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Help / advice required, Swan neck pivot points.


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Well, after much delay I am about to put my 78 Manta onto the rotisserie.  During the process of making up a frame brace to keep everything aligned I thought I would run a steel bar through the pivot points in the swan necks and weld a pair of locator arms to the frame to pick up on the bar.  The bar is a nice tight fit in the pivots and I managed to get it through both pivot points but it was quite stressed and looked to be bending which gave me cause for concern.  I then ran separate bars through each of the pivot points the result of which you can see in this photo.


This is obviously why the single bar experiment looked bent and under stress.  I ran measurements over the various reference points of the shell and everything appears to correct other than the pivot points not aligning.  So my dumb question of the day is “Is this normal ?”.  

Thanks in advance for your responses.


Edited by Limeysore
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Hi Chris, so you had no welding work on those "swan-necks"? The B1 Manta's were always better than their B2 brothers. Into the swan neck there is another chassis rail with a tube. You can see it on next picture when I restored my swan neck:


If there was no tube in it we would deform the rail while turning the big bolt. When I look at your pic it is the left side that points a little up (or forward?). I think this little anomaly won't have an influence but as you I would wanted also to be straight. Before welding I fitted also a long bar in both pivot points and checked the measurements with the other side and the ones you can find on this plan:


If the measurements are ok as you wrote above the angle of that tube in the chassis rail will be a little bended (in production?), do you find any signs of a collision? 

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Hi Herman, thank you for your response.  There is significant rust in the swan necks and I’m panning to use Eckhards replacement sections to rectify this.  There is no sign of any accident repair, however the car did have a very heavy cast iron Chevrolet 2.8 V6 in it when I purchased it. I was wondering the shear weight of thee engine and the rusted swan necks may have caused some distortion.  The V6 is now on the scrap pile and a CIH engine is currently being built so weight should not be an issue in the future.  I’m pretty sure that I can get better alignment on the pivot bolts when the new swan necks are installed and hope that the bushings will also take up a lit of the difference.

To get the V6 into the car the previous owner hacked the front cross member and had the front of the engine sitting on the steering rack.  This has worn the top of the our housing of the rack flat.  The crossmember can be repaired and strengthened but I’ll probably replace the rack just for my own peace of mind.   3F85121E-BD7F-4CF0-A144-0BB81DEC5347.thumb.jpeg.865c071bb93af4b389f4daacbddff176.jpeg


Thanks again for your reply,   Chris.

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Hi Chris, so the problem of the pivot points will be solved when you fit those Eckhard rails. The metal that is used is a lot thicker, but they are not plug & play. I used them also on my GSI but after some grinding and welding they fit nice. Have a look at my topic "New swan neck".

Grts, Herman

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