Giulietta Manifold/ Exhaust Questions

3945 Views 17 Replies 6 Participants Last post by Gordon Raymond, Jul 29, 2015

Italiar79

Discussion Starter · Oct 25, 2007

I just purchased a two piece Giulietta exhaust manifold for my Sprint, and now need to replace the exhaust header that attaches to it. Anyone have a stock cast iron exhaust header, without cracks, that is taking up space in their garage? Another question..If I go with a veloce type header, or something aftermarket, I probably do not use the exhaust manifolds I just purchased, correct? Just trying to figure out where I'm at. Thanks!

1 - 18 of 18 Posts

Steve O

· #2 · Oct 25, 2007

Manifolds replace headers

The two-piece manifolds take the place of headers in the exhaust system. They connect to the twin down-pipes that merge just ahead of the first (smallish, flat) muffler. This down-pipe assembly is fabricated steel, and is part of the front half of an OEM-style replacement exhaust system. If someone has either used after-market headers, or Alfa veloce headers, you'll probably be best off to replace the whole front half as a single piece. I always try to get my exhaust parts from Al Cosentino at FAZA. Be careful when connecting the cast iron 'headers' (stock parts for normale) to the steel parts, so as to avoid cracking at the down-pipe connection flanges. Get everything fit together snugly before tightening anything, is my procedure.
Also make sure the down-pipes' protruding pipe 'lips' fit into the ends of the cast iron pieces.

Italiar79

Discussion Starter · #3 · Oct 25, 2007

Steve,
Thanks for the help, and I hope you guys didn't get too hot down there in So Cal.

Gordon Raymond

· #4 · Oct 25, 2007

I think I may have an old Giulietta 101 cast iron spider assembly in my shop attic. Check with other BB members if it will work. If your interested send me a PM and I'll drag it down and get you some photo's.
Gordon Raymond

Italiar79

Discussion Starter · #5 · Oct 26, 2007

I just pulled the manifold out of the box it came shipped in and, par for the course, the gentleman I bought it from was wrong. It's for a 101 Sprint, but a 1600 Giulia, not a Giulietta, as the 10112 part number pointed out, as well as the larger diameter. Son-of-a. Okay, brain storm, will the 1600 Manifold fit on a 1300 Block, i.e. a larger diameter header for better breathing, or are the mounting holes spaced differently, etc. Any help...

Gordon Raymond

· #6 · Oct 26, 2007

Old iron Giulietta exhaust manifold.

Yes it should fit, though there is little or no advantage in the larger holes

. I know the one in my attic is a 60 Giulietta as I removed it when I converted the car to a Veloce

. (many,many

years ago!)

Gordon Raymond

180OUT

· #7 · Oct 26, 2007

Gordon Raymond;440035]Yes it should fit, though there is little or no advantage in the larger holes. I know the one in my attic is a 60 Giulietta as I removed it when I converted the car to a Veloce. (many,many years ago!)

So, if you're building a 1300 motor you should run the small tube Veloce headers instead of the large tube headers? I always thought the large tube 1600 Veloce headers were better.

Gordon Raymond

· #8 · Oct 26, 2007

Large diameter 101 Veloce tubular headers.

They are the only ones easily available new these days. Exhaust port pocket, and valve size in the 101, 1300's are a limiting factor. It's not like a 2 cycle where an exhaust expansion chamber aids combustion. With the 1300, 101, exhaust valve, valve pocket, and port size as well as the head design, will limit what can be gained even in a pure race engine. The actual design of the 1300 and 1600 Spider veloce headers is very similar, having to do with space constraints in the chassis

. While some more modern, odd length tubes might offer gains in particular RPM ranges, these gains are not significant throughout the useful RPM range for any street and most all race applications. It is not that you should, or should not, use the smaller or larger diameter tubes in either tubular steel, or cast iron. Tubular Giulia Veloce headers from Centerline, or other sources, new, are now the larger 1600 port sized tubes, I believe, and will offer no real world difference in performance. Used iron style, 1300 or 1600, on a 1300, 101 will also work about the same. 1300 engines I have built in the past, even with a 1400cc kit, used tubular 1600 veloce headers, as the smaller style is just harder to find, and generally belong on a period correct restoration. IF the engine is a 1300, 105,

then the larger tubes are correct as these engines have the larger exhaust ports. For your Sprint Normale, the smaller iron headers are period correct. HOWEVER, not having a parts book in front of me, I am unsure if the iron Sprint 101 manifolds are exactly the same as the iron 101 Spider manifolds. Having worked on Sprint Normale's in the past, I believe they are the same but you should check either a parts book, or with the owner of a correctly restored Sprint. As all these Alfa's are becoming more valuable, it helps to use the correct parts wherever possible

. I hope this helps Jim.

