V8 Saloon - too loud

KV8
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Location: Cambridgeshire

V8 Saloon - too loud

Post by KV8 » Thu Jul 19, 2018 8:35 pm

Hi

My1966 V8 Saloon is great but the interior noise is not what I think it should be.

In 2015 the engine was rebuilt and installed by Russ Carpenter who also installed a new Bell Stainless exhaust for me. The car performs beautifully and revs freely. External observers say it sounds great. But internally the sound level is very tiring.

It is not road noise and it is not wind noise. It comes from the engine/exhaust.

Part of this noise seems to come from the engine air intake suction. This is not exactly standard as the original air intake / cleaner combo did not fit as a PO had converted car to -ve earth and fitted an alternator. It is thus now fitted with the twin air cleaners from the V8 250 which were fitted as standard to this later model as it also had an alternator as standard.

However the intake is only part of the problem. I feel a lot of the problem comes from the forward stages of the exhaust. I have fitted 12mm soundproofing carpet underlay to the front carpets with no perceptible improvement.

I am now thinking of lagging the exhaust from the manifolds back to the silencers and across the link.

At a constant 40 Mph in top it purrs along beautifully but any acceleration with an auto drop to 2nd or maintained higher speed virtually requires ear defenders.

Any comments or suggestions appreciated.

Regards and thanks

H

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captain bobo
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Re: V8 Saloon - too loud

Post by captain bobo » Fri Jul 20, 2018 10:32 pm

The old forum had a coupe of threads about 4 or 5 years ago discussing saloon exhausts. I seem to recall reading that stainless exhausts were "noisier" than regular steel exhausts.

Although the saloons had a reputation for being quiet in their day, modern cars are significantly quieter & so Daimlers seem noisy by comparison.

It would be interesting to get together with our cars & take them out for comparison. I still have your phone number somewhere; I'll get in touch & see if you're interested in comparing exhaust burbles.
Best wishes, Dave B

Sydsmith
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Re: V8 Saloon - too loud

Post by Sydsmith » Sat Jul 21, 2018 2:07 pm

Howard, I have almost the same set up as yours, though mine is a V8 250 manual overdrive. My engine was rebuilt by Russ Carpenter and a new stainless exhaust fitted about 12 years ago, before I bought the car.

I had quite a lot of noise coming in when I bought the car, I found it was coming through holes in the gear lever boot, which I was able to sort. As your car is an auto that cannot be the problem.

As Dave says the stainless exhausts are noisier than mild steel and the exhaust note has a sharp edge to it, but with the gear lever boot sorted it, it is reasonable quite. But again as Dave says, not anything like a modern car, my wife is quitely spoken and she has to raise her voice for conversation on the run. Mainly from road noise rather than engine/exhaust noise.

I have the twin air cleaners and alternator of course and I have never noticed any noise from them.

Just been out for a listen, stationery on tick over 800 rpm you can hardly hear the engine running, both inside and out, at 1500 rpm it has a gentle pleasing V8 roar outside and an increased noise inside, but nothing that disturbs the peace. There is no noticeable air cleaner noise, either inside or out at 1500 rpm. Hope that helps. Syd

tjt77
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Re: V8 Saloon - too loud

Post by tjt77 » Sun Jul 22, 2018 3:37 am

I doubt lagging the exhaust pipes will improve matters much.. many people have fitted the bell stainless system (and other aftermarket makes) and find the noise levels acceptable.. there are many issues that allow noise to be transmitted inside the car and the fact that these cars are very low geared in just one of many issues surrounding noise generation.. you might check to see if there are any loose cables that are in contact with engine,gearbox or body..including the kick down cable, and if so rectify the situation..
With the bonnet open, listening for outside the car, if you compare stationary engine noise at idle, to noise levels at 3,500 rpms there is a HUGE difference.. I dont think there are any 'fast' or inexpensive fixes..a lot of noise and harmonic vibration is transmitted through the engine mounts which are not effective isolators due to design, but upgrading them to something more absorbent would be a time consuming and hence costly exercise ..if you have already added extra sound absorption under the carpet and its not made much difference, do consider that type of sound absorbing materials used is also a huge variable.. some work well...others dont do much..
personally I'd consider raising the gearing via a 3.77 diff (as per manual overdrive Jaguar 3.4/3.8), and using some high tech sound absorption material (such as 'dynamat') on the inside of the bulkhead and footwells.., or if you are not too concerned about appearance, then also use it in the engine compartment on the bulkhead as well.. compared to a modern there really was not much thought put into sound insulation.. also consider than most moderns cruise with engine speeds in the 1,800-2,200 rpms range.. 12-1,500 rpm less than 'our' cars..

