Some TLC for my QV

Yes:
While I can't say I'm the target customer for your more exact repros in 17", one useful bit of data I see missing is the rim width. At least in the US, that would help determine what tires would fit and what tires would most closely match the stock diameter.

7j and 8j are unfamiliar nomenclature for me here in the US.
ET51 seems to denote offset.

 

Gunn, 7" for the front and 8" for the rear, J designates the flange section.
Here the screenshot from the US version 3.2L owner's manual: Image Unavailable, Please Login
Essentially I am keeping the wheels the same width and offset, but increase the diameter.

 

Urs.
Huh. You should absolutely pick whatever wheel dimensions you want for your project but my gut feel is that 7" width seems a bit narrow for a 17" rim. I fiddled with this a bit and did test fitments before going to 18s on my Mondial. Maybe I'm not accounting for the offset difference, but here are my thoughts

I believe the design goals you have are as follows (please confirm)
- Keep the stock look but in a larger, more standard diameter.
- Retain a similar overall tire diameter once mounted vs stock. For 220/55 VR 390, that was 25.1" according to my calculations. This means the speedometer/odometer will read correctly and won't require adjustment.
- Don't overdo the width so the wheels/tires stick out beyond the stock fenders like a Jeep or UTV.

Thoughts
Q: What tire size were you aiming for?
- To keep the stock 25.1" diameter, Tiresize.com says we are talking about 205/50R17 tires. Those are pretty tall and skinny and selection looks to be pretty sparse although the a few "high performance" tire choices (at least those common in the US) like Michelin PS2 are available. Curiously enough to me, these are pretty pricey compared to other tire sizes (even 18s).
https://tiresize.com/tiresizes/205-50R17.htm

- I think this cost/availability is much higher with a more common tire size like 225/45R17. They SEEM to fit 7" wheels so that might be a good choice as the rubber options are less than half the cost of the 205/50R17
https://tiresize.com/tiresizes/225-45R17.htm

- It should also be noted that most aftermarket wheels seem to be 17x8 or 17x9... but this is also accounted by a different offset (20-45mm), whereas you are sticking with +55.

- Looking at alot of the pictures I took on fitment (around https://www.gunn.com/mondialEV/37.jpg to https://www.gunn.com/mondialEV/45.jpg), I noticed that the stock wheels/tires bow out a bit more because of the metric tires taller sidewall. Going to a larger diameter wheel, the tire sidewall height (aka the aspect ratio) needs to be reduced to retain the tires overall diameter AND the wheel width is widened. If you enlarge the wheel diameter but keep the same width for the same outer tire diameter, you'll end up with a narrower tire.

- Unlike you, I no longer need to keep the stock diameter tire since I'm no longer using a stock odometer/speedometer OR stock ride height/suspension. As long as I can clear a big brake kit and the tires don't stick out beyond the fenders, I'm good. I originally went with 225x40R18 to go with my 18x8.5" wide wheels, but in hindsight I'll probably choose 235x40R18 tires next. They'll still fit on my rims but will offer an upgrade in traction b/c of the wider width. Visually, they'll also fill the wheel well better which is a more modern stylistic choice -- unless you are doing a safari build. In that case, go knobbies

 

Gunn thanks for your feedback. I am personally, and for purely stylistic reasons, not a fan of 348 wheels on the Mondial ( I don't think their style fits the car's styling) but slightly larger rims do improve the look of the car, by today's expectations.
The original TRX rims were and 7" wide, the overall tire 240mm wide as measured, with an offset of 51mm. By the way, the Superformance 7Jx16 repros have an ET48 as measured on my set of wheels.
Agreed that the 17" rim would be of slimmer proportion than the 16" with the same width, but the overall wheel with the same diameter would still be of identical proportions on the car, albeit with a lower section tire. That's the only thing that theoretically would improve steering response a touch. It would also degrade the ride, as would the resulting heavier rim.
For information, the 8s and QVs came with 240/55VR390 all round, and on my car, with the specified tire pressure, I measure an SLR of 309mm in the rear, which was likely due to wear as the suspension drawings mark it at 314.

