Timing Cap/Cover Venting and Cooling Mods - UPDATE Pg. 5

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Re: Timing Cap/Cover Venting and Cooling Mods

Post by mr. cob » Tue Jun 26, 2018 5:20 pm

T-Bear wrote:Brains a going'

1. Assuming a fan/housing would be mounted around the horn area...

Any need in front of the fan for a moisture filter to sort out water/rain being pushed in? The more moisture kept out of the timing cap area the the better I'd say. Any thoughts on moisture in that timing/Hall Sensor area?

The first fan I pulled up says its waterproof rated. But I'd assume a pre-filter would prolong - but add that additional length/profile that may not be easy to position. For the price, these fans may be a yearly consumable depending upon climate.

Or could we assume the rain/moisture would be pushed out by the fan with a basic hole/drain output?

2. Or a fan/housing mounted some were protected and perhaps rear facing to limit rain intake? Where might this be?
Howdy T-Bear,

Water or any debris will in short order kill or mess up any sort of electronics but a speck of dust or a drop of water will INSTANTLY stop a Power-Arc or C5 ignition as they use an optical disk, water or dust on that disk and its game over until you do whatever is nessisary to clean the disk. So in my opinion if you have a Power-Arc or C5, ignition and your going to be doing ANYTHING that could possibly allow water or debris into the ignition cup you would be wise to filter as well as possible any intake or exhaust opening you make in the cup.

This brings us back to air flow, the fan being discussed will flow 200CFM ( Cubic Feet of air per Minute ) under unrestricted ideal conditions, anything you do that will restrict air flow will have a diminishing affect on actual air flow. Adding a intake filter will restrict flow, the size of the intake opening and the size-length of the path will restrict flow, the same can be said for the exhaust. This is why in reality in my earlier posts I estimated that when all is said and done a system using a 200CFM fan would in the real world considering all the restrictions that would be incurred when building a system to work on our Ural's would probably provide about 50CFM of actual flow, still a considerable amount of air to be passed through an other wise CLOSED ignition cup.

Dave
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Re: Timing Cap/Cover Venting and Cooling Mods

Post by T-Bear » Wed Jun 27, 2018 12:54 pm

Thanks for more explanation Dave.

My initial thought was to push air INTO the cap and exhausting out.

What about reversing the fan such that it would PULL OUT of the cap. This would eliminate the worry of pushing moist air/rain into the cap and eliminating need for a filter for the fan.

For intake then one or two:

a. Differential breathers tapped directly into cap. Some are filtered. https://www.amazon.com/gp/product/B00BM ... 0DER&psc=1

Image



b. Route intake hose with filter at top (like your version 2).
Last edited by T-Bear on Wed Jun 27, 2018 1:57 pm, edited 1 time in total.
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Re: Timing Cap/Cover Venting and Cooling Mods

Post by T-Bear » Wed Jun 27, 2018 1:56 pm

I ordered the fan. Let's see where this goes. :oops:
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Re: Timing Cap/Cover Venting and Cooling Mods

Post by T-Bear » Wed Jun 27, 2018 2:22 pm

Here's my current working idea... I'm gonna try sucking that heat out of the timing cap. LOL. :foilhead: :|

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Re: Timing Cap/Cover Venting and Cooling Mods

Post by Lokiboy » Wed Jun 27, 2018 2:42 pm

T-Bear,

Mr. Cob rides his rigs like few others. Therefore, I would not sweat the heating problem based on one individual’s antidotal experiences. You are far more likely to induce more problems then what you perceive to be an issue.
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Re: Timing Cap/Cover Venting and Cooling Mods

Post by rivers » Wed Jun 27, 2018 3:00 pm

T-Bear. I haven't had the timing chest heating issue but kinda like the idea of pulling out hot air rather than forcing in external air. On cargo vessels deck mount exhaust funnels are common. Think along the line of an aft facing tuba funnel. As the air flows past, it creates a vacuum at the opening drawing out heated air w/o worry of ingesting rain, sea spray etc. Hi speed isn't critical cause cargo boats don't cruise fast. I would think on a bike timing chest a reverse facing street elbow or a straight tube end cut at 45 degrees facing aft in the air stream would/could create a beneficial effect?
Just a thought...
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Re: Timing Cap/Cover Venting and Cooling Mods

Post by T-Bear » Wed Jun 27, 2018 3:11 pm

Thanks for the comment. I'll take all the advice I can get from you more experienced guys. :cheers:

Are you running OE or the spin-on kit?

Compared to the OE timing cap to this cap there sure is a big difference in heat. I never put the IR gun to the old cap, but I do remember it was simply warm to touch. This new one is burning hot and the IR gun registered 200-225 on the exterior surface. This was after a 10-15 minute cool down. Imagine what the temp is inside.

From reading past Hall Sensor threads the heat rating was around 247 degrees F.

In addition, what concerns me is the wire harness as it passes through that small gap. The wires are laying up against two heat sinks. I'd been looking at high temp resistance looms that I could split and place over the wires at that area to eliminate the direct heat transfer to the wires.

While I don't ride like Dave, I do ride a lot in high heat here. Common to be 95-105. Combined with steep and hilly rough Ozark rock roads in mostly 1st-to-3rd under 33 mph. Not a lot of airflow there and a working engine. I don't bang it, just keeping it happy in it's RPM range. This wasn't an issue last summer with the OE cover. This summer I anticipate problems.

