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Great road trip into Germany so far - the ferry from Dover was smooth, visited friends in Maastricht, went to a wedding in Bonn, hung out in Cologne, and now I'm a Hamburger. All good.
But as you can imagine, these long runs have a way of shaking out mechanical bugs - and I'm faced with the decision for each to try to A) make some sort of on-the-road improv repair B) Ignore it and drive on or C) say "oh dear" and get towed home.
Anyway, perhaps you might have some suggestions for the following niggles...
Rear-end rumble. The Herald rear end has always had a bit of a harmonic noise at about 70mph, but I dare say it's seems to have become a bit worse, and the speed range it acts at has widened to about 50mph to about 90mph. At about 55 in top gear, it almost sounds like a slow rhythmic pounding - perhaps in time with the wheels? But it seems a bit slower than the wheels. Further, it changes pitch upwards if I switch to 4th gear at a similar speed. Calms down quite a bit over 90 and up. (Autobahns, remember...) But anyway, the sound is _only_ when I'm applying power. if the driveline is coasting, it's silent. But the tiniest feather of throttle brings it back? Ideas? I've decided to drive on it, but should it be towtruck time?? Anything I should look at?
Also, just before I left I went ahead and re-shimmed the valves on the Fiat twin cam according to Guy Croft's suggested clearances - 0.3mm intake and 0.4 exhaust. The engine was running way to wide clearances before, as I re-used the old shims when I rebuilt the engine last year with new (apparently a bit thicker) cam box gaskets. Anyway, the engine is nice and quiet valve-wise now, but the idle has suffered! I really liked my nice even idle from before. Also, the powerband has really moved upstairs, so there's not much torque below about 2k. Great top-end performance, mind. I understand that this is what's to be expected when running valves a bit tighter, but have others found this? I'd love to bring the valves back a bit, but alas it's not possible on the road. Suggestions?
Other than that, having a great time. Cheers for any ideas, esp re the rear end. Thanks, Ty
But as you can imagine, these long runs have a way of shaking out mechanical bugs - and I'm faced with the decision for each to try to A) make some sort of on-the-road improv repair B) Ignore it and drive on or C) say "oh dear" and get towed home.
Anyway, perhaps you might have some suggestions for the following niggles...
Rear-end rumble. The Herald rear end has always had a bit of a harmonic noise at about 70mph, but I dare say it's seems to have become a bit worse, and the speed range it acts at has widened to about 50mph to about 90mph. At about 55 in top gear, it almost sounds like a slow rhythmic pounding - perhaps in time with the wheels? But it seems a bit slower than the wheels. Further, it changes pitch upwards if I switch to 4th gear at a similar speed. Calms down quite a bit over 90 and up. (Autobahns, remember...) But anyway, the sound is _only_ when I'm applying power. if the driveline is coasting, it's silent. But the tiniest feather of throttle brings it back? Ideas? I've decided to drive on it, but should it be towtruck time?? Anything I should look at?
Also, just before I left I went ahead and re-shimmed the valves on the Fiat twin cam according to Guy Croft's suggested clearances - 0.3mm intake and 0.4 exhaust. The engine was running way to wide clearances before, as I re-used the old shims when I rebuilt the engine last year with new (apparently a bit thicker) cam box gaskets. Anyway, the engine is nice and quiet valve-wise now, but the idle has suffered! I really liked my nice even idle from before. Also, the powerband has really moved upstairs, so there's not much torque below about 2k. Great top-end performance, mind. I understand that this is what's to be expected when running valves a bit tighter, but have others found this? I'd love to bring the valves back a bit, but alas it's not possible on the road. Suggestions?
Other than that, having a great time. Cheers for any ideas, esp re the rear end. Thanks, Ty
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