Yikes MM would be a cruel fate indeed. To be fair to Pedro, I think he was only suggesting the carbs be sent there.. not a motor rebuild. I agree with Steve that 15 x 6 wheels would look better, but 16" SC wheels are cheap and available. And they do ride nicely. Except you will need to set the ride height for the 16's and later. As well as the gearing issues Steve mentions. If you can find 15's it's a better deal all the way around.

Vol

 

I was under the impression that a 16x6 rim would open a whole world of performance tires to me. Also, I thought that the 16" tire had a smaller profile, as to provide the same overall diameter. I see no reason to reduce un-sprung weight if I am adding to the final drive ratio in the process!- Gringo

 

If you provide the original tire size, I can do the math to see what size 16" tire would have the same overall height to preserve gearing.

Jay
90 964

 

One of the easiest ways to calculate & compare the effect of alternative tire / wheel size changes to gearing, speedo & etc. is to use the tire manufacturer's "revs / mi." spec. These are included in the specs at Tire Rack (among other places). This yields a % change, high or low. {of course, it is useful to have the OEM supplied tire's rev/mi # for accuracy}

 

Ked,

I agree that the rev's per mile is the most accurate calculation. I think in this case, we'd never find the specs on the original tires though. So, doing a height calculation based on the tire size would be pretty effective to keep an original diameter even though 16" tires are being used.

Jay

 

True, in '71 the OEM tire selction was probably (don't know for a fact) Michelin (XAS), Pirelli (CN something-or-other / 36?), Dunlop &/or Conti. A revs/mi for the Michelin might still be available. I have been curious if the factory established a revs/mi for each model as part of their engineering spec & if that info is available somewhere. Would make a good article in Pano or the 356 Registry... Funny how Porsche tires went from 16" (pre-A) to 14" then back to, & past 16 to 18 & 19". I wonder how the revs / mi for that pre-A compares to the current wheel / tire combos!

 

here's a decent java based calculator for tire size ...

http://www.miata.net/garage/tirecalc.html

 

Do we know what the original tire size was? I'm itchin' to do the math!

 

After looking for 356s for the last several months, I can not say enough about keeping the car as original as possible. If you have a fully original car, I wouldn't do ANYTHING to modify it beyond factory spec. It will kill value and will make your car no different than so many others.

As Pedro mentioned, get a Cert of Authenticity from Porsche to verify engine and tranny numbers. If those are matching, I would keep the car clean, get the engine tuned up the right way to factory spec, and enjoy it. If you aren't going to show your car, have fun with it but keep it original. It will be worth a ton of money when you get tired of driving or owning it and you will thank yourself you didn't muck with any of the factory parts

Great find it looks like!

 

Hi Jay... I meant just the carbs not the engine...thanks Volney...there are just a few Zenith rebuilders available...he could also try Don Marks from Gearhead Co. He Does Zenith rebuilds for 356s and he might be able to work with the 40 TIN as well!

 

.

The original tire says, Michelin 165. (I think it does say a couple of letters after that, probably XAS.-Gringo

 

Thanks for clarifying Pedro! We're all on the same page now!

 

Well, we know the width of the tire should be 165 mm. What is the rim diameter in inches? Would anyone know the aspect ratio of this old tire?

[edit] ...or, maybe these old tires were never labeled with the more modern tire size labeling that we have now...

A 205/55 16 tire is about 24.88 inches tall. Gringo, you could measure the diameter of the original tire (off the car to avoid any tire sag while on the car) and see how close this original tire is to a 205/55 16. A 10% variance in diameter is probably pretty acceptable. Clearance issues might be something else to consider (and one issue that others could probably answer better than me).

Jay

 

Hi Jay...I totally agree with you...I'd never send my own engine as well...I'd prefer a local reputable shop where I could follow the progress...as far as the carbs, what is important is who has the tiny rare parts for the rebuild...

 

Gringo,

Did that car come from the east coast not too long ago? I looked at an extremely low mileage '71 Burgundy 911 with 4-speed and chrome wheels awhile back that looked just like yours. The car was absolutely immaculate and all original. I still regret not buying it. If this is your car, you got a great one.

And not to repeat the same thing, but you really should keep that car original, worn out shocks and all. If you want a car to drive, I would sell this one and build up one that is not so pristine.

Whatever you decide, good luck.