Adapting Doghouse Oil Cooler to '69 Crankcase
by Jim Thompson
You must first change the stud on the top of the case. Ask for a Step-Stud. This is a stud with the original 6mm thread on one end and 8mm thread on the other end. Length would be 31mm. As a reference, the VW PN is N14402.1, shouldn't be more than 50 cents and these are used to repair the original 6mm Intake Studs on Single Port Heads when the hole stripped and has to be re-tapped to the next size up. Screw the 6mm end into the case so that the 8mm end is sticking out. Get a Self Locking Nut and a Spring Lockwasher (8mm thread/13mm Hex) to secure the the cooler stand there. In addition, you may have to *slightly* drill the "ears" on the case to accomodate the two 8mm studs on the other side of the cooler stand. Use 8mm Self Locking Nuts and Spring Washers there too.
DO NOT OVERTORQUE THESE NUTS. Book calls for 5 foot pounds. That's all that's needed. Otherwise you'll crack the cooler stand, break the mounting ears on the case or at the very least deform the seals from the case to the cooler stand.
Re: oil cooler rubber seals: What you need are two seals with different sized ports on each side of the seal. Large (10mm ID) side goes to the cooler stand, small (8mm ID) side to the case. The other seals to use for the stand to the cooler (if unattached) are indentically sized at 10mm ID on each side. Both styles should be in the gasket set. IMPORTANT! Do not use the real thick cooler seals that come in the gasket set - these are for Type 3 Squareback/Fastback engines/coolers. If you do, you will leak as the seals don't fit properly and they will deform.
METRIC HARDWARE LESSON #101: Lastly, an important note to all. PLEASE indicate the fasteners by their thread diameter size, NOT the Hex size. This will go a long way to properly identifying hardware when asking questions or placing an order. A 10mm Hex Nut could be either 5, 6 or even 7mm thread (6 is the most common), depending on it's application. Had a customer order two dozen "#10" Hex Nuts one time and dumb-dumb me, I sent him 10mm thread nuts (17mm Hex). I'm sure this would be a help to any place you order or ask about fasteners.
