Author Topic: 535 pston kit  (Read 14629 times)

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Ducati Scotty

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Reply #15 on: February 23, 2011, 03:57:00 am
Just to clarify, you've put the Z91439 in a UCE engine?  Anything else get done (intake, exhaust, etc.)?  What were the results in a UCE?  Just calarifying since it says it's for the Electra and not the UCE specifically.

Thanks for the info SB.

Scott
« Last Edit: February 23, 2011, 04:01:15 am by Ducati Scotty »


r80rt

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Reply #16 on: February 23, 2011, 04:00:43 am
Looks like a good bump in compression would be had, should be a drop in too.
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ace.cafe

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Reply #17 on: February 23, 2011, 04:02:15 am
Got bumped out of queue so here goes again.   

Thanks ACE.   From the picture this looks like a flat topped piston.   Seems to me that for the Iron barrel there are both flat top 535 and "high compression "dome topped 535 postons.   Would I be aproximately right in guessing that a dome topped poston fits into the heat prot area tighter for greater squish of the same swept volum and thus even higher (than 7%) increase in compression ratio, with resultant bigger bang and greater power increase.?
To do to the UCE what  you did to the Iron Barrel would you need a dome topped piston?   Does this casue valve float problems in the confined space with your high lift cams.   do you think a high compression 535 piston will be coming down the pike no that we see a 535 kit. ?  Maybe things are moving along faster than we imagined in our earlier discusions on "48 hp bullet" ....Fortune favours the prepared.   Nigel.

Now, what about that name................flamethrower......Naw      Nigel

Nigel,
Yes, the dome crown on the piston creates a smaller chamber volume when the piston is at TDC, and the cylinder volume gets compressed into a smaller chamber, and the compression is raised.
Using the dome AND the larger bore volume will add together for final compression increase. and that will make a bigger bang.
Additionally, the larger piston area on the crown of the larger size 535 piston creates more area for the combustion pressure to work on when it burns, and this increases the force exerted downward on the piston(force=pressure x area), so this will increase the torque production of the engine.
So, you are increasing the combustion pressure AND the area that the pressure acts upon, so you are boosting both factors in the Force equation, and that results in more torque increase than just either one of them alone.
Since hp =torque x rpm/5252, this means that the increased torque will also result in more hp at any given rpm too.

My understanding is that the UCE uses an 8.5:1 piston as standard equipment.
That's probably about as high as it wants to go for a street bike on pump gas. Maybe there might be a little more room to raise compression, but not to the degree that the Iron Barrel bikes do, because the Iron Barrels use 6.5:1 compression as standard, and we raise it up to 8.5:1 or 9:1 with the domed piston.
The crown shape on the piston for the UCE will be different than the Iron Barrel piston, because the combustion chamber shapes are different, and can't use the same dome shapes. I think that the UCE has enough compression so that very little increase, or no increase may be needed to do the job on pump gas with the existing cam profile. If  cam profile is changed significantly, that will likely require a change to the piston to work properly with the new cams. Cam timing, particularly the intake valve closing timing will significantly affect the actual working compression ratio, and this must be taken into account. Compression doesn't actually build quickly until the intake valve is closed, and the later after bottom dead center(ABDC) that the intake valve closes, the less actual swept volume is available to build compression, because you are only working with some reduced length of the compression stroke after the intake valve closes. The dome size on the piston is sized to provide the desired working compression with the length of the stroke available after the intake valve closes. A good engine builder knows how to make this relationship work out in the desired way.

The piston has reliefs cut into it to allow clearance for the valves durin the overlap period, and this needs to be considered when cam lifts are increased. Sometimes there is enough room so that nothing needs to be changed on the piston, and other times changes are required. It depends on how far from the standard lift profile that you go. If you change lift profile enough, you probably need to change the valve reliefs on the piston crown.

In the UCE, I'm seeing a compression ratio that is sufficient for pump gas with the standard cams. If cams are changed to later intake valve closing timing, the piston may require some extra dome.
I think that with most engines, the power is in the head, and that's where the gains are to be made. Breathing is the key to performance.

