View Full Version : How to Ream an odd(?) sized hole

08-28-2004, 01:08 PM
Hi I'm new to the forums and have a quick question on general machining.

I am making a new fuel rail to respace some motorbike throttle bodies to fit a Weber DCOE manifold and the injectors I am using require a Diameter 10,80/10,85mm Hole (this hole will need to have a good finish to help the O ring to seal) I have never had to drill and ream an odd sized hole and was wondering how to go about it ?

Does anyone have any advice ? I am little lost to say the least :) (used to specifying the tolerances not trying to hit them :banana: )

Regards ~ Mike 'Last Minute' Rallying

<edited to change the size of the hole>

08-28-2004, 02:08 PM
The injector supplier should carry the reamer needed. If not almost all reamer manufactures will take orders for non-standard sizes.


08-28-2004, 05:15 PM
You can buy adjustable reamers that will cover this hole size, they are made to cover overlapping hole sizes from small to large dia. Just get one that covers your requirements, adjust it using a mic or vernier and your ready to ream. Try to use it on some form of fixture to hold the reamer as you turn it....a lathe or stand drill works great...if not just use by hand and take your time...keep checking alignment with a square untill your are through.


08-29-2004, 05:30 AM
MSC advertises reamers in the size range you need.


08-30-2004, 10:04 AM
If you are going to machine ream the hole, leave about .012 - .015 stock for the reamer to remove. If you are going to hand ream it, you might want to drill a bit bigger - leaving only about .005 stock to remove.

08-30-2004, 10:12 AM
cheers for replies, think I have got it covered for now as I have found another fuel rail that fits the bill. Will keep all this is mind as I will be making another to replace it once the car is running.

Cheers ~ Mike

08-30-2004, 09:09 PM
You can get a standard, next size up ground down by a tool grinding shop.