Triple Mikuni Air Filters

[Moridin]

When I bought the car, it had an ITG filter on it, but is has now fallen apart. I was wondering if anyone knew where I could get those custom assemblies that K&N makes for the Mikunis. I think I may have found a place but I don't know what size I need to get. These are the dimensions and part numbers that I've found.

 

Outside Height Element Foot Assembly

dimension part # Note Part #

4-1/2 x 7 1-3/4 E-3321 12 56-1310

4-1/2 x 7 3-1/4 E-3341 56-1350

5-1/2 x 9 1-3/4 E-3441 12 56-1330

5-1/2 x 9 3-1/4 E-3461 56-1360

 

I found them at this WEB SITE

 

I found another site, but I need the specific part number. Thanks for all your help. Everyone has been extremely nice on this forum so far.

[Mike C]

Do the Mikunis use the same setup as the Webbers? I know my Del'Lortos do. At least the 40mm ones. I just couldn't stomach the price and used a 3" stainless elbow connected to a K&N cylinder filter in front of the radiator. I am planning on building an aluminum air box that bolts to the three carbs then connecting it to the filter. I figure in the end I'll have about $150 in it, which is the same as the 3 individual filters, but won't feel quite as taken as I do with the $50 each price tag.

[Moridin]

Its actually closer to $65 a filter, than $50 a piece. I was thinking about building a box with a cone filter myself. I kinda need it now though, need the car running. I mean I have the ITG filter, but the front part fell off and its falling apart. Don't trust it to do the job it should. Does anyone else have any triple Mikuni's? What kind of air filter set up are you using?

[Icehound]

I was thinking about getting these from Pierce Manifolds, but I have to check the horn size on my Mikunis.

 

http://www.piercemanifolds.com/airfilters.htm

[JMortensen]

If you read up, screens and socks are supposed to be the MOST restrictive. ITG style is the best, K&N and similar with the metal cap is in the middle.

[PanzerAce]

Don't know which one you need, but if you figure it out, let us know. This seems to be the best solution to my problems with my ITG filter...

[SHO-Z]

Here is an air box that will work. http://www.twminduction.com/airbox.htm They use to sell SK Racing and webers

 

Here is a picture of my air box These are SK Racing carbs.

It is set up for blow through supercharger

Edited August 12, 2009 by SHO-Z
add pic

[Icehound]

Here is an air box that will work. http://www.twminduction.com/airbox.htm They use to sell SK Racing and webers

 

 

I was thinking about this air box - $375.00 is a bit expensive for what you get. I would like to retain the air horns for the ram effect and it seems, from what I have read, an air box causes a restriction at the outside edge preventing direct induction. Does the ITG style allow free and direct air flow straight into the horns?

[PanzerAce]

I was thinking about getting these from Pierce Manifolds, but I have to check the horn size on my Mikunis.

 

http://www.piercemanifolds.com/airfilters.htm

Do you know if the larger filter setups on that site will bolt to a mikuni? my ITG filter today decided it didn't want to stay together, so I'm exploring options now...

[PanzerAce]

I was thinking about getting these from Pierce Manifolds, but I have to check the horn size on my Mikunis.

 

http://www.piercemanifolds.com/airfilters.htm

 

just call them up then. Just ordered new filters from them, and they were really helpful about it. Even if you don't see the part you need exactly on there, they might have it in stock. None of the stuff listed on their site would fit my air horns, but they had some stuff in stock that would anyways

[JMortensen]

Be careful with the carb spacing on these airboxes. The carb spacing on my Cannon manifold was different than a Mikuni (and spacing between the first two carbs was different than the middle and rear). I can only assume that TWM is different than Mikuni is different than Nissan Comp is different than Cannon. I suppose if they have a backing plate it might not matter, as you can just make a backing plate to fit the rest of the box.

[Sam280Z]

For what I did, see post 11 in the following thread.

 

http://forums.hybridz.org/showthread.php?t=125227

 

This allows the use of air horns.

[PanzerAce]

For what I did, see post 11 in the following thread.

 

http://forums.hybridz.org/showthread.php?t=125227

 

This allows the use of air horns.

 

ITG filters also allow the use of airhorns (if you get big enough ones).

 

This is more a "what *other* that ITG works" thread.

 

Gotta admit, that's an interesting solution, but it seems to me like a lot of fab work...

[brokebolt]

Be careful with the carb spacing on these airboxes. The carb spacing on my Cannon manifold was different than a Mikuni (and spacing between the first two carbs was different than the middle and rear). I can only assume that TWM is different than Mikuni is different than Nissan Comp is different than Cannon. I suppose if they have a backing plate it might not matter, as you can just make a backing plate to fit the rest of the box.

