Retorque Question

[Laqota]

I have an 83 C10. It has a 305 motor (My Profile Picture) that I replaced both head gaskets on because they were toast. It's been running great and driving great until I noticed a miss and an external leak (seeping) on Number 8 Cylinder. So, I retorqued both sides and the miss is gone, and the leak is completely fixed. The bolts near number 8 were also super loose.

When I fixed this though it runs nice and smooth until the RPMs go a bit high. Then it starts shaking a tiny bit. It's not excessive but it's just feels odd in the steering wheel. I used my timing gun, and it seems like it's 3-4 too retarded (I set initial to 8 advanced with a miss and now it's on 5-6). Is that normal if you fixed a misfire for timing to advance? Thanks. Just curious. I've never had that happen.

(Yes, I made sure all the Rockers were adjusted)

 

[Chevy 88]

How were the bolts loose to begin with? Torqued with oil on the bolt holes?

If the gaskets leaked, I think it would be worth replacing the gasket or performing a leak-down test.

 

[Laqota]

How were the bolts loose to begin with? Torqued with oil on the bolt holes?

If the gaskets leaked, I think it would be worth replacing the gasket or performing a leak-down test.

I am tired and I don't think I wrote it right. I'll have to laugh at myself in the morning.

The head gaskets are brand new. Fresh machined head surfaces and valve guides and I adjusted the valves the ol'fashioned way (while its on). The head gasket I bought suggested a retorque after first heat cycle and I never did. So it started seeping out a little bit on cylinder number 8 because it had expanded and so did the bolts (fresh bolts with oil, and thread tape and sealer and stuff). I had no coolant or oil in the combustion or anything it was just straight coolant to the outside of the block. So I loosened each bolt, one by one, in the suggested circular torque pattern and straight to 65. I don't have to go quarters since the other bolts are already holding it down flat.

I have no more problems. A constant misfire I had also due to the seeping gasket is gone. And I'm not getting any coolant in the combustion or in the oil. I just wanted to have some reason that timing retarded a little bit due to having the 8th cylinder work, since I'm still quite new to this stuff and I would like to learn about how that works.

 

[fast 99]

Couple degrees timing shouldn't effect a misfire to that extent.
Perform a general inspection of ignition, check for vacuum leaks.
Compression should be close to other cylinders.
If possible check total timing. 35-38 would be a good starting number. Adjust base timing to achieve total.
Do you have any idea if vibration damper was checked for slippage?
Who adjusted the rocker arms? It's possible one is a little tight.

 

[Ricko1966]

Was the vacuum advance can disconnected and plugged both times you adjusted timing. Was the idle speed the same. My guess is you timed it at 2 different idle speeds. I'd 8nspect my centrifugal part of my distributor for sticking weights,grooves,broken springs etc.

 

[Laqota]

Was the vacuum advance can disconnected and plugged both times you adjusted timing.

Yeah I bought these rubber plugs so I could do that.

Was the idle speed the same. My guess is you timed it at 2 different idle speeds.

That is interesting because the idle did raise a bit after I got all the cylinders running so I had to lower the idle speed and high idle screw a quarter turn.

I'd 8nspect my centrifugal part of my distributor for sticking weights,grooves,broken springs etc.

I probably should have done this a long time ago. I'll check it out

Couple degrees timing shouldn't effect a misfire to that extent.

Im not sure if you understood or I'm not good typing on a phone. The constant misfire is gone (Cylinder 8 was a dead cylinder before), so is the seeping, but now the motor is a few degrees retarded. (So instead of it being 8 advanced, its 5-4 advanced). I'm mostly just asking because I've never had it do that.

Perform a general inspection of ignition, check for vacuum leaks.

Now I did find that I forgot to hook up the vacuum tree on first start cause when I first checked it was at 0 or -1 on the timing marks and running rough. And now it was about 4-5 on the marks afterwards and it only shakes a tiny bit upon acceleration.

Who adjusted the rocker arms? It's possible one is a little tight.

I may have adjusted them wrong. I've always done what my old neighbor does grab the end of the rocker that touches the valve and pull up and down, get it where there isn't any play and go a quarter turn. (And just to make sure, it gets adjusted this way while the lifter is bottomed out)

And then starting the motor and doing fine adjustment if there is still any clattering.

 

[Laqota]

Also, I just took it for another drive, and it drives way better than before just with that little shimmer still. I have not re-timed it yet so I'll update once I do.

 

[Ricko1966]

You are not adjusting the valves correctly. Not far off but not right. You bring the motor to TDC # 1 compression stroke then you can adjust 1/2 the valves,rotate the engine 1 complete turn then you adjust the other 1/2 of the valves. But if you already adjusted them all again running afterwards,you are fine. Here is the real procedure. TDC 1 compression stroke you can adjust Ex. Valves 1,3,4 and 8 Intake 1,2,5 and 7. Rotate 1 complete turnadjust Exhaust 2,5,6 and 7 intake 3,4,6 and 8. To adjust back the rocker off until you can spin the pushrod with 2 fingers,tighten it until you can't turn the pushrod then give it another 1/4 turn to 1/2 turn,depending on who you want to listen to.

 

[Laqota]

You are not adjusting the valves correctly. Not far off but not right. You bring the motor to TDC # 1 compression stroke then you can adjust 1/2 the valves,rotate the engine 1 complete turn then you adjust the other 1/2 of the valves. But if you already adjusted them all again running afterwards,you are fine. Here is the real procedure. TDC 1 compression stroke you can adjust Ex. Valves 1,3,4 and 8 Intake 1,2,5 and 7. Rotate 1 complete turnadjust Exhaust 2,5,6 and 7 intake 3,4,6 and 8. To adjust back the rocker off until you can spin the pushrod with 2 fingers,tighten it until you can't turn the pushrod then give it another 1/4 turn to 1/2 turn,depending on who you want to listen to.

Sorry man I forgot to mention that I did that (get the motor top-dead, adjust, and rotate another revolution and do it again). Im bad at giving full information. I've learned from my old neighbor and a really old manual for my year of trucks from the library.

Yeah it runs great now though since I've readjusted the timing back up to 8 with the VA disconnected and plugged on the carbuerator. And that shimmer, which feels in the wheel like a controller vibration, is pretty much gone too. I was just curious if anyone could give me a reason timing would retard down when running on a cylinder it wasn't running on before just for learning sake.