Mechanical Engine Tuning

[Sputniks]

I talked to Dyno guy at the race track today. I've mentioned to him that after Double Dog Exhaust + EVR airbox and short velocity stacks combo was installed the bike lost 15 HPs (comparing to what it was making with a stock airbox - stock velocity stacks and a full termi exhaust system). But I said that re-tuning the Power Commander's map returned 5 HPs back. But still the motor produces less HPs than it used to. We've talked for 15 minutes or so. He said that in order to get the best performance out of the motor the valves need to be tuned up first. The exhaust valve checked. The timing adjusted and so on. He said it takes about two weeks and 2.200 dollars to tune up the motor to its fullest potential. That work would be all mechanical and would not include the Power Commander tuning which is a completely different task.
It is not really an engine rebuild... Only the parts that show an excessive wear get replaced...
So the question is what kind of tuning is it? Why the engine would need a tuning like this. Once again, there would be no stock engine parts replaced or switched with some aftermarket... like with the titanium rods for example. The engine is being "tuned up". How come those local generic-motorcycle-mechanics tune the engine better than Ducati factory? Does anyone know anything about this kind of tune up work?

[Oahu_fighter_pilot]

that could be something akin to "blueprinting" your engine, but it sounds more like he wants to tuneup your wallet...

[Sputniks]

DucShop does the engine work:

A blueprinted engine will produce more power and last longer than a stock engine and anyone thinking of racing or doing track days on their Ducati should seriously consider the investment. When you get a street bike from Ducati it is assembled with very tight clearances so it is more likely to spin a rod bearing or wear other parts prematurely. Blueprinting will set the clearances closer to Corse specs as well as ideal cam timing, etc.

Blueprint:
Disassemble, clean and inspect
Blueprint rods
Check crank run-out
Polish and measure crank journal and install race specification bearings
Shim trans, shift drum and crank to Corse specs
Set ring end gap
Check piston-to-cylinder clearance
Shim cylinders to set piston squish
Adjust valves to Ducshop specs
Degree cams to Ducshop numbers per application
Set up clutch pack
Set up shift linkage and update
Lap-in valves

But since the entire engine is being dissembled and assembled again it would make sense to replace the stock key elements with the high-performance ones such as the ones distributed by Fox Racing:

a. Crankshaft Balancing
b. Valve seat and guide machining
c. Carrillo Con Rods
d. Pistal Pistons

[tjt1990]

Sputniks, have you tried putting your stock velocity stacks back in? I hear of no good results putting those on top of a basically stock engine. Might try simple things like that first before giving thousands away to some dyno guy. If you are having your dealership keep your cams degreed, belt tensions correct, throttle bodies sync'ed, etc, there shouldn't be anything else needed. Just bad combination of parts cutting some hp from your engine, some parts just don't work well together.

[Jonny DeWog]

Originally Posted by Sputniks

......
It is not really an engine rebuild... Only the parts that show an excessive wear get replaced...
So the question is what kind of tuning is it? Why the engine would need a tuning like this. Once again, there would be no stock engine parts replaced or switched with some aftermarket... like with the titanium rods for example. The engine is being "tuned up". How come those local generic-motorcycle-mechanics tune the engine better than Ducati factory? Does anyone know anything about this kind of tune up work?

If he's not replacing parts, then it's not blueprinting. Mechanics rarely give fixed quotes for engine blueprinting simply because they never know how many, and which (if any) of the engine's moving parts they will need to replace.

My guess is that he is talking about "dialling-in the cams": this is a routine improvement that is basically adjusting the timing so the the inlet and exhaust valves closure are centred at the exact degrees at TDC (there are some +/- tolerances from factory spec, so depending on how well or not your bike was assembled, you may or may not see some improvement). From the sounds of it he may also do a regrind of the valve seats and/or replace the stem seals if necessary (?! - Though I'd have to question why;how many kms has your bike done...??????)

At any rate $2200 seems excessive for this service.

How come those local generic-motorcycle-mechanics tune the engine better than Ducati factory?

Again, you'd only see improvement over stock output if your timing is to either side of the +/- tolerances. SInce your engine has been modified to give 15 horsepowers less, it's unlikely you will regain that much with simple timing adjustment.

I don't understand why you wouldn't just go the cheaper route of returning your engine to stock: instant 15hp gain........!

Never mind: your antics always keep us entertained.



jdw

[Sputniks]

Originally Posted by Jonny DeWog

My guess is that he is talking about "dialling-in the cams": this is a routine improvement that is basically adjusting the timing so the the inlet and exhaust valves closure are centred at the exact degrees at TDC (there are some +/- tolerances from factory spec, so depending on how well or not your bike was assembled, you may or may not see some improvement). From the sounds of it he may also do a regrind of the valve seats and/or replace the stem seals if necessary (?! - Though I'd have to question why;how many kms has your bike done...??????)

