Author Topic: Modifying Olds oil pressure tubing  (Read 1160 times)

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Offline Aus78Formula

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Modifying Olds oil pressure tubing
« on: April 08, 2012, 09:48:21 AM »
This is a common problem that comes up for anyone trying to piece together a 350 or 403 in an F-body, the original loop-bracket holder that supports the smaller original oil pressure senders. Of course, no one makes them this size now, been searching for years and chasing leads that went nowhere of the 1-1/2" bodied senders. The only type available these days is the standard 1-3/4" body which doesn't fit into the original loop bracket. This is why many are long disappeared; replace sender unit, bracket doesn't fit anymore, chuck it.

But the problem doesn't finish there, the newer oil units also have a much longer threaded stalk which pushes the completed setup beyond the mounting hole in the block. Even if the bracket fit over the unit, it wouldn't be able to slide along enough to locate.

Not the best angle, but here's an early shot showing standard length tube. The large rib around the body of the sender is right about the bracket hole, far too long:



I had an assortment of original extension tubes in worn and damaged condition so decided to source the repro tube by Inline tube. Of course, this turned out to be slightly longer than stock, making the problem worse. I eventually ordered another, a spare as I wanted to modify one. It was also a touch longer than original, but again had slightly different angled bends to original. Neither of the repros would have been a bolt-on fit without adjusting the angles regardless.

So this is what I did. I wanted to both support the new, larger-bodied sender unit but also keep the original appearance. I needed to shorten the tube by approx. 20mm but taking the end flare into account shortened it by 15mm. It turns out I could have gone 10mm as I lost another 5mm just when tightening the threads up along the length, but still fine.

To reflare the end I had to straighten it, not easy in stainless, and rebend without kinking once done. As usual I had mine perfect but decided to go just a touch more when it creased the wall a little. I managed to smooth most of it out, but out of sight when fitted anyway.

Here's the repro tube and the shortened and rebent tube below:




I also cut up some 1-3/4" pipe to suit from some old exhaust stock and cut the wall through. I also made some small angled tabs, bolted through to allow easy placement when tig-welding them on. You can see the diameter difference here between original bracket and what was actually required, yet to be welded on:




And all installed. It is clear of the oil filler but not much, not that it can move either. An extra 5mm longer would have been better, but any longer and the other end starts to foul the fuel line. Does the job though, and looks original for those who don't know otherwise!


Offline RENOVATIONS

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Re: Modifying Olds oil pressure tubing
« Reply #1 on: April 08, 2012, 11:07:46 AM »
Very nice!
Thanks for sharing
Jeff

Projects:
_____________
1978 Trans Am
1970 Camaro
1970 'Cuda

Offline dewcrazzy

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Re: Modifying Olds oil pressure tubing
« Reply #2 on: April 08, 2012, 12:25:34 PM »
looks fantastic.

Offline winks79

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Re: Modifying Olds oil pressure tubing
« Reply #3 on: April 08, 2012, 09:55:40 PM »
Great info. Thanks for posting. You do awesome work! ;)

Offline Aus78Formula

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Re: Modifying Olds oil pressure tubing
« Reply #4 on: July 31, 2018, 12:17:58 AM »
Older thread, had some pics of used original sender unit that may assist. The finish is not accurate as appears to have been cleaned up with blasting.

403 Firebird oil sender and bracket 3 80psi by Aus78Formula, on Flickr

403 Firebird oil sender and bracket 2 by Aus78Formula, on Flickr

403 Firebird oil sender and bracket 1 by Aus78Formula, on Flickr

403 Firebird oil sender and bracket 4 by Aus78Formula, on Flickr

403 Firebird oil sender and bracket 5 by Aus78Formula, on Flickr
« Last Edit: July 31, 2018, 12:19:36 AM by Aus78Formula »

Offline Nexus

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Re: Modifying Olds oil pressure tubing
« Reply #5 on: July 31, 2018, 12:30:48 PM »
Nobody making these yet?
Charlie
1979 Transpit...(T/A Clone) (19 years and counting)

Offline TLTONEY

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Re: Modifying Olds oil pressure tubing
« Reply #6 on: August 05, 2018, 05:47:50 PM »
Great job!