in via the 50mm tb would give me heat/detonation problems in heavy traffic? Naturally I'm all for max power as long as its reliable. I've seen some pretty impressive dyno sheets for the 211 and the 251 but since I already have the 211's I'm thinking how much difference can a 1/16" of lift make. Mike, I guess what I'm sayin is if you were building this bike for your brother that rides in NY what combo would you go with? I also want to shut up all the people that bad mouth HD/SE equipment by making a bad ass build. You guys have a great site and I really appreciate your help.
Thanks,
Mike

[Mike]

Thank you for the kind words.

I'm really a highlift fan and like to take advantage of that whenever possible. But it's really about the heads ability to take advantage of the added lift. On one hand, if the heads do not flow well, the added lift will not help high end power. On the other, high lift also means the valve is farther off seat at any point in time which helps cylinder fill and increases torque (effectively acting like a bigger valve). So there tends to be an advantage to go with high lift. The throttle body is also a function of the heads, but unlike the cam lift, if the head flow cannot support the added flow of the t-body, there is no advantage to installing it. My rule of thumb is that unless the heads are ported, the stock t-body is fine.

The added compression to 10.5 would help overall numbers and would be worth doing to get corrected closer to 9.4. I do not believe the 251's, 50 t-body or .3 more compression would cause issues when correctly tuned.

So, in the end, stock heads will do fine with 211's and stock t-body. Ported heads would do much better with the 251's and 50 t-body. The SE stuff has come a LONG way in the last 10 years and is proving hard to beat in many cases.