Growing a Grumman - Part 10


Cooling System

After waiting 5 weeks for a local supplier to get me a new Mercedes 230 radiator header tank I gave up on that supplier and started shopping around - finally found one not too far away and got it fitted - the used one that I had previously had the slightest weep from a tiny crack in it's body - probably as a result of the smash that wrecked the car it came from! This header tank carried 2.5 ltrs of coolant and has a built in low-level sensor, so I now also have a yellow warning light just above the water temp. gauge on the panel.

All I need to find now is a suitable 1 ltr catch tank which fits in place of the Coke bottle (see middle pic) The suction return works fine however, although very little or no coolant is forced out of the header tank when the level is set correctly with a space for exapansion above the coolant level.

The belly housing for the rad is finally almost done - just had to add a nosepiece which I made of 2024 T3 - this is an expansion duct with diverging sides to allow for incoming air to slow down and pressurise before entering the rad cooling fins.

Without this duct, cooling was great - I suspect the duct may make little difference - we'll see once we can start testing the setup soon.


The ongoing saga of the brakes is still with us - but I managed to cobble together a correctly - sized brake caliper and piston from some bits I had lying around - this has the right size piston - 1.5in - and the pedal feels right and works great.

The left hand brake however is still the 2in piston, so has more pedal travel - until I can locate a suitable replacement it will have to do. However this caliper has no bleed screw only a blanking plug where the bleed screw used to be - once that is sorted out I sould be able to get a decent pedal on the left hand side!


More pics! Click the image for larger (1024x768) view - I have provided the large size images as I know you guys want to see DETAILS!

>>> Next - Part 11


Header tank from Merc 230 - 2.5 ltr capacity and stoutly built even though it's plastic - also lightweight.
Header tank position for easy access - just flip up the pax-side hinged cowl-section - also has low-level warning light - handy.
Underbelly rad housing - was hoping to make a swoopy curvy thing out of fibreglass - just could not bear the thought of working with itchy, sticky stuff though.
Yup it's boxy-looking - but it works!
Have not finished riveting yet - need to be sure it is easily removed for servicing of radiator before we finally close everything up.