I've been thinking.....always dangerous.....

We currently have one mini. A 998cc mini, completely stock as far as engine/exhaust is concerned.

Now, at some point I would like to put my 1380 back into service. Wifie has driven it, and made the point that it would never go in her car, simply because of noise. She doesn't mind the nature of the motor (pretty grumpy), just the noise.

Now when she drove that it was in my old MKI which was basically a stripped out ex-race car. No sound proofing under bonnet, none in car, one layer of thin carpet. It rattled, it resonated, the gap in the doors whistled.....

SO my question is, how much of a difference does the sound proofing make? Can a grumpy arsed big motor be made tolerable? The unknown for me is, was the difference between the two cars because of the motors, or because of the sound proofing?

The alternative is I get myself another car.....but the space really is a problem.

Soundproofing helps a lot, most of the noise in my car now is induction roar (45 Dellorto).
I had an HS6 on it for a while (when the 1412 stroker was in there) and it was much quieter.
I cut down the ~3000 rpm exhaust drone a lot by sticking a hotdog resonator in front of the muffler (running a 2" system).

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Yeah sound deadening does make a big difference, My warm 1100 in a sound deadened mini is very tolerable but my mates hot 1275 in a mini with no sond deadening is just horrible, even closing the doors on it makes a clang

And a big baffled muffler is always helpful.

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Dean Hutton's first car was a Mini.

Sound deadening is definitely worth it - it quietened the induction roar from my dellorto a fair bit.

Best solution would be a twin box RC40 and an HIF44 with a stock airbox on it. That would be positively luxurious!!

Hmm....the set-up was twin box RC40, HIF44 with cone filter. SO I'm thinking the killer is the lack of any kind of deadening.

If it were me, I'd change the cone filter to stock air filter. It doesn't flow as badly as you may think, and can be improved by drilling some extra holes (or even fitting a later Metro air filter)

Getting busy with the sound deadener will definitely help though. I used some spare carpet underlay on my firewall, with vinyl trim glued to it. You would also consider using some bitumen sound deadener, especially around the centre-speedo hole in the firewall if yours is an early car.

Carpet underlay in the car works well too.

Keith Calver did a test on stock air cleaner box vs a K&N cone, K&N loses, here's the article-
http://www.minimania.com/web/SCatagory/ ... ticleV.cfm

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Ya I did a lot of reading on the stocker filter holders when I was running a modified 850. Did all the hole drilling etc to that one.

Oddly, stocker filter boxes for 1 3/4" carbs are like hens teeth here. Nobody seem to run them, which means they must be SOMEwhere. Unfortunately I suspect they're at the tip.

If I get to put the 1380 in this car, it will definitely be a bit of a stealth beast. I like the idea of the stock filter from that perspective

The HS4 air box fits a HIF44 fine. It's not as good as the later ones, but it works fine.

I did a project a couple years back where I jammed a Supercharged VIVIO Subaru into a Fiori. (Why?) because we could!
(It goes like a sewing-machine on steroids!)
Anyhow, as it was an east/west, I remember it has the flexible exhaust. I thought it was to stop cracking under load (as the motor torques back and forth).

I was told that this joint also dispurses the rigidity which causes vibrations (noise).

I was interested if anyone has used a flexi joint on their Mini and if the vibrations (noise) was quietened?

Alex.

I have used the Dynomat all over the car, and then added 3 layer sound proofing... Its very quiet....

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I'll be using Dynamat when I rebuild my car. I've used it in my Alfa and it's great stuff.

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1967 Cooper S - new front bearings to do.
1965 Cooper S shell - Slow progress. No time or money!
1966 Deluxe- next rustoration!
Mk 2 & XJ6 Jags. Less said the better.

My mate bought a Minivan that had a flex joint added to the main pipe, behind the LCB.
Did it work?
It might have, except that:
1. Both the steady bar bolts in the block were sheared off.
2. It had Morris 1100 clutch side engine mounts (more flexible) on both sides.
3. It had a top steady (!) made of a bit of 1" x 3/16" flat bar, bolted from the firewall onto the front exhust manifold stud. Noooooo rubbers here.
4. It was a rodchange box so no remote shifter mount for stability.

It's worth doing IMO but only if you have either a remote box, or extra steadies (underneath where they belong).
On Oz cars with both magic wand and rodchange boxes, the stock rigid exhaust pipe is a crude torque arm to resist engine torque.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Drmini.

See your point. There would still be that top "Hammering" against the firewall. The Subaru's only had a small rod (certre) at top, and decent engine mounts to the side rails.

I'm thinking some good insulation and a trim across the speedo hole may be the best option. That Duramat sounds (pun) good for the underside of my roof.

Cheers and nite all.
Alex.