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Ducati Scotty

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Reply #18 on: February 23, 2011, 04:03:14 am
I like a mod that's reversible and doesn't need a machine shop.  I guess I'd hone the cylinder walls for good measure but that's an easy DIY thing.

Scott


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Reply #19 on: February 23, 2011, 04:30:28 am
Now that I read SB's message, and look at the Nfield site again, I actually see a Z91442 piston which appears to be the same "high quality US manufacturer in conjuction with the RE factory" effort but in 535 cc.  ( How big a deal is it to rebore a cylinder head to 535? )
This also seems to be new.   (Seems like we have all been napping)   Taking this together with ACES comments about adequate compression ratio ot the stock arrangement, it is beginnning to look to me like we already have the basic essentials of a "Fireball" UCE., or at least a good part of it. 
 We have previously established that the "bottom end" of the UCE may already be beefed up enough to handle the extra power.   So with adequate copression , slightly larger displacement, "polished  heads" a la Mondello , ACE do we have the rudiments of a Fireball UCE?  Do you think your cams would require a different piston profile, or is that impossible to say without getting one on the bench.?  Would there be good benefits from using this piston, stock cams, and your head upgrades? (Maybe not as good as the whole monte but significantly better than stock without loss of reliability. )  I guess what I am getting at is how essential are the cam mods in the UCE where the compression ratio is already good?  Because if it is do-able without cam changes that necessitate a custom designed piston (which I gather is a tricky thing to engineer or fabricate) then the only missing piece of the puzzle may be the head mods.      Nigel
ACE could you use the   . laftoglt


Ducati Scotty

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Reply #20 on: February 23, 2011, 04:46:15 am
Ok, so my UCE factory manual has an Electra on the cover.  Was there also one based on the AVL?  That's what the catalog says it's for.  I'm so confused :P

Looking at the Z91439 domed piston, does that require a bore?  It doesn't say that and doesn't spec a bore for the part.

Nigel, I think the cams are part of the total fireball equation.  The sums is greater than the parts, each part plays its role.  I think there's some more to be had in a still reliable package with just things like intake, exhaust, EFI mods, maybe a drop in piston.  But as Ace says, work in cams and head work to the equation and you really start to get payback for your investment.  It's a system and no single piece would be the magic bullet.

Scott


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Reply #21 on: February 23, 2011, 04:57:43 am
I reread your earlier message ACE in which you referred to cam mods that delay the closure of the intake valve and thus limit the portion of the rising stoke of the pistom in compression during which effective compression can actually occur requiring a greater piston head dome to offset the loss of compression at the beginning of the stoke.   .   Is the reason that this delay in closure would be a desireable outcome of the cam mod that the benefit of the inertia or mementum of the moving incomng fuel air mixed stream a little later into the beginning of compression cycle outweighs the loss of effective compression at the same time?    Just trying to understand what the tradeoffs are.     Thanks very much by the way for your patient explanations for my benefit (and the benefit of the many silent listeners to these sites0.  I am sure explaining what seems obvioius to you can seem tedious.  I hope my questions are sufficienty mechanically naieve that the answers are  of use to the majority of readers.  For those of you out there that already get all this, apologies.      Nigel. 


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Reply #22 on: February 23, 2011, 05:13:33 am
Sorry to have so many tags in sequence here but the messages are crossing in the mail.   Scott,:  So far as I know   Electra = UCE.   It appears that there is some interchangeability between AVL and UCE bits because they are both allow cylinder heads......at least that is how I read it.   SB could clarify.   
The original piston I noted on the Nfield site at the beginning of this thread seems to be the heavy German one SB is dismissing.   The one he mentioned seems to be a drop in 500 cc that is just "better" than stock  though I don't know in what particular ???slipperier?     The last piston I mentioned , noting that it too appeared to be new is the Z91442/ 535 (not a drop in, but a cylinder bore job) though it appears to be made to the same standard as the one SB mentioned, and would therefore be the logical candidate for a fireball UCE .   The compression ratio may not need to be improed since it is already good, but the corollory of that is that the relative performance gains of Fireballing a UCE would be somewhat less than similar mods to Iron barrel because there you are getting multiple benefits including both increase in bore/displacement and surface area for downthrust AND increased compression ratio (more gasoline per cc of explosion) , whereas with the UCE you would just get the bore/displacement /suface area hike and , unless you deliberately raised compression from 8.5 to 9 (small incement) no compresison benefit.    At least I thikn that is what everyone said. 

