Cast iron 4:2 exhaust manifolds

[Rod Midkiff]

Even if it was doable. It is usually best if one person makes edits/changes (or a small group) Get the wrong person permission and I could see the table getting trolled. (please no one take offense at the statement and by no means am I saying anyone here would do such a thing. But trolls are trolls..............

 

[AKimball92]

That thought crossed my mind as well. I was just ass-u-me-ing that tables like that (and anything else valuable to the general group) would be left alone by the Fiatisti trolls on this forum.

 

[dcioccarelli]

I cannot remember who set up the latest Xwebforums being really terriblewith names. Is there a way to embed the excel doc into the site and make it easily accessible and modifiable to all members? Is that within the capabilities of the Wiki or a major pain? I also have done some similar research in cams and cylinder heads, collecting many pieces of the puzzle one piece at a time.

This can be done pretty easily in the Wiki. Have a look at the camshaft page for an example. Alternatively, check out the mediawiki documentation on the subject.

Cheers,
Dom.

 

[Jeff Stich]

Next time Im at the salvage yard, Ill have a look at the Yugo there, and take a pic of its 4:2 manifold part number.

If it's a fuel injected model & in good shape, I'd be interested in "acquiring" that manifold.

 

[Jeff Stich]

A few SOHC 4-2 exhaust manifold numbers & photos I have:

1974-only USA X1/9 - 4310369


CA Vendor "replacement" for '74 USA X1/9, (Euro Fiat source model unknown to me) - 4310368


1974 USA 128 - 4252518 (similar to '74 USA X1/9, but #2/#3 collector & downpipe flange shifted slightly left)


Strada USA fuel injected - 4411460 (Yugo fuel injected is very similar)


Yugo carbed - 46620089 (mine - shown with emissions check valve mount/extension cut off from left side of #4 runner)


Euro 128 Coupe - 4252318


Euro X1/9 1500? - 7691880

 

[Dr.Jeff]

I also have done some similar research in cams and cylinder heads, collecting many pieces of the puzzle one piece at a time.

As the originator of this thread I welcome you to include any/all info you have collected on cams, cylinder heads, intake manifolds, or any other components into this discussion. I think opening up the concept of tabulating such data for a Wiki (or similar) post to include those additional items (in separate tables) is a great idea.

To the powers that be, I don't know who has the authority or ability to create the tables and make them a reference for the forum? But please assist, thanks.

 

[dcioccarelli]

As the originator of this thread I welcome you to include any/all info you have collected on cams, cylinder heads, intake manifolds, or any other components into this discussion. I think opening up the concept of tabulating such data for a Wiki (or similar) post to include those additional items (in separate tables) is a great idea.

To the powers that be, I don't know who has the authority or ability to create the tables and make them a reference for the forum? But please assist, thanks.

In theory anyone has the ability to request a Wiki account (we can now even use the same login as for the forum). In practise, I was mainly responsible for converting forum "threads" into wiki pages, although since the kids arrived my bandwidth for that activity has decreased somewhat. That said, I'd be happy to hep out and can certainly put something together with the information we have accumulated thus far.

There are also several threads (e.g. Steve's ultimate SOHC thread, Bernice's recent transmission thread) that I think would work better in wiki format, so I'll also look at converting them (obviously at the author's discretion).

Cheers,
Dom.

 

[Janis]

I'm not sure did I understood idea of whole discussion.
But if it is important I can take of heatshield of my Punto 1.6 (1581cc) and read part number and if needed measure diameters. It has 4-2 manifold. If You don't already have it as I started to use it as my daily car today.

 

[Dr.Jeff]

I'd be happy to hep out and can certainly put something together with the information we have accumulated thus far.

Thank you Dom, your assistance would be greatly appreciated. Unfortunately we don't have a lot of data yet. But it might be best to create the format now so everyone can add directly to it as new info comes along. I think we sort of covered what would be a desired format (to some extent) but we can discuss it more if needed. While typing the response below I had a thought; would it be easy to include the option for a couple basic photos of each manifold into this chart's format? That will help visualize the item's configuration, like where the outlet end is located relative to the whole manifold. Otherwise please feel free to do what you like. Thanks.

part number and if needed measure diameters

That would be great. As far as I know your Punto's exhaust manifold is a direct fit onto the X1/9 - 128 head so it certainly will help. And I'm not sure but I believe it may be one of the better ones to use from a performance perspective. I think the basic measurements should include the diameters of the inlet ports and outlet ports, and any others that you think will be useful. Also the part number and year, model, and country it was originally from (if you have that). Possibly even a photo to help see what the overall shape is (for example where the outlets are relative to the rest of the manifold). Thanks.

 

[AKimball92]

I took measurements off my two manifolds. Turns out my new 4-2 curves a little to the left. Looks like I will have to get a welder for some exhaust pipe manipulation... oh rats! Although I already knew that, just realized I think this exhaust belongs to a 128 or something similar?

