mke
mke Dork
1/28/23 1:16 p.m.

I think this is ready to print a test part once my printer operator gets home.  CAD it not my first love so it took me longer than it should have but I did eventually  figure out how to make the curves go the way I wanted (I should probably fix my mirror caps now) , I hollowed it out to make it light and it streamlines the filter face for reduced drag and increased flow to the filter so its a race part.  Back to real work

 

preach (dudeist priest)
preach (dudeist priest) SuperDork
1/28/23 2:50 p.m.

mke
mke Dork
1/28/23 5:56 p.m.

Ahh, the ocra surprise

After I was done screwing around with the filter cover I made a template and cut the passenger side to match the driver side

Then rough out the foam and filled the holes

then started the duct for the drivers side.  I kind of mitered the pieces then used construction adhesive

The shape will need to start changing now to get around the fuel filler neck and not hit the tire..you can see the green foam trying to find a path through all the wires.

 

 

 

mke
mke Dork
1/29/23 9:15 a.m.

The shape is not quite right butvit seems to help I think

mke
mke Dork
1/29/23 9:43 p.m.

Still don't love the filter

 

And I may 2nd filter housing didn't come out great so I ground, filled and reglassed leaving my patience frayed....so I spray foamed the last bit of the duct

mke
mke Dork
1/30/23 6:48 p.m.

I pulled the duct out and now fully understand why I was having such a hard time mitering pieces.......this will require some redesign

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
1/30/23 7:06 p.m.

That is an interesting mockup method that never occurred to me and now I will have to steal it, if I ever decide to start playing with composites.

84FSP
84FSP UberDork
1/30/23 7:07 p.m.

I think the cap helps a great deal.  You should actually have a pretty efficient intake setup there sir.  What is the plan for the intake tube mockup?  3D print something?

mke
mke Dork
1/31/23 9:32 p.m.

In reply to Pete. (l33t FS) :

But now I can't just dissolve the foam I don't thing...the spray foam doesn't dissolve like the other stuff.  

Added a bunch more more tonight

orangecruz
orangecruz New Reader
2/1/23 4:39 a.m.

awesome work as always 

mke
mke Dork
2/1/23 11:18 a.m.

Starting to look like it could be a functional duct someday.  It has an honest 4" round effective area everywhere and not horrible turns.

I still don't like the filter to duct transition so I'm going to remove the rubber adapter from the filler and attach directly to say about an inch....more foam

 

There is some thinking that this is just a big waste of my time and what I need to do is reposition the side windows and put a big duct there like was done on the Michelotto 308 and remove the window like the  288GTO.  Then build a much larger airbox that holds a filter somehow and it would be better.  But this seems like a hold thathtoght until I see bad dyno results type thing.

 

Rigante
Rigante Reader
2/2/23 5:08 a.m.

In reply to preach (dudeist priest) :

ahhhh great to see my meme come back

Rigante
Rigante Reader
2/2/23 5:39 a.m.

Although I love everything so far, i don't love this filter setup.

I can't really see how much space you have, but could this work? duct the side vents to an airbox, through a water trap, then to the biggest paper filter element you can get [what do the latest BMWs use?] then create a flexi from the metal airbox  [on top of the engine] with a nice bellmouth on the end into this airbox. One each side of the engine, maybe partly tucked under the wing ahead of the wheel

I've not sketched the actual airbox, just the things floating in space, so imagine a GRP airbox encapsulating it all with a split line flange that clamps the panel filter 

Rigante
Rigante Reader
2/2/23 5:39 a.m.

my handwriting is terrible  laugh

AngryCorvair (Forum Supporter)
AngryCorvair (Forum Supporter) MegaDork
2/2/23 11:48 a.m.
Rigante said:

my handwriting is terrible  laugh

your handwriting is soooo much better than my 17-year-old daughter's

Rigante
Rigante Reader
2/2/23 12:31 p.m.

Nukem
Nukem Reader
2/2/23 1:13 p.m.

In reply to Rigante :

These sketches are rad, and this build is rad.