What I still don't get is how all these great bits and pieces appeared without any fanfare. Nigel.


ace.cafe

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Reply #23 on: February 23, 2011, 05:50:02 am
I reread your earlier message ACE in which you referred to cam mods that delay the closure of the intake valve and thus limit the portion of the rising stoke of the pistom in compression during which effective compression can actually occur requiring a greater piston head dome to offset the loss of compression at the beginning of the stoke.   .   Is the reason that this delay in closure would be a desireable outcome of the cam mod that the benefit of the inertia or mementum of the moving incomng fuel air mixed stream a little later into the beginning of compression cycle outweighs the loss of effective compression at the same time?    Just trying to understand what the tradeoffs are.     Thanks very much by the way for your patient explanations for my benefit (and the benefit of the many silent listeners to these sites0.  I am sure explaining what seems obvioius to you can seem tedious.  I hope my questions are sufficienty mechanically naieve that the answers are  of use to the majority of readers.  For those of you out there that already get all this, apologies.      Nigel.  

Nigel,
Yes, that is part of what's involved.
One of the aspects of the port/cam match is to time the intake valve closing timing in synchronicity with the ability of the inlet tract to provide best cylinder filling.
After bottom dead center, the piston has already stopped at the bottom and is beginning to rise in the cylinder. We can make use of some of this time after bottom dead center to continue to fill th cylinder with mixture, even though the piston is no longer going down. The air/fuel mixture has mass and velocity, and there is inertia that drives the mixture into the engine for a certain time period after the piston stops going down. The ability of the intake tract to do this is dependent on the flow characteristics that are present.
So, the goal would be to set everything up so that during hard running, the intake flow continues to come in after BDC by inertia as long as it can do it. At that point we close the intake valve, capturing as much as we could get in there, and not leaving the valve open any longer than necessary to do that. Then, after capturing as much cylinder fill as we could get, we close the valve and begin to compress that mixture in the remaining part of the compression stroke.
I seriously doubt if anyone here has any idea how difficult that is to analyze and predict, and make parts that will do it. There is a huge amount of engineering required to reach that goal, and then testing to see if it really is doing it, and probably making change to the parts after finding out what isn't quite right, and testing again.
That's part of what went into the Fireball.
This stuff is not just happenstance. It is serious engineering that takes alot of study and math work, and then engineering the parts that will do it, etc.
It's the difference between having a "half-assed" job, and a job that really works right.

If somebody were to buy a "set of cams" that were designed for a Bullet with a different port flow characteristics than what they have in their head, or in a modified head, there is no hope that this port/cam match could possibly be correct. The cams absolutely need to be designed with the exact flow characteristics of the head included in the design, or it's wrong. That's why almost every cam you could buy off the shelf is wrong for your engine. It might work ok, and it might go fast, but it is definitely not optimal. The chances of optimal port/cam match with off the shelf cams and head from different manufacturers is probably nil.
And that is just one little part of the whole job.

You'd be surprised at how many racers and engine builders out there today don't even know what I'm talking about with this subject, or how to achieve it.
« Last Edit: February 23, 2011, 06:05:28 am by ace.cafe »
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Ducati Scotty

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Reply #24 on: February 23, 2011, 06:19:03 am
There was a pre-UCE Electra as well.  Not sure which markets it was sold in.  Looks like electric start and electronic ignition but still carbed. 

http://www.royalenfield.com/Motorcycles/retired-models/Electra5s.aspx

The UCE Electra on the cover of my manual has flat black hot dog boxes and a slightly shorter front fender but otherwise looks just like the G5.

Yeah, I guess some of the parts could swap between the motors.  My guess is weight, build quality, and shape are the main differences between the accessory piston and the stocker.  It may raise the compression a bit but who knows for sure.  As Ace says, it may give a little more power in a UCE engine but maybe more by coincidence than design if the UCE just happens to mirror the AVL engine closely enough in specs.  Either way, that's something I'd consider.  Also, as Ace said, we're starting from a higher point with the UCE than the modest 6:1 compression iron barrel.  Getting similar improvement in performance percentage wise may take a great deal more effort.

