Hi all These are my existing hardboard sound deadening retainers in my engine bay! As you can see they have been sprayed but when handled have started to break up and are very brittle! The actual sound deadening material appears to be in great nick! My question is are they what I think ie sound proofing, if so do I need to put them back in or can I just stick modern day sound deadening up onto the roof of the engine bay! If I can't and need to use the original design where can I source new hard board retainers please Thanks in anticipation
Is there any reason why I can't just stick modern sound proofing up instead? Especially if I stick some in engine bay and on floor of inside of van?
my originals are long gone, the previous owner has fastened some sort of foil covered lagging to the roof of the engine bay.
I've started to put modern insulation in. Just bought some mdf to make up new boards from a template that is available on the forum. If you cannot find it, pm me and I'll send the file to you
Strictly speaking, it's impossible to soundproof your engine bay...you can keep it down to a dull roar by observing the following principles: you need to add mass and reduce transmission There's insufficient mass in the metal panels surrounding the engine to provide any meaningful sound retention, and the engine sits directly behind a large resonating chamber (fuel tank enclosure), in which sits another resonating chamber (the fuel tank). Both will need treatment to reduce resonance and transmission. If you're serious about reducing noise you'll have to pull the engine and remove the firewall. Dynamat the tank (approx. 30 % of it's surface area) mount the tank on rubber plinths and put high density foam between the tank and the tank straps. Dynamat the rear and floor of the enclosure plus the inside face of the firewall. Wrap some rockwool batten in plastic bags (with duct tape) and place around the sides and back of the enclosure and a piece to drape over the top of the tank. You could use bin bags full of Polyfill (similar to soft toy stuffing) to fool the enclosure that there's more air space than there actually is...this will reduce flutter and higher frequencies..(common dodge so speaker cabinets and woofer boxes can be made smaller). Replace firewall. Next, turn your attention to the soundproofing (!) above the engine. Remove the perforated panels and junk the original proofing. Buy some Code 4 lead from a builders merchants, and a few square metres of 10mm LD foam or Camping mat. Cut to size of original proofing and make a lead sandwich (foam lead foam, using trim spray glue). Reattach with long pop rivets with rubber washer between rivet head and perforated panel or suspend with wire. Working from inside the van....remove rear seat, dynamat both wheel arches and all the areas around the cargo bay...use a roller to get rid of air bubbles. 25mm LD foam or Rockwool batt (cut to fit and bagged up as before) to cover the same area. 9mm Plywood over this (doesn't need screwing down if you make it to fit properly. Automotive or Acoustic carpet over this. Fit a quiet exhaust...set your tappets...it's a big job to properly reduce noise in a bus as there's so much transmission/vibration and resonant panels to consider....and that's before you think about wind noise....soft furnishings and curtains will go some way to reduce resonance, but without concreting the floor, doors, changing the engine mounts, plugging transmission lines and air holes, it's never going to be Rolls Royce Phantom quiet... I didn't mention expanding spray foam as I can't imagine folk would want to use this on their precious, but this could be used to good effect on panels and box sections... and finally...Dynamat isn't the same stuff as B & Q bitumen flashing tape...it does exactly the same job though...only better...at five times the price....