FCP has reasonably good pictures and stock of panel air filters for BMWs.

https://www.fcpeuro.com/BMW-parts/Engine-Air-Filter/?year=2020&m=20&e=180&t=6&b=9&d=5147

 

Maybe something useful in there.

mke
mke Dork
2/2/23 2:29 p.m.

They are nice drawings and fine hand writing, WAY nicer than either my sketched or writing.

Just for a bit of perspective so the scope of the [problem is more clear, I don't think I posted this.  Stock 308QV vs the V12

Flow is about proportional to HP, so the new engine needs about 3.5 times what the old had so even with both side vents its probably not enough.  I cut them back and bent the outside edge so they are bigger....but still probably not what they should be.

Here are some short of a 308 air filter in different locations, and remember this filter is much too small

There is a chance of getting an undersized filter  in a more undersize box on the left, about 0 chance on the right.  Behind the engine is about the only place for a properly sized filter & box if it's to get a cold air feed. 

I could put the filter around the TBs and pull hot low pressure air easily but I'm not sure where the lines cross between that and a restrictive cold air setup without actually running to to find out.  I could (but won't) cut a big hole in the deck lid with a snorkel over the roof.

I'm going to finish what I'm building and then try it with and without the air box cover and see the change in MAP which will tell me the change in hp, maybe confirm on the dyno.  Maybe also try with and without the filters themselves.   Once I know what's possible and what I have  I'll know how badly I want to change it....the 288GTO ducts with a filter box behind the engine is probably the winning setup but a lot of work.

I'm pretty sure this is going to cost me around 30hp which is a lot.....but I honestly don't think I care anywhere near as much as I care that I get to finally drive it wink

 

 

Rigante
Rigante Reader
2/2/23 2:34 p.m.

it was a long shot that it might fit, but as long as there's some airflow and insulation over the exhaust the rear mount sounds goof

mke
mke Dork
2/2/23 2:46 p.m.
Rigante said:

it was a long shot that it might fit, but as long as there's some airflow and insulation over the exhaust the rear mount sounds good

Good thoughts...but the engine takes up a LOT of space...its 7 or 8in wider than the V8.  I don't think I mentioned this in regard to the filter problem but I also put 2" wider wheels under the fenders so side to side I've lost about 12" of space that the stock 308 has .  I did however move the engine forward 3in and the V12 is about 3-4" narrow  V then the v8 so I created about 6-7 inched more space behind the engine s  yeah, behind over the headers or even in the trunk is ideal other than cosmetic concerns.

frenchyd
frenchyd MegaDork
2/2/23 4:04 p.m.

I'm sorry if this has been asked and answered but do you know how much your engine weighs?   

mke
mke Dork
2/2/23 4:15 p.m.
frenchyd said:

I'm sorry if this has been asked and answered but do you know how much your engine weighs?   

I weighed it a while back and posted  but don't recall other than this photo I found.  Engine with the trans is 622lbs it looks like that scale says.  Exhaust, water pump , alternator will add some, 700 with all that maybe?

APEowner
APEowner UltraDork
2/2/23 4:31 p.m.
Rigante said:

Apologies to mke for the thread diversion but what software/hardware did you use for this sketch?

Rigante
Rigante Reader
2/3/23 3:54 a.m.

In reply to APEowner :

Hey it's just old skool Photoshop, but I'm a designer, so there's a lot of hours practice over the last 30 years behind a quick sketch like this. there are lots of apps now that don't cost much and allow the same outputs, or there are clones of Photoshop online for free like
https://www.photopea.com/ 

 

loads of youtube guides on how the software works
https://www.youtube.com/watch?v=BGzzpX8j3cs

frenchyd
frenchyd MegaDork
2/3/23 5:28 a.m.

In reply to mke :

Thank you. That's very kind of you. I wonder what the old 3.0 used in the 1950's weighed.  
 So Ferrari is lighter than my Jag V12 but heavier than a V8. 
  I for one think the trade off is worth it.  Smoothness, torque and power potential. Not to mention it's so unique.  
  

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