Ace has it all right, there's serious engineering getting all the parts to play well with each other.  The stock UCE configuration was just as much of a task but had other goals as well, like meeting all the various international emissions rules. 

Just another 'what if' thread for now but thanks to everyone for their input.

Scott


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Reply #25 on: February 23, 2011, 11:39:55 am
Nigel - You are about to lose your pea pickin' MIND here over this! My mod with the piston was a cheap, down and dirty, get it done with what I had to work with mod. I didn't wring my hands for days wondering about it or doing esoteric calculations. I measured the diameter .... good, the pin height ..... good, noted that the dome was flat rather than soup-bowl shaped, did a quick scratch-paper compression calculation and plopped it in. AND it worked WELL to improve the "butt dyno" feel - and since the first bike I did it to was slated to have the hell and be damned run out of it - I thought it'd be a good choice for that purpose. Again - check the clearance, drop it in, get more zoot ......

Of COURSE you can go a lot further with this .... ACE's hard work and research are proof of the concept. He has been a CHAMPION of the Iron Barrel development - and mighty nice to explain all the stuff in his head in infinite detail as well. I don't have the time or the facility to go that far with the mods that I want to see for the UCE. I have about 200 dealer technicians to attend to, so GO most often takes precedence over GO FAST. This is why the PC-IV project has been so drawn out. The piston was easy - and a no-brainer from my standpoint. Plus - research and development occurred between phone calls .......  ;)
Spare the pig iron - spoil the part!


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Reply #26 on: February 23, 2011, 12:37:33 pm
I can only imagine the complexities of these matching  issues.    I am sure also that the time honoured way of  engine performance enhancement  is expertly informed trial and error with continual adjusting of the interdependant parts back and forth to discover the "sweet spot" for any given desired performance parameter ---gas flow in this case.  
I wonder if there are Computer Assisted Design models of the flow /turbulence characteristics of gas/air mixtures from the automotive racing world  that could be applied to take some of the preliminary guesswork out of at least the initial stages of performance enhancement.  I don't suppose there is a lot of difference between single or multi cylinder applications in this regard.  Might reduce some of the finessing or at least move it to a closer to final approach.  

Quoted from an earlier thread:

"The cams are another thing again, because the UCE chamber is a different design which requires different things from the cams. However, cams could be made for that UCE platform to suit most any application. And the best choice would be to make them to suit, and if the hydraulic roller lifters are to be retained, there is no way to use solid lifter cam profiles with roller lifters. So, that would need to be done specifically for the UCE and my cams or Hitchcock's cams are not suitable for use with roller lifters. Again, it can all be done."

I am not sure that I fully picked up on the significance of that statement.
  When you say "solid lifter cam profiles could not be used,...but  it can be done"   What is the alternative type of cam that could be used, and , ACE can you do it?

Given all that you have said about the complexity of pairing cam profiles to the breathing characteristics of a modified head, would some of the fiddly work you did with the Iron Barrel Fireball mod  serve as a learning curve to effectively shorten the potential development path of a similar undertaking with the UCE, or is it  a whole new ballgame from the ground up with the same number of engineering and bench hours .
You implied earlier that the performance objectives led the design of the head modifications.  There was talk of RPM limitation of hydraulic lifters , changing stoke and bore , but in the end you came back to keeping the same stroke and using the RPM lints available -under 6000 I believe.    

SO   IF the goal was to more or less duplicate the performance characteristic of the Fireball,  could a head be designed for the UCE guided by exactly the same performance profile expectation without changing the hydraulic lifters or  fuel induction system keeping the same stroke , conrod , shaft and bearings,all below 6000 RPM, TRUSTING that the UCE bottom end and con-rod improvements are what they say they and if so  THEN ACE, does the Z91442 standard (8.5:1) compression  535 piston bring us a step closer to Fireballing a UCE?  You said before somewhere that half the cost went into "bottom end modifications"  I don't know if this means strengthening the bottom end or if it includes the cam profile work , and if so, how the cost was apportioned between these. (If only the cams need work then costs may be lower)

Yes all  just dreaming  of future possibilities, but then so was the Fireball project.  If my speculations about the market potential of the UCE are correct, the Iron Barrel Fireball may become a preparatory footnote to the next step.  Again fortune favours the prepared.   Nigel

PS In my defense, about typing, for some reason I only get about a 1 inch window to type in, and once a message passes a certain length, I am typing blind because it always reverts to the top of the box.  Weird.  I'll try the spell check .  


