Mystery solved??

xsjohn · Posted: August 17, 2009, 2:50 pm Post subject: Re: Mystery solved??

With pete's scoops and "proper" R/L carburation and a bit lower CR and the right gearing I would think 220 cylinders or even a bit less would be possible at 85-90 degree ambient..........I'm pretty happy with 230 or so though..........down 30-40 or so from square one..........and she runs so good I can't stay off of it now......and I bet it will run longer now before catastrophes .....so smooth.........

next would be to build an 8-1 CR mikes 750.........bigger fins on the 650 would be good too if one was a good welder.....which I am not......all this kind of stuff is of great interest to me .......rather than choppin a bobbin and still have a rat..........

xsjohn

xsleo · Posted: August 17, 2009, 2:59 pm Post subject: Re: Mystery solved??

Harbor Freight has the one to get. On sale for $24.99. Item #93984. They sll a few. The cheaper one only read to 230 degrees. The #93984 reads to 482 degrees, more than enough.

TeeCat · Posted: August 18, 2009, 11:28 am Post subject: Re: Mystery solved??

Spectre, the outfit that makes performance automotive air intake systems, has some inexpensive polished aluminum fittings that might make for an attractive and functional ventilation plenum for each cylinder with a little cleverness. I might see what's available. It might be able to be accomplished with as little as one 22-degree tube per side.

TC

pamcopete · Posted: August 18, 2009, 2:23 pm Post subject: Re: Mystery solved??

TeeCat,

Well, that's what is needed. Something that looks godd but doesn't cost a bundle.

I also think that the asymetric look has some apeal, so just install one scoop on the side with the hottest cylinder.

TeeCat · Posted: August 18, 2009, 5:46 pm Post subject: Re: Mystery solved??

Pete, PepBoys has the gear. I might pop down there and see if I can gin something up with a 22-degree tube and a "Spectre"-emblazoned coupling as a leading lip, and affix it to the header.

You like just one on the right? I'm just assuming my right cyl is hotter... I was thinking of symmetrical. You like one better? I can't decide!

TC

pamcopete · Posted: August 18, 2009, 6:37 pm Post subject: Re: Mystery solved??

TeeCat,

Well, certainly at this stage just one would suffice. You first have to try it on the hot cylinder so you want to keep the othert cylinder the way it is for comparison.

If it works to reduce the temperature on the hot side, then you can just duplicate it on the other side.

TeeCat · Posted: August 19, 2009, 9:19 am Post subject: Re: Mystery solved??

Okay, so Pete... I have a layout in my head based on your idea. If all goes accordingly, it will use inexpensive components from Spectre Performance Engineering. I plan on using a small-diameter velocity stack to collect ambient air at speed from forward of the exhaust headers, and force it into a lightly curved plenum which will direct it at the hottest part of the cylinder head. If it works in practice, based on your numbers, it could reduce "at speed" op temps considerably.

TC

pamcopete · Posted: August 19, 2009, 11:24 am Post subject: Re: Mystery solved??

TeeCat,

Well, it's not so much the head as it is the barrel that does not get the same cooling air flow.

TeeCat · Posted: August 19, 2009, 11:26 am Post subject: Re: Mystery solved??

The lower segment between the head (proper) and the crankcase, yeah?

xsleo · Posted: August 19, 2009, 11:52 am Post subject: Re: Mystery solved??

On the older Suzuki's they had a ram air type head cover. I saw a guy with one on an older shovel head. He mounted it above the front head to push more air down around the rear cylinder to help keep the rear cooler. One of these might work and be from the same era as these bikes.
I'll try to find a pic and post it to show the cover.

pamcopete · Posted: August 19, 2009, 12:55 pm Post subject: Re: Mystery solved??

TeeCat wrote:

The lower segment between the head (proper) and the crankcase, yeah?

Right.

xsleo · Posted: August 19, 2009, 1:14 pm Post subject: Re: Mystery solved??

This is what i was talking about. Not a great pic, swiped from ebay.

xsjohn · Posted: August 19, 2009, 1:49 pm Post subject: Re: Mystery solved??

Mine already runs cool..........both sides are the same at about 320-325 at 85-90 ambient...........this it seems drops another 10-15 degrees and is pretty easy........bending the emblem brackets a bit............plan to use some carbon fiber I have from a hood but aluminum would work fine.....this one is stiff cardboard for testing.............guess mine could be exaggerated some more.......but not needed.........plan to put them on both sides after I have decided the shape........

xsjohn

pamcopete · Posted: August 19, 2009, 2:49 pm Post subject: Re: Mystery solved??

xsjohn,

Well, that's impressive. I gather you meant to say 220 - 225?

That design is unobtrusive, easy to install, looks like it belongs there. Does this mean that you could make your needles the same for left and right?

xsjohn · Posted: August 19, 2009, 3:47 pm Post subject: Re: Mystery solved??

