Author Topic: Low Buck 750 Cylinder Head Project (Read 23731 times)

TurboD · « **Reply #100 on:** January 06, 2014, 02:02:50 pm »

I got the chance today to work on the intake a little more, I mainly worked around the guide area. I thinned and streamlined the guide a little more, I did not reduce the length. I also very slightly took more material from the roof on both sides of the guide area. This little additional work helped to bring the numbers up more, I'm sure that with even more work in this area the numbers should continue to increase some.

Here is progress so far.
Flow CFM @ 10 Inches

Before Basic Clean Light Reshape Latest work
.100 24.7 24.7 25.0 25.1
.200 46.1 46.2 46.8 47.0
.300 52.1 56.6 58.4 59.2
.400 54.3 57.7 60.0 61.5
.500 55.1 57.9 60.1 62.0

EnginebyAdam · « **Reply #101 on:** January 06, 2014, 03:05:28 pm »

With the guide reshape, did you basically taper it by hand? If so how much guide thickness did you leave at the tip of the taper?

TurboD · « **Reply #102 on:** January 06, 2014, 05:43:49 pm »

Yes it was by hand, I slightly tapered the guide and then put a small radius on the end. I would say the tip is still half thickness, nothing to radical.

dragracer · « **Reply #103 on:** January 06, 2014, 06:21:00 pm »

Great tutorial with good numbers. Still above my pay grade- lol. I'll leave the porting to you guys and do what i do best and thats building the motor from the parts and pieces the experts prepare for me to the best of their ability.

Thanks for sharing this venture with the forum. We do appreciate knowing how each change brings about increased flow.

dusterdude · « **Reply #104 on:** January 07, 2014, 09:39:47 am »

Do what you do best?i thought gladys was the engine builder?

Sent from my iPhone using Tapatalk

johno · « **Reply #105 on:** January 07, 2014, 01:13:46 pm »

Turbo,
time for the simplest thing of all, 3 angle valve seat and back cut valve, lets see what happens to the low lifts

MRieck · « **Reply #106 on:** January 07, 2014, 02:24:09 pm »

Quote from: johno on January 07, 2014, 01:13:46 pm

Turbo,
time for the simplest thing of all, 3 angle valve seat and back cut valve, lets see what happens to the low lifts

I'd bore that seat/throat too.....the F2 head can definitely use it.

dragracer · « **Reply #107 on:** January 07, 2014, 08:21:28 pm »

Quote from: dusterdude on January 07, 2014, 09:39:47 am

Do what you do best?i thought gladys was the engine builder?

Sent from my iPhone using Tapatalk

Damn, you would give up the truth. Some friend you are-lol.

johno · « **Reply #108 on:** January 08, 2014, 04:01:29 am »

just in case your not sure what I meant .......30 deg back cut from 45 seat edge

In conjunction with a 3 angled seat it forms a nice venturi which maximises the flow past the seat
Turbo try this first then bore to .9 ( as per Mike) and do again , it will surprise everyone I'm sure.
ciao johno

johno · « **Reply #109 on:** January 08, 2014, 04:04:08 am »

3 angled valve seat the other half of the venturi effect

turboguzzi · « **Reply #110 on:** January 08, 2014, 09:24:11 am »

interesting discussion indeed... kevin cameron, who's been tech inspector in AMA and peeked into plenty of works motors wrote once that he saw everything, from full blended, through 3or 5 angle to even "single angle" (just a 45 cut) seats on the podium at the end of races....
Johno, I like your approach. dont know if this story is true, but some say that john britten developed his ports simply building them up from the valve seat with plasticine while running them constantly on the flow bench and going with the path of least restriction.
If i had the time, i'd build a mock head out of silicone and check any porting changes there before doing anything on the real one. toyed with the idea of building a flow bench once, but realized i better build running bikes i can race rather than fine flowing heads that sit on a bench with the time i have!
BTW, this is the only way to really know how your ports look IMHO.... your finger is NOT a 3D scanner

http://forums.sohc4.net/index.php?topic=82510.msg928138#msg928138

Jerry Rxman Griffin aka MuthaF'er · « **Reply #111 on:** January 08, 2014, 11:45:40 am »

