CANAMSA - SA stratch build

[Fred W Ballinger]

Hi Ian. Thanks for the comment. Yes, the seat is fixed in the cockpit paneling, save for any padding or a foam seat insert that could be added. Having the pedal box movable is more about making sure the car could be driven by someone taller than me. I don't anticipate it being moved often so I opted to keep things simple.

Hi Doug. Thanks for the very kind words. I have found forums a great help over the years, both in helping to answer questions and source parts and also contributing significantly to keeping up my motivation. It is gratifying that others take inspiration from what I am doing. This project has taken so long it predates Facebook, and we did see a slump in activity on forums as Facebook gained traction but now it seems the tide is turning back as people realize the transient nature of Facebook. Good luck on getting your car finished.

 

[Fred W Ballinger]

Been a little while since an update.

I've been collecting another batch of parts for plating.

 

[Fred W Ballinger]

I often find that rather than agonize forever on how to design or make something its easier for me just to dive in and start making a rough version of the item. As you make it you discover ways to do it better, or more accurately, or make it more functional or look more elegant so I don't feel bad about then making another better one.

An example of this is the accelerator pedal. This is actually the third iteration I have made.

I know personally several people who have suffered damaged cars and injuries, in one case fatally, due to stuck throttles. This made me determined to have a good spring return on the accelerator. You can see a torsion spring return on the pedal pivot point, and there will be 2 further spring returns on the carburetor end of the accelerator cable. You can also see adjustable positive stops for the pedal open and closed position. The assembly weighs 790 grammes (1.74 lbs)

The mounting bracket is secured to the chassis by 2 of the bolts that also secure the pedal box. I put 2 weld nuts inside the bracket to allow this, and the mounting bracket then also forms a nut plate for the pedal box bolts. Obviously, the accelerator pedal mount will move with the pedal box if the longitudinal position is changed. The bracket that holds the forward end of the accelerator cable outer sheath then also needs the alternative mounting positions.

 

[Fred W Ballinger]

I've now got the front suspension bolted on.

There is quite a lot going on in these photos, Ill add some more explanation in following posts

 

[Fred W Ballinger]

Here you see the various front suspension components

The wishbones are made from 21.3 od x 2.11wt Schedule 10 stainless tube, with machined inserts plug and fillet welded into the ends. The inner end joints are M12 rod ends. The choice of stainless steel for wishbones was down to me being able to source the schedule tubing easily. It's pressure rated and so must be better made than ordinary carbon steel tube. Chrome moly is not easy to find in these parts. The finish is bright electropolish. The straight leg of the shorter upper wishbones was machined in one piece.

I've never designed a car before so I have tried to incorporate provision for adjustments where I can. The wishbone attachment brackets are made wide enough so I can adjust the castor from 5 to 10 deg by shimming the inner mounts. To keep the wheel in the center of the wheelarch both the top and bottom attachments have this detail.

 

[Fred W Ballinger]

The coilovers are Protech aluminium body single adjustable with spherical bearing mounts. I bought these many years ago while on a visit to the UK , picking them up personally from Protech. During storage the bodies had tarnished somewhat so I polished them, they came up very nicely.

I decided to go with an inboard mounting for the coilover. The major issue it solved is that, with the coilover in the conventional position, I could not use all of the damper travel. Plus positioning the coilover so it can be mounted at something like a sensible angle, and still clear the top wishbone was problematic. If you lay the coilover right over as you see on some cars the damper travel becomes less than the wheel travel and as I am using not very expensive coilovers I though to give the damper every chance by keeping the damper travel as long as possible. Another advantage of the inboard setup is that the pushrod length can easily be altered, to give a fine adjustment of ride height and while corner weighting the car. The rod ends in the pushrod are left and right-handed to enable this.

This early pic shows the concept with a mock-up bell crank rocker that has ratios that give a one-to-one relationship between wheel travel and coilover displacement.

A stumbling block with inboard coilovers is that you need to engineer a decent pivot detail in the rocker. Instead of reinventing the wheel, I contacted Dennis Palatov of DP cars in the USA.

DP Cars - Palatov motorsport

I had corresponded a bit with him and he offered me some of his old stock rockers at a very fair price. They were bigger than I needed but I was able to cut them down and redrill to suit my application. They contain no less than 4 bearings, 2 seals and a hardened pivot sleeve each.

The lower mounting of the coilovers is a long M12 bolt that runs between two frame bulkheads. Aluminum spacers locate the mount longitudinally and there is an 8 mm aluminum plate support just offset from the mount that runs to the bottom of the chassis to support the bolt against bending.

The full set of front wishbones and push rods weigh 4.22 kg (9.3 lbs). The coil overs with springs weigh 2.36 kg (5.2 lbs) each.

 

[Fred W Ballinger]

The front uprights are Ford Cortina. The geometry of the Cortina upright is not great, with a large king pin offset and I considered making some front uprights but decided to use what I had in order to not delay what was becoming a very long-winded project any further. I might still do that one day.