Worse case if I modify the cap with drilling for fittings, I will just cap them if this doesn't work.
Last edited by T-Bear on Thu Jun 28, 2018 3:41 pm, edited 1 time in total.
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Re: Timing Cap/Cover Venting and Cooling Mods

Post by T-Bear » Wed Jun 27, 2018 3:15 pm

Thanks Rivers, I appreciate you taking the time to comment!

I wish I was better at engineering and could calculate vacuum rates and situations like you posted that perhaps a simple elbow would work.

Right now after mocking up a cardboard box for the fan size, it looks like the best place would be to mount it to the tub. Facing backward or angled down to perhaps help cool that inside jug (it's always 20-30 degrees higher on that side for me) for a side benefit if the exhaust is cooled sufficiently by then. Power is right there too.

ETA - might need to push back behind jug if it restricts air flow.

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Re: Timing Cap/Cover Venting and Cooling Mods

Post by mr. cob » Wed Jun 27, 2018 4:43 pm

Howdy All,

Great more folks are making suggestions, using a fan to draw the hot air out or force cooler air in both would work until its tried we don't know if one will work better then the other but both would be better then nothing. The problem I see using the breathers in the cup is that they are very small and the amount of air that can be sucked through them will greatly restrict the air flow the fan your talking about using is capable of. That and I don't trust a breather of the type you showed being able to prevent fine dust or water vaper from entering the cup, with a Hall sensor that's not the big of a deal but take my word on this a bit of fine dust or a drop of water will stop a rig equipped with any ignition system that uses an optical disk such as the Power-Arc or C5, DEAD, I have seen it, I have experienced it.

Dave
Last edited by mr. cob on Wed Jun 27, 2018 5:05 pm, edited 1 time in total.
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Re: Timing Cap/Cover Venting and Cooling Mods

Post by T-Bear » Wed Jun 27, 2018 4:58 pm

^ Dave thanks for those with the non-Ducati systems... Cool to do a system that everyone could benefit from.

Thus, I think what makes most sense on the intake side is the filter like on your version 2. Agree about the diff. breathers I posted.

So ya'll give me a little lesson about vacuum. How to create maximum vacuum? Smaller suction hose (to fan for exhaust) with larger intake via filter? Or vice versa?

ETA - thinking about my shop vac. It has a smaller intake hose than the output/exhaust (in vac mode).

From Jegs.com on cylinder heads (not interested in anything but air flow here) ...

Intake Runner Volume - A larger intake runner volume allows more air and fuel to flow through it. However, the larger "tunnel" will slow the velocity of gases moving through it. Smaller intake runners would speed up the flow of gases through the cylinder head and increase throttle response and torque.

As long as your headers or exhaust manifolds are bigger than the port on the head, and the gasket seals well, the gas will exit as it should.
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Re: Timing Cap/Cover Venting and Cooling Mods

Post by T-Bear » Thu Jun 28, 2018 3:51 pm

Yeah Dave after research I reached your same experienced wisdom.

Likewise, I think air flow through that cap is the limiting factor to success. Not alot of room to mess with.
The cap on the side has about 1 1/2" height/space to install fittings. At best, I see 1/2" NPT fittings - which are close to 3/4" drill/tap size - being prudent. So roughly 1/2" in and out at a safe bet.

Thinking it's best to have the input and exhaust opposite one another, so that is where I'm thinking of installing the fittings. To get that air flow crossing as big of a section as possible.

I'll silicon the fittings so I can tinker with hose input/output size. Then IF (ha) it works, I'll do your JB weld seal.

From other research, it seems as big as I can get those input/output lines relative to the power of the fan is best.

I've got fittings coming and will evaluate once I get my eyes on them. First up would be 3/8" NPT fittings with 5/8" input/output hose. Second would be 1/2" NPT fittings with 3/4" hose.

I actually think that high output (200 cfm) fan might be to much and lead to it burning up due to insufficient pull/air flow across the bearings. I'll try it and worse case perhaps drill extra holes in the fan housing to allow more air flow past the fan.

Worse case I'm out some $ and cap the modified cap fittings. Sure cannot hurt!
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Re: Timing Cap/Cover Venting and Cooling Mods

Post by xpatriot » Fri Jun 29, 2018 4:00 pm

Has anyone thought about putting a series of fins on the front cover? Seems to work pretty well on the cylinders.
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Re: Timing Cap/Cover Venting and Cooling Mods

Post by gobium » Fri Jun 29, 2018 5:23 pm

T Bear.
I try not to post much on ss.
I done everything to cool hall sensor.
Only solution for me is a small fan aiming at the sensor.
Venting not effective, especially and low moving speed

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Re: Timing Cap/Cover Venting and Cooling Mods

Post by gobium » Fri Jun 29, 2018 5:24 pm

T Bear.
I try not to post much on ss.
I done everything to cool hall sensor.
Only solution for me is a small fan aiming at the sensor.
Venting not effective, especially at low moving speed
Hall sensor is sensitive to wet and moisture!

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Re: Timing Cap/Cover Venting and Cooling Mods

Post by xpatriot » Fri Jun 29, 2018 5:34 pm

Fins = blue
Fan mounted aiming at fins for low speed, no speed cooling help = red
Green= airflow

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