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Peter
23-04-2012, 10:46 AM
There's quite a bit to write so I cheated and scanned it in, (dedication to Bob Tomlinson and the Tech Book "The DellOrto Superperformance. book) :thumbup:
I would also STRONGLY reccomend to all DellOrto owners to get it. I would also reccomend a visit to eBay and alfa1750 's shop in Italy for all DellOrto bits including his extended adjustment screws, (eBay number 290328373341) they save sooo much time and scapped knuckels. :notworthy:
Also clear argument about foam versus mesh filters, (yeah, I have mesh ones :tongue: )

http://img.photobucket.com/albums/v219/Ukhozi/DellOrtocarb1.jpg
http://img.photobucket.com/albums/v219/Ukhozi/DellOrtocarbs2.jpg

NovaF4
23-04-2012, 05:15 PM
Peter, thanks for this. I'm sure Lauren and Dave will find this interesting too. I'm not sure if they are using the original air filter box or aftermarket filters though but I'm sure they will make comment soon. Out of interest, have you ever seen an Alfa Boxer engine? Only I just wondered if you've seen how it is set up on the original car with the rounded alloy castings that turn 90 degrees from a horizontal plain that fits onto the air box to a vertical plain which bolts to the carb intakes. I guess they could be termed 'velocity stacks'. You can see them in this photo on either side...

http://www.thegoodwebcompany.com/sfy36k/asus307.jpg

In fact, that photo has made me realise why my old filters, which are too knackered to use any more, each had a hole on the side. It was for the oil breather pipes. I remember sticking a pipe in to each one. That's why the alloy castings you can see in the photo have a breather pipe sticking out. I'll have to ask Dave what he recommends I do about this as I'm not sure making a hole in the filter like I did all those years ago and just sticking the pipes in is a good idea or not.

Of course, for aftermarket filters to be used they just plonk straight on top so there's no air rushing round a smooth bend as Alfa intended.

I've just found out that I only have 8cm above the carb intakes before the engine access hole edges are so there's not a great deal of room. Even with the original engine lid that only offers about 6 cm more. although anything more is a bonus I suppose. Also the boxer engine's carbs are staggered and one of them is not far from the engine access hole edge; possibly too close to fit anything like you are suggesting.

I'll print off your findings and show Rusper Dave. He's built more boxer engines, mainly for race cars than you and I have had hot dinners, so it will be interesting to see what he thinks.

I've just remembered that Dave likened my new engine to that he used to build for Group C racing Alfas. I haven't a clue what that means. Maybe someone here will enlighten me.

G

NovaF4
23-04-2012, 07:16 PM
I've just read an interesting article that Lauren posted on the Alfa Romeo Forum which was all about the air filters and what to do with the breather pipes. I'm now liking the idea of the K&N's with expensive part that allows the breathers to be attached. Also they have a metal top plate which would stop any water falling on them and soaking through and a faily hard core filter as opposed to sponge which would also be much more suitable where water is concerned - when driving on wet roads the Nova engine bay becomes a vortex of wet air which the sponge filters would quickly soak up therefore effecting their performance.

Spacenut
23-04-2012, 09:18 PM
Hi Giles - the usual racer trick is to use a catch tank to collect the condensed oil and not try and re-cycle it through the carbs. I always railed against this policy for road use, but my new Alfatune engine doesn't have any facility for doing anything else, so catch tank it will have to be!

My current K&Ns don't have velocity stacks in them and performance suffers accordingly. The Alfatune engine has medium length velocity stacks with foam air filters over them. Total height is greater than my current set up which will require a re-design of the parcel shelf/rear window to accommodate.

The Alfa 90° castings are a pretty good approximation for velocity stacks - their only drawback is the lack of radiusing at the inlet. Is that your engine in the picture? Looks really nice :D

Lauren

Peter
24-04-2012, 11:24 AM
As you can see here I had to reshape the engine access and I incorporated a higher surround too.
My stacks are 50mm with 85mm Bugpack alloy plated mesh filters, K&N are the same but with chrome plates and more costly
http://img.photobucket.com/albums/v219/Ukhozi/engine/engioe3.jpg
As can be seen behind the shroud I use a Impi breather box which enters the filler tube.
Two pipes come from the rocker covers to the box. Two more will go from the box to the air filter bases. I use ordinary stainless steel braid covered plumbing pipes for the none pressure system and loom covers as they are really cheap (about £3 on average) but last well even with oil vapour.
The Impi breather box vents out of a gap under the cover with the inlet and drainpipes entering the bottom half beneath a foam filter inside, I intend to seal the lid and vent from above the foam filter to the air filters so as to recycle the fumes. There is not much room in the bottom plate of the filters but I'll find somewhere to fit a 3/8" fitting. I also need to reroute the drain pipe a bit, possibly drill and tape entering the other side and a smart, flush plug in the original hole.
http://img.photobucket.com/albums/v219/Ukhozi/enginebaylables.jpg

Peter
26-04-2012, 10:11 AM
Stacks of room with it's own thread, I can breath easy knowing that. :facepalm: :outahere:

NovaF4
26-04-2012, 02:25 PM
You can breath easy knowing that it isn't taking up half of my topic more like! :wink:

Peter
27-04-2012, 11:19 AM
Don't worry young man, I'll think of something :dunce: