Projects My GN Cycle Car tribute build

Tough days. Hopefully you have some good memories which brings light to the darkness.

 

Thanks guys for your thoughts. Much appreciated. It has been a tough go the last three years especially dealing with all the Covid BS on top of it.

 

Started on the frame! Wooden jig made, but they gave me one incorrect size bushing which I installed in the centre position. Also, due to the 6” length of the bracket, it hit the spindle before I can align the drill bit with the spindle. I think I have a longer 3/8” drill bit,

 

It’s a start. Wood is already cracking. Will add a few screws. The L-bracket is not exactly bent at 90 degrees, but easy to position. Looking at this, I realize I will now have to add some triangular shaped pcs on the top and bottom to stiffen the crossmembers. Also need to think this area over a bit as the front friction shock and engine mount towers need to be located/installed. Will need to do a bit more layout work. Hopefully, I can get all four crossmembers installed by the end of the weekend. Next will be working with the oak beams to fit them in all the C channels.

 

Made bracket/joint for front crossmember and RHS rail. Cut rear crossmember. Issue is rails were supposed to be 3.5” in height, but they are slightly less, so I have to sand down each bracket to match height of rail. Also, the bends in the rail are not exactly 90 degrees, so that compounds setting up the brackets when drilling. Was setting up to drill one of the rear crossmember brackets and had issues setting it up. Then noticed the length of the top and bottom of the crossmember were not the same, so this resulted in it being canted or angled when setting it up on the drill press. It’s frustrating having to deal with all the inconsistencies in the frame rails as it takes so much more time to compensate for them. Pic below of the rear crossmember. It was cut off from the end of the RHS rail piece just as the front crossmember was cut off from the LHS rail. Due to the bend not being exactly 90 degrees and the fact that the left side is a bit longer than that of the right, it results in a fairly substantial gap when a straight edge is used. The gap at the other end of the crossmember is not as noticeable. Not sure yet on how I will deal with this.

 

A great build. A friend of mine has a Fraser-Nash - (being the partner N in GN the new company after GN folded,) - which was a factory racer, after time the twin supercharged Goff engine was replaced with a flathead - a 99a - & continued to be raced, in the immediate post war period. The chain drive was replaced with a gearbox & I am not sure what was done with the rear axle. Keep up the good work.

 

Interesting. Wish we had all the good bits on this side of the Atlantic. Was actually thinking of cobbing up a chain drive, but then gave up on it.
Need to do the layout tonight for the triangular gussets for the crossmembers, as well as the engine mount brackets. Also ordered 4 sq ft of 11Ga for all the bits. Picking it up tomorrow.

 

We're are you getting your metal now a days?

Phil

 

It's all in the definition of what the 'good bit's' are lots of Aussie's look to the States (I know you are in another Commonwealth country.) For the cool cars & parts a plenty. & Some look to Europe. We do have a reasonable survival rate though.

 

Mostly Loucon. They bent the frame rails and made the brackets. Used to go to Metal Supermarkets but they had issues during Covid and they can’t do any value added stuff like bending. Also picked up lighter stuff from MetalPros for my IH project.

 

Very nice! That is exactly what I need to build. What axle is that?

 

Hello, I follow this project since beginning, nice build. I also working on a JAP build, but that is not a real deal just a cyclekart. I wish you much endurance to finish your project.

 

That front end is a new replica of an original front end made with high tensile machined fitting's & forgings. It was made at work, we have a couple of GN's going together at the moment.

 

Excellent! Looks awesome. I think I’ve seen a vid of a GN JAP inspired cyclecart. Watched them race in another vid and they said it was the most fun they ever had.

 

Excellent! Looks like the real deal. I just got the JAP logo on the engine.

 

What are your front end plans?

 

Was just going to reuse the front spring and axle from a Model A I picked up when I started this project.. Same for rear, but of course I’ll cut the springs in half. This was supposed to be on the cheap (less than $10K) build project. I did see a straight axle way back from Speedway which would have been better, but at the time, it was around US$300. Can’t imagine what it is now. The other issue is of course the width of both axles. Too wide of course for what I require, but again I want to keep the costs down.

 

Original GN's were about the same wheel base as an A. 102" ish
The front axle was also much wider than the rear,

 

Always wondered why that was. Front axle wider than the rear? I’ve seen stuff of how folks have shortened the Model A real axle, but seems like a lot of work. I’ll be going with wide rear tires like the 3D model in Petro’s creation, so I can offset the width of the rear axle a bit with some offset rims if that doesn’t get crazy expensive. I’ll need to watch Bennetts Customs again to refresh my memory on what his proportions were on his incredible build. Maybe it won’t be an issue as his body/chassis was pretty narrow IIRC. I had to lengthen my WB to About 106” to accommodate my 6’-6” height and 34” inseam.

 

Interesting enough. This just popped up as the next vid after watching a recent Goodwood pre-war one.

 

I'll see if I can find it but there is a build thread by Jordan Bennett here on the HAMB.

The wider front track was about road stability, think Morgan 3 wheeler.

 

The GN's had no differential, just a solid axle (think spool) To make them less twitchy in turns, a narrow track was used. Same reason dragsters have super narrow rear tread width. The two tires close together, act more like one, so as to less likely misdirect the car's trajectory. Up front for cornering stability and roll reduction, the track was wider. GN's were a real cross between a car and a motorcycle.

 

I would like to see that build thread. Was watching a few of his 29 Roadster build on the 32 frame. One of the better ones where he pints out all the subtle differences. At least for a newb like me. Ordered a couple of his tees as well. Lol !

That makes a bit of sense. When watching that Goodwood race there were a couple of GN’s and the Owlet. Really beautifully executed controlled slides in the corners. The forerunners to today’s drifting cars. Lol!

 

Also did a bit of layout work. Sorry about the poor pic, but I ran out of tracing paper so used some old plotting paper from work. I think I figured out how I’m going to integrate the front engine mounts to the frame rails and front crossmember. Had me scratching my head for a bit, but I’ll just make my gusset big enough to provide sufficient surface area for a box like engine mount tower to sit on. Gusset will be hot riveted in place with the engine mount tower either welded or brazed to the gusset. I’ll use the 11 Ga material for everything.

 

While working today on the frame brkts, and looking over the engine, it dawned on me that I didn’t give any thought to clearance for the tubes that will need to connect to the water pump outlets. After a bit of research, I found some 180 degree copper pcs that I might be able to fit inside the water pump outlets. I could braze them onto the pumps saving me some room because they are are avail in a 32 mm ID with a 1.2 mm wall. I measure the ID of the pump outlets at 35 mm. Assuming I can do that, they will still slightly interfere with the front crossmember with the engine mounts drawn as located. To clear the crossmember, I would have to move the engine mounts rearwards by about 3/4” - 1” depending on how much clearance I wanted. Another option is to rotate the 180 degree bend towards the chassis centreline to clear the crossmember. It would clear the pulley and v-belt and likely the front of the oil pan, but then would need a dogleg to clear the rest of the oil pan. Think I will just move the engine back an 1”.

 

Pic of the 180 degree bend pcs. Avail on eBay, by from UK. Will message them for more details tomorrow. At one of my previous jobs, all this would have been so much easier, as I would have had access to our metal shop, CAD folks, and vendors. Oh well…

 

Got the front and rear crossmembers bolted in place to the frame rails. Not much to see really, but for me this is a major milestone to see the chassis starting to come together.

 

Here is his looonnng build thread
https://www.jalopyjournal.com/forum/threads/bennetts-‘midnight-special’-speedster.1257714/