Page 5 of 8
Posted:
Thu Jul 28, 2011 2:24 pm
by Steveyk
Forgive me for asking, but why aren't the ports polished, whats the thinking behind that?
Posted:
Thu Jul 28, 2011 8:27 pm
by Megaman
I cant wait for EngineSpecialists to finish your engine Rocko, that way he will have the skills needed and have secured adequate supplier discount deals to be able to offer me a bullett proof engine for my 2k budget
ol
Posted:
Fri Jul 29, 2011 10:00 am
by CAVEMAN
Steveyk wrote:Forgive me for asking, but why aren't the ports polished, whats the thinking behind that?
Not quite sure if this is applicable to the specific reasoning behind this build or not, but I think it is something to do with keeping the fuel atoms suspended in the air mixture. An old motorcycle racing friend of mine who worked for BAE did some research into this many years ago and went from perfectly polished to slightly roughed up.
If the port walls are perfectly polished then you will get a far smoother air flow, however the mixture has a tendancy to seperate in the boundary layer and fuel sticks (for want of a better word) to the side, making the overall mixture lean.
The tiny surface imperfections disrupt the boundary layer and prevent a pure laminar flow keeping the fuel nicely suspended for combustion.
Posted:
Fri Jul 29, 2011 1:15 pm
by Steveyk
CAVEMAN wrote:Steveyk wrote:Forgive me for asking, but why aren't the ports polished, whats the thinking behind that?
Not quite sure if this is applicable to the specific reasoning behind this build or not, but I think it is something to do with keeping the fuel atoms suspended in the air mixture. An old motorcycle racing friend of mine who worked for BAE did some research into this many years ago and went from perfectly polished to slightly roughed up.
If the port walls are perfectly polished then you will get a far smoother air flow, however the mixture has a tendancy to seperate in the boundary layer and fuel sticks (for want of a better word) to the side, making the overall mixture lean.
The tiny surface imperfections disrupt the boundary layer and prevent a pure laminar flow keeping the fuel nicely suspended for combustion.
Er, yeah, that's what I thought!
Posted:
Fri Jul 29, 2011 2:44 pm
by rocko
CAVEMAN wrote:Steveyk wrote:Forgive me for asking, but why aren't the ports polished, whats the thinking behind that?
Not quite sure if this is applicable to the specific reasoning behind this build or not, but I think it is something to do with keeping the fuel atoms suspended in the air mixture. An old motorcycle racing friend of mine who worked for BAE did some research into this many years ago and went from perfectly polished to slightly roughed up.
If the port walls are perfectly polished then you will get a far smoother air flow, however the mixture has a tendancy to seperate in the boundary layer and fuel sticks (for want of a better word) to the side, making the overall mixture lean.
The tiny surface imperfections disrupt the boundary layer and prevent a pure laminar flow keeping the fuel nicely suspended for combustion.
Fair play Caveman .. I knew some one would hit the nail on the head ..
Nick from advanced Told me about this in the week as i asked the same question ...
All rough'd up Just like the Birds around my end ... but PASTY loves Em
Posted:
Fri Jul 29, 2011 6:19 pm
by Advanced Automotives.com
Megaman wrote:I cant wait for EngineSpecialists to finish your engine Rocko, that way he will have the skills needed and have secured adequate supplier discount deals to be able to offer me a bullett proof engine for my 2k budget
ol
Posted:
Fri Jul 29, 2011 6:38 pm
by Advanced Automotives.com
rocko wrote:CAVEMAN wrote:Steveyk wrote:Forgive me for asking, but why aren't the ports polished, whats the thinking behind that?
Not quite sure if this is applicable to the specific reasoning behind this build or not, but I think it is something to do with keeping the fuel atoms suspended in the air mixture. An old motorcycle racing friend of mine who worked for BAE did some research into this many years ago and went from perfectly polished to slightly roughed up.
If the port walls are perfectly polished then you will get a far smoother air flow, however the mixture has a tendancy to seperate in the boundary layer and fuel sticks (for want of a better word) to the side, making the overall mixture lean.
The tiny surface imperfections disrupt the boundary layer and prevent a pure laminar flow keeping the fuel nicely suspended for combustion.
Fair play Caveman .. I knew some one would hit the nail on the head ..
Nick from advanced Told me about this in the week as i asked the same question ...
All rough'd up Just like the Birds around my end ... but PASTY loves Em
Caveman has it in one
Keeping the fuel in the airstream so it does not seperate and cause areas of weak/rich mixture, can allow a better burn and more ignition timing before detonation becomes a problem. The nett result also means that the fuel burn speed is more stable and therefore the cylinder bmep is higher so more power for longer.
The problem with high boost is that the flame travel speed will slow down (more too burn) so so we need to keep things nicely mixed up. Don't know if your birds are like this as well Rocko
Posted:
Fri Jul 29, 2011 8:28 pm
by Megaman
Posted:
Fri Jul 29, 2011 9:29 pm
by Chris 280
youll wear her down in the end mate
Posted:
Sat Jul 30, 2011 3:06 pm
by Cozzy 481
Caveman you stole my thunder....thats what i was gonna say!!!
(Yeah right!)
