Technical Spider 1608 Engine Build Suggestions

[IndianaAndrew]

I posted this to both Xwebforums and here. True Fiat diehards might see it in both.
"Indiana"Andrew is now "Michigan"Andrew. I don't think the site allows me to change usernames.

I am working on my childhood car, a Bottle Green 1971 124 Spider with the 1608 engine, purchased at age 14. I drove it through most of my high school, graduating in 2011. It hasnt ran since then really. I purchased a carb kit for the original 28/36 DHSA and one of our vendors called up saying he really dislikes selling kits for that carb and provided a chinese knockoff weber of the recommended model for this car. The original was looking pretty sad. That was a year ago and i forget the "weber" model. I also have a single plane intake. Engine fired up with new carb to find out i was running on 2 and 2x 1/2 cylinders (head gasket failure in 1, bad spark plug threads in 4).

The engine is going through a full rebuild, everything removed. I painted the block Detroit Diesel Green. Well this weekend I tried honing the cylinders. Cyl 4 has some marring maybe from rust midway down. All cylinders have a visible ridge at the top that was considerably more than I could clean up honing, and very tactile. piston to cylinder clearance is greater than acceptable range. Pistons, class A, do look really good with minimal wear. Cylinder 4's pitting/marring/rust was probably from the spark plug threads being messed up. That's since been drilled out, tapped, and a solid insert installed. Valves should be stock. I had intended to run it as is even after the hone. Then rebuild later after seeing how this car is suppose to behave and feel.

It looks like i need to get it properly bored. I measured bores at the ridge and at the largest diameter. The max OD I measured was 80.096 mm. The ridge delta looks to be about 0.0030 inches = 0.0762 mm.

• What do you all recommend for pistons?
• I need to get my flywheel resurfaced; it's got a nice layer of surface rust. Are there any lightening suggestions or no one has a trusted design beyond one off the shelf. I read there's a 16 and a 19 lb flywheel. How to tell the difference beyond weight? My only scale is doesn't reach that high. New clutch already purchased.
• Any other go fast goodies while I'm here? It doesn't look like I'll have the A to B comparison, stock to built.

Other items on the to-do list:

• Rust issues: Shock towers, left jack point, engine bay battery box, wheel well at front left anti-roll bar mount, left "frame rail" where it curls up at engine bay. Floor pans were redone but could be better. These I will improve over time.
• Hard brake lines show rust. intending to replace while engine is out. I'm looking for a roll of tube at proper size.
• Rear axle pinion seal, check condition of diff and Bevel Gear Set.
• All bushings and ball joints purchased to redo full front suspension.

 

[bugsymike]

You said "I purchased a carb kit for the original 28/36 DHSA and one of our vendors called up saying he really dislikes selling kits for that carb and provided a chinese knockoff weber of the recommended model for this car"
Personally I would sooner rebuild the original that touch a chinese **** carb.
You said "Cyl 4 has some marring maybe from rust midway down. All cylinders have a visible ridge at the top that was considerably more than I could clean up honing,"
Personally if noticeable wear ridge at top of bores then only option is a rebore and set of pistons, If available I like Mahle German pistons. If you have a wear ridge and only hone and then fit new rings/pistons in old bores what happens is the pistons when revved hit the wear ridge at top of cylinder bore and break the new rings. In the old days garages had a tool that would cut away the wear ridge or you could buy ridge dodger rings that were stepped to miss the ridge, but best to have rebored.Generally the company that does the rebore is the best one to supply the pistons as if any matching issues it is their fault. Make sure if you are assembling, that the new rings are checked for correct gap and positioned on piston so each ring gap is equidistant from the other rings. Make sure the cylinder block is dead flat/true and the head the same, clean all bolt thread holes thoroughly so when torqued down they are all good and tight.
You said "I need to get my flywheel resurfaced; it's got a nice layer of surface rust. Are there any lightening suggestions or no one has a trusted design beyond one off the shelf. I read there's a 16 and a 19 lb flywheel"
Personally if only surface rust I would clean old flywheel up unless worn clutch rivets have eaten into the flywheel surface. Machine shop can skim/machine flywheel once dowels have been removed, if they think it safe to do so they can machine the flywheel down lighter at the same time. Note a lightened flywheel will allow engine to rev/respond quicker , but at the expense of smooth idle.
You said " Rust issues: Shock towers, left jack point, engine bay battery box, wheel well at front left anti-roll bar mount, left "frame rail" where it curls up at engine bay. Floor pans were redone but could be better."
Personally a 45 year old vehicle that is a never ending job.
You said "Hard brake lines show rust. intending to replace while engine is out. I'm looking for a roll of tube at proper size."
Personally I use 3/16 Kunifer brake pipe in 25ft rolls it is copper and nickle so strong and doesn't rust, also better than pure copper which is soft and weak but some use.
You said "Rear axle pinion seal, check condition of diff and Bevel Gear Set."
Personally check all measurements and be careful when reassembling as it is very easy to end up with a howling diff/rear axle if preloaded wrong. Also check half shaft bearings if noisy, bearings should be straightforward to obtain but you will need the shrink collars that hold them in place I think assuming available and oil seals.
You said "All bushings and ball joints purchased to redo full front suspension."
Personally one of your US compatriots is just experiencing that pleasure on an elderly Spider so read his thread on Forum.
Finally if in need for more power isn't there a US saying "There's no replacement for displacement!" or similar? I was thinking there is 2litre versions of your engine.
Incidentally my knowledge is over many years on many different makes of vehicle, there are some on Forum with a lot more specific Fiat Spider knowledge who I am sure will be able to advise.