Small block chev trigger wheels

[Stephen Dean]

Hi guys

Just trying to get some stuff sorted before I head down the wrong track.

On a small block chev with a m800 and cdi8 individual coil setup, I am looking at running a simple 60-2 steel wheel mounted of the back of the harmonic balancer crank hub for the ref signal. Would a gt101 be suitable or is the resolution to fine? What would be a recommended sensor for the 60-2 missing tooth wheel of the gt101 is no good?

For the cam sync sensor, would this setup from Holley work ok? It's a single magnet installed into the belt drive aluminium hub.

http://documents.holley.com/199r10801.pdf

Thanks Petar

IMG_7767.JPG (673.13 KiB) Viewed 16776 times

[Sean]

Petar, what is your application, and how hard will you be turning the engine? Internal or external oil pump?

I don't see why 60-2 can't work, depending on revs and sensor. We run 40-1 with a Delco mag sensor. There's a few posts on here mentioning that GT101 doesn't like missing tooth modes, I have not tried it myself

You realise that with that Holley cam sync thingy you cant run a water pump? Or at least one that mounts conventionally.
I changed 3 of the nuts and bolts holding the Jesel pulley to the hub to titanium, and left one steel, then used a Delco magnetic sensor reading off the one steel bolt for the sync. Sensor is on a bracket that sneaks it past the water pump.

[Stephen Dean]

Thanks for the feedback Sean

It's a majority street/ drag setup. Hoping to turn 8500 rpm

I'm running a remote Meziere water pump so clearance shouldn't be to bad.

I was going to mount the trigger wheel of the back of the crank hub to give me some more room out the front of the engine, only running a single serpentine belt for the alternator which will run of a crank mandrel.

Doing some more reasearch it looks like I'm far better with a magnetic sensor and the 60-2 wheel for the crank

And a mag sensor and a single steel pin for cam
Sync. I might do the same as you and run titanium hardware for the belt drive and just pick up of the one stud.

The pic below shows the front setup, ignore the msd pickup that is going.

Thanks

IMG_7778.JPG (1.53 MiB) Viewed 16751 times

[Sean]

It appears to be wet sump with an internal pump, given no belt driven pump off the front? If you are running std style sbc oil pump setup you will need a distributor stub anyway to drive the oil pump, so you could use that for cam sync.

There's no easy way to attach a trigger wheel to the back of the ATI damper hub, you won't have room to run it between the damper and the front cover without spacing the damper forward, and then you still have to locate off something.
You may be better to make a trigger wheel that is hollow, and fits from the front back over the damper. You can make the mounting face quite thin, maybe 3mm , so it doesn't move your mandrel out far.

[PetarL]

Yep that is correct, it's wet sump and I was going to use a msd distributor block off,
Was there any other brand that has the cam sync inbuilt as that will surely make things easier.

This damper is a two row one so buy making a 1/4" aluminium spacer and a 3mm trigger wheel it just fits with low profile bolts, bolts will pass right through to act as studs for the crank mandrel.


It will be tight but I'll give it a go

Thanks again

[Sean]

Maybe something like this.... https://www.eficonnection.com/home/prod ... bc-engines There's a few options, but takes a bit of googling. MSD used to do one but discontinued it years ago due to slow sales.

If you go with a 3mm thick trigger wheel you will need to face read with the sensor, likely it will be too thin for edge reading. Maybe you can thicken the trigger wheel once its outside the balancer shell.

Can I ask how many cubic inches? What stroke? A 2 ring 6.325" damper only has a 2,2 lb inertia ring.

[PetarL]

Hi Sean

It's only a 383, 3.75 stroke 4.030 bore

It's a 7" 2 ring dampener

Assembly is very light weight gear, je pistons, Oliver rods, Lw lunati crank

All of it was "overbalanced .5 percent) for a 8500rpm redline.

Ati claimed the 3 ring balancer doesn't clear the belt drive so I didn't have much choice, looking at it I have around 12mm of clearance from the back of balancer to the belt drive so it probably would have been fine to run the three ring.

If I swap this out for the three ring I would probably just get ati to cut the trigger wheel into the balancer


Thanks

[Sean]

The 7" 2 ring will be ok for you I think, certainly better than the 6.325" 3 ring. If you get more serious with the combo I would recommend going to a 3 ring one, we run the heaviest 3 ring 7" in a road race application at 3.8 stroke.

Good luck with your project.