1967 Fiat 850 Coupe

really well done. great looking little car!


JP

Really stunning and well thort out, bookmarked for sure

Harness Bar

Never too late for adding some safety equipment, but it sure would have been easier if the car was still in primer.
These are 4-point 2" wide seat belts and shoulder harness being installed a bit too late in the build process. That is the reason for all the sheets and covers to prevent weld spatter from melting into the Lexan rear windows and front windshield. You can see where I had to sand off paint on the rollbar too. Nothing like doing things over again.
I decided on a proper install directing the shoulder harness nearly straight off the shoulders rather than bolted to the floor. For access to the rear of the interior I chose a harness bar install which was removable and hence required all this fabrication. The removable harness bar kit is generally marketed as a door swing-out bar, but I adapted it to a removable harness bar. The kit came with the weldon ears which were a bit too large and interfered with installation of the belt retainers (i.e. loops on top of the bar). There are ways to fabricate these pivots or just weld the harness bar directly to the rollbar, but these CNC pieces look impressive and work great.
Here are some sources for the Kits:
Chris Alston Rollbars Similar to what I used
Applied Racing Tech What I used with an extra pin added to the order
Mcdonald Bros Racing One of my favorite kits with extra nice pins



Test install after all the welding was complete. The car is so small that the left shoulder belt is almost on top of the pin location. This is the reason for shortening the ears that weld on to the main hoop and getting the pivot nearly up against the main hoop.


Here the initial tack welds are complete


Retainers are big enough for 3" belts in case I decide on wider belts in the future


Ears had to be shortened so the harness retainers could be installed. Otherwise the pins would be located where the retainer needed to be welded.


Cutoff wheel used to make a v-cut and a hole drilled in the middle made it easy to remove a section of the ear.
A grinder was then used to get it back into shape and a final finish with a half-round file.


Initial mockup of the retainers in place with magnets while I sat in the seat to get the belts where I wanted them.
The black wire is holding the extra belt in a roll to keep it from hanging to the floor. After I paint the bar and do the final install, the extra length of belt will be rolled up tight and held in place by a zip-tie.

Didn't really make my own since I couldn't move my car to a tube benders shop. I looked around for a main hoop to start with. Found and old 850 spider rollbar and modified it to fit. I'm just guessing it's a Fiat bar, maybe it's for another car, but the point is I think I could have started with just about any rollbar. I was a bit reluctant adding this rollbar since the car is mostly a street car. I decided against a full rollcage due to all the weight. This is heavy wall tubing and is very heavy. If I could do it over again I would use thin wall chrome moly tubing.  

Added about 4 inches to the bottom of the main hoop since it was too short.
This is the main hoop after pool acid bath (hydrochloric acid) and extra tubing tack welded to the bottom. The little rusty pipe on the floor is what it used to look like.


New floor plates along with the old bolt-in's


Everything is tack welded in place and ready for final welding. This would have been a good time to install the harness bar. I just didn't have my mind made up yet on a 3-point, lap belts, floor mount and so on.


Steel floor plates being welded to the floor and the bar is being positioned for welding.


The most risk in this install was guessing how much clearance will be needed for a headliner.

The loop/bushing on the top was donated from my old 850 shocks and the bottom pin is from the top of some Monroe-Matics.  You can see a picture of the blue Monroe Matic (rear 1973 mustang)  in a previous post on modding some Spax shocks. A shock with a pin on the top is useless for an 850, so I chop off what's needed from other shocks to make them work on a Fiat.
I've given-up trying to locate shocks for an 850, since they are usually expensive Koni's that need a rebuild. Plus, my car is lowered and needs more than a replacement shock, so altered spec shock is needed that has a reduced travel distance between compressed and expanded.
The new top and bottom are mig welded using a spray water bottle to reduce heat between tacks and prevent burning the rubber bushing and exploding the canister.  Sometimes I use a clay heat barrier, but I think water cooling is fool-proof.
I have never met anyone willing enough to weld on a gas shock and I'm not endorsing it, cause I sure wouldn't want anyone to get hurt. Personally, I'm more afraid of working under a car on my back, even with  jack stands.    If you dissect a shock, you'll find the bottom cup you weld on is really thick and it's not likely that you would blow a hole though it during welding.  Plus, what I attempt to do is leave some "meat" from a left over loop or pin from what was cut off. Actually the most ideal shock for welding are KYB's with a bottom strap mount (60's Ford Mustang?).  I just cut the ends of the straps off and weld on the center left-over strap.