 

I can't speak for the Nissan Competition parts manifold, but the Cannon, TWM, and Mikuni Manifolds are all the same spacing. Even the FET manifold I have is the same, so is the generic no-name that came on a set of well worn rebuilds. I wonder if the holes were simply miss-aligned when machined after casting clean up. Maybe the guy running the mill had tied one on at lunch. Just a thought.

 

Those Mikuni air horns are horrible to try and wrap a filter around. I have, in the past, just bought the oval K&N filters and cram the air filter around them. It causes the filter to protrude out a bit around the ends but it's either that or cut them (eeeeeeeeaaaaaaakkkkkkkkkkk!!!!!!!!!!!!!!!!!).

 

Custom air boxes are always nice. The guy that sells those extrudabody throttle bodies shows you how to make a low buck, easy to build air box. You only need the air box back plate/carb face plate.

 

http://extrudabody.com/TechInfo/Plenum_Building.html

 

I haven't built one using this method yet so I can't comment on that. But I can say I am a fairly experienced fiberglass man... pay special attention to item "C"... get a box of good nitrile gloves for about 7 bucks for a box of 100. You will thank me later. I promise.

[JMortensen]

I can't speak for the Nissan Competition parts manifold, but the Cannon, TWM, and Mikuni Manifolds are all the same spacing. Even the FET manifold I have is the same, so is the generic no-name that came on a set of well worn rebuilds. I wonder if the holes were simply miss-aligned when machined after casting clean up. Maybe the guy running the mill had tied one on at lunch. Just a thought.

In my case it wasn't a matter of the holes being misaligned. Maybe PeteW who bought my carbs can measure but the distance from the runners was VISIBLY off. You could see that the gap between the sets of runners was different. Unfortunately I didn't see that until I made a pattern for the backing plate using the first two carbs, then flipped the pattern and drilled holes for the middle and last carb and found that they were guessing 1/2" off. It's been a while so that is kind of a rough guess based on fuzzy memory. It could be that someone redid the casting along the way too (which would have been a good thing). The top and bottom halves were also not symmetrical on mine, the top half was situated probably 1/8" or 3/16" off to one side relative to the bottom. It's got the long runners which is nice, but the original Cannon casting that I have experience with is crap.

[brokebolt]

In my case it wasn't a matter of the holes being misaligned...the distance from the runners was VISIBLY off. You could see that the gap between the sets of runners was different...It could be that someone redid the casting along the way too (which would have been a good thing). The top and bottom halves were also not symmetrical on mine, the top half was situated probably 1/8" or 3/16" off to one side relative to the bottom. It's got the long runners which is nice, but the original Cannon casting that I have experience with is crap.

 

I would guess from my summation of your description, that maybe you indeed did have a copy of on original Cannon casting. We (friends getting together, not business) used to do stuff like this for one-off parts, never for resale. If you didn't match the mold up correctly when you mated the two halves of the mold together, then yes it would misalign the top and bottom half of the manifold like you stated... that was all sand cast stuff not modern technics like today. Normally, however, you scrub any indication of the original manufacture (like a logo or the letters C-A-N-N-O-N across the number one, or number four runner) to prevent copy write infringement and liability on your part. I heard a rumor that the TWM was a copy of the SK Racing manifold, it does look similar to me...

[JMortensen]

I would guess from my summation of your description, that maybe you indeed did have a copy of on original Cannon casting. We (friends getting together, not business) used to do stuff like this for one-off parts, never for resale. If you didn't match the mold up correctly when you mated the two halves of the mold together, then yes it would misalign the top and bottom half of the manifold like you stated... that was all sand cast stuff not modern technics like today. Normally, however, you scrub any indication of the original manufacture (like a logo or the letters C-A-N-N-O-N across the number one, or number four runner) to prevent copy write infringement and liability on your part. I heard a rumor that the TWM was a copy of the SK Racing manifold, it does look similar to me...

Why would someone copy the manifold and then move the runners? Not only does it not make sense to do that, it would also be a lot harder than just doing it right the first time. They would have to stretch the balance bar on one side and shorten it on the other side to do what they did, and then presumably they'd have to change the direction of the runners slightly to get everything to bolt to the head. I'm convinced that what I had was a Cannon manifold, not a reproduction that went to great lengths to screw up.

[SHO-Z]

I do not know if the SK racing and the TWM are copies. Here is a picture of the SK Racing carbs that I have. The carbs came from TWM from the little tabs that were on them when i bought them used. I do not think there is any marking on the maniflold.

 

[brokebolt]

... I do not think there is any marking on the (manifold).

 

Dead center between the number three and four cylinders, on the carb mounting flange it reads in raised letters "TWM".

 

Like this:

 

http://forums.hybridz.org/picture.php?albumid=181&pictureid=1377

[SHO-Z]

I stand corrected. I was just using the picture that I have.