Topic: cylinder head airflow figures

[sohc boy]

yea thats it, thanks retro rocket,  been a while , made  by Mark Walker

[Retro Rocket]

yea thats it ,  been a while , made  by Mark Walker

There was a sad story that went with that rotary bike, can't remember exactly but the owner met a tragic end....

[sohc boy]

yea ,thats right ,not sure myself , not much said about it

[johno]

GDay boys,
Some pics to follow showing the heads ready to flow.
3 heads,
69 sandcast head and valves stock.
72 K2 model with standard port shape but someone has deburred with some medium grit . std valves
Modified high port with big valves

The pics will tell a story, the bench will tell the story........ we hope !
Cheers Johno

[johno]

[johno]

K2 model head , standard shape but tidied with medium grit

[johno]

Sufferin catfish, maybe this time a K2 head !!!!!

[johno]

This the 69 sandcast stock

[johno]

This the hi port head.    hi ho hi ho off to the bench we go.

[johno]

Just a slight difference in the shot at the back of the valve , looks promising .
Cheers gents

[johno]

Time for bed but one last comment,
So just to state the obvious the two standard port pics and the hi port pic were taken with the port centred in the lens, both the standard port can only just see the edge or the valve at the top ( well lets imagine) the hi port check out how much valve can be seen from the same position. Its the same for the moving air / fuel mass as the eye at 300 feet per second just BAM ! straight out the hole like a rat up a drain pipe, or in this case , out of a drain pipe.

I see cycle X are offering a version of hi port in the states, big bucks, wonder how good they are !, anyone know ?

Ooroo  Johno

[bear]

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.

 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.

Sorry Johno I'm stuck in Melbourne at the moment.
But my crew will be about.
I have your number, I'll give you a call.
As for Micks motor, don't worry my old girl can hold her own.

Cheers,
Brian

[johno]

Hello all,
I have been fooling around with solidworks lately, the bloke who sold the system to me does the consulting flowing for this mob.  ( on the software not bench)  www.bulletcylinder heads.com.au then click on billet and check out the suzuki pro stock head they have done. Ol captain 754 would have an orgasm. They have the latest scanning and cnc babies, very nice machines.

Any way I am negotiating with them now to laser scan the honda cb 750 engine, particular interest to me is the head.  Ive got a foundary just up the road doing the internal moulds  eg ports and chamber , crankcase, with silicon cos they scan the silicon molds to get any internal dimensions then scan the outside of engine components then throw it onto solidworks , join together and presto, no more long nights grinding in the shed,

kind of looking forward to seeing what can be done with this baby. The software wasnt cheap but I have two draftsmen at work that are petrol heads and driving the exercise, also a little more computer literate than myself. 

A bit of dicking around really , bloke should ring Honda and ask how much $ cos they would have been their and done it a long time ago, and they should look after their beloved sohc forum bretheran

Cheers Johno

[NitroHunter]

Waiting on those flow numbers... 
Not to get off the subject, but how did that rotatary head function?   

[sohc boy]

Waiting on those flow numbers... 
Not to get off the subject, but how did that rotatary head function?      it was only raced (or practised) for a short while, as the owner passed away , was told went real hard , had Bold'or crank as far as i know ,dont think it was ever dynoed 

[NitroHunter]

I mean how was it's function different from a standard poppet valve head?

[754]

 Nitrohunter did you ever see that rotary valve head V-8 out of Vancouver? hink it was the Phillips dragster.. think he built blower snoutz and accessories...

[sohc boy]

see if i can get some pics's off him , with one pulled apart

[sohc boy]

this is a single cyl ,basically,rotating bar with holes , he has some photo's of the honda i'll get soon

[NitroHunter]

COOL stuff there! 
Should be able to breath unlimited... wow.

[johno]

[johno]

Hi guys,
Home tonight , been away for a couple of weeks and hard to do stuff, caught up with Bears mates on the way.

Re the head flows, two pics, setting up and the best number.

With the numbers from Larry caravan I have made an assumption , which is not generally a good thing but if I have assumed they were tested at 12 inchs  as the numbers from Jerry Branch. If anyone knows different please let me know.

So ! testing at 10 inchs, , temp 64 F
69 std K cyl head.   Inlet  .350 - 54 cfm      Exh. 41 cfm
                                       .400 - 59 cfm              42 cfm

72 std K2 cyl head  Inlet .350 - 65 cfm      Exh. 43 cfm
     light emery clean       .400 - 65 cfm              43 cfm

Jerry Branch           Inlet .400 - 68.5 cfm    Exh  ?
Std 32 valve

Larry C  F head       Inlet .375 - 71 cfm       Exh ?
34mm valve

12 deg K2 big valve Inlet ..400 - 74 cfm      Exh 50 cfm
                                       .450 - 78 cfm      Exh 54 cfm
                                       .500 - 83 cfm      Exh 56 cfm

Make out of that what you may, look forward to some thoughts, I would suggest that larry caravan produced a nice head and a pity we dont have more details.

So at the risk of admitting dementure I didnt do this head, it was a newer version by a chap in Melbourne, given that it has had 3 or 4 owners the couple of changes were acceptable but the two kickers were when I checked the carb flange pattern  which now is set up for RG suzy 500 carbs and the valve stem diam was 1mm bigger and a bigger valve machined down. When I done the 35mm valve I had the 34mm built up with stelite and ground back to 35 to retain std valve stem diam and I never ever cut the guides back flush with the port.

Bear will be happy as I have the details of the original owner, another crazy sidecar man.

The hi port shows potential, particularly at hi lifts, Bear has a cam in his bag of tricks that would work well at those lifts.  So my next exercise is the different average port diam, 30mm 31mm sizes to see if we can get higher port air flow speeds and hold flow. Doing it on the  solid works.
ciao ciao boys

[bear]

Sounds pretty exciting Johno.
Good news about the original owner.
Hope you enjoyed thirsty Thursday.

Cheers,
Brian

[johno]

Hi Bear,
Got em pissed , stole all your trade secrets.
Just wondering what that stainless pole and chair was in the middle of the room holding the ceiling up.
After looking at the pics on the bragging wall I reckon youll need a new set of leathers when you get back, didnt know they made the barstards so big.
Will ring you for a chat soon,
cheers johno

[bear]

Hi Bear,
Got em pissed , stole all your trade secrets.
After looking at the pics on the bragging wall I reckon youll need a new set of leathers when you get back, didnt know they made the barstards so big.

They don't we had to sew two together.
Looks like you've managed to find the only two idiots silly enough to get on a bike with me over the last thirty years.
I'm pleased to see you managed to survive the ordeal, there have been many that haven't.

Cheers,
Brian