Redo my Timing Chain?

[CatskillCruiser]

I have the top end off my 302. Replacing the heads, gaskets, water pump, hoses, belts, fluid, carb and headers now. While I am doing all of this work, does it make sense for me to go ahead and redo the timing chain while I have all of this off the motor? Welcome any advice here, thx!

 

[1969]

Yes. It is easy and inexpensive.

 

[Bajabrewer]

Short answer - I would
Questions - why are you replacing the heads - how did it run before & are you looking for more power or just a good runner - how many miles on the lower end - what are your goals for the engine & what's the budget - ever rebuilt an engine before? And I'm sure there are lots more questions

 

[CatskillCruiser]

Short answer - I would
Questions - why are you replacing the heads - how did it run before & are you looking for more power or just a good runner - how many miles on the lower end - what are your goals for the engine & what's the budget - ever rebuilt an engine before? And I'm sure there are lots more questions

New Bronco for me, with the original 302 in it. Ran pretty well when I got it, but I want to spruce her up with a little pep and more reliability. Some seeping in the engine bay now. I am upgrading the heads to early 70's 351 Windsor heads that were fully rebuilt and I traded for with a buddy (New NOS push rods going in too). Have an exhaust leak, so pulling the stock exhaust manifolds and upgrading with short headers. Got a nice OEM 2 brl rebuilt carb, so no brainer to add that in. New starter, head covers, breather, hoses, belts, filters, fluids, plugs, pentronix flame thrower and ignitor also going in.

 

[lars]

In the event the timing chain is the original with plastic teeth on the cam gear, it will make the decision for you if you don't make it yourself. Learned that oh so long ago as I coasted to a stop on a rural mountain road.

 

[dmoses42]

At the very least I'd pull the timing cover and give it a look, since you are that deep into it.

 

[Broncobowsher]

Original timing chain, time to replace it. If it is ready for a top end, it is past due for a timing chain.
Amazing how much slop will wear into them and still run fairly decent. So gradual you never notice. But a new chain, valve timing back to what it should be, maybe even better if you have one of the emissions timing chains and go to a regular, so much better.

 

[jeffncs]

For the $75-100 a decent kit and gaskets will cost - that’s a “yes” for me

 

[CatskillCruiser]

Thx all! Parts Ordered and headed my way.

 

[EPB72]

Thx all! Parts Ordered and headed my way.

you can also check it before ter downn if you are so incline. hand turn crank to the timing marks and set it on tdc then turn engine backwards slowly untill you see the rotor on distributor just start to move and stop , check your marks on damper anything over 7degree's consider to much slop...

 

[Broncobowsher]

7° is holding a pretty tight tolerance for wear. I would consider that normal for a used, but still good, engine of this design. 20° is not uncommon and I have seen engines still running with 30° of timing chain backlash at the crank pulley. Those are the ones that you really question how they still run.

Now if this were a nice race engine, yea, 7° would be a lot.

Most old gearheads I know never actually measure the backlash. Pop the distributor cap, wiggle the crank pulley back and forth, you know if it is still good or too much just by feel.

 

[Bajabrewer]

New Bronco for me, with the original 302 in it. Ran pretty well when I got it, but I want to spruce her up with a little pep and more reliability. Some seeping in the engine bay now. I am upgrading the heads to early 70's 351 Windsor heads that were fully rebuilt and I traded for with a buddy (New NOS push rods going in too). Have an exhaust leak, so pulling the stock exhaust manifolds and upgrading with short headers. Got a nice OEM 2 brl rebuilt carb, so no brainer to add that in. New starter, head covers, breather, hoses, belts, filters, fluids, plugs, pentronix flame thrower and ignitor also going in.

Sounds like a good plan - I'd do the timing chain just for piece of mind

 

[dmoses42]

Amazing how much slop will wear into them and still run fairly decent.

My first car was a 1972 Nova (which I still have) that was bought new by a family member. Most of my family drove that car at one time or another. 2 door, 307, automatic. When I was still a kid, my dad noticed a larger than normal oil leak on the front of the engine. It ran fine, just leaking oil. He had my brother in law check it out, and it was the timing chain. It had so much slop in it, it wore a hole in the timing cover.

 

[LUBr LuvR]

Not to hijack, but looking at doing this as well - what timing chain and water pump recommendations for a stock 302, primarily street driven?

 

[jamesroney]

At the very least I'd pull the timing cover and give it a look, since you are that deep into it.

...Thanks. Your's is the best advice that I would follow on this thread.

He might open it up and find a classic morse silent chain with an iron gear just doing its job. Or a brand new Cloyes double roller timing set, or maybe there's a Jesel dry belt running in there. Or a Pete Jackson quiet gear drive. Or he might find a chunked OEM plastic gear.

If I'm working on an old Bronco, and its history is UNKNOWN, and the timing cover comes off...then the pan is coming off too.
He's got the top end off, so he knows exactly how much ridge it shows, and whether it's been bored. If it's standard bore, and there's any ridge, then it's going to get a set of bearings and an oil pump.

And if the pushrods are out of it, and the heads are off...I'm pulling lifters, (one at a time) and inspecting lifter wear. Just pull, wipe, look, and insert back.

It's easy, it's free, and it's silly not to. The ONLY question is whether I put a new rear main seal in it, or risk it leaking.

But yeah, If I'm there, I'm measuring, checking, and inspecting FIRST. And if I own a dial indicator, I'm going to check the lift, duration, and lobe separation on the cam. Because as soon as you put it back together, and drive it...you will forever wonder, "hey, what cam is in this thing?" Which is why Im doing this exact exercise today.

 

[rjrobin2002]

I just wiggle the chain in the middle left to right and decide. I read somewhere what an acceptable movement was but forgot the exact amount.

 

[Broncobowsher]

I just wiggle the chain in the middle left to right and decide. I read somewhere what an acceptable movement was but forgot the exact amount.

I think they are trying to figure that out without removing the timing cover.

Doesn't take much of 'while I am here' and the next thing you know the engine has a full rebuild. I did a 460 and refused to remove the heads. Because if I did I knew I wouldn't like the bores, and the low compression ratio. I still did bearings (should have done a crank kit), cam. lifters, oil pump... I just wanted it good enough to decide how I wanted to really build the engine later. Really wanted a stroker kit but needed the rest of the truck sorted first.

 

[ntsqd]

There's a reason why I call the '96 FSB "Snowball", it's not merely because it is white but also because of the "while I'm there" syndrome.

But in this case I'd just replace it with a quality morse type timing chain kit.

 

[DirtDonk]

So James... Is that a Chrysler product? Or a Buick maybe? Something else?
Did AMC make them like that?
Can't really tell if it's some shade of orange, or red.

Paul

 

[DirtDonk]

Oooh, oooh! An IH engine?
I love guessing games!

Paul