Olds 350 Timing Chain Woes

zipties

Apprentice
Feb 2, 2022
57
18
A bit ago after getting my 79 cutlass barnfind project back on the road, i already ran into a new issue. I lost all power on a cruise and the thing wouldn't start after. lots of backfiring and rough noises.

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Since I replaced every ignition component and it started up every time since that work was done, all signs pointed to the poor thing jumping time.

I was told the motor was cammed at some point, which led me to believe it had a fresh timing set installed as well. It seems like one of those supplementary tasks, and the nylon timing gears from these motors are infamous. Unfortunately for me, it seems that the motor still had its crappy gears and they finally gave up the fight.

I was waiting to delve into it proper until I got the balancer off. The brand new puller kit I got came with "grade 8" bolts that snapped in half and almost broke my thumb.

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After spending a bit more on real grade 8 bolts, the balancer is off. Would anyone be able to tell me if this is the proper balancer for the motor? Casting # is 557752 3B

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I'm going to start pulling the rest of the front drive off now. Any tips on properly installing the timing set on an Olds block would be greatly appreciated, I've never gotten much into their internals. Not sure how much chevy overlap there is here.
 

Texas82GP

Just-a-worm
Apr 3, 2015
7,733
113
Spring, Texas

zipties

Apprentice
Thread starter
Feb 2, 2022
57
18
got everything off. check out this carnage:

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don't think you can call those 'teeth' anymore.

not any worse than i was expecting, though. going to get these out of the way tomorrow and prepare for the wallet hit.

any PN#s for a good toming set and any other parts I may need would be a big help. I'm going to pull my pan as well since I'm sure there's all sorts of chunks in there.
 
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spidereyes455

G-Body Guru
Mar 6, 2013
717
93
Northeastern PA
If you pull the pan to clean it make sure to clean out or replace the oil pickup screen. All the broken teeth will find their way in there and wind up starving the engine for oil.
 
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69hurstolds

Geezer
Supporting Member
Jan 2, 2006
7,038
113
The pan has to come off or like spidereyes455 said, you'll be pulling it later after all the chunkies get sucked up into the oil pump. This is one of the worst ideas GM ever had was to put the stupid nylon teeth on aluminum.

The balancer you show is GM part number 417142, was used on a grunch of 70s and 80s engines. There's another one that they used on VIN Y and other engines that had the word "Malleable" on the front and was a solid chunk and didn't have the rubber damper ring insert. However, the rubber ring gets old and allows for slippage sometimes, and that can cause headaches trying to time the ignition system. Dorman makes a replacement for the 417142, under their own part number 594-117. Some of the pictures have broken links for whatever reason and can't see all of them. Make sure you haven't damaged anything as far as the valves. If you can get a boroscope or one of those tiny flexible inspection cameras, you can check through the spark plug hole. Bent valves could have you taking the heads off.

If you're going to be staying stock, generally you'll find that you can get by with steel gears and a single chain. No sense buying the double roller high-dollar stuff, but only if you really want to. MELLING 3498SC is one part number you can check on. Around $25 from Rockauto.com before discount.

If Fel-pro still makes their "timing chain replacement gasket kit" you'll probably need that. Or at least the oil pan gasket kit, fuel pump gasket, and timing cover gasket (if you hadn't already taken the water pump off- you don't have to when removing the cover, but most people do, then you'll need the water pump gasket, too). Also you'll need a new balancer seal that's pressed into the timing cover.

Either way, you line it up dot to dot, cam timing dot facing down and obviously the crank timing dot facing up. Wouldn't bother degreeing in the cam. Again, only if you really want to.
 
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69hurstolds

Geezer
Supporting Member
Jan 2, 2006
7,038
113
Just a note about oil pan gaskets. Don't go cheap.

GM used p/n 22519181 which was cork with the steel insert. Mahle OS30534TC is what I would consider the aftermarket equivalent as it's cork with the steel insert. It seals without crushing out, which is what will happen if you use just plain cork. So don't use just plain cork.

I used a fiberous gasket about 100 years ago on a Moroso pan on the 71's 455, and it worked very well as it was rather stiff. May have been a Moroso pan gasket included in the kit, don't recall. Anyway, don't use plain cork.

A word about dropping the pan...since you're doing the timing chain anyway, pull the distributor first before jacking up the engine a few inches so you can clear the pan out from underneath. The distributor is already close to the firewall, and if you leave it in while you jack the engine, you may hear a crunch. You may not, but be aware of that as a potential clearance issue. If the stock crossover exhaust pipe is in place, that's got to come off along with the converter cover.
 
