Comments for RET-Monitor http://www.ret-monitor.com/articles Specific mission-critical info for professionals Thu, 11 Mar 2010 16:48:31 +0000 http://wordpress.org/?v=2.7.1 hourly 1 Comment on Tractive Effort by Tony Morris http://www.ret-monitor.com/articles/885/tractive-effort/comment-page-1/#comment-3074 Tony Morris Wed, 24 Feb 2010 03:35:07 +0000 http://www.ret-monitor.com/articles/885/tractive-effort/#comment-3074 If we add in lots of gears and draw the corresponding tractive effort curves, you will see a hyperbola which touches each tractive effort curve begin to form. The equation for this hyperbola is T.E. = Power(peak)/velocity. This is also the T.E. curve for a Continuously Variable Transmission maintaining the engine at its peak-power RPM. It also represents the gearing required to maximise T.E. and therefore acceleration at any speed. If we add in lots of gears and draw the corresponding tractive effort curves, you will see a hyperbola which touches each tractive effort curve begin to form. The equation for this hyperbola is T.E. = Power(peak)/velocity. This is also the T.E. curve for a Continuously Variable Transmission maintaining the engine at its peak-power RPM. It also represents the gearing required to maximise T.E. and therefore acceleration at any speed.

]]> Comment on Friction and the camshaft by Tony Morris http://www.ret-monitor.com/articles/838/friction-and-the-camshaft/comment-page-1/#comment-3073 Tony Morris Wed, 24 Feb 2010 02:45:35 +0000 http://www.ret-monitor.com/articles/838/friction-and-the-camshaft/#comment-3073 By its nature the roller tappet will not experience the high levels of cam friction torque seen in figure 2 regardless of film thickness and entrainment velocity. Wear and peak pressures might be a different matter. By its nature the roller tappet will not experience the high levels of cam friction torque seen in figure 2 regardless of film thickness and entrainment velocity. Wear and peak pressures might be a different matter.

]]> Comment on CAMSHAFT DURATION by Danny Williams http://www.ret-monitor.com/articles/771/camshaft-duration/comment-page-1/#comment-3072 Danny Williams Tue, 23 Feb 2010 02:43:31 +0000 http://www.ret-monitor.com/articles/771/camshaft-duration/#comment-3072 The Helical Camshaft can perform about 90% of the useful "tricks" that a "camless" can do and being a purely mechanical system it is much more easily applied to existing engines than a "camless" system. The Helical Camshaft can perform about 90% of the useful “tricks” that a “camless” can do and being a purely mechanical system it is much more easily applied to existing engines than a “camless” system.

]]> Comment on A Most Unusual Engine by Tony Hall http://www.ret-monitor.com/articles/861/a-most-unusual-engine/comment-page-1/#comment-3071 Tony Hall Sun, 21 Feb 2010 23:34:29 +0000 http://www.ret-monitor.com/articles/861/a-most-unusual-engine/#comment-3071 very interesting project! A similar idea occured to me some years ago, but have never been funded, or under the neccessuity to try it. why was it not developed further? is there not an article for RET there? or are there too many confidentiality restrictions? regards, tony hall very interesting project! A similar idea occured to me some years ago, but have never been funded, or under the neccessuity to try it.

why was it not developed further?

is there not an article for RET there? or are there too many confidentiality restrictions?

regards,

tony hall

]]> Comment on Smaller and lighter is always better by Wayne Ward http://www.ret-monitor.com/articles/842/smaller-and-lighter-is-always-better/comment-page-1/#comment-3044 Wayne Ward Thu, 18 Feb 2010 12:29:49 +0000 http://www.ret-monitor.com/articles/842/smaller-and-lighter-is-always-better/#comment-3044 In reply to Jim Wolf's post, I can't mention specific applications as I've been shown these parts in confidence. However, we can say that it is sensible to design the rod such that the extra mass is around the big end rather than the small end. This brings me to answer Basil van Rooyen's post. The mass around the big end of the rod is classed as being part of the rotating inertia of the engine and is treated as such in most calculations. I've not mentioned specific applications, but there are instances where it isn't possible to just fit a bigger flywheel etc, hence the reason why these parts have been designed and run, in race series up to international level. The teams are happy with the parts and because the lap time and, more importantly, consistency of lap-time is improved, they see this as a performance increase when judging vehicle performance. I agree that, given the choice, we would certainly look to add mass to the flywheel etc but, where this isn't possible, it seems that an approach such as the one described seems worthwhile. Best regards, Wayne Ward In reply to Jim Wolf’s post, I can’t mention specific applications as I’ve been shown these parts in confidence. However, we can say that it is sensible to design the rod such that the extra mass is around the big end rather than the small end.

This brings me to answer Basil van Rooyen’s post. The mass around the big end of the rod is classed as being part of the rotating inertia of the engine and is treated as such in most calculations. I’ve not mentioned specific applications, but there are instances where it isn’t possible to just fit a bigger flywheel etc, hence the reason why these parts have been designed and run, in race series up to international level. The teams are happy with the parts and because the lap time and, more importantly, consistency of lap-time is improved, they see this as a performance increase when judging vehicle performance.

