Was driving home from work on christmas eve, and out of no where my car just died, so i put it in neutral while coasting to try and start it back up and nothin, so i finanlly coast by a turn so i turn and park the car, now when i try and start it is making nasty grinding noises, so today we went at it, and took the timing chain cover off to take a look, and the gear for the timing chain on the camshaft is toast, the teeth are down to nothing and I got chucks of metal all around. my question is does anyone know how much that gear would cost, and also how much it would cost or what i gotta do to get the lower gear off the crankshaft and a new one pressed back on. Also i have to replace the oil pump, this is a LB9 305 engine with around 168k miles. would it even be worth replacing all this as far as money goes, or to just put a 350 in, what would make more sense and be cheaper ? Thanks

 

For my V6 the timing chain set, including the gears, is $30. I don't know how much the one for the 305 is, but it can't be much more than that.

 

You can get a timing gear set from autozone or the likes for really cheap. about $20 for both gears and a new chain. it's really easy to do it yourself, once you get the harmonic balancer off.

The oil pump needs replacing...You'll have to atleast lift the engine off the mounts to get the oil pan off...168k miles is a lot. You're gonna run into more problems in the future. A fresh 350 is the best way to go, but probably the most upfront cost. You'll have to replace the engine sooner or later. better now, than when you're in a hurry and your car breaks down...

Looking around, there's some 4 bolt main 350 blocks going for really cheap. I saw one for $50. I'd also advise buying different heads, as it cost me $400 to have my heads rebuilt, for a little more I could have had a set of good flowing heads. Best to just keep an eye out for parts if you're building a 350 from scratch.

 

You will also need to check to see if your pistons hit your valves. If the cam gear stops turning for any reason. the lifters dont move the pushrods, which in turn doesnt move your valves.

And your crank turned when you tried to restart it in neutral. If for any reason it all didnt turn right........you unfortunatly probably have some bent valves and maybe some dinged pistons

 

Valve interference could be an issue, but probably is not if the LB9 has the stock "LA" cam. Gross lift is so low that the exhaust valves should just clear the flat pistons' valve reliefs. I've had to replace valves in LB9s with better than stock cams and bad valve timing, however.

 

with that many miles and the chance you ran a lot of metal in the oil system i'd consider taking the engine all the way apart for a rebuild or another engine.

 

I agree with ede, you have the metal that came off that cam and crank gear floating around in the engine somewhere. You need to get that stuff outta there. Probably be easier to swap in a 350 while you have the engine out.

 

I can't tell you how many SBCs, with any number of miles on them, that I've put timing sets onto when that happened.

This is not an "interference" motor in stock form, so your valves haven't hit the pistons. Don't worry about it.

Change the timing set out. That's the SET, which is both gears and the chain. DON'T get the shep "roller" chain; if it costs less than about $45, it's not a "roller" at all, it's the "truck chain, made with bushings. I'd put a regular Link-Belt style back on before I'd put one of those others on.

You'll probably need a timing cover; the chain has probably worn a hole in the pass side bottom of it, like it just about always does.

Screw a bunch of oil pump changing and all that. It's pointless.

Change the oil after you replace the gear, and again in a few hundred miles or so, to wash as much of the phenolic gear teeth out as possible. That's about all you need to do.

 

Actually Ive seen where the valves nicked stock pistons on stock 70's engines with dinky cams. The valves werent damaged but they did meet the pistons. I'd just slap a $16.99 Azone cheap double roller "fake roller" put it back togather and roll for 80,000 more miles.

 

It's best if you go through the motor. There's probably a bunch of junk in the bottom of the oil pan. Mine went and I'm rebuilding the motor right now. Better to be safe than sorry...

 

It's always best to "go through" the motor. But it isn't neccessary.

With the peanut cam in your car, there's no danger of the valves hitting the pistons. Won't happen. Don't worry about it.

Don't use the "fake roller". Use a stock Link-Belt style timing set, it's better than that crap.

Just fix your car. it's about a 2 hour job, tops. Very easy and straightforward. Just get a new cover and timing set and gaskets, and "rent" the harmonic balancer puller and installer tools from the parts store, you'l have it back on the road in no time.

This happens so often to old cars it isn't funny. I personally have 2 cars that I drive on a regular basis that have already done exactly the same thing, and all I did was swap the timing set to get them back on the road. Except one of the 2 was a big block, which is an "interference" motor, so it luinched all 8 intake push rods. That one has about 60,000 miles on it since that happened; the other is a 78 305 that toosed the chain at about 320,000 miles, and now has about 345,000 miles on it.

Just fix your car and drive it.