ST4 modifications at BCM Ducati

I just slipped a pair of Leo Vince CF cans on my ST3 a few days ago... curious how my bike will respond to that header mod. Will have to wait untill I can afford a PC]I[usb so I can map to match the new setup.

I really don't think that header mod does much. It may be worth it if you have the exhaust off or you just want to experiment. But don't count on much of a boost. It's just a small change in restriction.

That's a big improvement. My 04 ST4S stock max hp was 105, with Remus slip-ons, BMC
filter and Mathesis tune, it increased to 113rwhp.

sorry More coffe please. (Edit)

Thanks Dan! Impressive results.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sdg &raquo;</TD></TR><TR><TD CLASS="quote">Thanks Dan! Impressive results.</TD></TR></TABLE>

You're welcome. I've got over 3,000 miles on the modified engine and it runs great. Still getting over 50 mpg on every tank. It doesn't burn a drop of oil. Starts right up and idles fine. If I didn't tell you that it's been modified you'd probably not even notice; except for the additional 15% power. Oh, sometimes when I downshift for a turn and the rpm's are just so... I notice that "cammy" exhaust sound that comes from longer duration.

However these cams are close in duration to stock cams so it's barely noticeable. Too bad. I really like that "race bike" cammy exhaust. Know what I mean? I suppose the trade-off is good low end power with the short cams.

These engine mods are proving to be a pretty good bang for the buck (in my opinion). I was reading an old issue of Cycle, and it turns out my 1989 FZR1000 had 3 hp LESS then this modified ST4. Wet weight of both bikes was close. I remember that FZR and how fast it was. I never thought a Ducati Sport Touring machine could approach it. I was wrong.

Next up: wheels.


Modified by DanST4 at 8:16 AM 7/15/2004

fit the light closing springs if you want the cammy sound. my 851 has a great brump brump brump to it at idle.

and a heap of fuel coming out the exhaust. that kind of runny eye idle. can't wait till i get the 944 with heavy closing springs built.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by brad black &raquo;</TD></TR><TR><TD CLASS="quote">...brump brump brump to it at idle, and a heap of fuel coming out the exhaust. that kind of runny eye idle. </TD></TR></TABLE>

Good one...I've never heard it described quite like that (brump, brump, brump).

I've been getting quite a few e-mails with questions about the collector mod., so here are a few more photos of the collector modification on an ST2 and an ST4. It's really pretty simple when you look at it, and I think Mike charges $75 including shipping.

I think it's a little louder too, so, you know [shrug]... I got that going for me...

http://home.neo.rr.com/mkmain














Modified by DanST4 at 5:56 PM 3/20/2005


Modified by DanST4 at 6:05 PM 3/20/2005

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by infoage1 &raquo;</TD></TR><TR><TD CLASS="quote">
Dan, can you post your air/fuel charts?</TD></TR></TABLE>

Finally I have the full throttle A/F chart from last year. Top graph is from 2004, the AFTER run (after the BCM engine mods).




And then below, another full throttle run, from this year after BCM made some changes to improve low speed running. They leaned it out down low and it's much more "streetable" now and does power wheelies easier too. Red is NOW, Blue is last year right after the engine mods.







Modified by DanST4 at 9:31 PM 5/13/2005

Tried to post a link to an on-bike movie I shot, but couldn't get the link to work.

Well... I just reached 19,000 miles and it's still running great. Recently rode to the BMWMOA rally in Lima, Ohio and averaged 50 mpg. It didn't burn a drop of oil on that 1,700 mile trip. The engine idles perfectly, starts right up, and sounds so nice at idle. You can tell it's NOT a stock engine. Those Beemer owners were doing a double-take whenever I burbled by. I love this bike.

120 HP at the rear wheel is just about right for a sport touring motorcycle, but more is better in my opinion.

Too bad the ST4R is not going to make it into production. I was really looking forward to a 150 HP sport touring bike. I guess I'll have to make one because that's the ticket in my opinion. 150 HP, under 500 pounds wet, adequate wind protection, and the wonderful Ducati chassis. Can it get any better?

One option would be to drop-in an ST4S engine with all the mods, and add light wheels and a nice swingarm.

BCM did good on this one!

Bruce is selling a 1026 motor w/150+ hp for 4500. It's not a straight bolt in but I'm sure you could get it to work. Plus if you sell yours than it's almost free.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by foggy123 &raquo;</TD></TR><TR><TD CLASS="quote">Bruce is selling a 1026 motor w/150+ hp for 4500. It's not a straight bolt in but I'm sure you could get it to work. Plus if you sell yours than it's almost free. </TD></TR></TABLE>

I've been thinking about what to do next. I'd like another 30 HP but that's not gonna happen for any kind of reasonable expenditure. Too much money and too many mods. This 916 runs great and has been 100% reliable. I'm going to leave the engine alone and get some light wheels next spring to pep it up, lighten it up, and improve the handling and ride.

