cylinder 3800

"Pour solex 3800 5000, cylindre TUM 80A cm 6.5" , annons på ebay, min heter bara TUM 80, är det en trim cylinder eller...........

pelle

This is basically the differences between the cylinders TUM 80, TUM 80A, TUM 80A CM6.5:
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TUM 80 (1961-1966/67)
2200, 3300

7 mm inlet port & 7 mm transfer ports


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TUM 80A (1966/67 - 1974)
3800/5000

8 mm inlet port & 7 mm transfer ports


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TUM 80A CM 6.5 (after 1974)
3800/5000/4600
8 mm inlet port & open transfer ports



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Also, the exhaust port is smaller on the TUM 80.

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The TUM 80A CM 6.5 cylinder can replace the TUM 80 and TUM 80A cylinders with no problem.

Solexly, Brian
http://velosolex4600.over-blog.com

if i try it on my Solex-66, will it go faster, stronger, better with an TUM 80A 6.5 ?

pelle

Top speed will be the same.
Torque will increase.
It is best if you install a short-skirt piston with this cylinder.

This kind of piston you mean?
http://cgi.ebay.fr/SOLEX-PISTON-COURT-BIELLE-VELO-SOLEX-3800-5000-MICRON_W0QQitemZ350326828956QQcmdZViewItemQQptZFR_JG_Moto_Pièces?hash=item51911b2f9c#ht_500wt_1182

pelle

The piston is sold without piston rings.
How much shorter is the skirt, is that just turned off or is the piston balanced for material loss?

tvc15 skrev:This kind of piston you mean?
http://cgi.ebay.fr/SOLEX-PISTON-COURT-BIELLE-VELO-SOLEX-3800-5000-MICRON_W0QQitemZ350326828956QQcmdZViewItemQQptZFR_JG_Moto_Pièces?hash=item51911b2f9c#ht_500wt_1182

pelle

Yes.

Admin skrev:The piston is sold without piston rings.
How much shorter is the skirt, is that just turned off or is the piston balanced for material loss?

The piston is simply shorter...by 2.47 mm. The longer skirt partially blocks the inlet port. A long skirt piston can be modified by filing away material in the area of the inlet port...about 20 mm wide and 2.5 mm high in the shape of a crescent.

Long piston = 53.30 mm
short piston = 50.83 mm

long skirt = 49.45 mm
short skirt = 46.98 mm

Ok
I have made a bid on both cylinder and piston.
pelle

Don't forget new piston rings.