Manifold 1: 4-2
LHS: "Fiat Lancia"
RHS: "7691880 __ 3C ____" (cannot decipher "_" as its a different tooling format)
Inlets: 28-30 mm depending on angle
Outlets: 33-34 mm
Curved to the left

Manifold 2: 4-1
LHS: "Fiat"
RHS: "4337800-2"
Inlets: 28-30mm
Outlets: ~37.8mm with the exhaust cone shape joint
Curved to the right

 

[Dr.Jeff]

I love it when something requires purchase of a new tool/equipment to complete, making that purchase "justifiable"...even if it costs 10 times what it would have been to get it done by a local shop. There is something satisfying about doing it yourself.

Thanks for the manifold input. Interesting difference in outlet sizes. I'm not certain if my information is completely accurate, but I believe "7691880" is the late style Euro spec manifold found on models like Punto, etc. If that is true then I'm really surprised it has SMALLER outlet ports than the other manifold, which I believe is an older model. I was under the impression the newer versions performed better (however that was determined). Perhaps we will learn more as we collect more data to compare with.

 

[AKimball92]

I love it when something requires purchase of a new tool/equipment to complete, making that purchase "justifiable"...even if it costs 10 times what it would have been to get it done by a local shop.
...
I was under the impression the newer versions performed better (however that was determined). Perhaps we will learn more as we collect more data to compare with.

Yea I might have to take my car elsewhere or use a tech shop around here to do the work. I scour craigslist and Facebook marketplace about every other day trying to find the correct welder that fits my needs. I've been a welder about 8 years now and haven't had one in like 2 years. The crave is real!!

I think for which 4-2 manifold performs best might be down to the individual engine set ups. I've had a class on this and am trying to set us the analysis like we touched on. This time the struggle is real! as I haven't crunched any numbers in that same two years. But it all might come down to the primary and secondary lengths and diameters. If I had access to the WAVE program I could perform the DOE but I don't anymore. I might be able to solve it for a couple variables though given many of ours are fixed. OR Steve and those others who have sought to optimize these engines for years already know the answers and performed the calculations.

I just realized you might have missed that the second manifold listed was a 4-1 and the first a 4-2. The 4-1 outlet has by far the smallest cross sectional area of either end of either manifold.

 

[Dr.Jeff]

just realized you might have missed that the second manifold listed was a 4-1 and the first a 4-2

I completely missed that, no wonder the diameters were off. I need to go back through this thread and review things (think I even missed a couple of posts/edits).

Welders have certainly come a long way in the last couple of years. The technology is absolutely amazing...as is the price, amazingly high.

 

[Dr.Jeff]

Thanks to "mkmini" the port dimensions of the Euro spec 1600 Punto manifold (p/n: 7691880) are confirmed as follows:
Inlet ports = 28.5 mm
Outlet ports = 33 mm
Judging by the part number, this manifold appears to be the most common unit sold by the various vendors as a new replacement (the same one "AKimball92" noted above).

With regard to the inlet and outlet port diameters, it's interesting that we are not seeing much difference between any of the various manifolds so far.
In an earlier post I listed the following: "128 Rally 1300, part number (as given to me) 1612182, inlet ports 30mm, outlet ports 34mm". However that information was sent to me from a seller on eBay and we had a bit of a language barrier. So I am not 100% certain if it's accurate, or how the measurements were taken, but the diameters appear to be the largest of any so far (marginally). Although I suspect in reality they are the same as the others we're getting.
So far I'm not finding any specific part numbers or actual dimensions for the elusive "large port 1600 Euro manifold".

A few SOHC 4-2 exhaust manifold numbers & photos I have

Jeff, if you have some of these manifolds on hand could you please take some measurements of the inlet and outlet port diameters? I'd like to compare them to the ones we already have. Thanks.

 

[fiatfactory]

I actually have three different 4/2 manifolds on my workbench right now, in the morning I'll take some pics and measurements for you.

SteveC

 

[MikeHynes]

It would be interesting to know the volume of the manifolds.

 

[AKimball92]

Revisiting this thread as I have gathered some more numbers. Always on the look out for new exhaust manifold and cylinder head findings. This is what I have so far. Does anyone have any different readily available?

 

[dllubin]

Revisiting this thread as I have gathered some more numbers. Always on the look out for new exhaust manifold and cylinder head findings. This is what I have so far. Does anyone have any different readily available?
View attachment 12104

Andrew:

I checked the original exhaust manifold from my CA car (build date 6/74) and can contribute the following:

Casting number: 4510369(space)2
Inlet port: 27 mm
Outlet ports: 32 mm
Center outlet
4 bolt flange

Thanks,


Don

 

[ashmowerman]

QUOTE="dcioccarelli, post: 278875, member: 385"]So I'm using an Australian muffler which is exactly the same as the US one (stainless, hanging from a spring mount). The only difference is that in Australia the "test pipe" was factory ;-)

Here are some photos of the 4:2:1 config I'm currently running. Basically, the cast 4:2 manifold, a stainless 2:1 down pipe from a CSC exhaust (that was far too loud) and some flex stainless exhaust that connects directly to a US style stainless muffler (because I don't have a welder).

Cheers,
Dom.


I will throw in my 5 cents worth Australia 85s Regata 4:2 manifold 3990667 28.8/33.5 plus custom pipes to standard stainless

 

[Dr.Jeff]

Ash, I like the down-pipe.