oh snaps! Jaz you're gonna be eating people up this weekend on the short track. NOTHING has as much punch on the bottom as a fresh B5.:nod: You are gonna be at SRS this saturday, right?

rc pete

Ok, had to wait until I had some time to respond to your post in detail lol! So regarding your questions:

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Throughout my years of nitro tuning, I've been back and forth a couple of times now on exactly how much fuel needs to be run through the engine during break in. The answer is obviously more than race tune, but the question is: super rich bottom with lots of air gap as you suggest, or mid-way between that and race tune in terms of gap and mixture?
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First let me start by saying that in the break in system that I recommend I start with a super rich bottom with lots of air gap on the first tank of fuel only and that is done primarily to flush the internals out. After the first tank I reduce the air gap slightly and lean the LS needle slightly (to reduce lubrication), so I start to gradually reduce lubrication as the engine starts to break in.

You talk about going mid-way between that and race tune in terms of gap and mixture. What is mid point between rich and race tune? Better yet how do you quantify what is a mid point between rich and race tune lol? Even better yet, how do you explain to some one what that point is lol? The much easier way to do it is simply start off rich and then with each tank reduce the amount of fuel going through the engine (as in lean it out).

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Sure, more fuel provides more lubrication, but does it heat up the engine enough to free it up sufficiently?
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How hot is hot enough to free up an engine sufficiently lol? Also think about it for a second, what is more important during break in, gradually expanding well lubricated parts (which is what happens using my system) or getting new parts that are realy tight to start with as hot as possible so they expand to the max point with relatively little lubricant? The bottom line in my opinion is that with new engines, friction is your enemy (because there is already a lot of it to start with) the way to reduce that is to increase lubrication.

Keep in mind that heat in our engines is a bit of a vicious circle. Friction is the cause of the heat. The hotter the parts get, the more they expand. The more they expand, the more friction is caused. The more friction that is caused, the more they expand again ad infinitum until eventually everything eventually seizes up. Not something that you want to happen when breaking in an engine.

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The sleeve is engineered tapered/pinched at the top, because that is the hottest part of the engine. As it gets to operating temperature, it expands and just about straightens out... allowing the piston to move up/down freely.
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That is not really correct. The sleeve is engineered with a taper in it at the top because only at TDC is where the engine (piston/sleeve fit) needs to be sealed (to avoid blow by there by maximizing the amount of energy/force from the combustion of the fuel/air mixture pushing the piston down). We design in the taper so that when the engine is run the pinch area is confined to a narrow band around the top of the sleeve only, this is done specifically to minimize the amount of friction.


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By not heating up the engine enough and allowing it to expand, your piston is continuously slamming into the pinch zone, causing more stress to the internals, especially the rod and bushings.
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I see what you are getting at but your piston is going to continue to slam into what you are calling the pinch zone until you frankly have no more pinch at which time these type of (ringless) engines are simply worn out lol.

Having said that though there are different ways to make engines and frankly some companies seem to put a ton of pinch in their engines. From reading the forums it seems that quite a few of the uniformed readers on threads seem to think this is great with people saying things like "This engine is great, I have 4 gallons through my engine and it's still getting stuck at top dead center!". Frankly there is nothing good about this, all that it means is that the company that is making your engines is taking the easy way out by sticking oversized pistons into a sleeve which does nothing but create a lot of friction and puts a ton of strain on the components as you are mentioning.

Why do this, because the larger the piston the less important that metallurgy of it is because you do not have to be so concerned about the piston wearing and their by loosing compression. Or the company does not have the equipment needed to machine parts with the tolerances necessary to have a precise p/s fit. It amazes me some of the things that I see on here I mean there was even one Pro modifier selling OS engine on here where one of his features was the he supposedly matched the piston/sleeves. He did this by sticking the biggest piston that he could find into the sleeve, making it super, super tight. This was supposedly a plus, yea right like extra friction is a plus lol! You too can have the benefit of extra friction for a mere $450 lol!