Gordon Raymond

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Italiar79

Discussion Starter · #9 · Oct 26, 2007

Gordon,
Thank you for helping Jim and I understand how all this works a little better!Being fairly new to the Alfa world, I am still learning. Correct me if I'm wrong, but the Giulietta exhaust you have probably won't mount up to the Giulia manifold, or maybe it will since you said the new 1300 headers are bored to the 1600 size anyway. I know Centerline doesn't differentiate between the two, so maybe the Giulietta exhaust will mount up to either one, as they don't offer a specific Giulia front exhaust section. Thanks again for all the info off the top of your head. It is nice to have a resource like you that has built up different types of engines.

Gordon Raymond

· #10 · Oct 26, 2007

Most all parts easily available new, are currently sized as the 1600 ports. That would in most cases indicate the available tubular exhaust system would fit 1600 manifolds and, likely smaller 1300 as well. A call to Centerline would be wise for confirmation.
Gordon Raymond

6alfas

· #11 · Oct 26, 2007

Steve O said:
I always try to get my exhaust parts from Al Cosentino at FAZA.

Steve,

I've been to the Faza website but it's very crptic and I can't see to find a online catalog. Am I missing something?

Chuck
59 Sprint

Gordon Raymond

· #12 · Oct 26, 2007

Chuck,
Call Al C. You will find that even MORE cryptic

, but LOTS

of fun!

Gordon Raymond

Steve O

· #13 · Oct 26, 2007

The full FAZA Experience

A call to Al is always a required ritual to order anything, and practically an other worldly experience. He is one of the true eccentrics left in this hobby; he is also, shall we say, an acquired taste. Some people I know refuse to deal with his personality regardless of the quality of the product. I find him rather amusing, and love every product he has ever shipped. Some of the 'literature' accompanying the parts is bizarre, but some is also pretty interesting --just like Al, himself. His phone, last time I checked, was 818 707 2301.

Gordon Raymond

· #14 · Oct 26, 2007

Steve, you said it all! Al is unique, and has been around long enough to have the good products that will, hopefully, keep him around!
Gordon Raymond

alphil

· #15 · Jul 29, 2015

180OUT said:
So, if you're building a 1300 motor you should run the small tube Veloce headers instead of the large tube headers? I always thought the large tube 1600 Veloce headers were better.

So do I have this right...Centerlines' 750/101 header(the only one available for 1300,1600) with two 50mm collector pipes will work better on a 1600 engine,or later 1300 with larger ports.While all of these parts will fit the 1300 Giulietta,little improvement will be gained "because" of the larger(50mm)collectors.Factory 1300 Veloces' used 45mm collectors.Bigger is not always better?

Gordon Raymond

· #16 · Jul 29, 2015

Essentially correct. For concourse, 750 1300 Veloces must have the small tube headers,
while judges debate this on 101 1300's, for show, NOTHING is lost in performance with 1600 Veloce headers on any 1300, (750 / 101) engine.

180OUT

· #17 · Jul 29, 2015

So do I have this right...Centerlines' 750/101 header(the only one available for 1300,1600) with two 50mm collector pipes will work better on a 1600 engine,or later 1300 with larger ports?

Yep. But pay attention to Gordon. He knows a lot more about this than I do:

Tubular Giulia Veloce headers from Centerline, or other sources, new, are now the larger 1600 port sized tubes, I believe, and will offer no real world difference in performance.

The original small-tube headers are no longer made, haven't been for several decades, and if found should really be saved for period-correct restoratioins. You will be very happy with the Centerline headers. Just be sure you have them positioned in the engine compartment before you put the engine in. Ask me how I know?

Reactions: 1

Gordon Raymond

· #18 · Jul 29, 2015

Your last paragraph is the best! Lets go with "Ask US how we know!" or maybe ... better not!

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