exhausting work

[tbone]

Not being a proffessional metalologist i have to show warts n all or i`d have nothing to show  .
Seriously tho, theres no point me pretending i`m better than i am and that i get everything right first time, i dont, like a lot of guys out there i`m a bloke in a shed with basic skills thats willing to give it a go.
I think the hardest part of any project is overcoming the fear of failure,and having enough confidence to try n do things, i know my engineering `skills` will never win any prizes and i accept that, and i certainly dont set out to offer a masterclass in any subject (others here are far more capable of doing that), but if my warts n all attempts prompt someone else to think " if that idiot can do it, then so can i" then i`m happy to show them. 

[Manky Monkey]

You're showing exactly what the majority of us are doing out here TB -Great British shed engineering.
One of the most common comments we get here is that we show the real basics, the stuff newbies really need to know, which many sites either assume everyone already knows or won't lower themselves to explaining. Everyone's got to start somewhere & we don't all have more experienced mates or whatever to show us how. If we don't tell 'em, who will?

[Mr_G]

I've learned alot from this site as I'm sure many others have!

[Manky Monkey]

So have I -don't accept Jaffa cakes from strange Monkeys for a start. 

[brock]

   regarding the misalignment of manifold to head, it's not unusual to have the manifold slightly larger than the port in the head providing an anti reversion barrier, ie. preventing the inversion pulse from exhaust from applying back pressure to exhaust valve, our race heads are CNC milled in the exhaust runners with a series of very small radial steps that serve the same function, not highly polished as used to be the theory, I was quite disapointed when they first arrived thinking that for that sort of money I would have expected a better quality of machine finish  
   So as not to drag this to far off topic, whilst browsing my EBay favorites earlier for a tube supplier I found this:

  http://stores.ebay.co.uk/Tube-Bending-Fabrications_W0QQcolZ4QQdirZ1QQfsubZQ2d999QQftidZ2QQtZkm

   might be of some use to people building exhausts.

   Further to the slotted hole saga, piece of piss to do that, I've got a scrap bin of bits half a hole diameter out, I now keep a stock of 6 and 8 mil MDF offcuts to make templates from, much easier to bugger it up in glorified cardboard than steel, almost worth risking a couple of quid in B&Q to get a quarter sheet ?

[tbone]

Thanks for the confession Brock, its hartening to know i`m in good company 

[tbone]

Happy in the knowladge that i can make the flanges, its time to take a slightly different approach. Picking up from Brock`s top tip, i pulled the inlet manifold off and used the gasket to draw the holes onto a piece of paper. Then using my first attempt at a flange as a template, i transfered the shape to my drawing.

[tbone]

So then it was time to think about the pipes to connect to the flanges. The inlet manifold,albeit cast together, has two sets of small pipes, 30 odd mm outside diameter, to keep with the look of this i`ll use something similier for the exhaust manifold. Using larger pipe just doesn`t look right, as you can see, but i`m also hoping that by using smaller stuff it`ll be easier to shape off the head and it`ll be easier to fit the main exhaust pipe or pipes (cos i may go for a twin exhaust  ) into when i get that far. For now tho, i need to nip out and source some 1 1/2" id pipe, dont you just love these real time build postings 

[tbone]

The two outer ones are fine, i`m puzzling over the inner ports though. So far i cant get enough bend in the pipes to clear the inlet manifold 
1 1/2" is too large, tomorrow i`ll see if i can find some 1" id, this will still clear the ports but hopefully allow me a tighter bend.

[Hagar]

Looking good  .......   I would'nt push that 12 bore cartridge up there though  ......   

  ..  Hagar  ..   

[tbone]

Question for Brock, or anyone else that might know.
R.E back pressure, at what point (i.e. distance from the ports), if any, would it be `safe` to stepdown to a smaller bore in the exhaust system?

[ROD]

Sorry ,cant answer that,but ...just my 2p...if you cant get the bends tight enuf to clear the inlet manifold using a complete 90 degrees,what about bending the tube with as tight a rad as you can then fit the flange part way round the bend?ie sorta slash cutting the tube @say the 45 deg mark?

[Clive]

Or make a much thicker flange that the pipe connects to from the bottom with the 90 deg change of direction within the flange?

Clive

[tbone]

Rod, yep,thought of that one,will work if i can source some 1" tube.

Clive, i like your thinking, i`m considering a block welded to the flange that i can connect a pipe to the bottom of, hence my question to brock

[Manky Monkey]

I had to make up 2 inch extensions for the carb manifold, to bring the carb out clear of the petrol tank, (have you thought that far ahead TB?). More by chance than design, that means I can get away with less restrictive bends on the exhaust manifold.