Why I cut up an intake manifold.

[2002iii]

You may have seen my joke advertisement for a half price intake manifold in the classified section.

 

I found a crusty single barrel intake that was left outside under a deck for the past 30+ years. I was inspired by @Doug Riparetti and his motorcycle carburetors on his S14 engine. I thought why not on an m10, so I purchased a nice used set of 40mm Mikuni motorcycle carburetors. I then went to work with a hacksaw and the sawzall on the manifold. Here is my progress so far:

[tzei]

Interesting. How big of a task would it be to make spacing even?

[NickVyse]

thought of doing something similar but with the early tii manifold that has the plastic runners, as that would be easy to join up.

[2002iii]

41 minutes ago, tzei said:

Interesting. How big of a task would it be to make spacing even?

Its about as even as its going to get.

[uai]

with 3d printing or better SLS it would be doable.

Edited January 13, 2022 by uai

[kiva667]

3 hours ago, NickVyse said:

thought of doing something similar but with the early tii manifold that has the plastic runners, as that would be easy to join up.

Sounds with some baling twine and superglue and you'd be off to the races ?

[irdave]

When I was looking at putting FCR's on my previous car, the car racer guys reported noticeable gains going from dual Webers to a rack of FCR's on their Pinto (?) engines- 2L guys.  Like 20 hp gains.  Who knows the state of tune before and after, but I got to the point where I had a rack of 4 in the shop before I went down the path I did with the new car...

 

I think this is a worth while venture.

[TobyB]

I have yet to find the DCOE to be a limiting factor in horsepower....

 

...my wallet always stops flowing before the carbs do.

 

t

has half a manifold kicking around somewhere, too.

[Doug Riparetti]

I started off with the Lynx manifold with (2) 38mm Keihin flat-slide motorcycle carbs that were hogged out to 40mm, I could not get the car to run very well.

 

Then I installed (2) 36mm Mikuni round-slide motorcycle carbs, still was not happy with the performance. 
 

I sh*t canned the Lynx intake, installed the Cannon intake manifolds with (4) 36mm Mikuni round-slides, I ran the for a couple of years until I did the S14 swap with the (4) 44mm Mikuni round-slides.  
 

Just under 64,000-miles since doing the S14 swap with the motorcycle carbs. 

[2002iii]

10 hours ago, NickVyse said:

thought of doing something similar but with the early tii manifold that has the plastic runners, as that would be easy to join up.

Lol, I tried using early tii  manifold parts, but the spacing was way off and I couldn't see a way to make it work without cutting them up. I decided not to cut them up and instead I'm looking for some itb's with the right spacing or I was thinking about cutting the throttle plates out of some old carburetors.

 

 

9 hours ago, uai said:

with 3d printing or better SLS it would be doable.

The whole point of this experiment is to get cheap horsepower.

 

If this doesn't work out my next idea is to have someone plasma cut or CNC an aluminum intake flange and weld the proper size tubing on, but that's a lot of $$$.

 

4 hours ago, TobyB said:

I have yet to find the DCOE to be a limiting factor in horsepower....

 

...my wallet always stops flowing before the carbs do.

 

t

has half a manifold kicking around somewhere, too.

Like you said it's not the performance limit of the Weber carbs but the price limit.

 

If this works out I'll only have about $600 total invested in it, where a set of Weber Dcoe 40's and all the neccessary stuff will cost at least $1000.

 

Glad to hear I'm not the only one who has hacked up a manifold, lol.

[2002iii]

18 minutes ago, Doug Riparetti said:

I started off with the Lynx manifold with (2) 38mm Keihin flat-slide motorcycle carbs that were hogged out to 40mm, I could not get the car to run very well.

 

Then I installed (2) 36mm Mikuni round-slide motorcycle carbs, still was not happy with the performance. 
 

I sh*t canned the Lynx intake, installed the Cannon intake manifolds with (4) 36mm Mikuni round-slides, I ran the for a couple of years until I did the S14 swap with the (4) 44mm Mikuni round-slides.  
 

Just under 64,000-miles since doing the S14 swap with the motorcycle carbs. 

I'm using a set of 4 40mm Mikuni round slides that are attached to each other and use a throttle rod to operate all 4 with 1 throttle cable. It isn't making it any easier on the fabrication process but hopefully it will make Tuning them easier. 

 

I'm glad to see that you drive your awesome car so Much. Hopefully I'll get to see it again when there's another local gathering.

[Doug Riparetti]

Los Gatos “Neue Klasse” gathering this Saturday

[Doug Riparetti]

9 hours ago, 2002iii said:

I'm using a set of 4 40mm Mikuni round slides that are attached to each other and use a throttle rod to operate all 4 with 1 throttle cable. It isn't making it any easier on the fabrication process but hopefully it will make Tuning them easier. 

 

I'm glad to see that you drive your awesome car so Much. Hopefully I'll get to see it again when there's another local gathering.

What series Mikuni's are you running, I'm running the "VM's?

 

[2002iii]

1 hour ago, Doug Riparetti said:

What series Mikuni's are you running, I'm running the "VM's?

 

 Mikuni RS40-D1-K off of a late 80's Suzuki GSX-R.

[RichenFamous]

I have been thinking about doing this for a while. Glad to see the experimentation and can’t wait to see your results!