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Are they any differences between the manifolds of 1.3L and 2.0L engines. Maybe the 1.3L manifold is shorter in length.

I converted my Giulia 1300 to a 2.0L and kept the same manifold. I tighten the bolts into the down pipe fine but then I realized the down pipe muffler staying higher and can't bolt the transmission support to the muffler, since the muffler sitting high.

I assume the 2.0L manifold is little longer than the 1.3L.
 

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Pretty much all the cast 4-2-1 105/115 manifolds are the same height. They're PN 105.02... something. The height difference is in the downpipes.
Andrew
 

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The height difference is in the downpipes.
Andrew
Andrew is correct. There are differences in the downpipe dimensions, made necessary as a 1750/2000 block is taller than a 1300 block! When you swap in a larger engine you need the downpipe that goes with it.
 

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I'm doing a 2L conversion to my Super, and this is very timely.

However, I'm confused. The referenced post by Papajam indicates the 1300 manifold is different from the 1600/1750/2000. One of the other posts here indicates they are all the same.

Can the 1300 exhaust (and intake) manifold be used on the 2000 head?

Thanks.
 

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Can the 1300 exhaust (and intake) manifold be used on the 2000 head?
Exhaust Manifold: Yes, again with the proper downpipes. I think Papajam was stating that while the 1300 manifolds have different part numbers the length is the same.

Intake Manifold: Probably not. There are a couple of issues here. First, the port size would be too small on a 1300/1600 intake, but this can be solved by porting the manifold to match the head. Secondly, and more importantly, the 1300/1600 intake will not have a bypass port, which you definitely want, especially on a 2 liter.
 

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Discussion Starter #7
Thanks guys for all the help. I knew something wasn't right, but wasn't sure if it was the manifold being short or the down pipe.

Joe, I am using the European intake with carbs and also the front cover European with mechanical pump. What is the bypass port? are you referring to the small hose from the valve cover that goes to the carb intake.

In terms of the exhaust manifold do not need any changes since all are the same right.

Giorgio
 

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I am using the European intake with carbs and also the front cover European with mechanical pump. What is the bypass port? are you referring to the small hose from the valve cover that goes to the carb intake.
Giorgio:

No, when he says "bypass hose", Joe is referring to the coolant hose that runs between the intake manifold and the water pump. Alfa added that line with the 1750 and 2L engines. It comes out of the intake manifold directly below the thermostat, and enters a third bung on the waterpump (1600 - 1300 pumps lack that bung).

The bypass system allows coolant to circulate through the engine, but not go through the radiator, when the engine is cold. It speeds warm-up, while preventing overheating at the back of the head.

Note that the bypass hose for a Spica manifold is different than the one for a European carburetor manifold - Centerline carries both.
 

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Well, I didn't actually say that the manifolds are the same length; only that I could not find any Alfa documentation that says they are.

Alfa assigned different part numbers to the 1300 manifolds for a reason. Since these manifolds will physically fit a 2l, it would appear that the flange mounts and probably the port centers are the same. But it says nothing for pipe ID, OD, wall thickness, pipe angle, bottom flange angles, horizontal and vertical length, etc. anyone of which may make them unsuitable for this particular 2l application.
 

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Discussion Starter #10
Well, I didn't actually say that the manifolds are the same length; only that I could not find any Alfa documentation that says they are.

Alfa assigned different part numbers to the 1300 manifolds for a reason. Since these manifolds will physically fit a 2l, it would appear that the flange mounts and probably the port centers are the same. But it says nothing for pipe ID, OD, wall thickness, pipe angle, bottom flange angles, horizontal and vertical length, etc. anyone of which may make them unsuitable for this particular 2l application.
Jim, you are right the 1300 manifold is shorter than the rest. I called Dean Russell (Trail Alfa) this morning, and he said he converted a nuova 1300 super to a 2.0L and the only thing he replaced was the exhaust manifold from a 2.0L using the existing down pipe.

Giorgio
 

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Giorgio:

No, when he says "bypass hose", Joe is referring to the coolant hose that runs between the intake manifold and the water pump. Alfa added that line with the 1750 and 2L engines. It comes out of the intake manifold directly below the thermostat, and enters a third bung on the waterpump (1600 - 1300 pumps lack that bung).

The bypass system allows coolant to circulate through the engine, but not go through the radiator, when the engine is cold. It speeds warm-up, while preventing overheating at the back of the head.

Note that the bypass hose for a Spica manifold is different than the one for a European carburetor manifold - Centerline carries both.
i found the intake manifold on the spica 1750 is smaller than the 2000cc

save you some grinding time if you want to port them out
 

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im pretty darn sure...i have 3 2000 spica manifolds and 1750 series 1 with the funny block on top thats differs from the 1750 mk2 with the single idle circuit adjuster.

ive ported the mani myself to match up with the heads ive done...
 

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Discussion Starter #14
I only had to change the exhaust manifold from a 2.0L and there was a significant difference from the 1.3L manifold in length.

It fits perfect and kept the same downpipe.

The length difference was ~ 1 inch.
 

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Cast Iron Headers

Every once in a while Alfa throws a curve. I have a Duetto that had a 1600 motor with what appeared to be 1600 cast headers. When I installed the 2 liter with the 1750 '69 front head pipes from Centerline, the exhaust was too close to the chassis. I removed the cast iron headers and matched them up to some 2 liter cast iron headers from a '74 GTV and the 2 liter headers were about 1/2" longer. Same part number cast in both sets of headers. I bolted them up and everything fit fine. I've done probably 3 or 4 1750 or 2 liter conversions in early 105 chassis and this was a first. All parts are not created equal!
 
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