I've been test driving the coupe for a couple days and they are fantastic.  The factory spec shocks allowed the suspension to bottom-out very easily since they compress with no resistance, unlike GAS shocks. Now with the Gas charged versions I can go over any speed bump, dip or hard corner without constantly riding on the bump stops. I don't even think I'm hitting the rubber bump stops at all or just barely. It's a good firm feeling without the constant beating and hammering on the rubber bump stops.

Here they are just after welding the top loop and bottom stud. The dust cover is no longer needed IMO. But installing boots or the original cover is possible for extra protection.


After some paint and stickers they kinda look like they were made-to-fit.


Just started playing around with fabricating polyurethane bushings for the a-arms. So far I can't tell much difference with stock bushings since the shocks over compensate or coverup/eliminate any  sort of  fair way to make a judgment.
 To really feel the difference, only One change should be made instead of multiple changes and expect to tell what improvement was made my each modification. I would just have to say things feel more: precise, firm, controllable and predictable. But anything would be better than old bushings that tore themselves apart (see pic below).
What is the part number of these bushings? I'll have to dig it up, but just ask or post a question to remind me.

Note the chunk of plastic missing on the inner top hole of the bushing caused by running a drill too confidently through both bushings in one pass. Sometimes the cost of learning new things can be costly and time consuming, but in this case I don't think it impacts operation at all.  The zerks need to be removed during installation and you need lots of patients installing the second bushing and lots of coaxing with a small tool to help slip the bushing in it's position.


1/4-28 grease fittings/zerks might be more common in US parts stores but I chose the metric 6.00M x 1.00 style since they are slightly more compact. That is a small area you have to work with. I got a bag of 10 Dyna-Flow Zerks (made in UK) from Fastenal for $3.00. Harbor Freight also has an assortment box of fittings, but I find those break too easy. Of course there are many other brands, but I think something more robust with better metallurgy will holdup better during frequent grease gun attacks.


Surfaces that pivot against Steel  are polished to further prevent any binding. The flat washer was sanded on a scrap piece of carpet to hold it in place while using a DA with 120 grit for the 1st pass. I followed that with aggressive Black polishing compound on a buffing wheel to get a mirror-like finish. The concave washer couldn't be sanded by machine to easily, so most of it's polishing was done on the wire wheel then buffing wheel.



See this video to get an idea of what binding and careful fitting is all about. This video has excellent examples about how bushings are supposed to work and what makes them work right or be full of squeaks.



Here are the the rebuilt a-arms being greased along with the kingpin assembly. I used a very "sticky" trailer axle bearing grease for the a-arm bushings and Amsoil Synthetics for the kingpin grease. You can see the Red Amsoil grease still on the grease fitting before I wiped everything clean. I haven't greased the front end since building the car 2000 miles ago and they were empty or maybe you could say DRY. It took several pumps of grease to get some oozing out again. I would suggest greasing the kingpins every 1500 miles, which I think is what the factory says (I could be mistaken).
Next time I have the front end apart I'll be installing Delrin or Poly bushings in the upper kingpin bushings. If someone has already figured out the bushing part number or size of material to use, Please let me know.


These are my factory original rubber bushings. They exploded like this because they must hate being reinstalled on a different car or switching sides. Could be someone was driving the car to aggressively 

Great update! love to know the source of the poly-bushes also.

I think your explanation is pretty clear.
And I haven't seen or read any stories yet about putting PUR bushes on a fiat 850 or 600.
In Holland we probably can't find the bushes that cheap.
with my former job a had some bushes made up from PUR. they used a lathe but had to put the PUR in the freezer first.

still love the car and updates!

Since my Media blaster cabinet is too small for 13" wheels I used hydrochloric acid to get most of the rust off. Normally called "pool acid" or "muratic acid" is a diluted version of a potent rust remover.
These are X/19 centers with golf cart 7" rims I found in my inventory. I'll have to get a couple more made, but for now I'm going to try them for size.
Here I'm using large plastic trays to contain excess acid. Any acid that's left over, I put back into a plastic container for future use in maybe DE-rusting a pile of bolts.


More cleanup after the acid treatment with Wire wheels and 80 grit sandpaper.


Here are some rods of Delrin getting ready for forming into Fiat suspension bushings.

I really love these little cars, fantastic and thorough work being carried out here too. Well done.