Regarding the design goals:
- Keep the stock look but with a larger diameter as you said
- Keep the SLR very close to stock so the milage counter won't be affected too much (it can't be adjusted) and the speedo not beyond its adjustment range.
- Additionally, keep the overall diameter where it was to avoid wheel arch strikes on bump as I don't know how much clearance there really is. It also won't affect braking performance as the effective radius (SLR) will be the same.
- Keep the outer tire side wall within legal limits in relationship to the wheel arch (and to minimise pedestrian risks), plus keeping the inner side wall and rim edge where it was to avoid and contact with suspension components, especially in the front while steering at full lock, and in and bump/droop conditions.
Additionally, keep the offset where it was so the steering feel doesn't get affected and no toe-in trials are necessary.

Here is my tire choice -
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The 55 section 16"s are matching the TRXs perfectly on paper, and the 50 section 17"s are super close, so should not pose any problems. That would be my choice.

In your case with more power and bigger brakes, I think it's a wise decision to go wider while you getting a bigger diameter for the brakes. Have you noticed and potential interferences between the wider rims/tires with the car?

The tires on my car a perfectly able to handle available power ;-) So I won't be needing anything wider. Unless I find those missing horses hiding somewhere? I wouldn't know where to look for them. Cam timing?

 

Remember that original speedo sensor that developed a slight leak and then the wires broke?
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It works though

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I also had a bit of that plug left over - I couldn't identify it and source a new one:
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Worth a try to repair it...? That plastic sealing at the top is rock hard, as was the insulation of the wires: Image Unavailable, Please Login
I carefully saw off the surrounding frame and managed to salvage to wiring ends:
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It was composed as such - I don't know what the 2 metal sleeves at the bottom were for:

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Decorroding of the remaining wiring followed, the soldering of new wires. I kept them a bit longer. The black line on the yellow one is marker. Sealed in with heat shrink.
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I then glued the frame back on:
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Then came the plug:
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I refilled the frame with epoxy to seal up the sensor and reinforced the plug with wiring loom tape:
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The I filled the tiny gaps on the sensor and top side with superglue to stop the leaking.
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Testing
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All good, this one can be used again!

 

I also have an old laying around that could be fixed...looking forward to see what is the problem on that one.Thanks for this input.

 

In theory, a wider tire would make it harder to turn but since you already adapted power steering, I think it may matter less for you. That's on my radar as a future project (why not) and I think the Prius power steering is what I'm thinking about. The parts are readily available and not hard to wire in from all the folks who have added it to their vehicles (you don't have to mess with the rack -- just the steering shaft).

As far as rubbin when you go wider, I haven't noticed any issues even when moving the wheel to opposite lock but the car hasn't moved under its own power (just pushed around). I'll need to test this further BUT I think the more shallow offset of my aftermarket wheels vs stock helps (+45 vs +55) which tucks them in a bit more. I can always raise ride height if necessary and/or dial in a bit of negative camber if necessary. I won't go for the "hella flush" look though.

Finally, as far as getting more power here are a few ideas (from minimal to terrible):
- Index spark plugs so the igniters face the intake valves (<1% gain)
- Remove the intake filter (another terrible idea for minimal gains)
- Straight pipe the exhaust (not great for the environments if you replace the cats with a downtube)
- Lean out the engine a bit (terrible idea, but more power)
- Fuel injector + EFI conversion -- which you probably won't do because originality (<10% gain)
- Forced induction. A supercharger won't kill the exhaust note (just add some whine), but again, originality.

 

Gunn, adding power steering has made the car so much easier to drive in town. It's a very worthwhile upgrade. I guess there was quite a bit more wheel clearances in the "old days" that on today's cars. Please let us know if you experience any interferences in real life usage.

