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On 04/01/2020 at 14:37, OZ930 said:

Just read this:

According to a climate change expert, air conditioners cause bushfires.


Brian, I'm assured that since the air conditioners from Australian air cooled 911's only contribute 1.3% towards global greenhouse gases we shouldn't feel in any way obliged to change our ways.... 

 

Knock Sensor Locations

I find Neil Harvey a bit frustrating.  Certainly clever and well experienced from his years at Andial and Performance Developments, but a bit too coy to share information and a bit to quick to tell everyone how he does things better than everyone else for my liking! And some weird fetish for CDI that he doesn't explain very well.

However I was reassured when he recently let slip that he prefers to use 964/993 sensor bridges mounted on the underside of the heads on pre-964 engines: http://forums.pelicanparts.com/10690222-post2.html 

When I decided to do mine that way I was shooting from the hip and it was mostly good luck it turned out OK.

 

 

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  • 1 month later...

Hi Octane Coatings at Drummoyne came highly recommended so I used them to ceramic coat my headers to reduce radiant heat.  They recommend their black on the outside and something else that I can't remember on the inside.  The turn around was quick and the finish flawless.

9m03AzW.jpg

 

CAiWeDS.jpg?1

 

Got pulled today for breath, licence and logbook check.  Cheeky copper said with a grin "Is it quieter on the inside ?"

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11 hours ago, Peter M said:

Yes, actually.  Not one of the usual short guys that the Highway Patrol seem to attract......

Same guy that pulled me over for an RBT when I drove up for Cars and Coffee.

”have you had any alcohol today sir ?”

”do you want some ?”

”not so much want, but need”

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16 minutes ago, Peter M said:

Missus said to me yesterday: "You know those cars that wake you up in the middle of the night because they are so loud that you just wish the driver would crash and die so you can go back to sleep?  Your red car is that loud."

 

GULP!😨

That's so incredibly funny, I am having issues trying to read this out to my family and not die from lack of breathing while I laugh with tears in  my eyes......you obnoxious b#stard.....  I was told the same thing by my neighbour sometime in 2004 when I first fired up the Ducati 749s with the Termignoni 'race use only' exhaust pipe one 5am Sunday morning....

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On 17/02/2020 at 19:46, jakroo said:

...... Ducati 749s with the Termignoni 'race use only' exhaust pipe one 5am Sunday morning....

Ah, Testastretta Ducatis, is there anything in this world more magnificent?  Still miss my pair whilst conveniently forgetting that I sold them because I was too fat and inflexible to fit .  Bought my 749 just for track days.

SDtsLpm.jpg

 

 

Might be small and cute but is easily the most obnoxious thing in the garage because it's loud and takes a lot of throttle blipping and restarts before it will even fast idle.  Think of a 100 rattling dry clutches, it even annoys me!  At least with the red car I can drive off immediately.  But when it finally reaches 85 degrees and carburates perfectly, the noise it makes on overrun still makes me weak at the knees, bel suono!  Can't image ever selling it.

Zo8NQqJ.jpg

 

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  • 1 month later...

In taking a motor out to 3.8 or 4 Ltr is it a combination of stroke and bore size or do they  just stroke it ? Or is it pistons and bore size , To my way of thinking it would have to a combination  of both to justerfy the dollars asked.

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Yes, I understand they increase the stroke from the standard 74.4mm to 76.4mm by machining the crank using smaller 50mm big end journals (later GT3 cranks seem a common swap as well) and machine the cases to take new cylinders with 102mm bores (up from 95mm) to get them to 3.8 litres

Surely it would be more cost effective to go turbo or use a 3.6 litre engine as a base?

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1 hour ago, Peter M said:

Yes, I understand they increase the stroke from the standard 74.4mm to 76.4mm by machining the crank using smaller 50mm big end journals (later GT3 cranks seem a common swap as well) and machine the cases to take new cylinders with 102mm bores (up from 95mm) to get them to 3.8 litres

Surely it would be more cost effective to go turbo or use a 3.6 litre engine as a base?

I'm no expert and have not done this... yet!

My understanding is the 3.0 crank is 70.4mm stroke.. the 3.2 has a 74.4mm stroke which is where it gets the 3.2 litres. (or 3.15 i think to be more accurate)

The 964, 993 and 996 GT3 all have a 76.4mm stroke.. 964 crank is not favoured. But these cranks get you another 100cc with a stock 95mm piston. Upgrade to a 98mm piston and you can then get to 3.45 litres. Cannot modify 3.0 cylinders due to groove for head gasket/flame ring, but can use 3.2 cylinders, have them bored and then re-coated. Or you can buy some expensive slip fit cylinders from LN Engineering and probably go even bigger.

