FX Holden Race Car Project

[Holden202T]

I never posted any info about this before i dont think, but my plan when i rebuilt the motor last time was to machine down the mechanical fuel pump lobe into a tooth so i could use it as a home signal, so i didnt need to use the cam sensor on the dizzy i made, mostly for neatness.

so i made up a little jig to hold the camshaft in the vice and be able to rotate it in small increments, then i spent many hours hunched over a mill turning it down into a single tooth trigger.

FX Cam3.jpg (51.87 KiB) Viewed 5931 times

FX Cam4.jpg (52.64 KiB) Viewed 5931 times

FX Cam5.jpg (42.33 KiB) Viewed 5931 times

here you can see what a stock fuel pump lobe looks like ... and this is as far as i could get the sensor into the motor, it was a few millimeter gap so i was hoping it would be enough.

FX Cam1.jpg (70.08 KiB) Viewed 5931 times

FX Cam6.jpg (73.13 KiB) Viewed 5931 times

i had no end of issues trying to weld these two parts together so i gave it a good coating of JB weld 1. so it wouldnt leak, and 2. i hope to actually 3d scan this at some point and see if i can make one that will take an off the shelf sensor with a retaining tab that screws on.

FX Cam2.jpg (148.39 KiB) Viewed 5931 times

so with all that sorted i fired the car up and to my surprise it all worked! full sync!

IMG_8828.MOV

(3.4 MiB) Downloaded 144 times

[immortality]

Nice, great solution for a cam sync.

That would work on a 304/308 too but easier as the fuel pump cam is bolt on, on the front of the motor.....hmmm possibilities.

[Holden202T]

Oh yeah just cut most of it off and leave a tooth!

[VK_3800]

Well done, I never thought of using the fuel pump eccentric.

[vlad01]

That's a bloody good idea!

Not related, but I thought I'd post this. This is a local one that appeared in recent months. Took this pic at the petrol station a few weeks back.
Just noticed the dude in the background on the right lol.

[Holden202T]

Where's Wally haha

[heff0018]

Great idea for a cam signal & JB Weld should be fine on something like that.

[Holden202T]

Well i should have posted this a while ago, was an interesting weekend!

I had seen boost creep on the dyno prior to this, i thought it was just from heaps of power runs back to back and the extra exhaust heat making it higher boost.....

Turns out i had the same issues at gunnedah drags, and they turned into overboost cuts on most runs, then towards the end of the weekend i started to have issues of no boost on the start line, this was the end of the day anyways and i just dealt with it as there was nothing i could really do anyway.

So this was the best run of the weekend which had lots of boost but managed to not hit the boost cut! traction was an issue all weekend too!

https://www.youtube.com/watch?v=11Fln057ixE

So when i got home i pulled the wastegate off and everything became clear, i could not move the gate at all by hand, i ended up pulled the gate apart and hammering the valve out of the hole, there was a big bur down the valve stem

wastegate.jpg (52.24 KiB) Viewed 1104 times

i have almost always had boost creep with this car and i thought it was just the gate was too small, but it potentially has been the gate the whole time. i looked back at old logs and it looks like there was a time when it wasnt creeping!

[brindo]

Just an aside after seeing the JB Weld on the sensor again etc.
Had a similar issue recently with a sump repair where it wasn't practical to remove the engine to fix it properly and JB Weld was the go to.

But there is this product here. https://www.polywater.com/en/product/po ... ak-repair/
This stuff is not cheap, but it works. It handles a fair bit of temp and pressure too. Its not for everyone, but its something that until recently I didn't know existed, and might get someone out of strife one day.
I'd be confident the JB Weld will last forever where it is, but this PowerPatch stuff might be an alternative for anyone interested.

[Holden202T]

my goal with the JB weld was to actually shape it how i wanted, then 3D scan the part and hopefully then be able to use that to get something made! I also wanted to make it slightly longer so it could be machined to take an off the shelf sensor .... all part of the 10 yr plan