3XV-50

[Neal]

Hi guys ,
i have not searched it to verify but i have some 3xv-50 barrels that i can try and do a port map for anyone that is interested . I can try and copy the flange adaptor too . I asked my tuner if there was any porting that could be improved upon and he told me to leave them as they were good enough as is .

cheers

[maccas]

I for one Neal would be interested in seeing a port map of the spr cylinders mate! It would be good to compare figures against my 92 sp cylinders!

Cheers,

Dan

[EEKNOWS]

I would like to have a look at the map Neal

[Neal]

No problem , after work tomorrow I will give it a bash

[muz_j]

Is it the same as the 3XV2 SP port map? or has it been improved over the years?

[Neal]

I have given up trying to rub the ports with a pencil and my marking blue trick is not working either . I will try again .

I have been looking a stock 3xv00 barrels , i see that the powervalve protrudes a little into the ex port on the upper right hand corner . It looks like it blocks off the rhs extra exhaust port when fully open . Is that right ? 

Comparing the 2 different barrels visually , you can see that the 50 barrel has more exhaust area than the 00 barrels .
The inlet boost port seems bigger on the 50 barrel as it is split in 2 . The 00 barrel tapers from the base of the barrel smaller to the side wall .

[Kingy38]

just rubbed my ports with a pencil, l/h upper cylinder was done with A4 paper,clear but not as accurate as the r/h lower cylinder that was done with tracing paper,had to reverse the tracing paper so it didn't pick up all the pencil marks!!
R cylinders tuned by Martin to (almost) SP spec...

[Kingy38]

r/h lower cylinder.......

[Neal]

Were the powervalves tuned too ?

[Kingy38]

yeh, the powervalves were modded to match the main,and sub exhaust ports...

[EEKNOWS]

Any way you  look at it that cylinder is severely lacking in blowdown angle area. Opening 80 deg ATDC is a bit OTT.

[Kingy38]

EEKNOWS, i'm assuming you're referring to the l/h upper cylinder? it is a rough trace indeed,but the outline shape of the exhaust port is quite different to the r/h lower cylinder,i wouldn't take too much notice of the figures either,i've just re-measured using my vernier gauge,and the exhaust ports are 26mm from the top of the cylinder.......

[Crank]

Neal, did you ever get anywhere with the map?

Want to send my spare cyl's for plating and porting at some point. Would be interesting to look at the -50 map.

Is there an accurate SP port map available from anybody else?

[zoomzoom]

Yeah crank it owuld be interesting to see the port map on the -50 barrells, then we can copy it to our R heads....

[Crank]

Yup, thats what Im thinking. Not sure if the -50 with the tri-power valves will be possible to replicate on the R barrels.

SP may be the way to go.