81 1200 Project

[dan filipi]

I know exactly what you're saying. Had the same problem with mine and the CI manifold.
On mine I have enough flexible rubber on the VW intake side to make up the difference in width, just barely.

 

[slabghost]

You could cut the runners without any issue really. Easiest fix though would be remove the rubbers from the intake horns and use sections of rubber hose to attach them to the runners.

 

[Denver]

Easy for me to say, :headscratchifferent set up might be in order opcorn:

 

[brianinpa]

Is there any problem with having multiple steps in the inner surface of the runner? No matter what I do I will have a step from the runner to the rubber hose and then another step back up to the intake horn.

 

[slabghost]

No problems at all.

 

[dan filipi]

I don't think it will affect anything, air/gas mixture moving too fast.

 

[joedrum]

ok ...if it was me id put 1000 or 1100 intake horns on the 1200 heads ...the manifold shold hook up fine then ...though the spread is a bit wider intake should seal ....then the only off set will be at the head ...with the 1200s smaller head port ....

 

[ekvh]

+1 Kind of the only option short of making your own.

 

[brianinpa]

I am going to try it later today and see how tight I can get it with just spacing. If I don't like what I see, then I'll try clamping some reducing pieces over the horns.

 

[dan filipi]

The horns in your pic look like 1100 or 1000 already so I don't see any other simple way because the horns have a very short depth and sealing area.

 

[joedrum]

well this manifold must be made really short ...if i remember right if you take the rubers off horns it gives you about a 1/2" of flat sealing surface to clamp to...im thinking its about 1 9/16" OD there but that might not be right ...been awhile sense i work with one ....what the manifold OD ..that be the only fix really if a hose would work there .....

hmmmm ok i got a better solution you could cut runners in the middle....get hose that would make a connector there and extend runners so they fit in horn as they should be ,,,and install .....if you wanted you could fill the space inside with a sleeve of pvc ...could be ring with cut in it so it can march the size well ....this would keep runner as consistant as possible and add stability

 

[brianinpa]

dan filipi » Mon Mar 28, 2016 10:38 am[/url]":2sz283md]
The horns in your pic look like 1100 or 1000 already so I don't see any other simple way because the horns have a very short depth and sealing area.

They are the 1100 in the last pictures. These would give about 1/4" claping surface on the manifold, so I am going try. I don't expect good results. :hihihi:

 

[brianinpa]

joedrum » Mon Mar 28, 2016 11:25 am[/url]":2l12n3bb]
well this manifold must be made really short ...if i remember right if you take the rubers off horns it gives you about a 1/2" of flat sealing surface to clamp to...im thinking its about 1 9/16" OD there but that might not be right ...been awhile sense i work with one ....what the manifold OD ..that be the only fix really if a hose would work there .....

hmmmm ok i got a better solution you could cut runners in the middle....get hose that would make a connector there and extend runners so they fit in horn as they should be ,,,and install .....if you wanted you could fill the space inside with a sleeve of pvc ...could be ring with cut in it so it can march the size well ....this would keep runner as consistant as possible and add stability

Taking the rubber off only gives about 3/8". Cutting the runner in the middle and splicing with a piece of hose was a thought... I like the idea of filling the space to keep the inner wall consistent.

 

[ekvh]

Using stock intakes on a 1200 w/stock carbs there is only about 1/4" to seal. It works. I bought some toggle style clamps to spread the clamping as much as possible.

 

[brianinpa]

I proved a couple things to myself this afternoon.

1 - With the rubber removed from the horn, I can tighten flexible PVC to the lip that is left on the horn. Even though there is only 3/8" protruding, there is enough to get a tight grip, so if I have to go this route, it will work, and this is the gap that I am going to have to fill.

Rubber Removed

• brianinpa
• Mar 28, 2016

2 - By centering the manifold between both sides and clamping it in place, there is more aluminum protruding into the intake horn rubber than I first thought would be. Both runners have 1/2" of aluminum that is not painted so you can see exactly how much is in the horn rubber.

Compare

• brianinpa
• Mar 28, 2016

In addition, this shot shows just how far it is sticking inside. The runner is starting to touch the second rib.

Inside Horn

• brianinpa
• Mar 28, 2016

3 - Don't try this at home as I am trained in the art of caveman tech, but this manifold clamped in place so well that I could actually lift the entire motor by the manifold. :shock:

Intake installed

• brianinpa
• Mar 28, 2016

My first attempt with the single carb is going to be just like you see it pictured here. If I have problems, well then I will move on to try something else.

 

[brianinpa]

ekvh » Mon Mar 28, 2016 5:29 pm[/url]":1zawyork]
Using stock intakes on a 1200 w/stock carbs there is only about 1/4" to seal. It works. I bought some toggle style clamps to spread the clamping as much as possible.

I like the idea of the toggle clamps. I used a lot of those on the aircraft engines I worked on... I just forgot about them. They hold up a lot better than the standard hose clamp.

 

[joedrum]

okay brian ...it looks like a good gamble it going to be fine ....go for it .... opcorn:

 

[slabghost]

Looks like it'll work fine.

 

[dan filipi]

Looks good Brian. How much longer to ignition?

 

[brianinpa]

I still need to get clutch seals, shifter seal, and a water pump cover o ring but I am waiting for payday. Once that's done, I should be okay to stuff the motor and fire it up. Then it will be time to tear the rear end apart for cleaning and painting. The fun part is figuring out how to wire the 1200 motor to make lights on the 1100 instrument cluster work.