KV8
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Location: Cambridgeshire

Re: V8 Saloon - too loud

Post by KV8 » Sun Jul 22, 2018 8:27 pm

Thanks for your suggestions and comments tjt77.

Back in the 1960's I owned a variety of cars including a Wolseley 6/90 2.6 litre straight 6 and more recently I had a 1961 Rover 100 of similar engine size as my then classic car. Whilst noisier than modern cars none of these as I remember was anything like as noisy as my (contemporary) V8.

In respect of modern cars - I think you are in the US. Here in Europe modern cars with small engines are getting buzzy again albeit with excellent sound insulation. My wifes 2013 Astra 1.6 Sri (Was still GM then) registers over 3000 rpm at 70 mph in top. I compare this with the early 90's European Cavalier GSi 2 litre that barely registered 3000 rpm at 100mph on the German autobahns which at the time I frequented often on business.

I am not sure the sound proofing you suggest is available here - could you provide a link to a US site in order that i may see the spec and look for equivalents

Regards

H

KV8
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Re: V8 Saloon - too loud

Post by KV8 » Sun Jul 22, 2018 8:44 pm

captain bobo wrote:
Fri Jul 20, 2018 10:32 pm
It would be interesting to get together with our cars & take them out for comparison. I still have your phone number somewhere; I'll get in touch & see if you're interested in comparing exhaust burbles.
Hi Dave - sorry for delay in reply - yes this would be very useful. I am available most days . Only work I have planned for the Daimler is an oil/filter change which is dependent on my (local) son being available to see me up on ramps in a confined garage space.

Wrt oil change Russ recommended Texaco 15W40. rather than a "Classic formulated" 20W50 that I expected. This will be the second change since the rebuildl and will use Comma mineral 15W40 as I did for the first change.

Regards

H

tjt77
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Re: V8 Saloon - too loud

Post by tjt77 » Wed Jul 25, 2018 2:18 am

answer to KV8 ;-www.dynamat.com ... comes right up when I goggle it... you might try and track down fellow member with a manual /overdrive version, ride in the car and compare noise levels at cruising speed.. I dont have a manual to check, but seem to recall that when in overdrive the gearing is slightly above that of of a straight 3.77 diff..

Chris S
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Re: V8 Saloon - too loud

Post by Chris S » Wed Aug 01, 2018 4:39 pm

Hi H suggest to back to basics.
Check for exhaust leaks around the exhaust manifold and the manifold/exhaust pipe joint. The 8 studs corrode so making it difficult to tighten the nuts correctly. Some of the nuts are very difficult to reach, especially the one under the steering column.
Next check that the heat reflectors are secure and cannot vibrate.
Finally check that the pipes themselves do not touch the body anywhere. Especially check the U bolts as they often touch where it's difficult to see.
Hope this helps.
Chris S

KV8
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Re: V8 Saloon - too loud

Post by KV8 » Wed Aug 01, 2018 9:56 pm

Chris S

Thanks for reply but please read my first post in full.

Engine was rebuilt and re-installed with new exhaust by an acknowledged highly recommended professional in 2015. There are no leaks in the exhaust system! Everything is as it should be and as I would expect.

Regards

H

Christopher Storey
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Re: V8 Saloon - too loud

Post by Christopher Storey » Thu Aug 02, 2018 9:32 am

Well, I've read your first post in full and I cannot see anything in it which negates the advice ( good in my opinion) given by Chris S. The fact that the unacceptable noise starts with kickdown does indeed suggest that it might be related to the engine twisting under torque. The clearance between the downpipes and the frame is very limited, and the slightest touching will cause an intense buzzing noise. Ditto if a heat shield is touching when the unit twists. Also, the hanging of the tailpipes is not exactly straightforward on the Daimler as opposed to the Jaguar, and again, any anomaly here may cause the problem you are experiencing

I take it that your system does have the crossover pipe behind the downpipes. The absence of this can cause unpleasant resonances and a very characteristic V8 beat which the Americans seemed not to mind , but which to European ears is unpleasant .

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