Paul Slice
Jedi Hopeful
Offline
I asked this on another forum but am interested in another opinion.
I just purchased a 71 TR6 that I knew had been converted to SUs with a 73 twin exhaust manifold and 2 pipe system. When I drove it the 100 miles home it ran poorly and surged so bad at highway speed that I had to feather it all the way home. It had been restored around 13 years ago and I had planned to do a complete tune up as well as brakes, clutch system and full suspension rebuild to make it right. Also when I met the owner I knew that he had driven it very little during the 13 years he had it and when it started to run rough it was time to get rid of it as he did not have a clue, if you know what I mean..
So, the natural thing to do was to order lots of parts and the tuneup was the first thing on the agenda. After the Autolite plugs were trash canned for NGKs on went new wires, cap and roter as well as a Pertronix Ignitor to get rid of the points. She ran better and with the timing advanced pulled strong but still surges slightly when you level off at speed (say 70 on the interstate). The SUs have pancake filters on them and I wanted to see if the standard Stromburg airbox would fit on the SUs. When I removed the filters and held the rear airbox plate against the carbs I realized that these HDs were 2 inch carbs not 1 3/4.
Here is my question, should I go back to the Stroms or even get some SU HS6 carbs?
Are 2 inch carbs to big for a TR motor that is stock?
And could this be causing the surging?
I have syncronized the HDs but have not touched the mixture screws and it idles ok at 950 RPM.
here are some pictures of the 71 6 after polishing and waxing
All input welcome,
Paul
I just purchased a 71 TR6 that I knew had been converted to SUs with a 73 twin exhaust manifold and 2 pipe system. When I drove it the 100 miles home it ran poorly and surged so bad at highway speed that I had to feather it all the way home. It had been restored around 13 years ago and I had planned to do a complete tune up as well as brakes, clutch system and full suspension rebuild to make it right. Also when I met the owner I knew that he had driven it very little during the 13 years he had it and when it started to run rough it was time to get rid of it as he did not have a clue, if you know what I mean..
So, the natural thing to do was to order lots of parts and the tuneup was the first thing on the agenda. After the Autolite plugs were trash canned for NGKs on went new wires, cap and roter as well as a Pertronix Ignitor to get rid of the points. She ran better and with the timing advanced pulled strong but still surges slightly when you level off at speed (say 70 on the interstate). The SUs have pancake filters on them and I wanted to see if the standard Stromburg airbox would fit on the SUs. When I removed the filters and held the rear airbox plate against the carbs I realized that these HDs were 2 inch carbs not 1 3/4.
Here is my question, should I go back to the Stroms or even get some SU HS6 carbs?
Are 2 inch carbs to big for a TR motor that is stock?
And could this be causing the surging?
I have syncronized the HDs but have not touched the mixture screws and it idles ok at 950 RPM.
here are some pictures of the 71 6 after polishing and waxing
All input welcome,
Paul