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Mike9311 · Joined: 14 Dec 2004 Posts: 1798 Location: Chicago-ish

Hi All

Just wanted to get input on a 'not so important' side project besides tooling up for Morghen's 2470 wheel which I hope to do very soon before this project. Especially now that the hard deadline for the '82 has been delayed for obvious reasons. No joy rides here due to lock-down (back and forth to work however is still on table so far).

Been thinking of adding a temp gauge port to the turbo drain. Obviously the thread could be metric or inch.

Thoughts?

The last pic has me doing virtual test machining and you can see the boss for the sensor there. I likely would need to finish old school by hand since machining is somewhat difficult for the internals.

_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

924RACR · Posted: Sun Mar 22, 2020 1:55 am Post subject:

Interesting idea.

I'd want to make sure the boss is long enough that the probe doesn't stick too far into the flow and restrict it. I've seen some gauge adapters that aren't long enough and I've had to create extra spacers, particularly with the VDO temp senders, to get the probe out of the flow. Some would even go in so far as to touch the other wall of the tube, almost completely blocking the flow!

May also be worth verifying that the body (OD) of the sender will clear the turbo itself, housings, fasteners etc on installation. As that sits, it looks pretty close.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Mike9311 · Joined: 14 Dec 2004 Posts: 1798 Location: Chicago-ish

Mike9311 · Joined: 14 Dec 2004 Posts: 1798 Location: Chicago-ish

Decided to divert slightly off the cylinder head for a couple of days to get back to this project. Easier to install on two cars when one is up on the lift and the other with engine out. Plus my skills were warmed up after just completing another job. Just makes it easier. Sender hole thread can be 1/8npt or metric.

_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

Mike9311 · Joined: 14 Dec 2004 Posts: 1798 Location: Chicago-ish

Update

Thread in for drain and gauge sensor on the opposite side inline with drain. This one is 1/8 NPT but its easy to make any thread for a sensor

Drain fitting threads are milled which lets me control fit. Almost done. Side 2 next

_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

Mike9311 · Joined: 14 Dec 2004 Posts: 1798 Location: Chicago-ish

The rest of the inside to do and I'm done. Already farther than this pic

_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

Mike9311 · Joined: 14 Dec 2004 Posts: 1798 Location: Chicago-ish

Just needs some hand finishing and mount holes opened up to size. Moving on to the next project

_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

Fasteddie313 · Joined: 29 Sep 2013 Posts: 2595 Location: MI

Would buy..

Some day I’ll quit or get fired and have time for my cars again 🥺
_________________
80 Turbo - Slightly Modified

jacobroufa · Joined: 18 Nov 2016 Posts: 531 Location: Belvidere, IL

+1 Would buy
_________________
1980 Porsche 931
1981 Porsche 924 Weissach

Mike9311 · Joined: 14 Dec 2004 Posts: 1798 Location: Chicago-ish

Thanks guys

I feel you Eddie... I am working even when I'm not working. Got a 2nd on in the machine for the CS. Turns out these drop mass from 413 to -160g Side benefit to just wanting to know oil temp at turbo. Need to work on proper hardware too. Sensor is farther from exhaust than pic makes it seem

_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

Mike9311 · Joined: 14 Dec 2004 Posts: 1798 Location: Chicago-ish

Added simultaneous 5 axis porting now to improve the inner parts. I left material in the first one to port out by hand with a carbide burr. Not really fun and somewhat dangerous to the flange section if burr is too short and bounces why grinding.

CNC porting opened the second one up nicely. Still will clean it up manually but at a happier place with the finished product.
_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

924RACR · Posted: Mon Apr 04, 2022 1:53 am Post subject:

Haven't gotten around to replying, but have been watching: beautiful work.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Mike9311 · Joined: 14 Dec 2004 Posts: 1798 Location: Chicago-ish

Thanks Vaughn!

I have a 2nd one done now for the Club Sport. It got the extra full 5 axis porting treatment with the lollipop. With it being fixtured horizontally, it was at a machine axis limit which then causes faults. This added so much time for me to work through the programming. Good exercise for me though since I want to do a head once flow-bench is running etc.

It lost some grams yet again in the process. True mass loss is 380g down to 129g.

In all this I am realizing how massive the process really is for auto manufacturers. Safety features, and what not, being added to a new car design and then trying to find where they can lighten to offset.

_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car

Cedric · Joined: 27 Aug 2004 Posts: 2801 Location: Sweden

What a project, in the engine dev world we just drilled/taped or welded in a bung for pt100 or thermocouples where needed, this is much cooler though

A bit tricky to use the oil drain temp data for something useful, would be interesting to hear your plans

_________________
1980 924 Turbo
www.instagram.com/garagecedric/

Mike9311 · Joined: 14 Dec 2004 Posts: 1798 Location: Chicago-ish

Thanks Cedric

I was thinking it probably is near useless for standard oil temp but I am just curious. Realistically i'd better have another gauge which the CS already has right off the oil drain

This started simply because I was scanning so I scanned the drain for fun. Then it just kept going

Machining it was straight forward and everything I do helps me develop skills. Maybe I was avoiding the cylinder head project? No more excuses
_________________
1980 931 since 1989
1981 Ideola 931 Club Sport
1982 931 Entwicklungsfahrzeug
1979 924 NA ohne 650 mit 471
1982 931 Red Resurrection - 951 IC
1982 931 parts car / resurrection?
1980 924 NA (R&D lightweight)
1982 931 wana-be GTR race car