Project Car / Motorbike thread. Let's see 'em.

hifiandmtb

Sphincter beanie
With the leaf springs the lower link will hang down below the spring so the link will have to be inside the chassis rail. The upper is clear and can go through the spring space. With the BW78 the Watts link pivot on the cover is 85mm off centre. That affects how the link will be installed. It is imperative that the links are the same length. That means swapping the links side for side compared to the donor AU XR6 which is ok. Using the 'longer' side that means I can sit the chassis dropper just inside the chassis rail while the other will poke through and out the other side of the rail.
Sorry - read that three times & still can't get it.

#thisthreadneedspics
 

Dales Cannon

Adminerotic
Staff member
Sorry - read that three times & still can't get it.

#thisthreadneedspics
Had a bit of time this afternoon so hopefully this makes sense:



This is at midpoint of travel. What I was saying was that because it will have leaf springs the lower link would foul with the leaf trying to line up the hanger with the chassis rail centre. So it will sit inside the chassis rail and mount to the floor on a compensating plate. Gussets to the chassis rail and forwards (or backwards). The other side can poke through the gap above the spring and to keep the links the same length will line up with the outer edge of the chassis rail. Again gusseted as needed.

Option would be to scrap the leaf springs and run coils or coilovers. There is no perch for the coil on the diff and as the chassis is designed for leaf springs it would need stiffening up so lots of work. There are coilover mounts on the diff but that means making up some strut towers inside (standard shocks angle in and the motion ratio would make the suspension work less well than the leaf spring!). Putting in strut towers means the rear seat is scrapped and that starts all sorts of issues with sealing the rear bulkhead and trying to make something to cover the mess that is the body beneath the seat. If I was going to this much trouble I will toss up doing this versus doing things properly and bolting the diff to the floor where it belongs. Probably fit a baby BMW rear end in or something like an Explorer or Subaru diff and make the rear arms up to suit. Maybe. Probably leave it all alone.
 

Haakon

Not happy, Jan.
Leaves in an escort is correct. Keep it from getting unruly with the Watts and all is well I'm guessing.
 

Dales Cannon

Adminerotic
Staff member
Did some housekeeping on the XR4 today in preparation for log booking the car.

Cage finished and will go for registration in coming days. Then after some discussions with the CAMS technical people, who were really very good, I will arrange to take the car to the next event either sprint or gymkhana where there will be a CAMS scrutineer to get the log book application finalised.







I didn't weld the cage, just worked with the regs to get the design right.

XR4s suffer from a gear linkage issue which we thought was the usual worn out bush at the lever. Car has only done 110,000km but is now 11 years old and not cared for since about 1957. Changed the bush and it would still jam in gear. Dr Google told me that the linkage arm bushes get sticky and the pivot shaft rusts so all that came out and was cleaned up and redone with some moly grease. While I was there all the plastic guards, shrouds, liners etc fell off.



And the worst job of all. The power steering pump was leaking and horribly noisy so I swapped it with one that we knew was good. Absolute prick of a job. Usually you take out the inlet manifold but this has the Cosworth thing which has longer runners and getting to some of the bolts is nigh on impossible.



Removal was ok but getting the genie back in the bottle is always the hard part.



Back and no leaks!!!!! Yet. Managed to get the serpentine belt on and off on my own. Ripping out the headlight and taking the wheel off was the way to go.

Finally made that modification that will make this the fastest XR4 on track...



Getting closer. Still have to roll the rear guards a little as the tyres scrub after fitting spacers to square up the tracks and also need to put a bend in the exhaust to clear the rear antiroll bar.

We were going to fit a Mazda 3MPS 6 speed box in this but given we are going to go a bit crazy on the spare shell this might do until that is on the road.
 

hifiandmtb

Sphincter beanie
Huge update!!!

I boiled/overflowed the PS fluid on our Fiesta at Eastern Creek. They just seem to do that....
 