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Oct 14, 2008
8,326
113
Melville,Saskatchewan
Yeah, the nylon teeth suck, it wasn't just GM who used them either. As said, the pan should be pulled, it makes it much easier to reinstall. Unfortunately Olds adopted the sbc crappy design for the front cover. I bought a couple of sets of these pan gaskets, they look really nice. GM used to sell a set that looked similar. Fel-Pro Performance OS30471C Oil Pan Gasket Set https://www.amazon.ca/dp/B000C2EDGI/?tag=rippca-20
I am not a fan of the cork or cork rubber. The Mahle gaskets 69hurstolds mentioned would be the only exception, they are at least cork rubber. I just coated a set of the similar McCord gaskets with RTV before installing. I also used the fiber gaskets, used to be part of the Corteco gasket set. They were Ok, some seepage but fairly minor. Now would be the time to upgrade to a rubber rear main seal, the old one can be a PIA to remove. A basic replacement timing set should be fine. That looks like a full size balancer, not all motors got them from the last 70's and up, actually most didn't. Any basic replacement, should be fine. My bet is, it is still the stock factory peanut cam in that motor, unless a really idiot installed it. That is the shittiest of the Olds 350, the 77 to 79 windowed main motors with the 3A crack prone heads. Good luck, slap dual exhaust on the car, if it doesn't already have it and enjoy.
 
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64nailhead

Goat Herder
Supporting Member
Dec 1, 2014
5,121
113
Upstate NY
Hard to believe that ran bad :/


WOW, I've never seen one THAT bad. I assume that these must not be an interference motor, eh?
 

69hurstolds

Geezer
Supporting Member
Jan 2, 2006
7,038
113
Hard to believe that ran bad :/


WOW, I've never seen one THAT bad. I assume that these must not be an interference motor, eh?
If it was, it's not anymore, apparently. :(

Olds V8s SHOULD NOT be interference if stock cam lift and compression ratio, etc. If you change up cams and use flat top pistons, etc., all bets are off. Many "import" engines are usually tight tolerances and high compression engines and use interference engines. This is why they tell you to change timing belts every couple of hundred miles. :) (I exaggerate to clarify)
 
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78Delta88

Master Mechanic
Supporting Member
May 23, 2022
417
43
SW Arizona
Yep those are bad, seen worse. My concern is with the way those teeth look you need to pull the cam and see if one or any of the cam bearings fused or spun.

I was Line Mechanic back in the day when it was still NIASE, certified just when it changed to ASE and worked for Jay Pontiac out of Dekalb, IL. One of the things with Olds and Cadillac is pull the FP and stick your finger in the hole, it tells you right away if too much slop in the chain.

If your "cam was changed" and that is what the gear looks like I suspect "IF" it was changed I would not trust that "mechanic" to park a car, let alone touch anything on it.

A double roller set is available.

You would have to look at the distributor and see where the rotor is pointed to see if it retarded or advanced, along with if it was back firing though intake or exhaust. This would give you some idea where the valves were when it let go/skipped.

The look of the top gear is beyond what would be expected for excess wear. The way the tips of the teeth are pulled off, shows excess rotational drag, I.E.: excess friction. Low oil supply to the cam bearing would do this, and begs the question of if other areas also had lack of oil.

Before going crazy, just pull the cam and inspect the journals, check for bluing and deep scratches, and any fused-on bearing material. If the cam has indication of poor oiling, I would highly suspect the crank has the same issue.

I have (I think) a 330 forged crank collecting dust, have some 307 engines kind of on back burner, no longer any forged stuff, but do have some nodular iron if you need a crank.

Best case; you just need new gear set; Worse case a rebuild, BUT, it's still a keeper. Body looks straight, has all it's glass, wasn't vandalized over the years of sitting.

One nice thing today is technology has vastly improved. Get an inspection camera, pull some plugs and check to see if you can identify any damage to the tops of the piston. The 350/307 valves come in at 7% angle which is better flowing and better on emissions., so is possible maybe made contact. You will see the dents in the piston top if they did. If they did then it's rebuild time. Post 73 heads are garbage anyway, so unless you are going for Concourse restoration, just get some better aluminum heads. 87 Pump gas is crap, so go with flat tops with 2 valve relief or small 1/8 dome. Cam with moderate lift longer duration cam, think like Duntov did back eons ago. The Duntov cams were not high on lift, they had longer duration and allowed for better power production and driveability on the street.

I guess the pic is from before? If it isn't get the cars off the grass. Grass, (any vegetation) off-gasses oxygen and water, and this combination = rust. Always park on gravel or concrete. If the car is a driver/cruiser sits for maybe a month at a time between cruises/shows put a 2 x 12 section under the tires. Concrete is slightly alkaline and can break down the tire and on cruise night you have flat spots. If the car sits for six months or more between drives then on jack stands.
 
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