Indexing the spark plugs I have never heard of, that's an interesting one! And yeah, removing the air filter is not really an option with all the dusty air here. My car doesn't have cats, it's got a simple Euro exhaust. I am currently running an Ansa but other than a different sound quality, there is no noticeable gain in power. Which I am not surprised about, despite all sorts of claims by s/s muffler specialists. I did lean the engine when not under full load and gained quite a bit on fuel economy. I also got myself a new toy:

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I suppose if the K-Jet's control pressures are adjusted correctly and the injectors in good condition, the gain from converting to anything wildly more complex would be relatively small. And yes, originality is a factor, also when it comes to the annual inspection. So there goes the supercharger! Anyway, as long as the car runs reliably I am quite happy.

 

How exactly do you "index" spark plugs? I've never heard of that either. I understand that it means pointing the electrodes a certain way, but since the spark plugs thread in, how do you get the electrodes point the correct way?
Album

 

I first learned to index spark plugs as a neat project to tweak on my 24 Hours of Lemons crapcan racecar (powered by a 5.0L Ford Windsor engine). I can't say it really improved performance (because i had zero interest in dynoing the car) but it was an interesting thing to learn about (much like tweaking your own ECU tune using an Moates Quarterhorse EEPROM replacement module + Binary Editor).

There's a whole rabbit hole of ideas about the optimal placement of spark plugs but the gist is as follows:
- Mark the electrode position on the outside of each spark plug with a sharpie
- Decide on where you should position the spark plugs: towards the intake, towards the exhaust, or halfway between.
https://www.moroso.com/media/wysiwyg/PDFs/HRDP-200200-QUICK.pdf
https://www.spoolstreet.com/threads/spark-plug-indexing.4701/#post-66500
https://www.motortrend.com/how-to/how-to-index-spark-plugs/
- This is easiest with the heads off but when you tighten each spark plug in place, you'll find the tight spot to put the index mark in different points. Try one plug. If it doesn't work, try another one. With 12 plugs, I found it wasn't too hard to find the "right" plug for each cylinder. Number them w/ the sharpie. I used copper plugs on my lemons car so this was only a few dollars to buy extras which became "race spares"
- There are companies that also sell shims which you'd use to set the right position for each plug by adding a shim or two for each plug position.

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As far as a well setup k-jet system working as well as a modern EFI system using bosch injectors, I'm not so sure. While the fuel injection point (into the manifold above the intake valve) may be the same between a modern EFI system and the original kjet/jetronic/whatever system, I'm betting the fuel misting/atomization isn't nearly as good as with a garden variety bosch injector. The precision in the amount squirted with this distributor setup simply isn't there.

Its machining work + EFI setup, but others have done it. Passing local certification may be a challenge though.
https://www.***********.com/threads/qv-efi-conversion.37577/
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One more bad idea came to mind. In CA, things have to be a bit more stealthy as well because even an engine "sniffs clean" on a dyno, all fuel/intake/exhaust parts must have a California Air Resources Board (CARB Executive Order #). This means aftemarket turbos/superchargers are often verbooten unless the mfg paid for emissions testing AND for a CARB #). What some people do THOUGH is instead of bolting on a turbo, they'll opt for engine work instead and install a stroker kit). Of course, you'll need to upgrade the fueling/EFI to take advantage of the added displacement BUT its entirely possible. For these engines, swapping out the injectors for larger models AND a stealthy reflash of the stock ECU is good enough.

