Manifold isolator - SF750

S

Smartv11

Full member
Location
Meopham, Kent
These parts have failed in the same way with circular crack.

Any alternatives available (in UK), I note classic Ducatis have similar part, if suitable.

Paul

 

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i know there are some green color isolators made of fibreglass made for the 750 and 1000.

i would think that they could be easily done from a fabric reinforced phenolic similar to old circuit boards or simply machined from alloy.
 
I had a batch of these water jet cut and Wolfgang finished the recess on a lathe, they were made from high heat Teflon, very tough stuff and will withstand very high heat, the only thing better was PEAK, but that was more than 4 x the cost. The Teflon is white but it takes plastic paint well so that the sides show black. They are exact copies of the originals, contact Wolfgang for availability and price.







Cheers

Jim
 
The biggest issue with the original spacers is that they are made of Bake-A-Lite and brittle. It's about impossible to obtain the correct thickness "O" rings and consequently break the O-Ring lands on the spacer or even shatter it when you install them because the new O-Rings are too thick.

I've fixed the original spacers using metal 24 hr Epoxy Glue - File it to shape and use an Emphoric engine case sealer and throw them O-Rings away.

Them Carb spacers are essentially a heat isolator which you don't want leaking air causing lean outs.

We can't get the original parts but leave it to Wolfgang to solve the issue.

Canuck750 - That looks like a nice piece ;o)
 
Wolfgang machined the recesses into both faces of the isolators to accept new Viton O rings to his choosing, he made a perfect fit / seal.

The hardest thing was selecting the right plastic that was resistant to heat and hydrocarbons, will not compress or deform once hot and gave a clean cut from the water jet process and could be machined. The High heat Teflon is stable to 400 degrees F, has a very high compressive strength and is stable. The PEAK product has an even higher heat resistance and cuts cleaner but is just too expensive. I spoke to several plastic distributors in North America before settling on this product.
 
Ah, the perfect match for Cozi's boots  :D

IMG_0967_zpshb8ehng0.jpg.html
 
Cosi's a bear foot RAT like Niki Lauda.

Would very much like to race Cosi  - Why - Smirk and Kisses Bro but won't kiss your ass - He's completely insane ;o)
 
Look on Bevelheaven, Steve has insulators made in alloy with o rings to fit the 750/860 and I suspect they are the same size stud spacing. IIRC the port hole is 32mm ish
 
wdietz186 said:
Look on Bevelheaven, Steve has insulators made in alloy with o rings to fit the 750/860 and I suspect they are the same size stud spacing. IIRC the port hole is 32mm ish
Click to expand...

Yes - I've looked, and thats where i got the photo above from. I'm just not sure they are an exact match, and would need a 30mm bore / hole.(I'm guessing gas flow would be messed up by anything other than the same bore??)
 
Smartv11 said:
That looks ideal, but...

What sizes did you do?

I need a 30mm hole for my SF.

I'm guessing you had 36mm holes cut for the SF1/2

Paul
Click to expand...

I had isolators made for the SF 1/2 with 36mm carbs and I also had some made for the triples. Wolfgang told me that one of the purposes of these flanges is to 'isolate' the engine heat from the carburetor, using aluminum or any other alloy will transfer heat to the carb and effect the mixture. This is why the high heat Teflon was selected as it has a very low heat transfer characteristic.

I drew up the flanges in AutoCad and the water jet cutter's program indexes the cut pattern to make best use of the plastic stock. The thickness of the Teflon is different for each of the flange sizes. The water jet is a through cut process so it can not be used to cut the O ring recess, this must be done on a lathe. We didn't make too many isolators, limited to the size of Teflon pieces I could bring with me on the plane, I brought the stock in from Phoenix while on vacation. This was a prototype test that worked out very well. Wolfgang has the cad files so I assume he could commission more in the future if demand warrants.

If you need some of these flanges contact Wolfgang.
 
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