Chapter 5 - An Evolutionary Design
So, the subframe was complete, the music played and the beer flowed. There were smiles in the camp at Qik Brix Racing. It was about the time that the subframe was finished that the QLD Mini Muster came around. So, in the interests of professional curiosity, my mate Tony and I decided to go along.
While at the show, I had the fortune to meet a really nice guy called John Carter, or JC to his mates. He had a 1963 Morris that he was putting a Swift Gti motor into, so when I told him about the Starlet, we kind of bonded right away. Most of you know JC on the forum as Whitestripe 63. It was JC who actually introduced me to this forum in fact.
Anyway, JC and I would form a strong friendship over the next year and a half, and in my book, he is a really top bloke. The first I saw JC's mini (Hefty) was when I offered to help him move it from his old digs to his new place. It was a really nice deseamed 63 Morris in Midnight blue with twin white racing stripes down the centre of the car (hence the name!). Anyway the car was delivered successfully but JC then informed me that he had sold all his GTi stuff and was intending to do a 4EFTE instead. Since he had no workshop of his own, I offered my place, and Hefty's new heart transplant was started in earnest.
Now, doing a 4EFTE in a Morris poses some serious design challenges. Its obvious that the engine bay is some 50mm shorter than the Clubman, and not as wide due to the way the inner guards angle in, and also it has a swooping bonnet line. So, some design criteria had to be adhered to to make the transplant successful. These were:
1. The motor had to sit far enough back as to get a front mount radiator in the engine bay
2. Minimal cutting of inner guards
3. No changing of the bonnet or bonnet line
4. Enough space at the front to allow the turbo to sit behind the grill.
5. The original Toyota factory mounts had to be in the std factory position (or as close to it as humanly possible)
6. Impact zones and crush zones still had to be engineered into the design
7. The engine had to be able to be removed from the top
Tough!!! So the std Qik Brix Racing (QBR) subframe had to be redesigned to accomodate the above. The drivers side spars would work with only slight modification - but the passenger side would need major rework. Lets look at the drivers side first.
Because the engine bay is shorter than the clubman, back-to-back, it became immeditely apparent that the drivers side spar would never meet the eyelets at the current angle of declination of the spar. Two possible courses of action.
1. Increase the existing angle until it meets the eyelet at the front at the same level, or:
2. Put another set into the pipe to get it to drop almost vertically onto the eyelet plate.
The second option was chosen because of two reasons:
1. The existing spar design on that side was rock-solid and worked.
2. Increasing the angle decreased the length of the underside supporting spar, therefore decreasing its supportive load carrying ability (not good)
3. The engine mount 'ears' on that side would have been grossly uneven, and would have been much harder to manufacture
4. The engineer had already signed off on my frame so why mess with a good thing!
Here's pic of Hefty before the operation:
The subframe stared out exactly as before - single spar on the passenger side with lateral and longitudinal support spars, and drivers side single spar with longitudinal support spar:
So, on the drivers side we swooped the spar down well after the engine mount position so that it met the eyelet plate. Then the spar was slach cut and welded into place. It was extremely important to keep the spar perfectly plumb throughout the process.
Right, passenger side. This posed some problems, but we decided that the easiest way of dealing with them was to keep the spar out of the engine bay altogether. In fact, the passenger side spar reflected somewhat that of the drivers side. The only difference was that the angles changed because we needed a flat (horizontal) area to locate the engine mount. The spar was slash cut at the end to make it fit onto the eyelet plate as per the drivers side. This is how it turned out:
OK, spars done and looking good. Onto the engine mounts. The drivers sdie posed no problems. Two upright ears straddling the factory mount, located in the existing factory position. This side always seems to be dead easy - and it is. The standard mount for this side could now be utilised. However, instead of making it out of 6mm 250 grade steel I decided instead to make it out of 340 grade 5mm plate. Much nicer and just as strong (especially in shear).
Now the passenger side. There was no way, come hell or high water (very biblical that!) that the passenger side mount was going to either utilise the factory cast mount, or be located in the factory position - no way, just not enough room. So instead, the mount was located higher than the original, and further rearward. To do this, a custom engine mount plate had to be made. This was done by profiling a length of 75 x 5mm 340 grade plate with a series of grinder cuts to the profile of the gearbox casing. This is what I mean:
Once the plate was drilled and bolted down tight onto the gearbox casing, it was tack welded, removed and then fully welded up. This is it back on the gearbox for a test fit. It utlised all six 12mm mounting points (rock solid anchoring!!)
The upstand part of the mount was then fabricated to allow the mount to be positioned in such a way that a box section subframe mount could be used. This mount took me one whole day to do - a lot of that was just in the design!! Once the pivot pin is removed, the mount can now be unbolted from the engine plate, and then the engine plate unbolted from the gearbox casing. Once this is done, it is easy to get the engine out from the top. here are three pics of the passenger side engine mount - I can honestly tell you I am very proud of how this came out.
Okay, onto the rear engine mount. The tried and true procedure that i used on my subframe for El Gato was used for Hefty - it was dead simple to make, and it worked!!! Why mess with it. Firstly, a spreader plate was cut and welded in between the 'ears' of the subframe and two blind nuts welded on:
Then the rear mount engine bracket was made. Simply, it was the same as what I had used on El Gato except the shape of it was modernised to follow the curves of the factory rubber mount:
The factory mount was then shortened. Once the engine-side mount was bolted up, and the subframe-side was bolted on, it was simply a simple matter of running in the pivot pin (engine mount bolt). This was high-tensile of course! Here are the pics of the finished product.
The end result was that we had heaps of room for the exhaust, and pleanty of under-car clearance.
Here is a pic of the finished subframe (with a smiling JC!). The cross-bar is in between the towers, and the subframe has been fully seam-welded up. Also, the tabs for the brake lines have been welded on (something I forgot to mention in Chapter 6).
Notice the front eyelet mounting plates. The return that you see jutting out to the front is for the link-bar between the eyelets. For the Morris, this link bar will be rmovable and secured by tapped 8mm bolts into the eyelet plate.
With the Clubman, the subframe is identical except the main spar angles where they bend down have been reduced slightly to cater for the longer back-to-front engine bay distance. Also, the passenger side engine mount is a straight forward drop-down mount consisting of two leaves either side of the rubber engine mount.
Here is the 4EFTE mounted in 'Barbie':
This is Barbie's drivers side mount. Nice and simple but strong.
And this is the passenger side mount. It gives good clearance, and keeps the mount in the factory position. Tony now has heaps of room at the front for radiator and FMIC!!
This is the design that QBR will stick with for any future Starlet conversions - simple, strong, and aesthetically pleasing.
A big thanks to JC for supplying all the photos of Hefty's conversion (thanks mate!).