2.5s closed deck (impressive triumph)

[Gerald]

Indeed, serviceable cylinders are nice touch... if you can keep a few extra.

In this case, I'll casually disagree with the 2.5 being any stronger until proven otherwise. While a closed deck would ultimately have a higher threshold for cylinder walk/shift/distortion if all other things were held equal, the block itself is ultimately weaker than 2.3 offering, what with it being split down the middle. At the power level that a closed deck becomes (more) necessary, you're going to have far more issues with cranks, transmissions, rods, and clutch components.... pretty much everything stock in that engine would likely fail before the cylinders started moving around enough to be an issue. If I were betting on it, I'd say around the 700-800hp mark at very high rpm is what it would take. and there is simply not enough chassis to put that sort of power down. Might be fun to find out one day, though.

Pretty certain I'll never have the opportunity to find out.

 

[Kevin frazier]

 

[Mongler07]

Who cars if its stronger. It probably isnt... the point is its strong enough to do the job 5 times over for probably 1/10 the cost it took last time.
Its design over $ not ..... is this the beast.

 

[GPMAZ]

Personal attacks, no matter how subtle, aren't appreciated. Please stop.

 

[Jagster]

My understanding is that the main design criteria for the redesign/revision of the Rocket, was to make the engine and frame more compact and to reduce overall weight. This intent was to improve the riding dynamics of the bike.
If the use of a 'closed deck' design helped achieve those objectives without blowing the budget, then they could conceivably have chosen this solution regardless of the pursuit of more engine performance.
At the end of the day, the limitations to a bike with an engine the size of the Rocket, is riding dynamics. Therefore, I deduce that more power wouldn't be be a priority over handling/dynamics on the 2.3 to 2.5 redesign.

...Just my thoughts on the subject.

 

[Kevin frazier]

big changes

 

[TURBO200R4]

That is one strong spring probably 1000 plus

 

[Speedy]

Freestanding sleeves have one very large advantage: they stay round either with temp changes or pressure changes. Closed deck motors always distort under both conditions, plus under cylinder head bolting loads. Thus, engine builders will resort to "hot" honing, using torqued in place deck plates when boring and honing, larger piston to cylinder wall clearances, and ring designs that are more tolerant of out of round bores. The top 15% of the cylinder undergoes the most heat and pressure changes during use. So, if a sleeve doesn't hold up under use, make them with thicker walls near the top. Additionally, how and where the head is bolted to the block affects the clamping load between deck or sleeve and head mating surfaces.

Another over-looked issue is cooling. Uniformity of cooling efficacy around the entire sleeve and from one end of the motor to the other is almost never achieved. Pumping coolant into a block at one end, metering its flow from block to head via hole sizes in the head gasket, and dumping it out the other end, is about equal in technological sophistication to Fred Flintstone's vehicle drive system.

Modern head gaskets can use self-energizing seal rings, copper rings, or other technologies to seal those mating surfaces. If a good head gasket won't maintain a seal on a sleeve, it is most likely a bolt/stud problem, a design issue with their location and/or quantity, or the rigidity of the block or head that is the root cause of the failures.

All vehicle manufacturers have cost/benefit issues to consider and manufacturing constraints. So, we get compromises best suited to intended use and profitability.

 

[Mongler07]

Freestanding sleeves have one very large advantage: they stay round either with temp changes or pressure changes. Closed deck motors always distort under both conditions, plus under cylinder head bolting loads. Thus, engine builders will resort to "hot" honing, using torqued in place deck plates when boring and honing, larger piston to cylinder wall clearances, and ring designs that are more tolerant of out of round bores. The top 15% of the cylinder undergoes the most heat and pressure changes during use. So, if a sleeve doesn't hold up under use, make them with thicker walls near the top. Additionally, how and where the head is bolted to the block affects the clamping load between deck or sleeve and head mating surfaces.

Another over-looked issue is cooling. Uniformity of cooling efficacy around the entire sleeve and from one end of the motor to the other is almost never achieved. Pumping coolant into a block at one end, metering its flow from block to head via hole sizes in the head gasket, and dumping it out the other end, is about equal in technological sophistication to Fred Flintstone's vehicle drive system.

Modern head gaskets can use self-energizing seal rings, copper rings, or other technologies to seal those mating surfaces. If a good head gasket won't maintain a seal on a sleeve, it is most likely a bolt/stud problem, a design issue with their location and/or quantity, or the rigidity of the block or head that is the root cause of the failures.

All vehicle manufacturers have cost/benefit issues to consider and manufacturing constraints. So, we get compromises best suited to intended use and profitability.

perfectly summited. The materials used today are VASTLY superior than the ones used even 10 years ago. i have no clue if these engines do or do not fall into that category but what i do know is tolerances have gotten 3x tighter in the last 20 years in most engines made recently in the last half a decade. There is a fine line between a thick distorting sleeve and a sleeve that is supper thin and dissipates heat evenly over uneven coolant passages.

 

[Dr.D]

Freestanding sleeves have one very large advantage: they stay round either with temp changes or pressure changes. Closed deck motors always distort under both conditions, plus under cylinder head bolting loads. Thus, engine builders will resort to "hot" honing, using torqued in place deck plates when boring and honing, larger piston to cylinder wall clearances, and ring designs that are more tolerant of out of round bores. The top 15% of the cylinder undergoes the most heat and pressure changes during use. So, if a sleeve doesn't hold up under use, make them with thicker walls near the top. Additionally, how and where the head is bolted to the block affects the clamping load between deck or sleeve and head mating surfaces.

Another over-looked issue is cooling. Uniformity of cooling efficacy around the entire sleeve and from one end of the motor to the other is almost never achieved. Pumping coolant into a block at one end, metering its flow from block to head via hole sizes in the head gasket, and dumping it out the other end, is about equal in technological sophistication to Fred Flintstone's vehicle drive system.

Modern head gaskets can use self-energizing seal rings, copper rings, or other technologies to seal those mating surfaces. If a good head gasket won't maintain a seal on a sleeve, it is most likely a bolt/stud problem, a design issue with their location and/or quantity, or the rigidity of the block or head that is the root cause of the failures.

All vehicle manufacturers have cost/benefit issues to consider and manufacturing constraints. So, we get compromises best suited to intended use and profitability.

So you saying you don’t approve?