Jim_P
Active Member
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- ATHENS GREECE
Hey hey,
I was trying to figure why i had a somewhat rough idle after a freeway run (the temp dropped a bit due to airflow) on my 3.5 V8 with the twin CD175 Stromberg setup. I found my issue and it was the temp compensators. They were out of sync and one closed more than the other when the air temp dropped (as well as the overall temp of the engine).
After a relatively long call with Burlen in the UK i managed to find out that the Temperature Compensators were not all made the same. Their opening temps varied and you could distinguish them by their marking. They have a letter stamped on one of their ''legs''.
Firstly, both of them need to have the same marking in order to achieve the closest opening rate possible between them. Some deviation from their nominal setting is of course something that cannot be avoided.
So what I have found will be listed below and indicates the factory set opening temperature relative to the marking on the compensators ''leg''.
''T'' marking ----> 27 degress Celsius
''N'' marking ----> 30 degrees Celsius
''U'' marking ----> 35 degrees Celsius
The best overall engine performance was made possible by using a set of ''T'' marked compensators.
There is one version that opens up at 20 degrees Celsius and has a ''120K'' marking on it but that was not ever fitted to the Rover V8 Strombergs.
The temperature compensator covers must fully seal against their body and not allow any air in. A bit of play is unavoidable in some instances but a good seal should be the primary focus.
That sort of possible issue checking however should come last in line and steps such as ignition timing check, air flow balancing between the carbs (which can be affected by a mismatched or not in synch temp comp pair), fuel mixture, spark plugs etc. must first be eliminated as possible causes for a rough running / idling motor.
Hope this helps anybody confused on the temperature compensators which usually tend to be screwed totally in (shut off) in order to avoid such issues. However i did notice poorer engine performance with them shut off and the mixture leaned out more.
I was trying to figure why i had a somewhat rough idle after a freeway run (the temp dropped a bit due to airflow) on my 3.5 V8 with the twin CD175 Stromberg setup. I found my issue and it was the temp compensators. They were out of sync and one closed more than the other when the air temp dropped (as well as the overall temp of the engine).
After a relatively long call with Burlen in the UK i managed to find out that the Temperature Compensators were not all made the same. Their opening temps varied and you could distinguish them by their marking. They have a letter stamped on one of their ''legs''.
Firstly, both of them need to have the same marking in order to achieve the closest opening rate possible between them. Some deviation from their nominal setting is of course something that cannot be avoided.
So what I have found will be listed below and indicates the factory set opening temperature relative to the marking on the compensators ''leg''.
''T'' marking ----> 27 degress Celsius
''N'' marking ----> 30 degrees Celsius
''U'' marking ----> 35 degrees Celsius
The best overall engine performance was made possible by using a set of ''T'' marked compensators.
There is one version that opens up at 20 degrees Celsius and has a ''120K'' marking on it but that was not ever fitted to the Rover V8 Strombergs.
The temperature compensator covers must fully seal against their body and not allow any air in. A bit of play is unavoidable in some instances but a good seal should be the primary focus.
That sort of possible issue checking however should come last in line and steps such as ignition timing check, air flow balancing between the carbs (which can be affected by a mismatched or not in synch temp comp pair), fuel mixture, spark plugs etc. must first be eliminated as possible causes for a rough running / idling motor.
Hope this helps anybody confused on the temperature compensators which usually tend to be screwed totally in (shut off) in order to avoid such issues. However i did notice poorer engine performance with them shut off and the mixture leaned out more.
