Interesting info about the Briggs cars being raced against each other hoser, did you have any pics of the hand built engines? I've found some of the early water cooled conversion FL350 engines on the forums.

Looking to power my chassis with a 500cc parallel twin from a kawasaki road bike, on the hunt for a low kms CBR500r Engine too. Waiting on CV axles to arrive so I can figure out some track widths and suspension geometry. Still want to do the 5 link rear suspension, no rear A arms to build and more ajustable to make sure it cycles correctly.

Here's the tube chassis drawing I've been working on, drawn and redrawn a few times, rear tire is 24" dia the placement is just a quess for now with 10"/250mm ground clearance. Noticed the front A arms are only inclined 5 deg not the usual 10-11 degree for a mini buggy, again this is as accurate as I could get scaled from a side profile photo of the Briggs chassis.

If you haven’t already checked it out this link shows an Engine I picked up that is a 420cc?. I haven’t messed with it much so far other than to trade some parts I had for missing pieces. I’m waiting on a Pilot Engine to come back then this one should be headed out.

viewtopic.php?f=124&t=20659

I drew a bunch of versions of this frame a while back then lost my computer (It broke, Didn't physically lose it) So lost all the info.

You try recovering the data from the broken computer hard drive, usually you can remove the drive and install it into a drive caddy then plug it into a USB on a running computer and access the data.

Today drives are cheap enough you can get a external backup and store that type stuff then access from any computer.

Let me know if you need any other measurements of the Gen 4 car.