sparks4540
Freshman Member
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Hey everyone. I'm new here to this site and also to British cars. I bought my first Triumph tr6 2 months ago, price was cheap and I also like the car, and just finished doing a 90% resto on it. The previous owner had it modified somewhat, header, Weber DGV carbs...
I have done nothing but musclecar restoration before and mechanical and engine rebuilding and tuning. I'm having some issues with this one though so bare with me..
To begin, the car has Weber DGV carbs, dual exhaust pipes with the stock muffler and electronic ignition. Recent tune up and plugs yesterday. So here come my two questions.
First off, the car has 170-180psi of cylinder pressure. This is a 72 TR6 and the prior owner told me that the block was rebuilt. On a 350 chevy, 130 psi translates to about 9.75:1 compression. I thought these motors ran about 8:1 or so stock. Does this compression check sound like the pistons may have been changed or is this accurate?? I know that camshaft duration affects compression and I didn't find anything in the shop manual, but then again I really was looking for specs on compression...
Secondly, the car stumbles at about 10% throttle in any gear. When the throttle is cracked open it stumbles and once you get about 1/4 of the way into the gas it goes just fine. I have done a lot of synchronizing with these carbs and adjusting the mixture screws and it has improved tremendously. I have also tried moving the timing up and down just a couple degrees. I should add that spark plug coloration looks good, however cylinders 1 and 6 were richer than the others. This was with the Bosch platinums that came in the car and I just installed Autolite standards yesterday and have not pulled them. Any other suggestions to get rid of this stumble would be appreciated.
Thanks for your help.
Chris
I have done nothing but musclecar restoration before and mechanical and engine rebuilding and tuning. I'm having some issues with this one though so bare with me..
To begin, the car has Weber DGV carbs, dual exhaust pipes with the stock muffler and electronic ignition. Recent tune up and plugs yesterday. So here come my two questions.
First off, the car has 170-180psi of cylinder pressure. This is a 72 TR6 and the prior owner told me that the block was rebuilt. On a 350 chevy, 130 psi translates to about 9.75:1 compression. I thought these motors ran about 8:1 or so stock. Does this compression check sound like the pistons may have been changed or is this accurate?? I know that camshaft duration affects compression and I didn't find anything in the shop manual, but then again I really was looking for specs on compression...
Secondly, the car stumbles at about 10% throttle in any gear. When the throttle is cracked open it stumbles and once you get about 1/4 of the way into the gas it goes just fine. I have done a lot of synchronizing with these carbs and adjusting the mixture screws and it has improved tremendously. I have also tried moving the timing up and down just a couple degrees. I should add that spark plug coloration looks good, however cylinders 1 and 6 were richer than the others. This was with the Bosch platinums that came in the car and I just installed Autolite standards yesterday and have not pulled them. Any other suggestions to get rid of this stumble would be appreciated.
Thanks for your help.
Chris