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Learning how to build Lotus Seven replicas...together!
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PostPosted: January 6, 2014, 11:55 pm 
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Joined: December 23, 2012, 6:04 pm
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Now I know "unobtainium/chris" is following.... I am going to be VERY self conscious about my welds..... Chris - your work and website is legend!

one more weekend and the beer money tsd rally car (aka diversion) will be largely completed....and I can get back to building.

calgarylocost (aka jamie)


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PostPosted: January 7, 2014, 11:08 am 
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Location: Langdon,AB
calgarylocost wrote:
Now I know "unobtainium/chris" is following.... I am going to be VERY self conscious about my welds..... Chris - your work and website is legend!

one more weekend and the beer money tsd rally car (aka diversion) will be largely completed....and I can get back to building.

calgarylocost (aka jamie)


Well I'm flattered, but you certainly don't have to worry about me passing judgment. I'll answer anything I can, and help endlessly, but far be it for me to scrutinize others in their hobby.
I love the diversion, sometimes we need that. You got what sounds like a great deal.
Looking forward to more pics. :cheers:

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PostPosted: January 7, 2014, 11:20 am 
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Location: Langdon,AB
xr4Bill wrote:
unobtainium wrote:
Great project!! Cool to see an Alfa build locally. You are in good hands with the local 7 group.


time to stop lurking and start building Chris, you know you want too.

Bill.


I sure do. The turbo project needs doing first, and I need to wait for the help to grow a bit!

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PostPosted: February 24, 2014, 10:10 pm 
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Okay..... the temporary distraction (aka bmw 318ti rally beater) is completed....and we have had one solidly mediocre but highly entertaining TSD rally under our belt.

This past weekend I started to mockup the front suspension for our build. My design philosophy has been to take advantage of the engineering that went into the Alfa GTV6 suspension design... with a couple of modifications such as a front-mid engine design rather than have the engine sitting over the steering rack.

I cut a large number of 1" and 3/4" plywood shims which in various combinations give me 1/4 inch increments on shim height.

Viewed from the front you can see how I used the shims....and how there is not quite enough room for the steering rack to fit in front of the engine. Note that the steering geometry is way off due to the weight of the calipers rotating the hub assembly to about 20 degrees of forward castor.

Viewed from the rear you can see the asymetry of the cast steel bar that holds the rear of the torsion bars. Also note the two mounting holes for bolting the assembly to the sub-frame. Given the forces involved under the weight of the vehicle the center of the cast steel bar is forced downwards....and the two bolts to the frame keep the center of the bar in compression at the top and bottom of the beam. While I could have made the geometry work by flipping the bar upside down this would place the beam center in tension with all the possibilities for failure that would imply.

Viewed from the side it is obvious that I will need to shorten the cast aluminum tail mount of the engine by 6-10 cms....so that the engine assembly will fit between the rectangle of the cast steel bar, the torsion bars and the steering rack.....

calgary locost


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PostPosted: June 1, 2014, 9:56 pm 
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Today I decided to build a correct mockup of the front end of my build and dispense with the wood shims. Using dimensions from a GTV6 frame pulling chart and some caliper work on the donor vehicle I built a jig for the a-arm mounts and for the torsion bar retainer behind the engine.

The steering rack is resting on a plate at the right level....but is rotated to investigate clearance for the steering rod...which has caused it to lift up. Just inboard of the steering shaft are the mounting holes that should lay flat on the plywood when un-rotated. In my build the mount for the steering will be rotated about 50 degrees so the steering mechanism will fit under the alternator.....and with everything in the correct plane to prevent bump steer issues. Burrowing Owl Meritage provided for scale....
Attachment:
June1_2014_front.jpg


The side view still shows that the aluminum tail mount will need a bit of shortening.
Attachment:
June1_2014_siderear.jpg


builders tip of the day...... put the centerline on the table -BEFORE- you start positioning heavy components on the table.

calgary locost


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PostPosted: June 2, 2014, 7:31 am 
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Builders tip of the day #2...... put the centerline on the table -BEFORE- you start on the Burrowing Owl Meritage.

There, fixed that for you...
:cheers:
JD

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PostPosted: March 25, 2017, 9:08 pm 
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In keeping with the design philosophy of using the original Alfa GTV6 suspension points.....I created suspension templates which document exact pickup points +/- 2mm or so. I also used the templates to help position the steering rack correctly (reduce bump steer) and facilitate the rotation of the steering rack to the correct angle. My neighbor is lathing me up some 1" diameter bushes that will be welded into cribbed 2*1 steel tubing to mount the lower A-Arms. Now that I have assembled a pretty complete collection of frame pull charts, and chassis dimensions.....it will be the lower a-arm bolt positions that will provide the starting point for all other dimensions.

It has been a busy few years since my last post. I am oil field trash (and damn proud of it) so the last couple of years have been interesting keeping my staff all together, and seismic processing work coming in, while pushing the R&D side. Mrs Calgary Locost and I are taking the year off from competitive TSD, having won our class in the local championship and in Western Canada in 2016. We also broke a lot of stuff on the bmw318ti (featured earlier in this thread) in 2016.....hitting a rock big enough to smash the oil pan through the skid plate on our last rally.....

