Topic: cylinder head airflow figures

[johno]

PPS  Sottly , the biggest main jet I ever run was on a 1,000cc plus , I think they were 145. it was a race only build.

ooroo mate

[johno]

this no 4 of 4
Old jigger sidecar donk, used to go hard.

Cheers Johno

[johno]

A better shot of the donk.

[johno]

walla, finally the port

[johno]

lucky last

[johno]

Finally, this will be my avatar, Scottly look closely at the manifold and carby

I didnt get to pay some bloke to downlod for me it was  tips from the forum that made it happen, was double trouble for me as I have just got an apple mac pro lappy and hells bells, like starting again
cheers Johno

[754]

  I found the 836 harder to ride off the line(and at low/mid rpms) with 32mm, and ET was about the same..had an unported head on that. I have a full range of jets to play withh and worked through everything on the 1/8 mile strip. 32,s might have helped in 1/4 mile. I will def use them on a 970cc.

 Anyone got info on running the Webers angled down.. Tank and Frame be damned, would like to see that raised port motor run with Webers on it.. How do you shift it or is the spline just not there in the pics?

[bear]

Johno

Do you know when the last time the chair would have raced?
The reason I ask is that the rule book will not allow us to use mods that affect the outward appearance of the motor unless it can be proven that the mod was used in competition within the period. ie pre 1972

Cheers,
Brian

[scottly]

 Anyone got info on running the Webers angled down..

According to my book, 0-5 degrees max, with the 5 degree angle sloping up towards the head, not down.
Johno, flow the modified head first, before deciding on carbs.

[johno]

Captain 754, note gear lever

[johno]

side of engine

[johno]

other side

[johno]

head 

[johno]

Barrels 73mm

[johno]

Captain 754, very observant noting the gear change, hopefully the pics show the gear lever behind the cover, its a welded lever to shaft.
Also put a couple of pics to test you out grasshopper, hint ............crank

Bear in there, the engine is now third hand and I,m still trying to contact the original owner for info and dates, he used to live near Warnable, I lll let you know,

Scottly, Captain webber I pulled the motor down on the weekend, was in reasonable condition with no major surprises, it needs a top end freshen up, the valve guides worn on inlets, rings sticky or tight, aluminium head gasket needs upgrading to something more modern, the head retaining nuts only had light stainless washers and with the big cyl studs and left dished compression under nuts, other than that enjoy the crank scene.

Im booked in next Monday arvo to flow the head, Hemi chamber, 35mm inlet, 30mm exhaust, 4.5mm between valves, 14mm spark plugs, average port diam is 32mm cant wait to see what the angle of the dangle does.  I managed to dig a couple of conventional heads out of the junk stash to flow at the same time. My plan is to doco them all for you and convert the test pressures of the two figures from the forum so we can compare.
Starting to get cold out in the shed now , time to crank the heaters up I reckon.
Regards Johno

[754]

 I noticed on the first pic, it had a cut-off crank. are those cases sandcast?? can you still see the numbers? Very modified, that one..

[sohc boy]

Gday Johno like the look of that head , good to see some one taking a s/cam to lake Gairdner, was going to take my 836 s/camer down in 2003 , but change of  plans ,ended up taking a  honda 985 cc DOHC BolDor in M/G1000  instead , ship load of fun allright, been trying to go back for while now ,but every time gets rained out    what class you thinking of ?  oh yea bought a lota bits  off Big Baz Taylor, real nice bloke ,an joker 

[NitroHunter]

 
I picked up an old race KZ head with some pretty wild porting, raised floors, bigger valves, etc, it had run pretty quick back in it's time. But once on the flow bench the numbers were not what we expected to see, and sure enough the throat  had never been opened up.  Larry did this (90% of seat diameter) with a valve job - and with NO other changes -  just like magic it picked up a full 10 cfm, and this was with the valve installed.  It was a real eye opener, as this thing had been pretty high zoot for it's time...

