Manifold Matching

[Owain1602 0]

hi, i have got my new peugeot inlet manifold gasket and im concerned about the ports my Mangelotti (sorry about spelling) inlet manifold has. They are nothing like the gasket or the head shape. I know a lot of people do some work on this manifold to match the port shapes.

 

It seems to me its the floor of the ports which require most work. Is it just with a rasp or file some of this metal can be taken away or do you guys use something else to do a better job of it? I was curious if the whole inside of the manifold could do with a polish as it seems quite rough.

 

Another area i was looking at is on the head. There is a recess going up on the head side of the port where the tip of the injector normaly sits. The corners that lead to the opening of the recess stick out of the gasket template, so if i matched the manifold to the gasket template, these corners will still be in the way of the incoming air. Is it possible to take away this chunk of metal and match the head side of the port to the gasket also? Or is it not recomended?

 

I am eager to know what and how you guys do it. Hope Puma Racing or someone else who does this sort of work everyday replies so i get an idea of how the pros do it.

 

http://i43.photobucket.com/albums/e396/owa...02/picsetup.jpg

 

http://i43.photobucket.com/albums/e396/owain1602/match2.jpg

 

http://i43.photobucket.com/albums/e396/owa...gasketmatch.jpg

[Miles 331 1 Cars]

I love these manifolds, They are fit for scrap and I do not know why anyone sells them, I would return it but no one else make them so it's catch 22. One reason I do not sell them.

To make them fit as they vary that much, sometimes some TIGing is needed to build the manifold up to enable porting or you'll go thru it. Allot of work needed to get a good fit.

I have thought about getting some good ones cast but demand is low so cost would be high.

[PumaRacing 1]

Fit all the studs into the head, put the gasket on and scribe out round the ports. You can match the head exactly to the gasket including blending back the 'ears' next to the injector.

 

Then scribe the gasket to the manifold and do the same but only open up to within about 1mm of the gasket line. You don't want the manifold bigger than the head anywhere and get a reverse step. At the bottom corners where you need to remove a lot of metal you also have to blend this back a long way into the manifold to get a good flowing shape.

 

Then you also have to check the carb end of the manifold as often this won't line up either. I have a specially made DCOE template for this but you'll probably have to squint through the carbs and see if there are steps anywhere. Finally the ports in the manifold can be improved and straightened a bit but be careful not to grind right through. It's thin in places especially next to stud holes. I do this by mounting the manifold onto the head and porting right through with long reach carbide cutters but you are unlikely to have anything that can reach in far enough. My cutters were specially made and are up to 8 inches long. Normal grinding burrs are only a couple of inches long.

 

You can spend several hours getting one of these manifolds right and it'll still foul the alternator mounting when you've done. The aluminium quality sucks too and will probably have lots of nasty little holes in it. I also run a 5/16" UNC tap through the stud holes as these can be a tight from the factory.

[christopher 5 1 Cars]

There will be many camps that tell you different stories about this kind of thing..so I'll won't give an opinion either way...

 

Some people will tell you its a crap manifold and you should match it and then it will increase flow velocity through the inlet..(some say exhuast too) Others might say that such a mismatch give the fuel a much needed trip up on the way to the cylinder so aiding in a good fuel mixing...especially in cold engines and at low rpm.....

Edited April 26, 2006 by christopher

[smckeown 1]

But no one else make them so it's catch 22.

 

Chadil are an alternative. I'll have one for sale next week.

Edited April 26, 2006 by smckeown