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Boring a hole?
coozer - 19/1/14 at 06:58 PM

I need to enlarge a 38mm hole in my V8 manifold to take a piece of 1.75" tube.

Will a hole saw be accurate enough to ensure a good seal?

Say I run a 44mm hole saw through and use emery paper to enlarge to a nice snugg fit?

Basically I want to replace these tubes with 45mm 60 degree bends..

gingerprince - 19/1/14 at 07:10 PM

Based on the subject title I was expecting this thread to be about an exceedingly dull and dislikeable person! (boring a-hole).

rusty nuts - 19/1/14 at 07:23 PM

Unlikely to be accurate as a hole cutter relies on a drill bit to centralise the cutter. Scribing around the ram pipes and using a file or die grinder would be better if you have to do the job by hand

BenB - 19/1/14 at 08:15 PM

Have you got a 38mm hole saw? If so clamp the workpiece to a big old bit of wood. Put the 38mm bit on the drill, insert into the 38mm hole and therein drill the center hole, swap to the 44mm hole saw and job's a good'un.

ste - 19/1/14 at 08:30 PM

If doing the above, when you move onto the bigger hole saw, swap the drill bit in the centre so it faces upwards and the shank of the drill will spin in the hole in the wood and not enlarge it

theprisioner - 19/1/14 at 08:51 PM

Clamp on to milling or vertical drill bed and use a Rotabroach. Rotabroach is +/- .25mm depending on well you clamp it possibly use a custom mandrill.

MakeEverything - 19/1/14 at 09:19 PM

quote:
Originally posted by ste
If doing the above, when you move onto the bigger hole saw, swap the drill bit in the centre so it faces upwards and the shank of the drill will spin in the hole in the wood and not enlarge it


Or replace said drill bit with a 1/4" rod.

The standard tubes are tapered so you'll need to understand the effects of replacing them with a parallel tube - unless of course youre not worried!

dave_424 - 19/1/14 at 09:30 PM

I don't know how thick the material is, but would a large step drill work? drill from both sides and grind out any part in the middle that the step drill can't reach

Talon Motorsport - 19/1/14 at 09:31 PM

Is that the bottom plate of an injection plenum? If so I have just thrown one in the scrap bin I also own a mill with an adjustable fly cutter.....

coozer - 19/1/14 at 09:46 PM

quote:
Originally posted by Talon Motorsport
Is that the bottom plate of an injection plenum? If so I have just thrown one in the scrap bin I also own a mill with an adjustable fly cutter.....


yep, how easy is it to cut?

Talon Motorsport - 19/1/14 at 09:51 PM

With the mill it's as easy as it gets, how ever if I remember correctly you are trying to join mild to cast ali?

coozer - 19/1/14 at 10:08 PM

quote:
Originally posted by Talon Motorsport
With the mill it's as easy as it gets, how ever if I remember correctly you are trying to join mild to cast ali?


Yep, I'm trying to make a manifold with mild steel. The tubes that are in there are stainless atm, I believe they are glued in..

Talon Motorsport - 19/1/14 at 10:32 PM

Just checking...

bi22le - 19/1/14 at 11:33 PM

I had to do very similar with an inlet I made. I drew round the tube with a sharpie and dremel out the last 5mm with a metal grinding wheel.

slowly does it but worked a treat.

redturner - 20/1/14 at 08:39 AM

I have a set of commercial vehicle king pin bush reamers which would make a perfect finish. Don't you know any one local who could do it for you.....

Krismc - 23/1/14 at 07:07 PM

quote:
Originally posted by gingerprince
Based on the subject title I was expecting this thread to be about an exceedingly dull and dislikeable person! (boring a-hole).


Coozer, I thought it was going to be about a Bore-hole. We just drilled one at work under a shopping centre 36 inch circumference 20 meters deep through rock. Took 4 days none stop.