993 crank is better but lacks cooling/oiling mods necessary for a hard run motor. It can be modified or you can buy a ....GT3 crank which has same stroke but is well designed to already flow plenty of oil to rods 2 & 5.. which are the last ones to get oil.

The GT3 4.0 crank has an 80.4mm stroke..  with 95mm cylinders you are up to 3.42litres. or with 98 up to 3.64l.

I am hoping to do an 'in between' motor in the coming weeks.. 3.0 with a 993 crank and some higher compression 95mm pistons. With a decent cam, headers and itbs, I am hoping to make a VERY strong street car.

 

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9 minutes ago, Mike D'Silva said:

I am hoping to do an 'in between' motor in the coming weeks.. 3.0 with a 993 crank and some higher compression 95mm pistons. With a decent cam, headers and itbs, I am hoping to make a VERY strong street car.

Mike,

Looking forward to another of your builds!

So 76.4 stroke and 95mm cylinders gives only gives 3.25litres.  Wouldn't it be A LOT cheaper to stick with standard 70.4mm crank and go a set of bored out 3.2 cylinders giving almost the same capacity at 3.19 litres? (Also known in the trade as a 3.2SS I believe!)

Also wouldn't you need a set of special conrods with the 993 crank because the big end journals are shorter? (I think!  The conrods are thinner??)) 

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This is the age-old question that women have been asking for centuries... what is more important.. Girth or Length??? 

Or in our engine case, stroke or bore.

I'm being educated as I go along.. but I'm told that bore tends to favour a higher rpm situation.. where stroke tends to produce more torque down low. If budget is not a constraint, then I'd do both. But if money is a limit and the car is mainly a street car, and the goal is not to produce a dyno sheet to impress your mates, then stroke will give real world performance (I think). 

Yes, I am planning to use stock 993 rods with the 993 crank. We will get a custom piston from CP that uses the same pin as the 993 rod. Not sure how high compression to target just yet. 10.5 seems to be maybe a tad too much.. probably get it down to 10.2 or 10.3 to be safe?

For capacity calculation, I am just using an online calculator.. https://spicerparts.com/calculators/engine-displacement-calculator

On 17/02/2020 at 18:31, Peter M said:

Missus said to me yesterday: "You know those cars that wake you up in the middle of the night because they are so loud that you just wish the driver would crash and die so you can go back to sleep?  Your red car is that loud."

 

GULP!😨

haha, just saw that. Your wife sounds funny!

 

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Playing with that online calculator makes you realise a couple mm either way doesn't make a big differences to the capacity but I would imagine a huge difference in $$$$$!

Mike,

I don't think it is as simple as "stroke will give real world performance".  For the likely combinations in the same capacity class, I think cam and induction choices will have a greater effect on real world "feel".  Not that I'm dissing 993 engines, I actually wanted my 3.4 build to have the same feel as my old 993 engine.

I'm very interested in following your build and seeing your results.

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12 minutes ago, Peter M said:

Playing with that online calculator makes you realise a couple mm either way doesn't make a big differences to the capacity but I would imagine a huge difference in $$$$$!

Mike,

I don't think it is as simple as "stroke will give real world performance".  For the likely combinations in the same capacity class, I think cam and induction choices will have a greater effect on real world "feel".  Not that I'm dissing 993 engines, I actually wanted my 3.4 build to have the same feel as my old 993 engine.

I'm very interested in following your build and seeing your results.

Totally agree with you on the cam. But I'm led to understand that if you compared just the bore vs stroke argument, stroke rewards you down low, and bore rewards you up top. These are not my claims at all.. 

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Well I am not sure of the exact specs of the bore and stroke, but the genuine '71 911ST that was at Symmons Plains last week with a 3.0RSR engine had 12:1 compression, revved to 8700rpm and peaked at 350hp on an engine dyno. The thing screamed, but I suppose when money is no object, the sky is the limit ;)

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I always understood that bigger bore, shorter stroke provides higher revving, racier motor.  Longer stroke is more torquey and probably more driveable but doesn’t rev as hard so not as exciting for a performance engine.  Completely uneducated on the matter, just my perception from decades of reading car mags etc.

ive seen a couple of racy old 911s with “short stroke” motors which I assume is like the ST mentioned above.  Hard revving, high compression and a bit cantankerous for road use.

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Shorter stoke and larger bore for the same capacity = lower piston speed for the same revs, hence the ability to raise the revs to get more power for the same piston speed,and with a larger bore There is more room to fit bigger valves 

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