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[kevin]

Jim, i have your 24v manifolds . Pm your address details and i will get quote here to freight them . I will send pics.

[Zagato]

Talking about manifolds, is there a supply somewhere of manifolds for 3L 12V along the lines in the book?

[Jim K]

http://www.myalfa.eu/product_info.php?c ... 75-V6.html

http://www.ebspares.co.uk/news12.htm

http://www.performatek.com/frOnlineCatalog.htm

http://www.centerlinealfa.com/cgi-local ... 1352174316

There are many other vendors worldwide that carry these exhaust systems.

Jim K.

[Zagato]

But these are CSC or very similar, that would mean too small in diameter? I already have ANSA (the ones that CSC copied) and Supersprint. Both most fitting for 2,5L.

[Jim K]

There is nothing larger available commercially. I tried to have a set made with 42mm OD primaries (CSC has 38mm) working with THS but it proved to be not feasible, as they didn't have a V6 car to try it on. They faithfully copied the CSC I sent them as a pattern, but when I received the set, it fouled the chassis in several places and installation was not possible. I had the set corrected in Athens (for...1100€!) and its in my 3liter 75 -which I sold last week to a friend. If there's enough interest around for a run of these manifolds, maybe something can be done...just a thought!
Jim K.

[75evo]

If the car has mildly ported heads and stock valves, what is the point of big headers? Jim's car had oversized valves and a mega port job. As long as the stock cast iron manifold's crazy entry angle is eliminated, then you should be ok with any headers out there.

Doesn't Glenwood have something close to being long primary headers? I looked at Kevin's post. If they are 40mm primary ID or bigger why not? Bulk order a few of them.

Actually I even asked Alexis Walters (scuderialfa on youtube) about the sodemo headers. Nobody wants to make them apparently BTW his car revs to almost 8K rpm!

[75evo]

If the car has mildly ported heads and stock valves, what is the point of big headers? Jim's car had oversized valves and a mega port job. As long as the stock cast iron manifold's crazy entry angle is eliminated, then you should be ok with any headers out there.

Doesn't Glenwood have something close to being long primary headers? I looked at Kevin's post. If they are 40mm primary ID or bigger why not? Bulk order a few of them.

Actually I even asked Alexis Walters (scuderialfa on youtube) about the sodemo headers. Nobody wants to make them apparently BTW his car revs to almost 8K rpm!

[Jim K]

Since very few people bother with 46mm valves and extensive porting, the CSC pipe size is very good for most purposes, in the real world everyday driver; fact. For race engines however, if we go by established rules, pipe ID must be ~25% bigger than exhaust valve size....38.5x1.25 = 48mm ...Yes, yes, these are the sizes used in proper Godzilla motors...Ever seen the manifolds of the 4cyl M3 (all of 22 years ago!) But then, those mothers revved to 9200...
Have a look here:
http://www.e30m3project.com/e30m3perfor ... header.jpg
And see this:
Header Type...Primary O.D....Secondary O.D.
Stock 2.3L.....42.0 mm.........48.0 mm
Two-Piece......50.0 mm.........55.0 mm
Evo III........50.5 mm.........55.5 mm
* nominal tube thickness is 1.5 mm


Jim K.

[Zagato]

Jim, looking in your book, the THS manifold is a direct copy of the ANSA/CSC type with long primary pipes. When I use these i have a feeling that they are very good for midrange, but not so good for high rpm. The engine feels a bit strangled on top. I have tried engines with the ES30/SZ manifolds that has short primaries, and the feeling is that they are more willing high up in the rew range, but maybe not so strong on torque. Is this some thing you have considered?

[75evo]

Could be true. Look at the S14 (M3) race or even street engines. They have short but fat primaries. Good for top end power for high revving engines, which is where most 4-valve engines make their power anyway.

With some of the new lobe designs, you can make the 2-valve V6 make power all the way to 7K rpm. Only worry is the sodium cooled exhaust valves will drop or old-style rocker will break.

That's one reason why I'm not too keen on replacing my SZ manifolds because I think the biggest restriction of the stock setup is the entry angle of the cast manifolds. The exhaust gas just runs into a wall! Actually even Beninca told me, go for bigger but shorter primaries for a track bias car.

One thing I don't like about the SZ manifolds is that the collector is small. Compare that to the supersprint V6 manifold where the collector is nice and big.

[Jim K]

My first 3liter 75 came with CSC headers, so I never had cast iron jobs in my car and never even considered trying them on. The only comparison I ever did on the road with another 3liter 75 (who also had CSC headers) was with a std Jetronic engine (and gearbox) and he was generally faster than my std Motronic until about 3500rpm. That was the difference between cams (Jetronic/Motronic)
IAP sell short headers; they look like CSC tops with single collector. Has anyone tried those?
Jim K.

[Zagato]

Could be true. Look at the S14 (M3) race or even street engines. They have short but fat primaries. Good for top end power for high revving engines, which is where most 4-valve engines make their power anyway.

With some of the new lobe designs, you can make the 2-valve V6 make power all the way to 7K rpm. Only worry is the sodium cooled exhaust valves will drop or old-style rocker will break.

That's one reason why I'm not too keen on replacing my SZ manifolds because I think the biggest restriction of the stock setup is the entry angle of the cast manifolds. The exhaust gas just runs into a wall! Actually even Beninca told me, go for bigger but shorter primaries for a track bias car.

One thing I don't like about the SZ manifolds is that the collector is small. Compare that to the supersprint V6 manifold where the collector is nice and big.

Do you know the diameter of SZ Collector? To compare with my Supersprints!

[75evo]

I don't know the diameter. The inlets are 1.5" and exit is 2", but the volume is very small. One side is a parallel 3-1 and the other is like a triangular 3-1 collector. The supersprint collectors, visually, look a lot nicer. Some people say collectors aren't that important. But if you speak to people at burnsstainless.com they will say otherwise.

[Zagato]

O.k. Thanks anyway. Does anybody know if CSC still makes the SV manifolds and exhaust with bigger diameter tubing? It was sold by AV-Delta in Germany.

[Giuliettaevo2]

You could ask AW-delta... www.aw-delta.de