[scottly]

Scottly, Captain webber

LOL! More like captain of the Webber cheer-leading squad.
So whats with the right hand side of that crank??  

[754]

 Oh that side.. looks like a mag drive?

[johno]

Hi guys,
Bear in there and too much water at lake Gairdner,  you guys in NSW should drink more , water the gardens more, do what ever you have to do to stop the water flooding down south. I'm visiting Griffith and Leeton on business next week if your around ? Love to see these chairs, I couldnt find any sidecar records for chairs on the salt in OZ, may be none set ?  Give your donk a rest , borrow micks beast motor for the week and bed the rings in.

Old 754 and Captain Webber,  yes the R/H side is maggy drive, I thought it kind of looks like the crank was swapped end for end , just my mind. dont worry I thought of it for a fleeting moment.

Camboy, Your the man, If you get bored sling me a contact as I'm desperate for info on the salt set ups, other than how good the evenings are. Mind you I have been warned you need a big Esky.
For a long time I have been focussed on M/G 900 as easy option with no record, however now that time is getting close Ive been thinking that being s/ cam honda I should run with a 750 class M/F 750 to complete the nostalgia rush, the modified classes are fairly soft so at the last minute I'm thinking of two bikes for two classes, might get lucky with one.  Then if bear took a chair that would give us 3 chances for a sohc record, with Micks motor of course, try out those barrels.

Nitro Man, that info gets me going, in one of the earlier threads I mentioned I'm not a fan of big flow and ports and made comment HP for the bar and Torque for the track based on having a look at the Byron Hines head on the No1 pro stock Kwaka 900 versus some hi flow heads I purchased,  similiar to what you found above,  port size was small compared to customer heads but lots of work in the bowl between the guide and seat very very big. This changed my life forever, might be just a coincidence but every single national or state record of achievment with my engines in what ever style of motor sport was when I went against the temptation for HP.   got to be a hard habit to break.

If the results on Monday warrant it With these hi port styles my plan is to jig up and do 4 different sized inlets diameters 32mm, 31mm, 30mm, one tapered down from 32mm 30mm , all with 34mm valves all on the one head  so i can see how small I can go without losing too much flow,

Time for the shed,  Cheers Gents

[sohc boy]

Johno, its a great week of speed down there , an yea you need a really BIG esky ,an plenty of small rear sprockets, got me thinking again bout taking a s/cam instead of a dohc   

[johno]

Cam boy, never to late to show the world how good the old s / cam hondas were, I still remember the pain racing at Macnamara Park when the first kwaka 9 went past, I vowed revenge as I cursed, never forgotten.

Not sure if you have checked out the web site lately, the traditional end March meeting was washed out and they have a rain date for end of this month, I will take a drive for a look if it happens. The talk is after a few washouts they are looking at changing the time from late march back to Jan or early Feb, I'm not sure thats a good idea as autumn we get those nice sunny days and cool nights, Jan is peak summer regular 40c deg days, bad for records , bad for both my bald patch and my complexion, no bloody bonfires at night, too hot for a good port.

If it gets changed to bloody hot Jan and there were a couple of other honda guys fronting I would go to the trouble of decking out a 20 foot box container for day use / workshop bolt an airconditioner on the end and run a gen set, would keep the beer cold anyway, could go all out and paint honda SOHC forum on the side of the box and get some mag coverage after the event when we set all these records LOL

To quote the master , just do it grasshopper.

[sohc boy]

have been up to speed with DLRA goings on ,got some mates with vw's go down there ,went with em other year , set a few records,  may be going with them in a few weeks , not sure ,if they do change it to Jan,  feb , yea you'll need to get outa the sun, so the container sounds the ticket,....Have old drag race mate , loves making things outa chunks  of alloy , machined a rotary valve head for a cb 750, was used in a sidecar i think ,i'll try n get some pics of it ,

[Retro Rocket]

Hi Sohcboy, that rotary valved chair now resides at the Australian Motorcycle Museum at Haigslea.
Here's a pic...