Getting back on the road

Progress update. So, all the dirty stuff is done, with the exception of cavity wax. Today was fitting the damping membrane and closed cell foam heat and sound insulation. My back aches from the weird angles I had to use to get it all in place. But the good news is that she's ready to accept carpets and interior at long last! I have a little time tomorrow morning and this weekend to re-install the interior. After that and the wax I can enjoy her again. Looking forward to it!

Int1.jpg
Damping membrane reduces vibration in the panels, its a sort of high mass rubber with a heavy aluminium foil face. Pretty easy to install.
Int2.jpg
Sorry about the poor quality, light had gone and I was ready for celebratory pint after this. So the foil covered closed cell insulation is in place. Its about 12mm thick (1/2" in old money). Little harder to fit and the instructions say you shouldn't have gaps. I sealed seams with heavy foil tape as per instructions. It looks like the interior of the Apollo capsule now!
 
Carpet set from Josh Ingram at Tech Auto. He’s been very good at tech support and the carpet feels very nice. Fit seems pretty good.
7C24EDBC-6BAD-49EF-900D-C03A83D2A0E9.jpeg
 
As someone who has done plenty of such work in the past, you really don't need as much vibration damper. What you need is 30-50% coverage on large, flat panels only and concentrate on certain key areas. Where panels are formed with creases or are small and can't resonate, it has no effect and only adds weight - so I would not for example apply it to the iner sills. It's isn't an effective sound barrier used as a continuous cover. In fact the P6 has fairly thick gauge panels, where this stuff really works is on thin door skins on something like a Honda. Closed cell foam, like the original jute stuff doesn't do much as it isn't dense enough to block sound, what it is useful for is as a decoupling layer under a barrier layer which is usually mass loaded vinyl. I've used stuff called TecSound 50 (which is a building material) in the past on top of 1/4" closed cell foam (aka cheap exercise mats).

Certainly, it's worth replacing the bitumen based damper Rover used because it dries out and no longer sticks to the panel with a modern, butyl product. After that, you really need to understand where noise actually comes from. On a P6 road noise overwhelmingly comes from the firewall where the suspension acts backwards against it. It's here you should start and also the transmission tunnel.

Good to see you've taped-up the gaping holes in the trans tunnel - the P6 cabin leaks a lot of air (and sound) through here and also in various places on the firewall and this is an easy win. Also goodness knows what noxious gases get in the car as well!

Unfortunately, after this the main source is wind noise as a function of aerodynamics (or lack thereof). If you want to reduce noise in any meaningful sense, then you need to look at improving the door/window seals - if these are old and flat, your best bet would be to replace them. I know it's a neat thing the close a P6 door with one finger with a neat click, but what you really want is a spongy door seal pushing back against you - it's doing its job. The worst offender of all is the deep step on the windscreen rubber, which would require a bit of reengineering to fix!
 
Last edited:
I agree about the damper material. I did notice the original stuff on the trans tunnel pretty much covers the whole tunnel, hence going down the same route. I did have a fair amount of damper to work with so just went further than I needed. I did run the car with just the damper fitted and it did reduce noise some, vibration by a lot.

I used a lot on the bulkhead area, the inner sills and floor as I noticed I could feel a lot of vibration through them in the past. The last picture is all closed cell foam, I also applied the foam to the bulkhead and sealed any last gaps. With the carpets fitted and the drivers seat in place the car is noticeably quieter than before. In fact if you turn the fan on full you can’t heat the engine at idle now. With the engine off the clock seems almost too loud.
 
Those replacement carpets look very origional with the same looking finish, how much did they cost for the set and what colour did they supply?
 
Those replacement carpets look very origional with the same looking finish, how much did they cost for the set and what colour did they supply?
I used tech auto for the carpets
Carpet Set Tufted Deep Pile Made to order. Rover P6 2000TC

The top line one costs £203 (I went for this option) their mid range product runs at £175.

Ordered them in champagne beige with the same colour for the edging. The deep pile carpet feels a little coarser than the original, but I think that’s down to the fact it’s not worn. Josh Ingram runs Tech Autos and was great to deal with. He sent small samples for selection purposes, when I had questions about fitting I was able to chat with him on Facebook in real time. I would certainly recommend him.

I used noico sound deadening 80 mil for the damper membrane and excell 10mm for the closed cell foam which were pretty easy to apply and seem to work well. They’re also a little cheaper than the bigger brand names over here such as dynamat. The total for the sound proofing material was around $210 plus about $60 for paint for the floor, aluminium foil tape to seal the foam edges and spray contact adhesive to stick the carpet in place on the sills, rear seat cross member and foot well wheel well areas. I try not to add together how much I spend on the car (plausible deniability reasons :) ) but not counting the rust repair I’d say the total was around $645 (£500 in real money). See why I avoid this?!?
 
I would definitely do a decoupled barrier layer on the firewall and forward trans tunnel. The boot also resonates a lot where the exhaust is. Some damping mat on that side helps. Rover clearly had problems with noise from the rear as there is a lot of material under the seats which is unusual.
 