I agree that, given the choice, we would certainly look to add mass to the flywheel etc but, where this isn’t possible, it seems that an approach such as the one described seems worthwhile.

Best regards,

Wayne Ward

]]> Comment on Applying Matinaglia’s good advice by Wayne Ward http://www.ret-monitor.com/articles/844/applying-matinaglias-good-advice/comment-page-1/#comment-3043 Wayne Ward Thu, 18 Feb 2010 12:18:42 +0000 http://www.ret-monitor.com/articles/844/applying-matinaglias-good-advice/#comment-3043 David, No there's certainly nothing new about it, but the application of many of the ideas in today's short-stroke racing engines is increasingly difficult and, owing to the rules in some racing series, impossible in some circumstances. Lightening of pins and, to a lesser extent, main bearings is common where tool access allows. Best regards, Wayne Ward David,

No there’s certainly nothing new about it, but the application of many of the ideas in today’s short-stroke racing engines is increasingly difficult and, owing to the rules in some racing series, impossible in some circumstances.

Lightening of pins and, to a lesser extent, main bearings is common where tool access allows.

Best regards,

Wayne Ward

]]> Comment on Smaller and lighter is always better by Basil van Rooyen http://www.ret-monitor.com/articles/842/smaller-and-lighter-is-always-better/comment-page-1/#comment-3038 Basil van Rooyen Thu, 18 Feb 2010 11:24:26 +0000 http://www.ret-monitor.com/articles/842/smaller-and-lighter-is-always-better/#comment-3038 I think Wayne Ward is plainly wrong, in asserting that a heavier rod may make for better performance because of a more drive-able throttle response - a result of greater or lesser inertia. Such rotational inertia, or damping, of throttle response is least appropriately sought in the reciprocating bits, as these are being accelerated and decelerated each stroke. Such drive-ability might be sought in the rotating bits, like the clutch and flywheel - but never the reciprocating parts. Before ANY power is transmitted to the crankshaft, the inertia of the rod must be overcome on every power stroke. At the end of each stroke there is no stored energy at the big end to assist the next stroke, but must begin again, unlike the rotating bits. I think Wayne Ward is plainly wrong, in asserting that a heavier rod may make for better performance because of a more drive-able throttle response - a result of greater or lesser inertia. Such rotational inertia, or damping, of throttle response is least appropriately sought in the reciprocating bits, as these are being accelerated and decelerated each stroke. Such drive-ability might be sought in the rotating bits, like the clutch and flywheel - but never the reciprocating parts. Before ANY power is transmitted to the crankshaft, the inertia of the rod must be overcome on every power stroke. At the end of each stroke there is no stored energy at the big end to assist the next stroke, but must begin again, unlike the rotating bits.

]]> Comment on Friction and the camshaft by John Coxon http://www.ret-monitor.com/articles/838/friction-and-the-camshaft/comment-page-1/#comment-3031 John Coxon Wed, 17 Feb 2010 18:04:59 +0000 http://www.ret-monitor.com/articles/838/friction-and-the-camshaft/#comment-3031 The graphs here refer to a typical flat tappet arrangement in a direct acting mechanical bucket. Other valvetrains will have a different mix of lubricant regimes and therefore may be less sensitive to anti-wear packages. However in any lube formulation one musn't forget the requirements of the piston ring. The graphs here refer to a typical flat tappet arrangement in a direct acting mechanical bucket. Other valvetrains will have a different mix of lubricant regimes and therefore may be less sensitive to anti-wear packages. However in any lube formulation one musn’t forget the requirements of the piston ring.

]]> Comment on Smaller and lighter is always better by Jim Wolf http://www.ret-monitor.com/articles/842/smaller-and-lighter-is-always-better/comment-page-1/#comment-3030 Jim Wolf Wed, 17 Feb 2010 16:24:21 +0000 http://www.ret-monitor.com/articles/842/smaller-and-lighter-is-always-better/#comment-3030 >surprising number of motorsport situations >a number of applications where low inertia is actually a barrier to performance >In some of these applications >In some instances The article caught my attention with the tongue in cheek title, but disappointed with no specific, IE. why choose reciprocating vs. prime mass if strength isn't the problem or how increased mass on the rod equates to which attributes a driver can benefit from, etc. Please finish your thought in part 2, I am interested! >surprising number of motorsport situations
>a number of applications where low inertia is actually a barrier to performance
>In some of these applications
>In some instances

The article caught my attention with the tongue in cheek title, but disappointed with no specific, IE. why choose reciprocating vs. prime mass if strength isn’t the problem or how increased mass on the rod equates to which attributes a driver can benefit from, etc.
Please finish your thought in part 2, I am interested!

]]> Comment on Friction and the camshaft by brianathasport http://www.ret-monitor.com/articles/838/friction-and-the-camshaft/comment-page-1/#comment-3029 brianathasport Wed, 17 Feb 2010 15:56:26 +0000 http://www.ret-monitor.com/articles/838/friction-and-the-camshaft/#comment-3029 What about on a roller rocker and cam? If I understand correctly the entrainment velocity is constant and this is less of a problem. What about on a roller rocker and cam? If I understand correctly the entrainment velocity is constant and this is less of a problem.

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