408 original air cleaner dimensions, please?
 

My car's non-original Chrysler 360 is currently fitted with an Edelbrock performance air cleaner.

Under acceleration, it is quite noisy. I want to forego this one's excellent throughput for something quieter but have been struggling to find something suitable that fits. Can anybody give me the diameter and height of the original factory fitted air cleaner, please? Does anybody know if it was a standard Chrysler item of that era fitted to some of their models? Thanks.

David

David No One Seems Willing To Help Possibly Because You Have A Non Original Motor That May Be Different To The Original. I Will Pass On My Experience With My 411 And 412. The 411 Came With A Standard Air Cleaner With The Standard Cast Iron Manifold Which Holds A Lot Of Heat. I Decided To Replace The Manifold With A Second Hand Alloy Holley Manifold. Great Until I Fitted The Original Air Cleaner And Discovered The Bonnet Would Not Close. I Note You Motor Appears To Have An Alloy Manifold.the Standard 408 Air Cleaner Is Quite Large Which Could Causes The Front Of The Air Cleaner To Hit The Bonnet So You Need To Check Closely Your Measurements.

In The Short Term I Found A Standard Round Air Cleaner With A Lowered Base Plate Which Gave Me The Clearance I Needed. Later On I Had The Top Of The Manifold Machined Down About 1/2 An Inch And I Can Now Just Close The Bonnet .

The Original Air Cleaner Certainly Reduced The Intake Noise Quite A Bit. All This May Not Apply To A 408.

Sorry about the capital letters . I typed it all in capitals and the software changed it to upper and lower

Morning - I must admit I was only holding back as I'm unable to answer your specific question. As I may have told you I've got a 410 with a 318 in it. It's got an Edelbrock carb on it and a big circular aftermarket pancake filter. With that set up I only get any induction noise on kickdown and personally I don't find it unpleasant. When pottering/cruising it's quiet. This is helped massively by the other big improvement from when I redid the heater matrix and fan motor last year. Encouraged by Roger on here I paid a lot of attention to re foaming/re sealing all the various joints and gaps and so on between the engine compartment and the interior. I found it a painful process but it has transformed the driving experience - most noise (and occasional smells) now stay outside where they belong.
Andrew

Thanks, Andrew. It looks like that's the kind of air cleaner I will end up fitting subject to finding one that will sit low enough. Good pointer on the heater seals for future reference too!

David

Peter, thank you so much. I have been mocking up a few sizes of aftermarket air cleaners (the pancake type with opening all round) and used snorkel types from Chrysler cars of the 70s (my engine dates to 1978). This showed anything that sits 3" high on top of the carb and has a diameter of more the about 10" will hit the bonnet! I couldn't work out how the original air cleaner could possibly have fitted!!! I had started wondering if the 360 engine was taller or had been fitted on mounts that were higher because something was clearly different from the factory set up. Your explanation of the intake manifold being higher provides the answer and, looking at the drawings in the spares manual, I can now see the difference. Thank you!

The aftermarket pancake types can be had with a lowered base plate. I also see some can be had where the carburetor opening is offset - thus allowing the air cleaner to sit a bit further back over the engine although I think the combination of lowered and offset may result in the air cleaner base sitting on the distributor ! It's a pity I can't buy a few and test fit them!

Anyway, some more mockups and measurement will need to be done but it looks like it will have to be an aftermarket pancake type that I fit. Hopefully it will help to reduce the noise a bit.

David

David

I love originality and went to a lot of trouble to get my original air cleaner to fit. Could i suggest you try and borrow an original unit and see if there is any way you might get it to fit ( eg machine the top of the inlet manifold or cut out part of the base of the filter canister and raise it which will lower the unit overall ).
As I said I know little about the earier V8 cars but a quick look at photos on Google indicates the 408 had a smaller but higher unit than the 410.
By chance how thick is the gasket/ block between the carbie and the inlet manifold. I found a very thin but effective one made by Holley which did the job.

Peter, thanks but I doubt I can find an original air cleaner to try that. I am in Florida and Bristols are a bit thin on the ground here!

I do take your point that there may be ways to make something original looking fit the car and I may resort to some. However, the engine is not original anyway (it's a 360 from a 1978 Dodge Monaco) and, I have discovered today, it has a 'hotter' performance camshaft fitted. So I am not sure now how much I should interfere with the breathing in trying to make it look original. My main objection to the current air cleaner is noise when opening the throttle.

I'll keep working on it.

David

I dont actually know but I am sure the unit would be off a chrysler car of that era. Your engine bay and motor looks very tidy and well presented but the air filter is just not BRISTOL.

These are 2 I found on Google Search. Could be MK 1 and MK 2 .Some forum member could surely post a picture of their car or have some knowledge.

The demand for original air cleaners and manifolds in the US is very strong as people would pull them off their cars and throw them out. Crazy prices are being paid for Big Block parts.

For want of something better to do was just looking at Dodge Monaco engine bays and the original air filter box on those looks more subdued/period than your current hi-flow arrangement and would certainly be quiet. I suspect it might need some modification to fit but I'd probably start from there if it was me.
Impressed with neatness and cleanliness of engine bay! I also have one of those bling alternators - also inherited!
If you're already way ahead of me on the air filter box, apologies.

