Cleaning the oil cooler

[neilbardsley]

I went through that debate. I had a very nice offer from Bruce Smith (http://www.sparkingplugs.com/2.html) to look at it for me but I figured that the time/postage and risk of damage in transit meant I should send to someone here.

The dwell angle does seems more stable. I can't say that the tdc mark is much more stable under the timing light. My first drive, without tuning the carbs, I would have to say that the car ran a little better pre distributor build. In particular from the transition from idle to main circuit. However, I then turned the carbs but decided to come out of the garage and spend time with the family rather than taking out for another drive.

Next on my list is getting the rpm and temp gauge to be spot on. Tim B has given me some advice and I've bought a book called Electronics for Dummies!

[neilbardsley]

I've finally been able to contact the previous owner of my car and he is mail me his folder he has from 51 years of ownership!

"Neil
Thank you for your very welcome email. I'm so pleased that you are enjoying the car as I did for 51 years. I was a professor of automotive technology at California State University, Los Angel
es for 38 years and did all the maintenance myself until later years when the old body couldn't get out from under the car. I am 86 years old now. The car was my daily driver for those years,all of it on the San Bernardino freeway between my home and the university. A round trip of 45 miles.
To answer your questions:
1: I don't know the gear ratios as I bought the 941 used but had it completely rebuilt by a Porsche trans specialist before installing it.

2: I never had an overheating problem here in southern California where it is very hot during the summer and fall months.The temp guage always did read a little high

3: When I installed a later year engine I had to change the mechanical tach to an electric. I do not believe it was ever calibrated.

I have a folder with years of of info for parts repair etc. which I'll mail to you along with any photos I may find.

Thanks for your email and please keep in touch. "

"Neil I just went out to the garage to find the Porsche folder and right on top was the info on the741 trans.The gears are BBBD
Hope this helps. Give me your mailing address and I'll mail the folder to you."

[jb]

That is a great result and what amazing history. The car really will be rust free.

[neilbardsley]

Now that I know I have 4D my rough calc (using ratio supplied by Vic's web site) says that 4k rpm = 80mph.

Seeing that sometimes I'm seeing 80mph at 3.5k means that either my speedo or rpm is out! I'm pretty sure the rpm gauge is out but I'm not so sure about the speedo

mm in inch 0.0393701
inch in mile 63360 W Profile Rim Diameter in Miles
Type Diameter Inch 25.3937064 165 80 15 0.0013

R&P 0.225806452 7.0 31.0
mph

rpm 3A 3B 3C 4A 4F 4B 4D 4G
1000 13.9 15.1 16.4 17.8 18.5 19.3 20.0 22.7
2000 27.8 30.2 32.8 35.5 37.0 38.6 40.1 45.5
3000 41.7 45.3 49.1 53.3 55.4 57.9 60.1 68.2
4000 55.6 60.4 65.5 71.1 73.9 77.1 80.1 91.0
5000 69.5 75.5 81.9 88.8 92.4 96.4 100.1 113.7
6000 83.4 90.5 98.3 106.6 110.9 115.7 120.2 136.5
7000 97.3 105.6 114.6 124.4 129.4 135.0 140.2 159.2

0.8148 0.8846 0.9600 1.0417 1.0833 1.1304 1.1739 1.3333

[Mike Smith]

Neil,

I do not know what tyres you have on the car but with 175 x 15 Avons or 165 x 15 Michelin / Firestone etc at 5,500 you shoud be getting :-

1B - 30 MPH
2B - 52 MPH
3B - 81 MPH
4D - 107 MPH

NOTE
D is a lower gear than C (Weird I know but that is the way it is) a C top Gear would give you approx 112 MPH for the same Rpm

RPM at 40 MPH :-
1B - Not Possible
2B - 5,250 Rpm
3B - 3,400 Rpm
4D - 2,600 Rpm

Or with a 4C - 2,500 Rpm

NOTE - everything is approx depending on Tyre Size and wear - Tyre Pressures - Accuracy of Instruments etc etc