t5 barrel ,backburner 1 .

[henri]

been a while coming this 1 ,welders kept retiring or dying on me ,but its ready to start now .IMG-20180209-00342 by henri briggs, on Flickr                              cases welded so packer plate can be bolted down outside the t5 barrel footprint ,decked thanks to oz ,dummy crank an shafts an old bearings removed ready to go inside an be mocked up for measurements. 
spec .t5 barrel ,spigot shortened 5mm an turned down , 
crank , a worb 5 51mm stroke ,110 rod 16mm little end ,balanced/cut an welded . 
clutch polini ali one ,cant remember the primarys off the top of my head but closest to primmy ratios .
drt short 4th runner tree .stock loose gears an selector .
polini manifold an starting with a 25mm phbl ,maybe looking for a 26/8 in future , not going to mental an would like to keep low revs throttle responsive .
hopefully i'll get it dummied up this week an get some measurements , the packers over thick an will need machining down ,expecting to have to remove at least 1mm from barrel top as t5's are 52mm stroke .do any porting work an maybe trim piston skirt before sending for re-plating ,an get on with drilling an tapping holes for packer plate bolts . H

[Juan]

Which way are you going to run this, conventional or reversed? That's in the T5 sense.

[henri]

bloody hell , with oz saying same , am trying for a "street sleeper" vibe, but thats 2 votes for cut the bubble an have a big ass carb on the beggar .slightly confused (not unusual for me ) t5 stock exhaust =forward , smallie = rear . was goin usual set up with a altered JL pipe to start ,but reversed barrel has its merits . H

[me]

?? H - that looks like a standard T5 Barrel - come on.... ! a Polini 152 or a Malossi 172 would be more you.... and same amount of work - the polini barrels are 10 a penny these days and being Cast they are lot easier to work.

[henri]

it has been considered ,the polini ,not a big fan of mallosi (grenades) . run a 152 on my super large frame an love it ,real torque-y . H

[henri]

IMG-20180212-00351 by henri briggs, on Flickr .quick fiddle around to get an idea of whats needed .looks like about 3.5 mm needs to be taken off top of barrel,an same amount to drop floor of exhaust port by .or raise exhaust roof an shave 3.5 mm from packer plate. need a more accurate measure up an a think on it . H

[tzsteve]

if you take that amount off the top the transfers will have pretty big timings why not a bit off each end

[henri]

at the moment exhaust opens/closes at 93degs , every mm i drop barrel takes roughly 14 degrees of a exhaust open timings .can be rectified by raising roof , havent got rough figures to hand an cant remember transfers .still in the roughing out the plan stage ,an rather than machining the spigot base have the option of shaving the packer .too many options at the moment to decide ,need a more careful measure up after packers secured down . H

[ginch]

Henri will you be fixing the plate to the case and then the barrel to the plate?

[henri]

the plate/packer will be secured by 4 m7 allen bolts outside the t5 barrel stud area ,then barrels down by usual m8 stud pattern to packer . when i started by rough eye/guesstimate thought i'd be able to use usual barrel stud threads to secure packer .but oz on starting to machine packer found out they intefere .i think tony (tango) when he did this rotated the packer/case stud pattern 45 degrees to avoid the interference. H

[henri]

got to love a snow day , marked up the footprints of cases an t5 barrel an worked out were to drill for packer plate securing holes .IMG-20180301-00396 by henri briggs, on Flickr . H

[henri]

IMG-20180312-00459 by henri briggs, on Flickr got a bit more done over the weekend , cases drilled/tapped for packer bolts , packer plate drilled to suit , titaiunium fancy-dancy race m7 allen bolts secured to fix packer to cases (£2.50 each,blimey) . now to start trimming to size an creating transfers ,considering getting fins/ribs machined in 3 sides to aid cooling . H

[henri]

IMG-20180315-00492 by henri briggs, on Flickr ,got a bit more done yesterday between hospital appointments .packer plate countersunk an bolted down ,dummy bearings an crank fitted an measured up port timings . as is it gives me 176 exhaust ,transfers 130 , an 22.5 blowdown an inlet of 190 .an a wall of 1mm at bottom of exhaust port a bdc ,an a squish of 3.5 mm . plan is to take 1mm off the packer plate to remove wall ,an give transfers of 123 degrees . raise exhaust port 1.5mm to give 180 degrees an 28.5 blowdown ,open inlet opening to try for 200 , an remove about a mm from top of barrel to get 1.4-1.5 squish . H

[tzsteve]

timings of 130 and 175-180 sound nice to me,
but i think i`d be trying for a squish closer to 1,5mm

[henri]

with the length of rod , 110mm ,i'm definetly aiming for 1.5 , just for safety ,measurements were taken without gaskets so final numbers will need to be jiggled.H

[tzsteve]

i have used 110 and 115 rods at 1mm without problems
my fastest was a 104 honda rod
135 transfers
185 exhaust
1.1mm squish

[henri]

IMG-20180512-00648 by henri briggs, on Flickr . got to love a rainy saturday ,no neighbours gardening or having a barby to complain bout noise .coz that bugger took some cutting an sanding . H

[henri]

IMG-20180513-00650 by henri briggs, on Flickr . trial fit ,inlet side needs more taken off to clear a inlet but happy with rest .H

[henri]

IMG-20180521-00679 by henri briggs, on Flickr . starting to cut the transfers into packer ,wish i had a mill .H

[tzsteve]

H.
get one of these you wont regret it

rotozip

the handle and the front both un-clip they take 3mm, 1/8, 6mm and 1/4 inch carbide burrs