Hi Chuck.I'm going to have some exciting news for you later today.I'll email you later with some pics and the news.
OK. I'll take a stab......Here you go Ace:With the hi-lift rockers and Magnum cams in place, just how much more can you 'fill' the cylinder i.e. how close to 535cc at 1 barr at sea level. I am guessing it will vary with rpm.
I was wondering if the factory 535 cylinders are just standard cylinders bored out to their maximum like the Fireball's or are they able to be bored oversize?Thanks,Roger
Well Tom another one from me. The piggy back ECU (I think it is Dynojet Power Commander) programmed for Suzuki ATV450 has been used on EFI REs to improve its performance with open pipe or other head/cam work. That ATV is also single cylinder 4 stroke engine but can rev way higher than G5, C5. Perhaps close to 10,000 as compared to 5500 or so for G5, C5. So question is what makes Suzuki engine safely rev so much higher and produce almost double HP than RE though both are about same volumetric size.
Tom, I think maybe it's time to dig out a few of those instructional threads from a few years ago. Y'know, the ones that began "Let's talk about...". Those were great.
+1 I read most of your Articles on the yahoo page( awful to navigate by the way) and I reckon ye should publish them in a chapter format somehow.... Didn't jump in right away coz well to many posts makes Aussiedave a PITA... But I was wondering about mixture flow as it leaves the injector manifold into the inlet chamber ( bowl?) does the bowl act as a Venturi type affair and speed up the flow as it reduces volume to the inlet port or does it act to slow the flow down and increase the static pressure? Or should it try to maintain the existing velocity? Also previous posts have mentioned that the length of the efi manifold functioned to decrease turbulence- I think some one said their mileage decreased when they put pods directly on the injector. But isn't turbulence a good thing - keeping the fuel in suspension and helping an efficient burn?
Yes , thanks Ace , that helps my understanding muchly. I find it remarkable that you are able to create a positive pressure in the cylinder with your raised port design, just using induction and the momentum of the air! My understanding is that most engines still have a slight vacume at the end of the induction stroke- that is , they don't fill completely to atpospheric pressure. It certainly is a tricky environment for air flow and I find it fascinating. Wish I could see your flow bench in action. I'm curious as to how you model the changes you make-are there simulations you can run try different shapes in the passages? I hope I'm not encroaching on your trade secrets:)
This is a general question on engines, related to kick start gear.The electric starter motor gears are connected to crankshaft through sprag clutch mechanism that transfer power when required. I guess there is no such sprag clutch mechanism for the kick start gear. How does kick start gear engage and disengage from the transmission shaft that it rotates to start an engine ? Do you have any pictures to clearly see how it is connected in RE ?
It is a simple ratchet/pawl system. It is not engaged during running, like the sprag. A sprag ts sort of like a ratchet mechanism too, but it stays engaged with the engine gears all the time, and so it is vulnerable.I am posting from my phone right now, so I can't put any photos up. The kick start ratchet and pawl parts can be seen in the exploded diagram in the parts book.Also, these kick start pawls and springs sometimes break too, but it is cheap and easy to fix it. I personally think that a "bendix" type of electric starter, like cars have, would be a better choice than a sprag starter system.
So the pawl can break on a kick back, if the kick lever is held down and not allowed to return !That would require splitting the crankcase, isn't it ?
Tom:Can you discuss on the use of two smaller size intake/exhaust valve set vs one larger size valve for intake/exhaust in an engine ? How do you decide when to use 2 valve-set and when to stick to 1 valve-set ?
Ace, since bullets make make most of their power at relatively low rpm's, has there ever been any work done in the "short rod engine" area? I know years ago it worked well with the harley flat trackers. The penalty is high piston side loading and shorter engine life, but if its a race engine or if you are going for a record, who cares? thanks cy.
Tom:Have you seen any kind of damage in the rocker assembly of REs and if so what was it ? What caused it ? Can engine kick-back crack or damage or loosen any part of rocker assembly ?
Here is another one:.....And I am only asking you to guesstimate (since your guestimate is much more informed than mine) : If the flowed, ported UCE head with the performance valve job was to be bolted back (without high lift rockers) on to the stock cylinder&piston, do you think the stock ECU would be able to keep up......If not, how much performance gain would you guestimate if this was mated with a remapped piggy back ECU that you are developing?
Here's another: Have you had an oportunity to look at the rare, almost mystical, twin exhaust port head. As rare as it is, would it provide with more performance options. This one: http://www.royalenfields.com/2009/04/for-sale-very-rare-royal-enfield-twin.html#comment-form
Tom - I have questions about porting my intake manifold for my twin. Basically I have a Y-manifold that is about 3" long. I'm not exactly looking to go Gung Ho, but I would like to be able to create a better fuel charge. As we all know these bikes aren't power houses, so every little bit counts. Last night I did a light porting job and nice polish. After doing so I discovered this was actually not the correct thing to do. So I did some research, basically freshened up and my P&P education. So, a perfectly polished finish like I did is actually good for forced induction, but as you previously said, a hindrance for N/A motors or anything that isn't direct fuel injection. I'm not going to touch the heads, but I would like to at least gasket match the runners into the heads. Also I noticed that the carb flange on the manifold is actually oval shaped and was thinking about opening up the lower and upper portions of the flange to make the mating surface to the crab more true and less restrictive. Then I'm thinking of going back and resanding everything with 320 grit paper and attempt to sand the runners in a spiral direction to try and achieve a bit of a swirl effect.What are your thoughts Tom?Scottie
So what you are saying is that it is ok to match the intake port on the heads to the gasket and manifold as long as I'm just opening the initial edge of the runner on the head?Scottie
............. So, if you ever wondered about something, I'll try to answer to the best of my ability.
concerning the UCE engine, Electra piston, and Is the compression height of the stock UCE and the stock electra piston the same ? Are there any clearance issues with this combo ? how much does it raise the compression ?
I'm also aware the modern electronic ignition sytems are very reliable and once the timing is set then it is set for good and you can forget it. (I've been told if a bike with e-ignition ever pings, it has to be due to fuel mixute and not timing.) Consequently, I am guessing, fuel economy and power generation are better.
The problem with the Enfield points ignition is not the points. The points are fine, considering what they are for maintaining etc. They perform the same switching function as any other switch.The problem is that the mechanical advance system is inadequate to deal with the engine needs in certain circumstances. This is where a more modern type of ignition system can be an improvement.
Fair point well said. What about the claims that e-ignition improves fuel economy and power?
Is there any advantage of long-skirt piston over short-skirt piston with bracing ?