I will be buying an '06 Dyna in the next few months. The stock engine just isn't going to cut it.

So the plan is to get new SE pistons and bore the stock barrels to fit. SE cams, 203's probably, maybe 251's. Push rods and lifters. Race tuner, not just a reflash. Air cleaner. Slip ons (2-1 not available). And a couple of other small things to make it all work.

The heads are the real issue. The new stock out of the box '06 heads are pretty good, but not good enough. At the very least a clean up and pocket port. Maybe a full port job ($$$).

So, here's my two questions for today (they'll be more):

1. With this package in mind, does the overbore actually add much value? It's only an 8% increase in displacement. It is cheap (relativly speaking), only about $200.

2. Head work. I want a torque monster which will rarely see 6,000 rpm's. How much head work is really needed? What was needed for the '01-'05 heads to make good bottom end torque?

Rumor has it the new '06 HTCC heads are shipping soon. But that could be just a rumor.

There will be other issues I want to address later. But I need a little more research before I can ask educated questions. Thanx.

 

Keep your stock heads and have them ported by a reputable company.Dont was your money of SE heads. Boring from 88-95" is very much worth it. Stay away from the SE 203 cams, they are real underachievers, and power comes on in the midrange and lacks down low. Depending on your compression ratio I would look to doing a good aftermarket gear driven cam and gear drive conversion. Best advise is dont buy a single thing till you have done ALOT of good research. Best thing to do is to learn how a cam works and how to match a cam properly with your other engine components and your own riding style.

 

American Iron Mag is running a series article on upgradeing the twin cam, cost vs performance. It started in last months issue.

 

Gear drive cams would be my first choice. But since this is a new bike, I kinda need to stay with SE parts to avoid any future warrenty issues. I know the chain drive is the weak link, and that means more maint and closer scrutiny. Maybe in the future I'll switch. Supposedly, the cam case is redesigned this year to eliminate those issues. We'll see. S&S doesn't have anything yet for this engine. When they do, I'll be looking to them for upgrades.

I've taken a close look at the cam specs. The 203's seem pretty mild to me. If I was building a small block ford, I wouldn;t even consider a cam that mild, even in a tow vehicle. The 511's appear to be a better cam for low and mid range torque. Do you think this is true? A well tuned EFI will tame a radical cam and yet still allow it to reach it's potential. I run a 290 roller cam in my Ford, and with EFI it's a sweet street driver.

I've been reading the AI articles. Read #2 last pm. Interesting, not a whole lot of solid data about what works and what doesn't. But a lot of good general info about the TC. Some comments seem to support my thoughts on cam choice. Maybe future articles will get down to the nuts and bolts.

As far as valve train goes, 511 cam, lightweight push rods, SE lifters, stock rocker arms and stock springs should carry the engine well through it's power band. ???????

 

Whether you use SE parts or aftermarket parts, your warrenty remains in tact, its just propaganda by the dealerships that you need to use their parts to keep the warrenty in tact. The cam chest was mildly redesigned, but the S&S geardrive setup is still superior and still fits in the 06'. All they did to the 06' was add hydraulic tensioners vs. the old spring loaded units. The oil pump in your engine was also improved. 203 cams are mid range cams, 204's are much better at low end torque, never heard of the 511's care to post specs?

 

Sorry, I meant 251 cam (brain fart). .579/.579, 244*/250*. I think the 203's are pretty mild. The 211 looks pretty good - less lift but more duration.

As I understand it, the new '06 heads and rocker arms are good to about .585 lift, and 5,800 rpm's. They already have the bee hive valve springs and light weight retainers (titanium?).

The cam plate has been redesigned this year, and the chains are single roller. The outer bearing ends are differant. S&S says they don't make any cams for it yet - I called and asked. Actually, they don't make any parts at all for the '06. Yet.

I'm shooting for about 10:1 compression, that works well at this altitude. The high comprression cast pistons with stock heads should yield about 10.25:1. The big bore flat tops about 9.4:1. Does that sound right? Either pistons will work. I'll have the heads shaved to make right compression. But from looking at them, the high compression would move the flame front up in to the head where it belongs.

As for head work, I'm leaning more towards a pocket port and general clean up. Shouldn't cost more than $500(?), and should be good at the lower rpm's where I need it. This isn't going to be a stop light drag racer. It's going to be a commuter and a long distance touring machine. Torque in the mountains is what I need.

Again, most of my high performance knowledge comes from V8's. So If I'm wrong here, please let me know.

 

Lift and duration(especially lift) specs on a cam are pretty useless as far as Im concerned. Duration just gives me a quick indication of what to expect from the grind, nothing more. The important specs are the timing specs, that tells me where the powerband is, and how strong that powerbandc will be. It also tells me what compression ratio will work best with that specific cam on pump gas.

About compression. Dont even worry about static compression numbers. They are pretty much useless until you know what cam you will be running, and then once you have figured out your cam, you will know what range your static compression should be set at to compliment the cams properly.

So lets start from the beginning real quick. Where do you want your bike to have its power range? What year bike do you have? 06' Dyna I assume? What is the stock gearing on the 06'? 3.15? Do you plan on doing mostly solo riding? Solo riding with alot of baggage? 2up riding? 2up riding with baggage? Are you a heavy twister on the throttle? Like to let the engine rev through the entire range? Or a grampa driver and shifter? etc etc etc

 

'06 Dyna Superglide, stock suspension and gearing.

I commute and ride alone. But we also do a lot of 2 up touring - loaded, through the mountains. By miles and time, probably 40% alone, 60% touring. I live at 6,400', and often travel to 11,000'. Most riding is two lane back country roadways, but there is some 85mph+ highway miles mixed in there. For the back roads, keeping it in 4th or 5th would be expected.

I like to use the throttle. A lot. I generally don't wind it up to 6,000rpm's, but I love torque. My last bike (turbocharged Evo) made 110 ft/lbs and I tried to use them all. Power band should be as low as possible, with a goal of 95-100 ft/lbs at less than 4,500'ish. It's a rare day when this engine will see 6,000rpm's. I generally short shifted at 5,000 to be easy on the motor. Banking into a corner, and then throtteling out is a whole lotta fun.

 

Hi bobcowan, decisions like yours are faced by everyone which part what price how much performance, there is a mod for every need. I have 3x Twincams 2001 fxstd,2002flstf,2005flhr all receiving engine upgrades which are done by myself none of my bikes ever see the inside of a service shop. Been engine building and servicing for 30+ years. MegaHDman is totaly correct in his advice research into where you do most of your riding and target the parts required. There is a list of upgrades I have just installed on my flhr, I use the bike for touring with heavy loads and also look for long engine life.

-Heads- used standard but cleaned ports up.
-crane roller rockers any good brand is ok.
-95" with flat top pistons.
-HD 95 cylinders.
-SE adjustable pushrods.
-Andrews 26G cams.
-S&S gear drive.
-Delkron cam support plate.
-Fuelling oil pump.
-HB 125 ptimery chain adjuster.
-Mikuni 42 carb & air cleaner.
-standard exhaust with left side removed(cut at Y piece and patched to form bend) fitted SE muffler from fatboy.

This combination gives good performance for the style of riding I do. But the more you research the harder it gets. Follow the basic rules dont go over the top listen to people with the proven records. I will be buying a streetbob for my wife when existing issues are addressed as I will not be taking bike in for warenty or service work.