My favorite belgian white provided for scale.


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PostPosted: March 26, 2017, 12:42 am 
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Joined: November 11, 2013, 4:47 am
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Location: No. Nevada
Glad to see someone else using Alfa bits in their build.
I'm recycling a rusted '73 Spider into a Dio Tipo build.
Your V6 should be plenty fast if you can keep the weight down in the Locust tradition.

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PostPosted: March 26, 2017, 8:44 pm 
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I found that the 1" plywood on the build table had sagged about 3/8" under the weight of the engine....so today was taking apart two sections of the build table and welding in a proper 2" by 1" steel tube to provide the center support. After a couple of hours its all back together and looking good. Should have done that up front. DOH!

RichardSIA - Not really looking to add lightness. The frame will likely be heavier than really required and it is thicker guage than locost standards...want to enjoy the drive rather than obsessing if "crossmember AB" might be a little under design. Looked up dio tipo and it looked to be a dead web site....maybe under maintenance?

calgarylocost


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PostPosted: March 26, 2017, 9:15 pm 
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Location: No. Nevada
The Dio Cars site does not get updated very often but they are very much still in business, $6,500.00 for a basic old-school kit.
I may be going to visit the factory this summer.
The greatest challenge in building them is that their traditional 50's - 60's donor cars are very hard to find now and virtually everything newer has a too-wide 60" track.
Alfa Spiders are narrow enough and running but rusty examples are fairly plentiful.
So far as is known mine will be the first Alfa/Dio Tipo.
My first effort may be repeated using a modified version of their professionally designed space-frame chassis.
Really the only major mod is attachment points if I reuse the stock Alfa suspension.
So our builds may be similar in some ways, but I am definitely looking to remain as light as possible since I may also want to do BEC versions later.

Now we just need to figure out how to squeeze Alfa 164 V6's into the Abarth bodies being offered on this site. :shock:

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PostPosted: April 14, 2017, 9:54 pm 
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After much measuring and fussing I started building the engine cradle which also serves as the lower a-arm and torsion bar mount. The holes are for bushings to be lathed out of the 1" solid bar seen resting atop the cradle. The side view is positioned directly underneath the front suspension templates.

Resting the remainder of the weekend as I ran out of welding gas....doh.

jamie


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PostPosted: May 20, 2017, 12:01 am 
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I picked up my suspension bushings (lathed up by a good friend) this afternoon.....and using the lower suspension arms, a template measurement to the outside faces of the bushings, and a fortunate set of washers from an overhead trolley... now have them tacked into the front carrier. The suspension templates to position the shock mount, upper suspension arm and drag link are shown in place.....along with a special Alfa tool for alignment of engine to driveshaft to transaxle.


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PostPosted: May 20, 2017, 1:01 am 
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Are you keeping your guibo's?

I plan to replace mine with CV joints, just not comfortable with the forward guibo right at my hip.
Sure a cage over the driveshaft can be made but the pics I've seen of failed guibo's were nasty. :ack:
Also the issue that modern guibo's are far too often lacking in quality or durability. :BH:

Have not found an adapter yet.
I do have CNC machines and wonder if anyone would buy them if I made them?

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PostPosted: May 20, 2017, 12:15 pm 
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I plan to keep the guibos and "cage" the drive shaft. I have seen guibo keepers that help keep the free ends of the bolts from spreading as revs reach engine speed....and have heard of driveshafts disconnecting hence the cage.

I have experienced guibo failure once in a GTV6 just after a friend had replaced a badly worn guibo.

Take it to the rev limiter he urged....so....7000 in first....shift....7000 in second....shift....reaching for 7000 in third.....!BANG!.....clutch in ....look in mirror and see parts bouncing along the road....coast to side of the road.....okay car is still idleing...thats a good thing....changed positions and let my friend drive his car home. It turned out that the replaced guibo was so bad...it had machined a bit off the metal ear of the drive shaft.....when Bang occured the metal ear failed taking a full 1/3 of the new guibo with it (that was the part bouncing down the freeway). The short form is that guibos need to be regularly inspected and replaced....but can take a fair amount of abuse....and are useful in damping the many vibrations / harmonics inherent in engine speed drive shafts.

Overall I hope to re-use most of the gtv6 factory parts in this build.

jamie


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PostPosted: August 4, 2018, 8:38 pm 
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When i welded up my suspension cradle a "while back"..I ended up with a few mm's of warpage. This was overcome with a couple of cuts and re-tacks. The first image shows the suspension from the front...with the uprights' temporarily welded for the moment. Torsion bars are in place now...with the connecting member bolted to the sub frame.

Looks like about 0.5 degrees of negative camber...so close enough for now while I sort placement of the steering column, pedal box, frame attachment to dedion rear end....and so forth.

To extend the frame outboard of the torsion bar I have some 1.25" ID tube and a holesaw for the 2"x1" tubing....

near beer provided for scale.

calgary locost


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