Toronado.org

Yes, use whatever the rebuilder recommends.

Here an update on what’s going on (sorry if I don’t explain it here, what I wrote on Instagram was kinda long haha):

https://www.instagram.com/p/CSTJi_Tr8NN ... =copy_link

Now's your chance to paint and detail the engine bay and paint the engine in the correct color, get rid of the nylon coated timing sprockets, etc.

With the engine out it will be very easy to replace the heater core, if necessary, or just for peace of mind.

Yes, hopefully I can paint the engine bay while the block is at the shop. I’m also planning on rebuilding the gearbox since there’s more room to remove it, and replace the timing chain with a double roller kit. Replacing the heater core sounds like a good idea, and I might or might not remove all of the air conditioning parts in the engine bay to make it cleaner (the system doesn’t work anyways).

What are nylon coated timing sprockets and how do they compare to a cast iron sprocket? I am planning on using a Melling high performance double roller timing set.

Also it’s possible to retrofit R134a into an R12 A/C system, right? I heard that adapters are needed, but not sure what else. I won’t have the money to make the system work any time soon with the rebuild, but I want to do some research by the time I can afford to do it.

In the '60s and '70s , GM used timing sprockets that were coated in Nylon as a noise reduction technique. Over time the nylon breaks down and flakes off the sprockets and often ends up clogging the oil pump.

They don't make them any more but you wouldn't want them anyway.

Otto Skorzeny wrote:In the '60s and '70s , GM used timing sprockets that were
coated in Nylon as a noise reduction technique.

Yes that was the excuse released to the public. I have been removing nylon cam
sprockets from my cars for decades, never could hear any difference in noise.
But I am sure a conversation like this was had in some private room. Bruce Roe

If we use nylon for the crank sprocket it will fail way too soon. But a nylon cam
sprocket will last well beyond the warrantee and probably beyond the first owner.
The inconvenience and cost of nylon replacement years later will encourage owners
to buy new cars instead or repairing their old ones. And it will fail even on low
mileage old cars.

A nylon sprocket can be used right out of the mold, no expensive machining needed.
But what excuse shall we give for this quality reduction?

Haha! Ya!

Bruce, are you saying the cam sprocket is solid nylon? I thought they were nylon coated steel. I've never replaced one, just know people who have done so.

Not solid, have a cheap aluminum casting inner support, Nylon then molded
around the the circumference where the chain rides. Bruce

Thanks.

Ah okay, I understand. I think all of the sprockets on RockAuto are just cast iron or steel.

I’m looking at the engine rebuild kit for the Toronado, and it comes with a stage 3 cam. They no longer sell a stock cam, but I kinda don’t want to have a car with a rough idle and sacrifice drivability. They do sell Stage 1 cam, but how much of a difference would it be compared to stock? I only know a little about cams. I also don’t want the car to sound obnoxious.