Well Pete I know kyou don't care for the R/L needles because of the hassel which they really aren't but the temps would not be controlable on the right without them.......the above temps are with them in there......corrected carbs knocks the first 25 degrees off......just got off the express....90 ambient and I saw 230 on both sides......back roads around 55 seems to be 225......my louvers are not very big and I suppose one could drive the temps down farther with larger ones.......might start looking dorky thouigh....?....and thanks for the compliment on the design........thought about louvers all over the thing for years just couldn't get a design that I could stand........

have to push the top of the reflector bracket inward and bend the tang out..........and the bottom bracket has to be bent outward.............both the top an bottom have to be bent outward right where the thredded portion is....best to heat that part..............getting a pic of both of them on there in cardboard.....

xsjohn

pamcopete · Posted: August 19, 2009, 4:08 pm Post subject: Re: Mystery solved??

xsjohn,

Well, then we are back to the basic question...what causes the right side to run hotter than the left? You offer a solution by effectively detuning the right side and enriching the mixture, but is that the cause? Too lean a mixture, but only on the right side?

I suggest a much simpler cause, that there is obstructed airflow to the right side that can be corrected without making the mixture in the right side different than the left.

There is a market for adjustable needles for the BS34's to replace the non-adjustable factory needles and jets. If you fix the cooling air flow problem for the right side using louvers, then you could offer your needles as a performance mod rather than a temperature equalizing mod. More people are interested in performance enhancements rather than temperature equalization.

xsjohn · Posted: August 19, 2009, 5:10 pm Post subject: Re: Mystery solved??

He mine are a performance mod and a temperature control for the right at the same time when used in conjunction with the correct jets and (and pilot jets)....I think the right is hotter because it is the "drive side" and it sits on the engine case where as the left sits on a air partial air cavity .......anyway mine is the same on both sides and I used the same louvers on both sides..........and anybody can do it any way they want.....the louvers account for about 10 degrees as I see it so far.....will update that if I discover something different.........

And Pete the compression on mine is the same right and left....didn't just lower the right if that is what you meant above........

BS34's
Custom 47 pilot jets
Custom right left needles
134 custom main jets
8-1 compression

xsjohn

TeeCat · Posted: August 19, 2009, 5:22 pm Post subject: Re: Mystery solved??

Guys, I picked up two 45-degree 3" ducts and some associated fittings, as well as a bracket assembly that might allow me to hang each plenum assembly from the outermost header flange acorn nut. Pete, is that nut/stud okay to use? The assembly should be really light. Mounting from the header itself would be really ideal, but I can't find any chrome t-clamps locally.

John... good thinking and nice practical job.

TC

pamcopete · Posted: August 19, 2009, 5:36 pm Post subject: Re: Mystery solved??

TeCat,

Well, that's what I used for my crude dryer hood, but from a practical view, it's not the best. You would have to not use the lock washer in order to get enough usable thread and the nut is not torqued on very much due to the expansion of the stud and the header.

I used electrical condiut clamps for my experimental "wing". At this stage, that's all you really want to do is to verify the effect of the mod and get a general idea of it's practicality. If you find a setup that works, then you worry about mounting it so it looks good.

xsjohn · Posted: August 19, 2009, 5:38 pm Post subject: Re: Mystery solved??

Finished the louvers out in carbon fiber......think they accounted for about more 10 degrees on mine which was already low ....might accont for more on a stock machine .......

xsjohn

TeeCat · Posted: August 19, 2009, 6:02 pm Post subject: Re: Mystery solved??

Thanks, Pete.

John, that looks clean.

xsjohn · Posted: August 19, 2009, 6:14 pm Post subject: Re: Mystery solved??

Just saw 220 @ 82 degree ambient......55mph.......15 miles after engine was at operating temp..................I ain't going any lower.......well then I say that.......the solid louvers seems to work better than the flapping cardboard test ones........ thanks TeeCat......

BS34's
Custom 47 pilot jets
Custom right left needles
134 custom main jets
8-1 compression

xsjohn

pamcopete · Posted: August 19, 2009, 6:26 pm Post subject: Re: Mystery solved??

xsjohn,

Got a part number and price for this yet john? My '81/H does not have the reflector brackets, so some sort of bracket would have to be supplied.

xsjohn · Posted: August 19, 2009, 6:46 pm Post subject: Re: Mystery solved??

Tee Hee.........I'm not selling these....

I wonder what models have the reflector.....or some have them and some don't...?.....and surely the 220 @ 82 ambient at 55mph will go up some on the express @ 65-70 on a 90 degree day....was seeing 230-235 @ 65mph ambient being 90 .............tomorrow it will be hot again (92) and I will run it up on the express for 30 miles this time and see what I get............hoping I didn't waste my time and what I find will be honest..........hey even 230 is good if that's what it has to be without huge louvers.......and these are bigger than I wanted but look ok I guess...... Laughing

xsjohn

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