I would definitely do a decoupled barrier layer on the firewall and forward trans tunnel. The boot also resonates a lot where the exhaust is. Some damping mat on that side helps. Rover clearly had problems with noise from the rear as there is a lot of material under the seats which is unusual.
The boot needs some work still, that’ll be my next welding marathon, but yes, the remaining damping material will be in the boot.

As for resonance, I do remember an article about the P6 development where an engineer said they were surprised how much noise was transmitted in the base unit construction. I like the idea of the decoupled later on the bulkhead. I’ll see how she sounds after the first run. So far she sounds much quieter than before, it’ll be interesting to see how it goes.
 
Back from my first test drive. Peter, you’re right. Over 45 the loudest noise now is the wind on the windscreen seal. A lot less road noise, engine noise is nicely subdued along with less vibration felt through the floor pan. I had the radio is on and at one traffic light I thought the engine had stalled! Clutch feels odd now. I think the spring in the master cylinder is failing as the pedal feel loose for the first 20% or so of travel. I replaced the seals recently, but unfortunately the master cylinder rebuild kit didn’t have a new spring. Hey ho....

So, verdict, worth the work. The body feels more solid too. The scary thing is that the rust at the sill front corner had obviously affected rigidity on the suspension. If I hit a bump mid turn before I could feel bouncing through the steering wheel. Now it’s serene. The gear shift feels like a switch now too, a little heft to the throw, but much more precise. Last added bonus: I have reversing lights that work for the first time since I’ve owned Beryl.
 
Great result.

There's no more frustrating an exercise than quieting a car. Two things tend to happen, firstly dealing with one noise will often just make another more noticeable. Secondly, the human ear has a massive range of "gain", so what happens is your ear and brain just "turn up the volume". If you've ever been in an anechoic chamber not only do you eventually hear your own heartbeat but you can hear your own blood in your veins. It's not a pleasant experience.

So basically what's most effective is pinpointing the sources of noise that trouble you most and dealing specifically with those and then think about general noise reduction. It's generally much easier to deal with higher frequency noise than lower frequencies. This means top-end engine noise (ticking) can be blocked quite well but low frequency booming from the road is almost impossible to deal with fully because you can't create a heavy enough mass barrier to stop it. The only way I know to get an appreciable reduction is use softer compound tyres and then change them well before the tread is worn - BTW if you don't have good tyres, almost everything else is a waste of time. Rover engineers were seemingly well-aware of how the unique suspension transfers noise into the cabin which is why it didn't feature in any future planned models, even the P7 prototypes. In theory of course, softer compounds in the suspension mounting will help but this is the opposite to maintaining good driving feel. Certainly I'd change any suspect rubber in the front suspension. An odd one which often helps and is really cheap and easy are the damper rubbers. Not only in themselves but secure location making the dampers work properly.

Another thing you might not have thought of is trim materials. Hard plastics like the centre console resonate also because although they aren't as stiff as metal, they are low in mass ans need less energy to move. Where plastic, vinyl or rubber meet often silicone spray will prevent friction and noises from rubbing or rattling. Quite a lot of trim is constructed by folding material over but not really joining it properly and this can cause issues - again taping or gluing the storage areas in the centre console from the rear and lining it with soft materials (I cut up ikea blankets) helps. You won't lose coins or parking tickets this way either.

There was a while back really good guides on a site called sounddeadenershowdown.com but sadly these seem to have gone and it is now more focused on selling.
 
Ahhh, so sometimes there are benefits to getting older, going deaf has got me out of having to sort these kinds of problems.....

I agree Harvey,
on a longer journey, I even remove mine and drive in more quietness, my car is so noisy that I cannot have a conversation with a passenger, so I wind down the window if its not too hot or raining and enjoy the fresh air and noise of the car.
After all , the majority of old cars were noisy anyway, well that's my story.....:rolleyes:
Peter
 
Peter, very interesting what you’re saying about the P7 front suspension. I had no idea, but it makes sense.

Road noise seems very well controlled. The gearbox already had a whine, but as you say, it’s there a little more. I thought I’d made a mistake until I tuned on the radio, and then immediately turned it down as it’s now way too loud! I can hear the indicators waiting at junctions for the first time. It’s much smoother and more than once I felt like it had stalled rolling up to a Junction.

One interesting thing is that if I sit in the car with the engine off the clock sounds very loud! Outside noise is that well controlled.
 
Steven, from your description i was reminded of this video:



I wish ads were this creative now. It’s not bad inside now, I’ll have to try at motorway speeds next! There’s some tappet noise, but rebuilding a spare cylinder head is the next expensive job. The cam bearing shells and journals are a little scored. Valve guides on one cylinder a little loose. Once that’s done it’ll be interesting to see what she’s like. Although, if I can find a genuine 2209TC head in good condition that would be grand. It would compliment the bored out block and HIF6 carbs perfectly with the bigger valves. No big hurry as she drives very well as is.
 
Last edited:
Took Beryl out today. Lost indicators, gauges and reversing lights. Checked fuses, all looked fine. Got out the multitester and found a fuse where it was fine but the solder joint to the end cap was dry. Must have been like it since new. Replaced and all is good. Never seen a failure like that before
 
Also wanted to post an update after all the work I did on the body and interior recently. Here’s a quick video of her starting with a few little revs. She sounds pretty good now, muted but still hearing the good noises.
 
Last edited:
Back
Top