Keeping Cool

My apologies that it's been a while since my last post. There was more time to write these in the winter months. Spring sprung and I became busy with lots of projects and activities. I have actually continued to work on Penny along with everything else, but writing posts has fallen to low priority. I always find it amusing when the subject of finding things to do in retirement comes up. In retirement, I'll finally have time to do perhaps 50% of the things I'm interested in. 😜

I'm going to give up on trying to write about, and post-date work done in the past. From this point forward topical posts will be dated when I publish them.

The last post discussed removing the engine and transmission. Since then I've spent time on three general things, although everything currently relates to making sure the Mazda KLG4 V6 engine will fit.
 

Figuring out how to verify that the basic physical dimensions of the V6 will fit inside the engine compartment with reasonable accuracy. Keep in mind I do not want to alter Penny's body or chassis until I'm confident the V6 can be made to work. This becomes a bit chicken and egg, and is harder to do than you might suspect. I can't just lower the V6 in and check clearances because it doesn't fit without cutting away some of the firewall and chassis. I am making progress on this, and it will be the topic of a future post.
 

The transmission is also being swapped; the Triumph 4 speed is being replaced with a Ford T9 5 speed. The T9 will be used with either the Mazda or Triumph engine. Since the engine is the start of the drivetrain, the transmission fitment also affects whether the V6 will fit or not.  I've been working on the T9, and this will be a topic of a future post.

The third item is the topic of this post. Since the KLG4 was designed to be a transverse mounted engine, its cooling hoses come off of what will now be the front and back of the engine. Here is a picture of the back of the engine.

As mentioned, the firewall will have to be modified to make the KLG4 fit. Having a cooling line on the back of the engine only makes it worse. The thermostat is inside that assembly in the center where the tube makes a 90 degree turn. Not a convenient location to work on once the engine is stuffed in the car. In the Spitfire, that will actually be in the start of the transmission tunnel. Given how close this is to the driver and passenger, I'm also not happy about boiling water routed through here.

I spent some time looking into rerouting these pipes out the front of the engine. There is very little space to route them forward. This photo shows the front of the engine where the cooling tube is attached to the block. It is attached here and runs straight back between the intake ports.

Above it is the "other end" of the cooling plumbing, the cast aluminum part that connects to both heads. It contains temperature sensors and merges the two ports into one line that goes to the radiator.

Here is the same location with the rear directed tube removed, and the timing belt re-installed.

My first inclination was to route the tube forward through that small opening below the timing belt. To see if it could be done I decided to take advantage of my son-in-law Ken's generous offer to 3D print parts for me. First step was to draw a part in CAD. I'm an Experimental Aircraft Association (EAA) member, and one of the membership benefits is a discount on a non-production version of SolidWorks called 3DEXPERIENCE SOLIDWORKS for Makers. There is a bit of a learning curve for SOLIDWORKS, but the tool is amazing. My only complaint is that is only runs under Windows 😈 and not Linux 😇. My first approach was to create "leggo" tubing that I could plug together to come up with routing that worked.

We printed other elbows in addition to the 90 degree, and a few lengths of straight. This approach worked reasonably well, but it proved impossible to route through the small opening. I tried going up and out, but it became rather convoluted.

Eventually this would have to be implemented in aluminum! I tried a different approach where I created a part shaped to conform to the small front opening. This went through a few iterations, the final attempt being this.

I don't have a photo of the final version on the engine, but here is an earlier one.

The difficulty with this approach is that it has to immediately jog down and to the left to avoid the timing belt. Attempts to design a second part that would bolt to this part and accomplish that jog always ended up being very constricted. Eventually I decided I was spending too much time on a problem that might not even exist. After all the V6 might not fit. So work on this was suspended for now.

This work was definitely not a waste of time. It forced me to become fairly proficient at creating 3D parts in SOLIDWORKS which is a skill that will come in handy at various points through this project. It also proved the value of 3D printing parts to test ideas quickly and cheaply. Kudos and thanks to Ken!