447 & 533

[funky]

Hi all Funky here hope you are all well.
I was looking through some engine parts on ebay cylinder heads and cylinder pots and liners and some where specified as 447 or 533 which i know are the con rod configuration, i understand that a cylinder head may be different as to the cam installed I.E 447 cam for 447 piston and con rods. or 533
I am assumimg that the cylinder head casing fits either cam 447 or 533 but why have some people listed there cylinder body ass 447 or 533 im thinking there all the same or are they different.
All the best Funky

 

[650Skull]

No difference in the head or barrels, they all 447 and 553 interchange or no change. Its the length of the con-rod and the placement for the piston pin for the little end on the piston, It is higher up, (longer rod), also the bottom end of the con-rod is a different.
.

The 553 engine was introduced in 75 in England and Europe, (not 100% sure on what countries actually got them), and for how long or what models and what year they changed back to 447 if they did. Standards were sold in Europe until 80-81 but some were still being sold in 82.US and most other countries discontinued the Standards in 80. Europe got a US Custom in 79 and these were 447 type engines.

Maybe someone who has more details will add to this.

 

[funky]

Thanks Skull so your saying the 447 cam, cilinders, and head is the same as the 533 cam ???? thats what i was thinking.
The reason I asked was that I am looking to re-sleave or re place my cylinder bores in my bike
I had it rebuilt some time ago to 707cc I am sure that the stock cylinders where bored out to 78mm
so dropping them out and fitting new 75mm stock ones was the plan returning the engine to 650cc
But if the rebuilder bored the cylinder body out and fitted larger cylinder barrels in i would need to buy another cylinder body to fit stock cylinder barrels ... If you know what i mean lol

 

[gggGary]

707cc, 78mm is the usual maximum bore limit into the stock sleeves.......

 

[funky]

Thanks gggGary So i must have standard bores,, bored to the limit.
My issue is getting a little bit of blue smoke when reving the bike. I remember when i rebuilt the engine it was right on the limit in terms of ring gap.
I have done a compression test and i gett 147.5psi and 155psi I also performed a leak down test which seemed to indicate the valves are ok
I have been looking for new rings but not sure where to sorce the right ones top ring is 1.2mm second is 1.5mm
and the bottom set is 3.00mm probably a 0.50 over would do it.
My other options are to re sleeve the bores to stock 650cc and get stock pistons and rings,,, or go for a 750cc big bore kit from Heiden tuning
The big bore kit is obviously the most expensive
the re sleeve with 650 barrels and piston the second highest in price and the new rings for the current pistons and bores would be the cheapest option.