What I did do was have made machined taper pins top and bottom to reposition the articulation points vertically and adapt to bearings to make connections to the wishbones. The lower one is through a 20 mm spherical bearing in a machined housing and the top one though a 16 mm rod end. The pin diameter is 12 mm and there are high miss-alignment bushes I had made to fit the bore of the bearings. I lapped the taper portion of the pins into the upright holes with some grinding paste to make sure the tapers were a good fit.

The upper wishbone pivot pin also has some spacers so that I can have some adjustment of the height of the pivot in 6 mm steps and thus change the swing axle length and resultant camber gain in roll and bump.

The top upright attachment incorporates an internal and external threaded bush between the left hand 1.5 mm threaded 16 mm rose joint and the M20 bush threaded into the top wishbone. A 360 deg rotation gives 3 mm of movement. This gives me a camber adjustment from 0 to a bit over negative 3 degrees without changing the position of the M12 rod ends on the inner ends of the wishbones.

 

[Fred W Ballinger]

The front hubs are Rally Design style aluminum hubs that were made by a contributor on the Locostbuilders website. I finally figured out that these needed early Ford Capri pattern discs. Solid thickness 12.5 mm, OD 244 mm, height 27 mm, bore 68.4 mm. I found a reference number DR 6332 in an old alfa brand brake catalogue and bought some new. I drilled and safety wired the disc to hub attachment cap screws.

At the moment the front brakes are still standard Cortina V6, these may get upgraded once I eventually get to drive this thing in anger. The calipers weigh 4.33 kg (9.55 lbs) each.

Apparently the original Ford pressed steel domed dust covers that go in the end of the hubs are no longer available anywhere, so I had a friend turn me some in aluminum. They are a tight fit so the M6 bolt in the end allows you to wind in a longer bolt to push them off. Also gives a nice flat surface to measure to when setting up strings for wheel alignment.

The uprights weigh 2.96 kg (6.53 lbs), the hubs 1.34 kgs (2.96 lbs) and the discs 3.96 kg (8.73 lbs) each. The weigh saving over the standard Cortina steel hub and disc is 2.34 kg (5.13 lbs) per side.

 

[Fred W Ballinger]

Deleted - Double post

 

[Fred W Ballinger]

This is the setup I used to check for bump steer.

Clamp the steering wheel in the straight-ahead position, put the road wheel at ride height and set it dead parallel to the straight edge by measuring from the forward and rear edge of the rim with a vernier while adjusting the tie rod length. Then jack the wheel to full bump and compare the dimensions from the front and back edge of the rim to see the toe change. Repeat at full droop.

By adjusting the shims under the steering rack to raise it and creeping up on it I was able to get the toe change at full bump to be zero and just on half a millimeter toe in (per side) at full droop. On a 15" rim that's less than 0.1 degree.

 

[Fred W Ballinger]

The anti roll bar is driven by an aluminium pushrod with M10 rod ends from the lower wishbone. It is made in three sections bolted together. It pivots on two 10 mm rod ends that screw into weld nuts in the chassis. I did it this way so that I can substitute different diameter bars to tune the chassis balance. The gold painted tube shown is a place holder while I source suitable roll bar material.

In the last picture you can also see the steering tie rod extensions I had made.

 

[Brian Kissel]

Very nice Fred. !!
Thanks for the explanation also.

Regards Brian

 

[Jerry Irwin]

I could be wrong, and are most of the time but...
The top mount looks like it could bend / break very easily when put under corner / impact stress.
Quite a large distance between hub and top wishbone gives a easy binding force ?
I do like the inboard shocks..

Jerry

 

[Chris Kouba]

The top mount looks like it could bend / break very easily when put under corner / impact stress.

I love the work Fred and have massive respect for what you've done/are doing.

On the front upright/A-arm connection, I am of the same opinion as Jerry. There's potentially a lot of bending moment in there, especially with any sort of shock or lateral loading. I know you've been prototyping stuff along the way, is this your final hardware?

 

[Fred W Ballinger]

Hi Jerry and Chris

Thanks for your concern. I do intend to keep a close eye on that top mount and possibly I am being a bit optimistic.

I have seen similar details used on other cars and a larger proportion of the loads go through the lower mounting. The pins were made from proper EN8 steel by a manufacturing company that does volume production of threaded studs for pressure vessel industry. We avoided stress risers at section changes, and the threads are rolled not cut.

I could make a thicker section part up to the rod end once the handling is proven.

Looking at the below general view pic again, and I went and looked at the assembly again. Possibly it looks scarier than it actually is. The offset from the top face of the original upright to the center of the rod end eye is almost exactly 2", with only just over 1" of that being the 12 mm diameter.

On the close up view (at full droop) you can see that it turns out that I might be able to get away without the miss-alignment spacer, in which case the pin could be 16mm diameter. When you draw these things out and mock up its difficult to be sure it will work in practice with real parts.

 

[Fred W Ballinger]

Older readers may recognize that some of the following content are repeats of discussions much earlier in this thread, I repeat some items for newer readers.

The next step was to get an engine prepared for installation. I say an engine as I have two Rover engines. The first one I bought many years ago from a guy who was removing it from a Bedford van. Remember the 70's craze for modified vans?