The factory that we produce our engines at has some of the most modern machining equipment out of any of the European engine manufacturers. Because of this we can have really tight tolerances, meaning we can design in a very precise fit of the piston/sleeve. Because we use really high quality materials for the piston, we can also design in a minimum of taper in the sleeve that can be maintained for quite a while because the piston experiences minimal wear (due to the type/formulation of aluminum that we use for the piston). The benefit of this is that the break in process is quite easy and I should say gentle and that the engine quickly comes to the point of maximum performance.

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Due to that, my current train of though is to run the bottom end leaner, in order to generate more heat at idle (and cover up the head), and run the top super rich so that the engine gets more fuel as I blip it. I also use the heat cycle method... 2-4 minute intervals.
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Everyone is entitled to their own method of doing things but running a lean bottom end is I have found the easiest way to wear out an engine (and something that I always try to avoid). All that I can say about this is please be careful when doing this.


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This method has worked great for me for a number of engines, and I'm sure that either one will work for my buddy, but any of your thoughts on this would be appreciated.
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Well I hope that the above gives you a little bit of insight into what my thoughts about all of this are. There are a ton of different opinions on what is right and what is wrong when it comes to breaking in and tuning motors. The system that I indicated is just one that I have found over the years works and gives good, consistent results. It is also basically the same system that I have found most of the European engine people that I have worked with over the years use to break in their own motors. Most of these guys have been heavily involved in 1/8th on-road racing and if there was another system that provided any type of noticeable performance benefits trust me when I say that these guys would have found it and been using it. Hope this helps a bit! Let me know if you have any questions..

Regards,

Ron

I will be at SRS but I will be running my Clocked JL. No way I can get the B5 race ready by Saturday. Still have 12 more tanks of break in

i must have cheated... i raced mine before 12 tanks:sneaky:

Ron, thank you for taking the time to put together such a thorough response. Your deep insight into the subject is appreciated.

Lol you can race em right out of the box but they won't perform like they should and you drastically decrease the lifespan. I want to baby my B5 to give it a really good test on longevity. I'm shooting for 8 gallons without touching any of the internals including bearings. See you Saturday

In case anyone is curious....here is an "RB Engine Protect" on a Werks B5!

I had to trim the back of the collet for proper gear mesh on my Hyper 9, but I think it was worth the effort!

http://i589.photobucket.com/albums/s...P/P1010894.jpg

Sound like a good idea, But if particules of dust going in the engine, fuel should go out even easier because the preassure inside the block. If Rb (http://www.the-border.com/product.ph...roductid=35457) said "To protect the bearing for logevity" sound more convincing. MHO.

Ummmm....they did basically say it was to protect the bearings for longevity. Not sure what you missed in reading it!

..."It protects the bearing by preventing dust from getting in, thus increasing engine lifetime and performance. A great improvement at an affordable price !"


The basic design of the engine is to draw fuel and air in from the front and blow it out the back. Air is definitely being pulled in though the front bearing during operation.

Innevitably, the seals on the bearings will not block all debris from entering the bearing nor prevent all crankcase pressure from escaping. Whether or not the RB product actually works is anyones guess.

I dont know that any air is actually being drawn through the front bearing since the vacuum created within the engine is fairly low and there is such a large orifice for it to enter via the carb.

I can't be more AGREED. An other way to suck your wallet.lol

What exactly are you agreeing to?

It's not meant to seal the front bearing....it's meant to offer better dirt deflection as it has extremely tight tolerances around the crankcase!

It actually spins with the crank!

Not sure how the Hyper flywheel is but the Losi unit actually covers part of the block. I cant see how this would work with the Losi flywheel (aluminum anyways).

That would depend on how tight to the crankcase the flange on the losi is. I am using the Asendancy clutch. In the pic you can see how tight it is to the case. If it fit inside the dirt gaurd on the Losi flywheel you'd be all set!

If you are really interested to know the dimensions I could pull my engine back out and put the calipers on it!