Maybe in a few years Ducati will come up with something in a Sport Touring type machine with a lot more power, or potential. Until then I'm sticking with this reliable, peppy ST4 Mod Rod.

[DanST4]

Just hit 20k miles and this thing still runs great. It actually feels faster now, does power wheelies easier, and is smoother too. I ride it like I stole it, use the engine, rev it up (but stay away from the limiter), treat it like any other bike I've owned and it just keeps ticking.

If I had to do it all over again I'd add some displacement (it's still just 916cc) and get light wheels right off the bat.

BCM built a good one for me and it was well worth it!

[DanST4]

I was looking on Ducati.Com and noticed the new Monster S4RS -

"the legendary Testastretta engine now powers the leading street fighter motorcycle. Designed with the most experienced riders in mind, who expect the best in terms of technology, performance and componentry, the Monster S4Rs sets a new standard in the category, benefiting from all the experience gained in the World Superbike Championship."

So... if they're putting the 130HP testastretta engine in the Monster, I would think the ST4R is coming. Right now all you can buy is the ST3, which is not a bad bike at all. But some of us want MORE POWER, big time POWER. And if they put the 130HP engine in the ST frame... they'd sell me one immediately (unless they screwed up the plastic and made it look like a Battlestar Gallactica thing).

All you'd have to do is port the heads, add R cams, maybe go up in displacement a bit, and you'd have a 150HP Ducati Sport Touring machine. Perfect!

It may be a year or two, and it may never happen. But I for one sure hope it DOES happen. The ST4R would be a great addition to the Sport Touring line. Offer the ST3 for those interested in a lower-priced, very nice, air-cooled touring machine, and the ST4R for those wanting the ultimate water cooled, high horsepower, GP Touring Machine.

Ducati, DO IT.

[DanST4]

Well I bought a 955cc Ducati Performance kit (at a very nice price) which includes the cylinders. Of course it also requires that the cases be machined! Oh well, maybe over the winter.

I was thinking of going a little bit larger on the intake and exhaust valves while I'm at it. Maybe the 955cc kit plus bigger ports will get me to 125HP or so at the rear wheel with a stronger midrange. That would be nice. And a balanced crank would be nice too. Yes I'm keeping this bike forever.

I picked up some forged magnesium wheels and hope that's a noticeable difference. Got a nice, clean used ST4S aluminum swingarm too. That's a winter project (once I find all the little hardware that's needed).

Now after all this watch Ducati release the ST4R with the testastretta engine. Doh!

[foggy123]

When you get your kit could you measure the cylinder stud spacings? Maybe throw a 900 crank in it to push it to 984 since you'll have it open. Or we could get some custom rods/pistons made for a 1000 crank. I think ducshop can have rods made if you order 4.

Originally Posted by DanST4

Well I bought a 955cc Ducati Performance kit (at a very nice price) which includes the cylinders. Of course it also requires that the cases be machined! Oh well, maybe over the winter.

I was thinking of going a little bit larger on the intake and exhaust valves while I'm at it. Maybe the 955cc kit plus bigger ports will get me to 125HP or so at the rear wheel with a stronger midrange. That would be nice. And a balanced crank would be nice too. Yes I'm keeping this bike forever.

I picked up some forged magnesium wheels and hope that's a noticeable difference. Got a nice, clean used ST4S aluminum swingarm too. That's a winter project (once I find all the little hardware that's needed).

Now after all this watch Ducati release the ST4R with the testastretta engine. Doh!

[DanST4]

Originally Posted by foggy123

When you get your kit could you measure the cylinder stud spacings?

Got the kit.

Measuring by eye, and using nothing more than a pocket scale, I measure approximately 3 11/16" x 2 7/8" which is about 94mm x 73mm.

Is that the same spacing as a ST4/916?

[DanST4]

The miles keep piling up on this BCM engine and it just keeps on ticking. I just did the first used oil analysis to see what's going on. The engine has over 23,000 miles with the R intake cams, SPS exhaust cams, and higher compression. Stock bottom end.

Chromium is at 0 ppm - the original rockers are still good.
Iron, Copper, Lead, Tin are all near zero.
Molybdenum is at 220 ppm - moly oil additive in the past.
Nickel, Manganese, Silver, Titanium, Potassium all zero.

All the oil additive elements are at appropriate levels.

Fuel dilution was below 0.5% so no fuel system issues.
Antifreeze was at 0% so no leaks there.
No water.
Insolubles were at 0.3% so the air and oil filters are doing their job.

$20 oil test from Blackstone Labs.