Oil leak from front crank seal 1979 2000

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aj81spider
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Your car is a: 1974 Fiat 124 Spider
Location: Chelmsford, MA

Re: Oil leak from front crank seal 1979 2000

Post by aj81spider »

Here's an off-topic rant:

Specifications like 180.3 (and even 181) are the plague of bad engineering and make me crazy. A spec of 180.3 implies that you need to torque the nut with enough accuracy to guarantee it is between 180.25 and 180.35 ft/lbs. 181 implies between 180.5 and 181.5.

The average torque wrench has a specification of around +/- 4%. That means if you can even set it for 180.3 it will actually deliver a torque somewhere between 173 and 188. The tooling available to deliver the accuracy implied by a spec of 180.3 (or 181) isn't available to the average garage, never mind hobby mechanic. A good engineer will understand this and know that no spec other than 180 is practically achievable (and you're even stretching that with a standard torque wrench).
A.J.

1974 Fiat 124 Spider
2006 Corvette
1981 Spider 2000 (sold 2013 - never should have sold that car)
18Fiatsandcounting
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Your car is a: 1969 and 1971 124 spiders
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Re: Oil leak from front crank seal 1979 2000

Post by 18Fiatsandcounting »

aj81spider wrote:Specifications like 180.3 (and even 181) are the plague of bad engineering and make me crazy.
A.J., I totally agree, and I have had this very same rant, many times. It all has to do with significant figures, and given the accuracy of torque measurement, at best you are dealing with two significant figures for the type of work we're doing. So, this particular torque measurement should be given as 1.8 x 10^2 ft lbs, which might appeal to engineers and scientists but not many others.

One of the best classes I ever had in college was analytical chemistry, where we talked about measurement and sampling error, and the difference between accuracy (how close you are to the true value), precision (how many significant figures your measurement has), repeatability (the variation in the number you get from one measurement to the next), and sampling error (when your sample is coming from something that isn't well mixed or is changing in time).

[/RantOff]

-Bryan
wetminkey
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Your car is a: 1979 2000 Spider
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Re: Oil leak from front crank seal 1979 2000

Post by wetminkey »

I only state what the Fiat Shop Manual does,...
I just use my big tools, and yank it as far as I can.
I do not measure crankshaft pulley nut torque!
I doubt that I get this nut to 181ftlbs., but I also doubt that it will come loose if it's as tight as I can get it with 2.5" tools,...
I wanna know what maxdog found!
1988 Mazda RX-7
1979 Fiat Spider 2000
1978 3/4 ton Chev 4x4 P/U "FRANKENTRUCK"
1976 Camaro
1972 VW Superbeetle
1969 Ford F100
1968 Mustang coupe
maxdog
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Re: Oil leak from front crank seal 1979 2000

Post by maxdog »

What did Maxdog find???
Well the all too short Montreal driving season finally arrived , so I decided to postpone serious dismantling to the Fall !
I cleaned off the underside to remove an accumulation of drips , replaced and dekinked the crank case ventilation hose , refitted the top of the centrifugal case crank vent oil separator . The Fiat now drips less oil than any of my old British cars ever did .
A big tray of kitty litter under the car keeps the garage floor clean .
Procrastination won the day !
Maxdog
wetminkey
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Re: Oil leak from front crank seal 1979 2000

Post by wetminkey »

I understand perfectly! You have NO IDEA how long it has taken me to get to the things that my car needs to run right! Years,...
Crankcase ventilation components can be a source of oil leakage,...hope that was the problem.
Enjoy your Spider, maxdog!
Todd.
1988 Mazda RX-7
1979 Fiat Spider 2000
1978 3/4 ton Chev 4x4 P/U "FRANKENTRUCK"
1976 Camaro
1972 VW Superbeetle
1969 Ford F100
1968 Mustang coupe
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