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Custom fan Shroud .
Posted: Sat Nov 26, 2016 4:38 am
by wreck
Since there's not much in the way of projects going on I thought I'd share a slow one I've been working on .
I'm in the slow process of building a 2.6lt for a Ghia ,After issues with uneven cooling and the price of 911 fan/alternators in Australia I decided to go with a Cali style cooling system with a difference . Getting the air to blow evenly between the cylinders .
If I was in the States I'd just get a DTM but because of freight and currency it would end up over $2000AUD . So I'm having a go at moulding my own design shroud that is centre mounted . Progress has been slow but it's finally starting to take shape .
http://www.shoptalkforums.com/download/ ... w&id=18246
the cylinder covers were made by using the original tin cylinders #1 and #3 as a plug , then joining the moulds and making the duct in the top , it's the same dimension as a type 4 1/2 side . the mould makes both sides .
I made up an Alternator /Ac compressor bracket , the plan is to run a single serpentine belt .Then started cutting and glueing pine blocks together to get the shape I'm chasing to make a plug for the shroud .
http://www.shoptalkforums.com/download/ ... w&id=18252
http://www.shoptalkforums.com/download/ ... w&id=18253
I'm getting to the stage of sealing the pine then using high build primer and rubbing back to remove any high /low spots . Hopefully I'll get a prototype moulded off the plug for flow testing in the next few weeks . I've a fan mounted to a 3000 watt brushless motor from an RC aircraft (another hobby) that I'll use to check flow .
Re: Custom fan Shroud .
Posted: Sat Nov 26, 2016 6:07 am
by doc
Wow, sure looks cool! Really nice work. Many will be interested in your results. DTM and Cali style have led the charge for many years.
doc
Re: Custom fan Shroud .
Posted: Sat Nov 26, 2016 6:11 am
by dragvw2180
Looks great , a lot of time and effort went into this. Mike McCarthy
Re: Custom fan Shroud .
Posted: Sat Nov 26, 2016 9:21 am
by Ol'fogasaurus
Very interesting! What, if anything will be inside your design; airflow guide wise or will it be just open? I am impressed for sure.
Lee
Re: Custom fan Shroud .
Posted: Sat Nov 26, 2016 2:17 pm
by NextGen
Wow,very nice cant wait to see it finished. Man you are handy with wood. This is what this forum is all about sharing ideas.
Keep us posted.
Re: Custom fan Shroud .
Posted: Sat Nov 26, 2016 3:42 pm
by wreck
Thanks for the compliments guys. Joe I started making balsawood model planes when I was a kid back when all you got in the box was a plan and a pack of balsa

.
Lee the plan is to make an internal wall that runs down to the 1/2 side , then test it with strands of wool to see if it will need guide vanes to get airflow to the inner area of the ducts . I've an micro pitot tube to measure air speed from a fixed wing drone that I can use to check airspeed after I'm happy with the wool strand method .
Funny how sometimes you stumble on things by accident . if you want to make a velocity ring for a type 1 fan , grab a fan and some fibreglass and lay up a bit of glass around the outside of the intake part of the fan , it gives a lovely radius the correct diameter . covering the fan in packing tape makes an easy mould release .
Re: Custom fan Shroud .
Posted: Sat Nov 26, 2016 7:47 pm
by NextGen
As you may know I have been doing industrial designs for the elevator industry for over 40 years and did may modifications to the original Twin Towers World Trade Center of 9/11. The elevators were at the time the fastest in the world at 1600 fpm. Elevators ride on rails like a train and also do there counterweights. In high winds the building swayed feet in each direction, which can cause the elevator or counter weights to derail. 3 cup Anemometers were used to tell the computers to slow the elevators to a safe 1000 fpm. Problem was the in NYC snow or ice storms also have winds and the Cups freeze. I was the guy that designed Pitot tubes into the system. No moving parts.
Re: Custom fan Shroud .
Posted: Sat Nov 26, 2016 10:52 pm
by wreck
Wow Joe that that's a great achievement and slice of history, very sad that the Word Trade Centre is now so famous because of that despicable act .
On the subject of Pitot tubes , sadly good friends of mine were badly injured on an Qantas Airbus that went into a rapid decent because of a frozen pitot , before Airbus rectified the heating issue . One of the friends will always have back and leg issues but are thankful to be alive .
Re: Custom fan Shroud .
Posted: Sun Nov 27, 2016 3:17 pm
by NextGen
Yipes!!!! Well I guess they fail to, but I can't imagine how long those 3 spinning cups would have latested on a jet doing 500mph . Pitot tubes win longevity contest. Ha
Re: Custom fan Shroud .
Posted: Sat Feb 11, 2017 3:47 pm
by wreck
Slowly getting there with the shroud after a break over Christmas /New years . I had friends staying for a few weeks and didn't think they would like the lovely aroma of polyester resin . It's also the hottest time of the year ,39c (102F) forecast for today

.so I can only work early mornings or the resin starts curing before I can finish laying down the glass.

.
http://www.shoptalkforums.com/download/ ... w&id=18503
Because of the complex shape a split mould is needed , one side layer up first , the blue colour is PVA release film,magic stuff.
http://www.shoptalkforums.com/download/ ... w&id=18501
both sides of the mould , hopefully have a shroud to start testing by next weekend .
There was an story in a local Aussie mag about a rallycross bug with a type 4 in the 70/80s in Australia , it is most likely the one Joe has mentioned a few times .
http://www.shoptalkforums.com/download/ ... w&id=18506
http://www.shoptalkforums.com/download/ ... w&id=18505
http://www.shoptalkforums.com/download/ ... w&id=18504
Re: Custom fan Shroud .
Posted: Sat Feb 11, 2017 4:27 pm
by BugUgly
Wow.
Re: Custom fan Shroud .
Posted: Sun Feb 19, 2017 3:14 am
by benito26
Nice work mate, good to see another Aussie thinking outside the box. The system may only need minimal directional vanes.
Keep it up, been a long time since i've been on here and it's good to see the forum getting revived.
Re: Custom fan Shroud .
Posted: Mon Feb 20, 2017 1:06 am
by wreck
Thanks Benito , Hopefully just a vane each side to direct the flow . I stuffed up a bit and didn't allow enough fan clearance with the thickness of the glass . So a bit more work before I can start testing . Did you ever use those Deutz cylinders ? John Alder at Volksengineering is chasing some used ones .
http://www.shoptalkforums.com/download/ ... w&id=18568
Re: Custom fan Shroud .
Posted: Mon Feb 20, 2017 2:13 am
by Piledriver
Stick a pre-doghouse fan in it for testing.
It should still work ~the same, plus its useful info as some folks swap fans out between summer and winter.
If it still provides good, uniform cooling that literally saves a few HP at high RPM.
Re: Custom fan Shroud .
Posted: Mon Feb 20, 2017 3:57 am
by wreck
I've an early fan but it was hitting as well .
I've cut down the lip around the fan so the fan protrudes out of the shroud , I'm going to pack up the fan with some tape to give a bit more clearance and glass over it, should work . I've a fibreglass velocity ring that I want to use so will need the shroud to go out past the intake lip of the fan . If that makes any sense .