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Reply #27 on: February 23, 2011, 02:04:11 pm
Messages crossed in the mail again

SB   Thanks for the warning but , alas, too late for me.   The signs of insanity set in soon after I first saw the Bullet on the website at Jim's Raceway .....    where I was at the time searching detail on URALs and sidecars.   Since then the image of the Bullet and it's potential has wormed its way into my fevered imagination and there is no digging it out.   In this respect I suspect I am as crazy as Chumma, Aniket, ACE and others. 
Actually , reading where a recent  string went on the topic of end of life arrangements I am not sure I am any crazier than anyone else on here, but be that as it may........long winter , no riding ,, we all get a bit restless..

"All the world'st odd 'cept thee and me, and sometimes methinks thee is a bit strange " they say in Cornwall.     Or as the bard said,"Though this be madness, yet there is method in it......   " 
Regards, Nigel


ace.cafe

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Reply #28 on: February 23, 2011, 02:38:06 pm
 

Quoted from an earlier thread:

"The cams are another thing again, because the UCE chamber is a different design which requires different things from the cams. However, cams could be made for that UCE platform to suit most any application. And the best choice would be to make them to suit, and if the hydraulic roller lifters are to be retained, there is no way to use solid lifter cam profiles with roller lifters. So, that would need to be done specifically for the UCE and my cams or Hitchcock's cams are not suitable for use with roller lifters. Again, it can all be done."

I am not sure that I fully picked up on the significance of that statement.
  When you say "solid lifter cam profiles could not be used,...but  it can be done"   What is the alternative type of cam that could be used, and , ACE can you do it?

Given all that you have said about the complexity of pairing cam profiles to the breathing characteristics of a modified head, would some of the fiddly work you did with the Iron Barrel Fireball mod  serve as a learning curve to effectively shorten the potential development path of a similar undertaking with the UCE, or is it  a whole new ballgame from the ground up with the same number of engineering and bench hours .
You implied earlier that the performance objectives led the design of the head modifications.  There was talk of RPM limitation of hydraulic lifters , changing stoke and bore , but in the end you came back to keeping the same stroke and using the RPM lints available -under 6000 I believe.    

SO   IF the goal was to more or less duplicate the performance characteristic of the Fireball,  could a head be designed for the UCE guided by exactly the same performance profile expectation without changing the hydraulic lifters or  fuel induction system keeping the same stroke , conrod , shaft and bearings,all below 6000 RPM, TRUSTING that the UCE bottom end and con-rod improvements are what they say they and if so  THEN ACE, does the Z91442 standard (8.5:1) compression  535 piston bring us a step closer to Fireballing a UCE?  You said before somewhere that half the cost went into "bottom end modifications"  I don't know if this means strengthening the bottom end or if it includes the cam profile work , and if so, how the cost was apportioned between these. (If only the cams need work then costs may be lower)

Yes all  just dreaming  of future possibilities, but then so was the Fireball project.  If my speculations about the market potential of the UCE are correct, the Iron Barrel Fireball may become a preparatory footnote to the next step.  Again fortune favours the prepared.   Nigel

PS In my defense, about typing, for some reason I only get about a 1 inch window to type in, and once a message passes a certain length, I am typing blind because it always reverts to the top of the box.  Weird.  I'll try the spell check .  

Nigel,
The statement about the cams and lifters was only that they must match in type. Roller lifters require a different cam profile than the flat-tappet lifters which are used in the Iron Barrel engine. So, the Fireball cams cannot be used, and a new set of cams which have a suitable profile for roller lifters needs to be made.
As for the hydraulic part of the UCE lifters, that could remain of the rev limits are not increased much, or they can be replaced with solid roller lifters which are not hydraulic
So yes, it can be done.
As for the rev limits, from what I have seen from Chinoy, who tried modding one of these in India, we can't reliably see 6000rpm with these hydraulic lifters in the engine.

