My '72 911T

defianty · Post by **defianty** » Fri Apr 08, 2011 10:46 am

Nice work Gary well done. Enjoy the car!

johnM · Post by **johnM** » Fri Apr 08, 2011 11:31 am

Great work as always Gary, must feel fantastic after to have it all sorted and ready for the summer.

Kind Regards

Gary71 · Post by **Gary71** » Sat Apr 09, 2011 9:37 pm

Thanks all,

To sum up the winter list...

Highlights are:
3.2 Carrera front brakes
Later 3.5" spacing front struts
Front lower ball joints
Brake pipe hard lines throughout
'74 spec aluminium rear trailing arms
Rear wheel bearings
Rear trailing arm inner bushes
iPhone dock
'72 Blaupunkt Frankfurt
1st/2nd gear slider
Gearbox seals
Needle rollers for free gears
Clutch
Speedo cable gaiter
Engine bay sound deadening panel
Loads of unplanned welding...
Vapour blast & ultrasonically clean carbs
Turbo spec rocker covers

Not to mention the hours spent farting about fixing stuff before the stuff I was supposed to be doing would fit.

Now done about 200 miles and all is sweet (apart from a confusing misfire after you have been over 5000rpm).

God know where the wheels are pointing, but where ever it is I'm loathed to adjust them too far from there as it feels better than is has ever done. Having said that is going on the alignment machine Wednesday night.

The gearbox is just fantastic now. Proper rifle bolt changes throughout, the chatter at idle in neutral has gone completely and the overall noise level has dropped massively. My thoughts are that the Honda needle rollers for the free gears being plastic caged don't rattle like the originals.

Next job is to set the carbs up and fit the MSD unit now I've proven the basics.

sdelan · Post by **sdelan** » Mon Apr 11, 2011 1:37 pm

Fantastic work Gary - well done!!

Sorry - but can I ask a technical question please - when your refer to "later 3.5 spacing front struts" - what do you mean? Does this relate to the change to 3.2 calipers?

Regards
Sean

hot66 · Post by **hot66** » Mon Apr 11, 2011 1:50 pm

sdelan wrote:Fantastic work Gary - well done!!

Sorry - but can I ask a technical question please - when your refer to "later 3.5 spacing front struts" - what do you mean? Does this relate to the change to 3.2 calipers?

Regards
Sean

it's the spacing between the lugs the calipers bolt to

early ones were 3"

2.4S / RS ( aluminium S calipers ) and later moved to a 3.5" spacing . If you have 3.5" lug / bolt spacing on your struts , you can easilly bolt on later 3.2 callipers ( when also fitting matching discs etc )

Nige · Post by **Nige** » Mon Apr 11, 2011 1:52 pm

Well done Gazzaroony!

Lightweight_911 · Post by **Lightweight_911** » Mon Apr 11, 2011 2:02 pm

All lwb 'S' calipers came with 3.5" spacing between the mounting lugs ...

911hillclimber · Post by **911hillclimber** » Mon Apr 11, 2011 5:51 pm

Is the 3.2 caliper an A type caliper spaced to allow the wider 3.2 discs?
Also, are the 3.2 caliper pads a large surface area than the A type caliper?

If the answer is no, then what is the advantage of the 3.2 other than heat absorption from hight speeds, or mountain passes that Gary will be doing very soon?!

I thought the pads were the same, but the servo on the 3.2 gave better braking for the same leg-effort.

Gary71 · Post by **Gary71** » Mon Apr 11, 2011 6:38 pm

911hillclimber wrote:Is the 3.2 caliper an A type caliper spaced to allow the wider 3.2 discs?

As far as I know yes.

911hillclimber wrote: Also, are the 3.2 caliper pads a large surface area than the A type caliper?

Nope.

911hillclimber wrote: If the answer is no, then what is the advantage of the 3.2 other than heat absorption from hight speeds, or mountain passes that Gary will be doing very soon?!

Only that.

And for me compared to the 'M' caliper and disc it's a significant step in heat absorption capability.

911hillclimber wrote: I thought the pads were the same, but the servo on the 3.2 gave better braking for the same leg-effort.

Servo? Only for wimps

One thing I have noticed whilst brake bleeding is a significant percentage of the flex in the pedal is the floor moving... along with caliper flex.

However the caliper flex is less than the 'M' caliper, again putting more of your effort into the pads.

In my short (and not fully bedded) experience with them I have seen a step increase in stopping power, which must just be pad area and reduced flex. I've certainly not challenged the heat absorption capability yet.

Reinforcing the floor would be a worthwhile modification for any hard used car as there is a finite limit to the pressure the pads exert before the floor starts to move.

hot66 · Post by **hot66** » Mon Apr 11, 2011 6:40 pm

I swapped my alloy s calipers over to a 3.2 set up purely because I was getting too much caliper flex

911hillclimber · Post by **911hillclimber** » Tue Apr 12, 2011 6:27 am

Interesting.
I was thinking of upgrading my 73T system (A calipers/stock rear/Green Stuff pads) for the summer and even wimping it with a servo because the 3.2 engine has the take-off for one.
To floor flex, my car has a thickening panel under the pedap floor from the factory.

I know someone who has a v fast tarmac rally 70 with a 3 litre and has S calipers etc which was challenging to stop (I've been inside at speed on a track and it does stop well compared to mine).
He has just added A calipers and metalic pads (Loraine) and is stunned by the improvement.
Pads are £250....

Gary71 · Post by **Gary71** » Tue Apr 12, 2011 7:04 am

911hillclimber wrote: To floor flex, my car has a thickening panel under the pedap floor from the factory....

As do they all I believe. It carries the studs for the pedal box. Still could do with something else down there!

Gary71 · Post by **Gary71** » Wed Apr 13, 2011 9:15 pm

Geometry all done now

Felt very stable (for an early 911!) on the way home

It wasn't that far off despite throwing it back together, the only real error was 0.5 deg of camber on one rear wheel and 1 deg on the other.

Just need to set up the carbs now and sort the random misfiring

Highfield · Post by **Highfield** » Thu Apr 14, 2011 7:08 am

Nice work Gary, and looks spot on now.

Enjoy the Spring / Summer touring etc.

Ian

Gary71 · Post by **Gary71** » Sun Apr 17, 2011 6:05 pm

Finally everything is done

The time spent yesterday setting up the carbs, cleaning the dizzy cap etc was worth it, it is running like a dream

So I had an early start today to put in a few hundred miles across North Wales just to make sure everything is working

The biggest changes I've really noticed after this Winter rebuild are the suspension and gearbox.

The rear suspension is just so tied down, I can only put it down to an increase in stiffness of the alloy arms over the steel. The steering and turn in is lovely, again I believe as a result of improved toe control at the rear together with fresh front ball joints.

The gearbox is so tight and precise, proper cliched rifle bolt change in all gears and half the noise. Result

Oh and 3.2 brakes are an essential upgrade to anyone without them!

Only downside of the rebuild is I have disturbed the slightly leaky oil tank so it's now a very leaky oil tank..