In Urs case, he's clearly not shy about spending money/effort on the Mondial: if he ever has to rebuild the block, why not resleeve it for slightly larger pistons and/or swap the crank to get more displacement?
- There seem to be folks here in the US who say resleeving with liners containing larger bores + stroker crank (or a 360 Modena crank) you can get to 4L.
- You'll still have to deal with an increase in fueling demands over stock but with a proper EFI, that would be entirely possible. Others have done this without drama. While I doubt just cranking up the fuel pressure on the stock K-Jet system would adequate to cover all driveability situations with a larger displacement engine, a similar technique was done with adjustable fuel pressure regulators and old turbo engines after they cranked up the boost and/or swapped to a larger turbo which shoved more air into the engine. This was popular with turbo-brick era volvos and mostly worked because a turbo charged engine would still operate pretty similarly to a stock engine when off boast whereas a bigger displacement engine (4L vs 3L) would be much leaner. I certainly wouldn't stop you from trying to make increasing fuel pressure to the k-jet work

 

Not to hijack your thread, Urs, but the spark plug index thing is quite the rabbit hole indeed!
I think I'll just hang a small vial containing some soil from Enzo's grave from my rear view mirror and call it done!
Alden

 

I am sure modern injection systems paired with ignition control is a whole lot better than the K-Jet, especially under partial load conditions and when it comes to emissions. That's why things have evolved in the first place. I was just wondering where all those horses went that the engine should have according to the original claims

 

Alden - hot rodders have been indexing spark plugs forever - To get the electrode in the right orientation, you use washers...I've never done it - it's for folks trying to get that last bit of HP out of their engines:

https://www.summitracing.com/parts/mor-71910?srsltid=AfmBOoo1kOH8xrRAY2BeaxlY_HUg1H_wqsV0_czVer2bfF5WPnfV2TCEBY8

 

My steering wheel started to show some usage related wear - old age, hands and UV:

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I cleaned and treated the leather with Color Plus' products, then re-dyed the affected areas:

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This turned out nicely; ready for use again.

 

The radio aerial started to act up, not retracting anymore... testing with a multimeter showed 12V at the corresponding connections so I suspected the motor or mechanism. That antenna is beautifully made: Image Unavailable, Please Login
and in excellent condition for something made in 1980
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Nothing wrong here, it works perfectly when bench tested with a good 12V supply. Back to the switch then:
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Disassembly is easy enough
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Burned out contacts!
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Cleaning them up and flattening the burned surfaces with 280 paper solved the issue. All back and working perfectly now.

 

I finally got the cracked exhaust flange welded up. The muffler just fits into the trunk!
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Also some smaller holes in the previous welds
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The cracks had propagated further than what I saw from the outside
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This would have cracked through pretty soon I guess.

 

The brackets removed for clean-up
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They have cracked too and will have to get welded up:
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Interestingly, the exhaust is stainless but the inlet flanges are mild steel, and rusty:
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Clean-up time:
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Incl. the threads
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Also, previous repair left big blobs of weld inside the conical sealing surface, which I removed with the Dremel:
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Cleaned up
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Rust removal on previous welds as paint prep:
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rust free ready for paint
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"paint booth"
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Done, ready to be used again:
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The ashtrays looked tatty...
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One spring was missing, it broke and lives in the centre tunnel now... I made a new one because without it, the cover rattles!
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I also, finally, removed the integrated ground switches, not used on the Mondial as the illumination is controlled by the light switch. The wires and insulation plates sort of interfere with the proper fitting inside the console unless things are "pushed".
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Preparation for repainting
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Repainted
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Looks clean again
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We had a long period of rain/typhoons. When the weather finally cleared up I discovered this during the walk-around... Image Unavailable, Please Login
No clutch - AGAIN
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Looks wet
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Removed
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That bellow is gone.. molten Image Unavailable, Please Login
replacement cylinder seems correct
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Replaced
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Next step will be bleeding.

 

Nice work, as usual. What paint did you use to refinish the ashtrays? Mine could use the same treatment.

 

Thanks Howard - I used Nippon Paint spray can. But - ideally, should have taken them apart and lightly blasted them before powder coating (as they were originally). The lid does scratch the sides, and impart the front edge so it's a matter of time until the paint will come off again. But since I don't smoke...

 

Sure they were powdercoatet initially? I redid mine as well and just sanded the surface a bit and used an ordinary matte black spray can in 2-3 layers. Works since three years.