Anyone have a 3D printer to play with?

turboguzzi · « **Reply #112 on:** January 08, 2014, 01:22:19 pm »

Quote from: Jerry Rxman Griffin aka MuthaF'er on January 08, 2014, 11:45:40 am

Anyone have a 3D printer to play with?

i do have an Objet 3D printer at work, but not the time to do the 3D modeling

That said, 3D printers have become such a commodity these days that you'd be surprised how cheap outsourcing the service is. some engine developing companies use 3D prints directly as lost cores for castings.

TurboD · « **Reply #113 on:** January 13, 2014, 07:31:47 am »

Johno I am working on getting a 6.5mm pilot, of all the ones I have, I don't have the one I need.

For the time being, I have just about put all of the time into this head that I can. I still have the entire bike to build before spring, This one came home in boxes (to the point that I picked it up in my car). I am also in the middle of a Kawasaki Turbo build that I have fallen a little behind on. Possibly in the future (if time allows) I will take another head and pickup where I left off on this one.

vbtravisd · « **Reply #114 on:** March 06, 2014, 06:34:47 am »

Great thread man... it has inspired me to at least clean up the casting while I have my motor apart. Probably wont take it as far as you have... but it will help a bit im sure. I've done my fair share of sbc and bbc head porting... so im not totally new to the game. Thanks for the info and pics man.

TurboD · « **Reply #115 on:** March 06, 2014, 08:20:25 am »

Thanks. My goal was to be helpful and give guys a little push on their own projects. Be it Sbc/BBC or SOHC, the basics are all the same, apply what you know and you'll be fine.

The first few steps is where the "biggest bang for the buck" are, after that the steps forward are more labor intense and costly.

01Thomas · « **Reply #116 on:** March 06, 2014, 01:31:23 pm »

Hi
I've tried going to this site but Norton's antivirus keeps on giving ma a malware warning. Has anybody else had the same experience?

regards
Thomas

Quote from: HondaMan on January 04, 2014, 08:00:09 pm

Wow, port-shaping deja vu!

http://cb750k2.honda4.nl/Technical/porting/Porting_the_Honda_Head.htm

My book:
Chapter VI, pages A-9 thru A-15 .

SNIP

FuZZie · « **Reply #117 on:** March 06, 2014, 01:46:51 pm »

The code on that page looks clean at this time Thomas

BUT I've only checked that one page, you should be fine but don't go elsewhere on the domain like I said I've checked one page!

01Thomas · « **Reply #118 on:** March 07, 2014, 11:00:04 am »

Thank You! It went through this time without a hitch.

DannyBhoy · « **Reply #119 on:** March 22, 2014, 06:03:51 am »

Many thanks to turbo for spending his time on this. It has been a great help. He kept to the basics, then slowly added more info and options. For most of you it was old news but for some it was perfect to give confidence to tackle basic performance mods.
For 5+ yrs I have be on again off again with months passing and not having the time, money or drive to push on.
I can honestly say that I have worked on the old girl every day for over a month and finally see some at the end of the tunnel.
Thanks again turbo and the rest of you who share your thoughts and ideas.
Cheers

TurboD · « **Reply #120 on:** March 25, 2014, 07:33:48 am »

Your welcome, happy be of help.

hotdog · « **Reply #121 on:** March 07, 2015, 11:16:59 pm »

Quote from: johno on January 08, 2014, 04:04:08 am

3 angled valve seat the other half of the venturi effect

Johno - what book is that..?

scunny · « **Reply #122 on:** March 09, 2015, 09:46:30 am »

John Britten experimented with 4, 5 and 6 valve heads, have some crappy photos I took that I shall try and find.

scunny · « **Reply #123 on:** March 12, 2015, 01:18:41 pm »

found them
4 and 5 valve heads
6 valve blank

News:

Author Topic: Low Buck 750 Cylinder Head Project (Read 23731 times)