Regarding development time and effort, it's all a new ball game with the UCE.
The most basic parameters like bore and stroke might be the same, but everything else is different. Alot different.
"Duplicating Fireball performance" would have to be done in a different way than what was done on the Iron Barrel. If we want to keep the hydraulic lifters, we will have a lower rev limit than the Fireball.  I think 5500rpm might be ok, but maybe a little lower would be more practical with the hydraulic lifters. And I can't make a definitive statement about the flexibility of the EFI system in the UCE, but I suspect it will need to be changed or modified to handle engine modifications of this nature under discussion.

Your question about using that specific piston cannot be answered at this time. It remains to be seen what the cams need to be timed at, and before we can do that, we need to see what the head can do. We also need to look at any mechanical limiting factors to see what limitations we might face from those.

On the Fireball, we had to deal with a weak con-rod and poor bearing quality, and sometimes poor assembly quality. But those parts to improve it were already available from vendors. I didn't have to develop them, but they are expensive. That was just "nuts and bolts" work. All of the development work was in the heads and cams and piston, and refining all the working relationships to avoid the previously inherent failures that plagued previous efforts.. The part about "half the cost is in the bottom end" referred to half the retail price to the customer to buy these parts to make the bottom end strong enough. The development costs to do the Fireball performance work was stratospheric in comparison, and takes a very long time.
Assuming that the UCE doesn't need bottom end improvement(which I am not ready to concede until that's proven) then the end user would have a lower overall cost because of the bottom end not requiring money to improve it.

Now, there ARE ways to approach this that could cost less money and be somewhat faster, IF a lower performance goal is deemed satisfactory. I could get a basic porting job done on the standard platform, and get a boost that people would feel, for not alot of money. It would probably need the Power Commander to go along with it, because the air flow rate would be increased.
That costs a whole lot less than an entire engine re-design. This is the way most other people do their mods, with more basic work and less intense design work involved.
No increasing of the rev limits or other drastic mods, and just give it a little more air.
It's not hard to squirt more fuel in there, and the PC could do that easily. It's getting the extra air in there to go with the fuel that's the hard part. And it's amazing what Joe Mondello could do with just a "Street/Strip" type valve job and blending for flow. I'd bet he could pick up an extra 15% flow in that head, with just a Mondello multi-angle valve job done on the Serdi machine, and a blending to the port. And that translates into power. Add the PC for getting proper air/fuel ratio for the new flow rate, use a free-flow exhaust, and you're probably going to like that alot.
Sometimes there is a middle-ground of some improvement for reasonable costs that people like.
Let's say for estimation that after a good stock UCE(21rwhp) gets a free-flow exhaust on it, that it pushes close to 24-25hp, just for sake of discussion. Add the ~15% increase with a PC and mild porting job, and you're possibly pushing close to 28-29hp at the rear wheel. And that's not bad at all.  That would come out to about 33% increase in power over a stock bike.
Of course, those are "off the cuff" estimates, but it's probably not far off.

The worst offenders that are normally seen in the stock head flow path are at the valve seats. Production  engines don't get hardly any attention to valve seat flow. they are just assembled enough to run, and they go out the door. It's too time-consuming and costly to pay attention to this stuff in a production environment. This is true of pretty much any production engine made, unless it's a costly performance engine, and even then it can be improved some. Any production engine can benefit well from more attention to the valve seats, and a blend to the port. It's a place where very good gains can be made, for not alot of money.
But it has to be done right, and that's why I have Mondello doing the work.

There's alot of ways to "skin the cat".
It all depends on how far you want to go, and how much you're willing to pay.
The early gains are usually some of the biggest gains, and as the engine gets better and better in its state of modification, it gets progressively more difficult and more expensive to get those last remaining hp.
« Last Edit: February 23, 2011, 02:57:29 pm by ace.cafe »
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r80rt

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Reply #29 on: February 23, 2011, 02:57:52 pm
On the eighth day God created the C5, and it was better looking than anything on the planet.
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