It is a very early 3.5 engine from a P6B, which was built between 1967 and 1976, according to www.rimmerbros.co.uk. I had this motor running in the mock-up chassis, and it then stood for a long time. Stupidly I had left some water in it, and I subsequently found that one valve that was standing open was seized in the guide due to rust, and to the detriment of the seat. A friendly local machine ship helped me to sort this out, and then found that corrosion had eaten thought the head in a port. Luckily, they had a set of decent condition (post SDI) heads under a bench, so I bought and fitted those. This cutting a long story short.

The other engine I have I was very lucky to find. It's a brand-new race prepared engine, built and blueprinted by a reputable local engine builder on a service replacement block (with no engine number) many years ago for a stillborn racing car project. It has never been started, still with assembly lube inside. Oversize valves, gas flowed heads, roller rockers, dry sump, even came with some of the dry sump installation parts. I don't want to fit this to the car until I have shaken the car down and fully engineered the dry sump installation. I also have yet to make intake manifolds for the 4 downdraft Dellorto carbs I have.

I weighed the motor, to find that the total mass, including starter (9kg!), water pump, alternator, engine rubber mounts, inlet manifold and distributor came to 125 kg (276 lbs). This excludes exhaust manifolds, flywheel, clutch, carb.

On the front of the engine I removed the water pump and replaced it with a flat plate with a connection for the water inlet. This made the motor shorter to facilitate the mid mount installation. I have previously discussed the electric water pumps.

I made a bracket to relocate the alternator to the lower left side of the engine, as well as a tensioner using my favorite aluminum hex bar material and M8 LH and RH rod ends.

 

[Fred W Ballinger]

The intake manifold on this engine had been modified to fit a weber 38 DGAS carb, as found on Ford V6s etc. It was not a great job, the flat adaptor plate was secured by only 2 bolts and held the carb at an angle, presumably to suit the previous installation angle. I made a new adaptor plate which positions the carb horizontally with the engine horizontal. The cut off manifold needed some exposed cooling channels filled with epoxy.

As this is not the final engine I did not spend a lot of time prettying up the engine. I just put a rough brushed finish on the rocker covers, which I quite like for an aged appearance.

 

[Fred W Ballinger]

Here you see the engine bolted to an Audi (AAZ 016) 5 speed transaxle as found in 1980s, Audi 5000 5 cylinder cars. The transaxle weights 70 kg (154 lbs). I haven't rebuilt the transaxle yet as I'm still trying to find a reasonably priced LSD for it. I know Quaife in the UK list one but transport and duty costs make that option very expensive for me.

The issue with this conversion is that the Rover starter ring gear does not fit in the Audi transaxle integral bell housing, and you can't make the adaptor plate very thick as then the Audi input shaft does not reach the Rover crankshaft spigot.

What I ended up doing was making an adaptor plate from a 1000mm x 500mm x 16 mm thick plate of 6082 T6 alloy, which a friend cut for me on a 3 axis CNC router. To keep the Rover ring gear inside the thickness of the adapter plate I positioned it 12 mm forward from the original Rover position. I did had to relieve some of the webs on the back of the block. I also had to make a stepped spigot bush and a spacer for the starter motor.

I drew up a flywheel which essentially has the Rover ring gear mounting detail on the front side and the Audi clutch locating detail on the rear, and with an overall thickness to suit where the Audi release bearing ended up.

A supplier to my company donated this huge (70 kg!) forged blank. The cellphone on the blank in the pic gives an indication of how long ago this was.

Another mate had a company with CNC machine centers, large lathes etc. and he was good enough to machine the blank down to this for me, and only charged a very reasonable fee. The finished part is dia 300 mm x 64 mm thick, weighed 7 kg without ring gear (15.4 lbs). The original rover flywheel weighs 14 kg. The wall thicknesses of all areas of the new flywheel are mostly 6 mm, with the conical center section 8 mm thick.

 

[Fred W Ballinger]

Here you see the adaptor plate, looking from the engine side. It is 16 mm thick, with an 8 mm recessed area for the flywheel. The plate to transaxle attachment bolts have countersunk heads. I dressed the starter motor hole with a file. The plate weighs 4 kg (9 lbs).

Here you can just see 3 x M6 countersink bolts that are tapped into the engine to locate the plate. The clutch weighs 6 kg (13 lbs). One plate to block securing bolt is black as I miscounted when I had the bolts plated but it is hidden when the transaxle is fitted. You can also see the crank spigot bush. The clutch plate is the wrong way up in the pic.

In this pic of the transaxle being offered up to the adaptor plate you can just see one of 3 spring pins that locate the transaxle on the plate

I had to cut a small relief in the transaxle case to clear the starter motor. One bolt only just cleared the starter motor, with the head cut off on one side. I milled slots in the ends of the transaxle securing bolts to hold the bolts with a screwdriver while you run the nuts up. This is still the standard Rover starter, I'm working on sourcing a smaller, lighter gear reduction starter.

 

[Ian Anderson]

Fred is the Rover engine zero internal balance? Or will the flywheel and pullies need weight adjustment?

I did some quick googling and some say yes and others no.

Perhaps best to check with your machine shop to see if they balanced it for a zero balance flywheel……in case it tries to destroy itself.

Ian