I think it is what he meant - the timing adjustment. Bike has 12.4K miles. He mentioned that they would replace only those parts that would show an excessive wear.
I have never heard about the "blueprinting". Here is what it is:

Blueprinting

In engine blueprinting, all the specifications are double-checked. Usually this indicates closer-than-factory tolerances, with custom specifications appropriate for a street car or a race car. The goals are either to re-manufacture the engine to the rated power for its manufacturer's design (because not all mass-production engines put out the rated power), or rebuild the engine to make more power from a given design than otherwise intended (because custom engines can often be redesigned to different specifications). Blueprinted components allow for a more exact balancing of reciprocating parts and rotating assemblies so that less power is lost through excessive engine vibrations and other mechanical inefficiencies.

Ideally, blueprinting is performed on components removed from the production line before normal balancing and finishing. If finished components are blueprinted, there is the risk that the further removal of material will weaken the component. However, lightening components is generally an advantage in itself provided balance and adequate strength are both maintained, and more precise machining will in general strengthen a part by removing stress points, so in many cases performance tuners are able to work with finished components.

For example, an engine manufacturer may list a piston ring end-gap specification of 0.003 to 0.005 inches for general use in a consumer automobile application. For an endurance racing engine which runs hot, a "blueprinted" specification of 0.0045" to 0.0050" may be desired. For a drag-racing engine which runs only in short bursts, a tighter 0.0035 to 0.0040 inch tolerance may be used instead. Thus "blueprint" can mean tighter or looser clearances, depending on the goal.

[Secret Squirrel]

I'm trying to be polite Sputniks. You're throwing away money if you do this. You're already in the hole 15HP with the combination of parts you've added. Lots of money spent and lessons learned. I hope. At this point you're paying to throw power away. Only now trying to regain some power by blue printing? To put this into perspective a stock SF off the showroom floor is making more power than your highly modified SF. I'm not trying to insult you at all here.

If you had a lot of miles on your SF and it was time for a complete engine tear down that would be another story. A good balance and blue print by someone that really knows what they where doing might be worth a few extra HP. But for you there is no need for this. The balancing is where you really gain the benefit. The blue printing is just the thin icing on the cake that goes with the balancing.

[Jonny DeWog]

You've answered your own question, but yes "blueprinting" involves disassembling and removing each and every moving part of an engine and checking each item to within the manufacturer's rated tolerance.

Any part is given as a measured size, give or take a little for machining/fabricating tolerances (given as "+/-" some small increment). Eg, here's a cross-sectional engineer's drawing of the valves/head on my old Guzzi:



You'll see that the collet distance is rated at 34.7 - 35mm, ie: a tolerance of +/- 0.3mm. A blueprinter would take that tolerance out and substitute it, or machine it, to give a part dead on 34.7mm and take out any play. Others may minimise it to 34.85mm as a "halfway point" (more important in air-cooled engines like the Guzzi that expand and contract with movement far greater than a liquid-cooled engine like the SF).

Rotating parts (eg gears, camshafts and crankshaft) are usually spun and calibrated for balance (much like your tyres on a car). Anything out-of-round, or unbalanced is adjusted (either re-ground or, in some cases, welded to give added mass) so that they spin perfectly balanced, (spinning unbalnced objects wastes energy and robs the engine of power).

Depending of how well, or how close to tolerance an engine was assembled, blueprinting can add up to 5% or so "extra" performance.

Dialling-in the cams (or zero-degree the timing) is a routine adjustment to ensure proper valve opening and closure in perfect synchronicity with the piston position. They involve vernier scales:



Again, I've used the image from my Guzzi manual, but the theory is the same for most any 90* v-twin. This is just another method of taking out any manufacturing "errors" (or more correctly, 'tolerances') and brings the cam timing back to dead-on 0*.......it can give some incrementally better engine performance, but that's only if your engine is poorly assembled in the first place.

But seriously, if your engine mods have lost you power, why not take it back to stock?? - that would make the most sense!!

You have to remember that our bikes are already in a phenomenomly high state of tune (specific power of 141hp/L...... The new Ferrari 458 Italia, by comparison, only puts out 124hp/L...!!!).

It just makes no sense that you make issues so complicated when there is no need for them to be so........

jdw

[Sputniks]

Is the dialling-in the cams (or zero-degree the timing) part of 7.5K and 15K miles scheduled maintenance work performed by Ducati mechanics?

[Jonny DeWog]

You would think........here in Australia they usually charge extra for that.

In theory it should be done each time the belts are changed. It's quite labour intensive so most Ducati mechanics simply "line up the notches" (near enough is good enough!!) and leave any differnces as being 'within tolerances'......

jdw