extending cam chain

[Jack]

If you wanted to extend the cam chain by one link,how much would it extend the chain as I'm a little confused as where to measure or calculate. I'm wanting to use 533 JE pistons for my Cr500 long rods and the differences in length is .159 to raise the cylinder block.
Example Shannon here from the old XSRider forum used a 3/8 block spacer but
doesn't go into detail modifying the chain

 

[GLJ]

If you wanted to extend the cam chain by one link,how much would it extend the chain as I'm a little
confused as where to measure or calculate. I'm wanting to use 533 JE pistons for my Cr500 long rods
and the differences in length is .159 to raise the cylinder block.

I may be wrong , from what I understand the length of the 533 rod and piston is the same as a the 447 rod and piston. The distance from the pin to top of piston was changed to accommodate the longer length of 533 rod. I may be wrong hopefully others will post.

 

[Jim]

Well the .159 raising would mean the front (descending) and rear (ascending) sides of the chain would need the extra length. So time 2 is .318
But technically you can't add just one link.

 

[Jack]

I may be wrong , from what I understand the length of the 533 rod and piston is the same as a the 447 rod and piston. The distance from the pin to top of piston was changed to accommodate the longer length of 533 rod. I may be wrong hopefully others will post.

the 477 and 533 pistons have different compression heights, the three XS's shared the same stroke just used longer rods. Using the 533 piston with the Cr500 rods would place the pistons compression height .159 plus above deck height.

 

[Jack]

Well the .159 raising would mean the front (descending) and rear (ascending) sides of the chain would need the extra length. So time 2 is .318
But technically you can't add just one link.

Jim I'm kinda lost has to why one link can't be added as it would give me the length based off half of .318. I read some where from Kop that raised a block to what height I'm not sure of or piston being used or rod length but he said one wasn't enough and two was to much.
The pistons I have would either require welding head C/C up or milling 1mm for ideal compression. Second pistons I have are Arias KZ 1000J put have been unable to get recommended piston clearance,have contacted Arias,who ever bought them out and are unable to help me not knowing the type of forging for that particular piston.

 

[GLJ]

I'm wanting to use 533 JE pistons for my Cr500 long rods

Sorry I'm not thinking the best today. I missed where you are using CR500 rods. Seems to me there were some threads about motors like what you are building. I think one of the guys was from down under.

 

[Jim]

Jim I'm kinda lost has to why one link can't be added as it would give me the length based off half of .318.

For every "outer" link added, you'd have to add an "inner" link... 2 links... for a total of .636

 

[Jack]

Sorry I'm not thinking the best today. I missed where you are using CR500 rods. Seems to me there were some threads about motors like what you are building. I think one of the guys was from down under.

They're using custom Ross pistons that are expensive like over 5 plus and JE's are like 3 and some change. I've looked for 140 mm rods and they either
have a crank pin diam of 24mm 25 or 28 29 no 26mm for the XS.

 

[Jack]

For every "outer" link added, you'd have to add an "inner" link... 2 links... for a total of .636

View attachment 165238

I see what you mean now,this totally sucks as I was hoping not having to modify the combustion chamber. Thanks for spoiling my day Jim

 

[Jim]

Sorry Jack.
I have a suggestion though... You could add the 2 links and then shim the (front) chain guide inward to take up the slack of the extra link.

 

[Jack]

Sorry Jack.
I have a suggestion though... You could add the 2 links and then shim the (front) chain guide inward to take up the slack of the extra link.

Jim thanks for the suggestions but at the moment I'm looking at other options to use the KZ pistons. I've removed all the epoxy in port floor to rework
the intakes like Chris's ports and re welding the combustion chamber to a pear shape like what came on the sportsters,so I'll be busy for awhile.

 

[TwoManyXS1Bs]

A half-link would do it.


Good luck finding one in the DID-219 series...

 

[650Skull]

Come on yous guys if yous cant buy one.........saw someone bend an actuator arm.......yous should be able to chop and make a one link for the cam chain..........where is your sense of ingenuity and adventure........letting the XS community down now..........

 

[xjwmx]

where is your sense of ingenuity and adventure

a used, stretched chain could be one link longer. look for used chains and ask them to measure its length for you

 

[Signal]

I haven’t thought too long about this and I am prepared to be shot down.

Would swapping the cam and crank sprockets to the XS1 34/17 ratio and using a later 36/18 chain work.

 

[Jim]

I haven’t thought too long about this and I am prepared to be shot down.

Would swapping the cam and crank sprockets to the XS1 34/17 ratio and using a later 36/18 chain work.

Interesting idea. Are the links the same length on the 34/17 and the 36/18 or are the diameters different?

 

[Signal]

From Mikes XS (probably not the best reference source but easy to find)

Endless Cam Chain - Daido 219FTSS x 106. Pitch .3061" (7.774mm.) Fits: TX/XS650's 1974-84 (36 tooth cam). The latest high strength cam chain from D.I.D. for late XS650's.


Cam Chain - Tsubaki BF05T x 102 with rivet link. Pitch .315" (8.0mm.)Fits: XS1/XS1B/XS2/TX650 1970-73 (34 tooth cam). Made in JapanNOTE:Link pitch differs from chains used on later 650's

So this is probably not a runner. It could be worth trying a used chain and seeing if it would run over the sprockets if the mix will sort Jack's problem.