I know! It just looks wrong in there, doesn't it?

I took a few more pics. It looks like there is some sort of mounting plate below the carburetor. If I can remove it, it may give me an extra 3/8" headroom.

I am unfamiliar with US V8 engines but the carburetor itself seems HUGE. It's this one: https://www.summitracing.com/parts/sum-m08600vs

As you can see from the side view taken from outside the engine compartment, the existing air cleaner barely fits. I'm really constrained by the height of the big carburetor sat on top of the high intake manifold.

David

I'd be very happy with either of those if I could fit one.

David

Thanks, Andrew. I will find some way to fit something more appropriate as an air cleaner.

I wish I could claim credit for the engine bay but it's the work of the previous owner. I will be challenged to keep it looking that good!

David

My guess is that the carbys that fit any mopar LA series or B/RB V8 will have the same top diameter (where the air cleaners sits). The Edelbrock on my 411 (B block 400) has a top outer diameter in just under 127.5 mm, so 5 inches. The flange on which the gasket sits, then the air cleaner, is about 5mm wide. The original Mopar air cleaners probably varied depending on the body type.

The air cleaner on my Bristol 411 is 90mm high, although the bottom is recessed, so the effective height off the top of the carby is 81mm. It looks lower in height than the original one fitted to the 408, but it is also wider, so that might be an illusion.

Mine also is also a dual snorkel version like this, whereas I believe the standard 360 air cleaner and the original one on the 408 are single snorkel, but from photos on the web it's clear that you could get a dual snorkel air cleaner for the 360.

As it happens, while I was taking measurements I noticed that the air filter on my car is about 4mm too high for the housing (another bodge by the guy who rebuilt my engine). Although, because the filter seals against the lid, too high is better than too low, so long as the bonnet still closes!

David, the crucial measurement for you is the height of the threaded post that goes up through the middle of the air cleaner. That determines the maximum height of the air cleaner, less the nut that secures the air cleaner, although the air cleaner lid is typically recessed in the middle. On mine, the post protrudes about 3mm higher that the highest point of the air cleaner (even with my 4mm oversized air filter). It is difficult to measure the distance between the top of the post and the flange on the top of the carby, but I'm sure its possible with a bit of mucking around. That will give you a very good idea of what you have to play with in terms of air cleaner height.

Bear in mind, that post can easily be cut shorter, so it might not be as high as it could be on your car. It could have been cut down to suit the current air cleaner. It would be interesting to know the clearance between the top of the post and the bonnet. Of course it's very hard to see, unless you could position a camera in the engine bay to give you a visual while the bonnet is closed. Alternatively perhaps you could tape a small slab of plasticine to the underside of the bonnet to see if you get an imprint from the post.

Kevin

Thanks. The carb has what seems to be considered 'standard' throat size for a 4 barrel carb here - 5 1/8" or, I calculate, 130mm (Sidenote - I am Brit born of an age when we learned 'imperial' units of measurements, then went Canada and became modernized to the metric system but now I am in the US most of the year and EVERYTHING is back to 'imperial' (except they call it 'US' and have smaller pints and gallons))

The threaded post for the current air cleaner is VERY short as its retaining nut sits within the air cleaner at the bottom!! I like the idea of using plasticine to establish what clearance I have. However, my challenge is not over the centre of the air cleaner or to its rear or sides. If you look at the 3rd pic I posted above, you'll see the front of the current air cleaner will almost touch the bonnet when it's closed. That front edge is about 4.5" / 115mm forward of the center of the threaded post holding down the air cleaner. So a round air cleaner of the same overall height (3" / 76mm) could be a maximum of 9" / 230mm diameter before hitting the bonnet. Anything of larger diameter needs to be lower. Yes, there are air cleaners with recesses so they sit lower on the carb but so far, I haven't found one that will sit low enough to avoid hitting the bonnet and/or not interfere with the throttle linkage and/or electric choke.

I'd love to fit a round air cleaner with one or two snorkels but I am beginning to doubt that will be possible. I'll keep working on it.....................

David

David,
I've just looked at some of the photos you posted and your air cleaner sits up quite high above the flange on top of the carby, whereas some original style air cleaners start below the flange because the bottom of the air cleaner is recessed.

Hopefully the attached picture of mine will give you an idea of what I mean.

I believe there is a good chance a standard Mopar air cleaner for the A (LA) series 360 engine will fit under your bonnet, or should I say hood!

If you buy a secondhand one on eBay, if it doesn't fit you can always sell it again on ebay :)

Kevin

David,
This one looks like it sits quite snug https://www.forbbodiesonly.com/mopar...01-jpg.532225/ .

For what it's worth, the height of your carby is the same as mine - 3.250 in.

Also bear in mind that the bonnet is higher in the middle than it is at the sides where it meets with wings.

