Timing Chain

[BigTady]

Yeah I agree, I'll do the leak down test as earl suggested and keep poking around to see what I find.

Symptoms were really ruff idle, he took it to Buick guy back in 95 and he said one of the cylinder walls was scratched due to oil pump going out. He got a quote to bore over and rebuild that was out of budget so he parked it.

The leak down should tell me alot.

Tad
87 GN
Sent from HTC Sensation

 

[highboostgn]

I really want to save the money right now but also am not interested in pulling all this part again. Really I have no clue if this thing will run well, need to get into that first so maybe rebuild on the oil pump and put it all back together and start it. I can always plan down the road for an upgraded timing set.

I'll have to think on this for a day and decide. It's only manual labor right?

87 GN
Sent from HTC Sensation

I gotta double roller in the garage right now that I ll sell you cheap. Pm me

 

[Pronto]

Since there were no bore scopes in 95, the heads had to have been pulled. If they knew it wasn't going to be pulled and rebuilt they might have just done a slam job to button it up. I would be prepared to do a build.

 

[BigTady]

Yep he said he pulled the head. I've been prepared to do a build since I bought it, that was fully disclosed when we talked. I am just running through things to make sure.

Tad
87 GN
Sent from HTC Sensation

 

[earlbrown]

An oil pump can't 'go out' and scratch a cylinder wall.

 

[GNONYX]

There are many mentors on board who told me when I replaced my timing chain, if you're building a big HP engine, then yes go with a double roller, but if you're staying with a stock engine then go with Single Row Chain with billet steel gears & tensioner.
You might want to remove the cam sensor and check to see if there is any side to side end play, ( should be none); there is very little up and down play since there is a waver washer.
Don't forget to grind off the center tip where the cam button ride on the timing cover.
Whether you know it or not ask the board members in priming the oil pump before starting the engine. I know it sounds elementary, but you be surprise how many asked, "I replaced the timing chain and the engine shows no oil pressure; why".

 

[Tom87GNX]

x2. I agree, unless your building it up for big HP a double roller is not needed. I'm using a single row chain with full steel gears. I also agree with the earlier response from earl brown that the nylon gear is fine. This is true, they are proven and have held up in all sorts of builds and performance levels, I myself was just suggesting while your in there why not change it, plus a replacement with steel gear can be very cheap depending on what brand you buy, at least then you know your chain and tensioner is new. Just my thoughts.

 

[turbojoe1]

There are many mentors on board who told me when I replaced my timing chain, if you're building a big HP engine, then yes go with a double roller, but if you're staying with a stock engine then go with Single Row Chain with billet steel gears & tensioner.

Why

Thanks Joe

 

[earlbrown]

No idea. The timing chain has no idea how much HP is at the back wheels. Since we only have 12 lobes instead of a v8's 16, there's more 'cogging' when turning the camshaft. Oddly enough when cams get wider the 'cogging' gets less intrusive. When you think about it like that, the timing set has an easier/smoother time when running longer duration bumpsticks.

 

[BigTady]

An oil pump can't 'go out' and scratch a cylinder wall.

The thought was there was no oil and he drove it scaring the walls, i haven't got in there so I could get lucky and that be no issue at all.

Tad
87 GN
Sent from HTC Sensation

 

[BigTady]

There are many mentors on board who told me when I replaced my timing chain, if you're building a big HP engine, then yes go with a double roller, but if you're staying with a stock engine then go with Single Row Chain with billet steel gears & tensioner.

I will be fairly stock, some mods but won't be heavy.


Tad
87 GN
Sent from HTC Sensation

 

[earlbrown]

The thought was there was no oil and he drove it scaring the walls, i haven't got in there so I could get lucky and that be no issue at all.

The bearings will get scorched to the point of catastrophic failure long before the cylinder walls will get scratched from a pump failure.

 

[Pronto]

Low cylinder pressure and scratched walls would point towards broken rings/lands.

 

[BigTady]

Ah ok... This is good info.

Tad
87 GN
Sent from HTC Sensation

 

[BigTady]

Finally enough time to make some progress here. Pulled oil pan and here is the timing gear debris. I'm do everything with the timing cover and new water pump, will be installing everything this week. Fingers crossed

Tad
87 GN
Sent from mobile

 

[Pronto]

How'd the oil pick up look?

 

[turbojoe1]

Holy moly

Thanks Joe

 

[BigTady]

Haven't cleaned it yet, thus is what it looks like.

Tad
87 GN
Sent from HTC Sensation

 

[highboostgn]

Holy crap!!

 

[earlbrown]

Damn. I went back to page to re-read this thread and it looks like I nailed it. It would appear the previous owner stripped a timing set, slapped a new unit in place and sold the car. I can see being slack about not cleaning the oil pan, not replacing the pickup, or getting a rollerized cam button.... but why in the world would you put a $100+ timing set in there when you're just going to dump the car (and leave another set under the seat)???

What really sucks is you still have a stock pickup with a bypass flap in it. I have a feeling your oil pump cavity is torn all to hell. Even then if the leakdown numbers look good it can still be an easy repair, just more money.

If the oil pump is torn up, it might not be a bad idea to inspect a couple bearings while the pan is off.