How to put the hole in the head for bypass hose
Turbo Mini Forums

Hi all, I have a bypass hose which I will be using, just wondering how to put the hole in the end of the head? Being on the end of the head is it possible to do with a mill?

www.topcatcustom.co.uk

Personally I would just mill a spot face (flat area) then drill/tap.

Two things to bear in mind,

1 - if you use the genuine Leyland/Rover stub it is the weird non-standard thread size same as the crank tail - taps are expensive.....

2 - where the hole enters the head casting waterway there is very little space before the other side of the casting so a normal taper tap may not fully cut the thread before it hits the other side and stops....


EDIT - I presume you are talking about the normal bypass connection, not dry decking or similar ???

Edited by Rod S on 17th Dec, 2012.

Schrödinger's cat - so which one am I ???

My head had a plastic bung in the hole for the bypass takeoff.

For dry deck ports, I believe Carl did mine on the mill. I now have a pillar drill with a rotating table, so could do it on there in theory.

Sorry I meant dry deck type bypass hose, the big one around 1" diameter!

I have a mill but not sure how I would hold a head on end as it would be a long way sticking up past a 90° angle block!

www.topcatcustom.co.uk

Or you could fit the spacer under the thermostat housing and plumb it to the bottom hose. Does exactly the same as the little bypass hose, just a slightly longer route.

Sorry, just re-read your last post......

Edited by ado15 on 18th Dec, 2012.

Steve
DSN Classics Ltd
www.dsnclassics.co.uk

Angle Grinder, get it nice and flat, 1" hole cutter. Then use RTV!

Piece of Piss.

1/4 Mile 14.3secs 96Mph Terminal 10psi of boost.


Fibreglass Parts? - http://www.tdkracing.co.uk/
Split Rims? - http://www.force-racing.co.uk/

Ahem, mine hasnt leaked yet lol

1/4 Mile 14.3secs 96Mph Terminal 10psi of boost.


Fibreglass Parts? - http://www.tdkracing.co.uk/
Split Rims? - http://www.force-racing.co.uk/

The head that is not the tin shed...That leaks lol

1/4 Mile 14.3secs 96Mph Terminal 10psi of boost.


Fibreglass Parts? - http://www.tdkracing.co.uk/
Split Rims? - http://www.force-racing.co.uk/

I guess I could side mill a flat on the end of the head, then drill through to 25mm by hand or on a pillar drill, it's only got to be watertight after all!

www.topcatcustom.co.uk

On mine I clamped it on a 45 degree angle block and rotated the head 45 degrees, used an end mill to create a flat (granted I then flattened more than I wanted), and then drilled it in a pillar drill with a rotating bed!

I haven't tested it yet, but it looks alright!