500 Unit Overbore .

Joined
Jul 25, 2010
Messages
5,863
Country flag
Stock : 69 mm × 65.5 mm

+ 40 650 pistons get you 72 m.m. , or 3 m.m. / 120 thou. ' over ' . On certain later barrels .

RIGHT , so .

500 Unit Overbore .


WHO has one ' on the bench ' . What Size are these orifices .

If a chap were to CAST a CUSTOM BARREL , like a 650 with a 750 barrel , one might BORE the CASES further . Perhaps . Where does it all stop . Is the Question . !

Looking ( at it ) ( Purely Hypothetical ) it seems ' theres a bit of potential ' .
A 40 over 650 is 660 , these in a 500 , I think , get you 560 . Been Done . With dual 30 concentrics , solo or both two up , It'd match ( or better ) a souped up Saint .
and its a bit lighter / Nimbler . There must be ' of the shelf ' sleeves , that'd do the trick . If such still exist . So a Daytona / 100 C , at 600 , should be no slouch .

Youd assume chamber / head stud would be the deciding factor .

500 Unit Overbore .
 
Last edited:
Just to STIR things along .
500 Unit Overbore .
500 Unit Overbore .


o.k. , so the THREADS from the HEAD BOLTS at the top of the barrel , are the first fly in the ointment ? . How FAR OUT will it Go .
 
Last edited:
I know some who raced one in MX years ago who used 650 pistons. It comes out at 518cc.

He didn’t go bigger, and he wudda if he cudda !

First bottleneck is the barrel spigots would be machined away, so liners required. But the barrels don’t have the sufficient meat for such liners, so custom barrels would be required.

Then the head bolt pattern needs changing, basically it needs changing to the 650 pattern. Actually the easier way to do this would be to use the 650 head I think.

IMHO that’s a lot of work to build something that gets blown off by the first T140 it meets !!
 
Last edited:
500 Unit Overbore .


Saw the thing , a thousand years ago ( 1978 ish ) assumed cast sleeves , all hoary below . Was told THEN ' late barrels ' dont break thru . Never Measured it 9 bore . but looked like the 650 slugs . = 040 .
ported ran dual 30's .
As it'd match ' the Saint ' woth thoughtitcould blow of anything , and did try . 2 - 1 - mega . usually unbaffled . O S inlet & bonnie cam with the short unit gearing , ran rd's ragged .
tho if it took it easy , id get pastem by past 60 .no sense abusing the clutch . That thing'd match a T 140 to that , 80 say or better , 100 / 105 perhaps . Then gearing shorthauled it .

But as this RAT T 100 ( in a 59 frame :confused: ) matched that , Id think about THAT . as the T 100s a wee bit lighter than aOil toob , on the dirt . Long Story . Only Honda to pass hit the gate as we were reading the map
Pass em by the dozen , down hill particularly , on unsealed roads .
The SPRINT at the end of the day , I didnt run . bike 7 ballast borrowed . Conundrum was 1/4 mile FINISH was into a 80 ? right uphill narrow in pine forrest , on a bank .
All the Hondas backed off .
The 58 stripped Speed Twin , with a 4.00 k 70 aft , speedmaster Ft . was thrown into the bend throttle on till it was outta da corner . the Hondas hadnt figured that out , and braked .
So the toitle bet the ear . Mon.
Its USABILITY , on a tight track , and the extra tourque PLUS the bilittie to rev out a way , for a ' Lite Weight ' means its worth a throw .HOE BIG are The HOLES in the CASE . ? Mate .

500 Unit Overbore .

Hoises fa Coises , in these doies , an whos gunnaknow , asitwere . Eh .

500 Unit Overbore .


If youve got yer revs , youve got your output . on a widdle won .
500 Unit Overbore .


155 ? Yer On ! . ;)
 
Back
Top