If you are prepared to take the plunge and buy a secondhand one on eBay, at least you are the in the right country :). If you do find one that fits, you can probably get a replacement post for the centre of the carby. It looks like you could buy a period single snorkle air cleaner for around $100.

Kevin

Here's a mockup I made of a 17" dual snorkel 3" high that I considered buying.

It might work if I can lower it but probably more likely to fit if I use a 14" dual snorkel. There are separate lowered 14" bases available. Maybe I could cut the base out of a factory dual snorkel one and rivet/solder one of the lowered ones in its place. I'll play with mocking that up today.

David

Interesting found on Austrslian Ebay

https://www.ebay.com.au/itm/Mopar-do...8AAOSwfD5dTqA7

Yes but a bit pricey compared to some local (eBay) stuff.

David

What diameter is your air cleaner, Kevin and also, how high is your intake manifold? Mine is about 3 3/4" / ~95mm.

David

David

The summit carbie you have does seem very tall and Kevin is right the air cleaner sits very high . My 411 Mk2 (high compression motor ) had a 750 holley on it and performed very poorly and used a lot of fuel. A friend of my brother Geoff who would likely be Australia's authority on all things Mopar strongly recommended going back to an original Carter (Edelbrock) 650 cfm carbie. I took his advice and it transformed the general running of the motor ( very pleased). Since then Edelbrock have released a new series the AVS2.They come in avariety of sizes and finishes, I plan to fit a 1906 to my 412 shortly.
You motor is smaller than mine but is warmed over therefore a 650 cfm like my new one would be ideal . Check the website for dimensions ( the video is worth a watch). One danger if you change carbies make sure you set the auto transmission kick down correctly or you will burn out thr transmission.

Your correct, the point of first contact with the air cleaner is at the front because the bonnet slopes down.

Thanks, Peter. Whilst the Edelbrock 1906 may well improve the drivability, it seems it is 3.25" high same as the Summit one currently fitted. I am going to focus for now on getting a quieter, more stock looking air cleaner on there somehow but will bear the carb change in mind for future.

My US born and bred neighbour who likes loud cars and motorcycles suggested I cut the 'hood and fit a shaker intake'. Heaven forbid!

David

What a great idea you would be the first Bristol owner to do so. Could I suggest a supercharger and 20 inch wide rear wheels.

Interesting the Edelbrock is the same hight , the summit in the photos looks much higher.

Shall leave you in peace

Best of luck

I hate to say it David - but same thought occurred to me about the shaker hood scoop! I did dismiss it though! Hope the air filter box solution works other wise I guess you have to start looking at low rise manifolds shallower carbs and so on. Bet the car goes well with the 360 and hotter cam though.

Peter, just as an aside: how do I check/set this anyway, please?

David

:eek: What a horrible thought!

I have ordered a 14" pancake air cleaner (the filter is exposed around the whole circumference) with a recessed bas to lower its overall height. I'll see how that does for fit and a first step towards quietening. I'll report back when fitted.

David

Indeed it does. Just a bit too noisily for my taste, Andrew.

David

Re setting the kick down lever I have no understanding of how to, I paid the guys who rebuilt my auto to do it. There is some infomation on the Web but I dont fully understand it. Just be warned

Hi David,
Sorry about the late reply. My air cleaner is 17" diameter (underside it's a little wider at the top). The hole for the carby is 5".

My carb is an Edelbrock (1812) 800 CFM AVS Thunder (manual choke, which is not used).

However, my engine is a B block, so possibly a little wider in the valley than the small block 360.

As stated previously, the air cleaner is 90mm high, although the bottom is recessed, so the effective height off the top of the carb is 81mm. So 81mm higher than the flange around the top of the carb.

Unfortunately I can't say how the bonnet of the 411 compares with the 408.

Kevin

Thanks, Kevin. It helps me zero in on what might fit although lots of mocking up and test fitting seems to be in my future. I'll keep this thread posted as ( or if ) I make progress.

David

I have fitted the 14" round air cleaner. It has a deep (~1") recess in the underside. I put 3/8" thick expanded polystyrene blocks on the forward edge and the top nut to see if closing the bonnet left any indentations. I didn't see any, so I tried to film the inside of the bonnet when closed to see how much clearance there was. The video is here: https://youtu.be/oX2-ctVTgs4 The film of the front edge is quite clear but the film trying to see the top nut didn't work as I couldn't get enough light on the place. Still, I am quite pleased with the fit. Now I need to go a drive to see if it's any quieter.

If I need more, the next step is to buy a used snorkel/silenced air cleaner and, if necessary, cut out its bottom and fit the recessed part of this 14" onto it.

David

Looks better - hope it's quieter!

[quote=Kevin H;10924Alternatively perhaps you could tape a small slab of plasticine to the underside of the bonnet to see if you get an imprint from the post.[/QUOTE]

Kevin, thanks for that idea. I did a variation and made two little columns of plasticene. I put one at the front edge of my new air cleaner and one on the nut on the top. The bonnet pressed them down when closed. This revealed I have 1.25" clearance at the front edge and 1.5" above the nut! So I have room to perhaps fit a larger silenced/snorkel air cleaner if I want.

David