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Dales Cannon

Adminerotic
Staff member
No diff work. #2 can fit the new bearings and he is tied up with end of semester assignments and exams coming up. The dead duratec is providing some material for his stress analysis assignments with main bolts analysis and gearbox shafts.

Raining today so I set about making strut brace. No one makes one that suits the duratec though I was always intending to make my own which will brace strut to strut and also back to the firewall. I will use some cold drawn steel tube either 1" od or 28.something depends on the dies that suit my mate's mandrel bender.

#1 is making a rack for his motorbike so I stole a bit of an offcut off that. 150x75x4 RHS. The other bits were left overs cut to size after I made the anti dive frame.



Hacked the bits off with the cordless bandsaw.



Some more cutting and grinding later. I drilled the holes on size at 8mm and bolted the pieces together and did the grinding thing and then spun one around and did it again so they should be symmetrical.



Welded the tie mounts together 35mm apart which will allow me to put a piece of pipe across the lateral pipe. Probably go to a 12nb pipe and weld that to the ends like a T at each end. Will use an M12 stud and nylock nuts each side for pretty.



And here they are installed.





Thinking of welding some 50x50x4 angle about 150mm long on the scuttle and the vee parts of the brace can bolt on top of that. Anyway ran out of day. The lower hole is just for pretty and is a 1/2" dimple! Quelle surprise!!

And speaking of rain as I was, if it doesn't rain tomorrow I should be able to post up something in what does you day look like...
 
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Dales Cannon

Adminerotic
Staff member
Back in my uni days I analysed a head bolt from a 917 turbo engine. The mix of magnesium and aluminium alloys meant the barrel/head bolts came loose under load and boost. So Porsche created their own alloy. I found an ASME paper on the issue and solution. Porsche even provided photomicrographs of the heat treated alloy. Amazing stuff for the time.
 

Dales Cannon

Adminerotic
Staff member
Saving you the tedium of the steps which were pretty much the same as the last instalment except for the brace material which is 31.8 x 15.9 (wonder where they got those measurements???) oval tube 2mm thick. Surprisingly using a little finesse it bends ok to 30 degrees.

Anyway this is where the strut brace is at. Still have to weld the gussets. The wind was getting up and blowing the shielding gas away so as these welds cannot be tidied up with the grinder I called it a day. A compensation plate will be welded onto the firewall and not sure at this stage whether to bolt the centre mount to that in the obvious location or weld it all out. Still a little grinding and despattering to do. Pretty happy with this. The scuttle is a little off centre from the centre of the body as is the scuttle drain. I gave up and just made the brace central to the body/chassis so too bad if someone points out that it is 5mm off centre compared to the scuttle.



And a more flat look at it.



Looks like I am going to have to make another...

I was planning on turning up the crush tubes that the brace is welded to but the lathe wouldn't go around yesterday. Commercial tube is a bit thin and I had already bored the vee brace to 19mm. Bit of investigation found the start capacitor was kaput. Some of the inside was outside which is not where it is meant to be.



$16 later and a new one was installed and some 25mm solid became nice tubes to be welded into the brace.
 

Dales Cannon

Adminerotic
Staff member
Finished welding the strut brace and compensating plate for the firewall. Was going to TIG the gussets but forgot how to TIG and then after several dead tungstens I got it together and of course there was too much gal left on the gussets and it looked like hairy pus. Anyway I grabbed the MIG and multi spotted them on. Really happy with this. It needs a final sand to get the last of the spatter off and be prepped for painting but that is #2's problem. Bent up another cross section for the my mate's van and will set about making up some carriers for that. Another job off the list.



I will bolt the brace in with M12 stainless studs with nyloc nuts and washers each end so it looks pretty. Stainless will be strong enough. Probably need to shorten the weld in studs on the firewall plate and it will get stainless nylocs too. The firewall is a bit wonky so the larger plate is a good thing.
 
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