Love the knowledge some of our members have on here
Posted:
Sun Jul 31, 2011 8:36 pm
by Advanced Automotives.com
I don't know but maybe you need to give her something like for like...something with a bit of grunt. Ask Rocko, he may have a few ideas
Posted:
Sun Jul 31, 2011 9:57 pm
by CAVEMAN
Without all the pics mate, you'd of been done by now!!
Bloody glad your not though, great work and even better that you have shared!!
Posted:
Mon Aug 01, 2011 7:21 pm
by Chris 280
,great thread mate,pictures say a thousnd words,well 666 words
Posted:
Wed Aug 03, 2011 9:15 pm
by Advanced Automotives.com
CAVEMAN wrote:Without all the pics mate, you'd of been done by now!!
Bloody glad your not though, great work and even better that you have shared!!
I agree with the time it has taken but as you say, sometimes it is good to share and thanks for your great comments by the way
Posted:
Wed Aug 03, 2011 9:40 pm
by Advanced Automotives.com
Chris 280 wrote:,great thread mate,pictures say a thousnd words,well 666 words
Talking of pictures!
The heads are now on, the cams are well lubed and we will be saying nitey nite to them for quite some time I hope when the cam covers are fitted tomorrow
Posted:
Thu Aug 04, 2011 10:08 pm
by Advanced Automotives.com
I think this needs a mention. Castle Combe had a track day (open pitlane) on Tuesday that was organised by Apex Track Trackdays. I asked Rocko if he would be interested in coming down for the day to show off his WR1. He said if work permits then he would, what a gent.
He found the time to come cross country and did as he said but not only that, he also took a number of people (they were queuing up for it) for a couple of laps around the track including myself. We all agreed that his WR1 has incredible performance but also just as impressive was the handling and the way it just stuck to the track. A real super car for the road and he can drive it too.
Anyway, I want to say a massive thanks to Chris for taking the time to do this and below are a few pics that one of the BBS members took. He too seemed to love it as well.
The new 666 improved version is going to be on another planet
Posted:
Fri Aug 05, 2011 8:41 am
by Autotecnica
hi nick, what's the cam duration on those cosworth cams?
i'm lookin for some cams to fit 2.5 avcs heads(hawkeye), need to be really wild to pump enough air with a gt42-35. i've already got the oversize cosworth valves.
any ideas? thanks adam
Posted:
Fri Aug 05, 2011 2:43 pm
by rocko
Well worth 222 mile round trip to Blow the Cobwebs out off her ...
And she never missed a beat thanks to Nick.." Legend" For Building my 2.1 stoker .. Ill miss her .. Or Will I lol
My favorite corner of the day is Folly as its Flat out 5th .. And Old Paddock Bend as its a Mint coner if you get it right out of the esses
Thanks for the Invite ..
Posted:
Fri Aug 05, 2011 6:54 pm
by Micktype WR1
Well done Rocko !
I guess that if you weren't before, you are NOW a member of BBS !
My WR1 has its history down there with it's previous owner. Yours takes the mantle !
Posted:
Fri Aug 05, 2011 7:13 pm
by Advanced Automotives.com
Autotecnica wrote:hi nick, what's the cam duration on those cosworth cams?
i'm lookin for some cams to fit 2.5 avcs heads(hawkeye), need to be really wild to pump enough air with a gt42-35. i've already got the oversize cosworth valves.
any ideas? thanks adam
Hi Adam, hope things are good. Kelford do a wild cam for this and I had some good feedback from a customer apart from a stupidly bad idle problem because of the low manifold vacuum, this also led to fouled plugs on occasions. They have an 11.55mm inlet valve lift but do have a slappy flank which will be noisey on the valve clearance. The spec is below:-
Posted:
Fri Aug 05, 2011 8:45 pm
by Advanced Automotives.com
rocko wrote:Well worth 222 mile round trip to Blow the Cobwebs out off her ...
And she never missed a beat thanks to Nick.." Legend" For Building my 2.1 stoker .. Ill miss her .. Or Will I lol
My favorite corner of the day is Folly as its Flat out 5th .. And Old Paddock Bend as its a Mint coner if you get it right out of the esses
Thanks for the Invite ..
She will have plenty of cobwebs and dust soon and I will organise for you to clean your own car so you don't feel left out...again
You could go back up Combe after and see if Folly still works flat in 5th. Left side of the car says it wont. lol
Posted:
Sat Aug 20, 2011 8:25 pm
by Matty WR1
Such a great read
Hope to see you at rallyday next month
Posted:
Sun Aug 21, 2011 9:08 pm
by Advanced Automotives.com
Matty WR1 wrote:Such a great read
Hope to see you at rallyday next month
I will be at Rally day on the Bath and Bristol Scooby stand but not sure if we can get Rocko finished in time for an appearance.
Rally Day is an awesome day if the weather is good
Posted:
Sun Aug 21, 2011 9:24 pm
by Matty WR1
I'll pop by and say hello
I'm on the SIDC stand myself
Posted:
Sun Aug 21, 2011 9:31 pm
by Advanced Automotives.com
Matty WR1 wrote:I'll pop by and say hello
I'm on the SIDC stand myself
I look forward to it and I will pop over to the SIDC just incase we get lost in the crowd.
Posted:
Sun Aug 21, 2011 9:34 pm
by Matty WR1
Pop over early dude, I'm the muffin man and will have team breakfasts