1971 C10 Starter/Timing/Transmission Issue

[geezer#99]

Now remember when you go to the parts store and ask for a spacer base gasket they’re gonna look at you like you got 6 eyes, 4 noses,a dozen ears and just got off the ship from Pluto!
There is no such thing!
You need a quadrajet base gasket.

[GreyGhost85]

Originally Posted by geezer#99

Now remember when you go to the parts store and ask for a spacer base gasket they’re gonna look at you like you got 6 eyes, 4 noses,a dozen ears and just got off the ship from Pluto!
There is no such thing!
You need a quadrajet base gasket.

The heat insulating gasket for edelbrock with the divider in the middle should work correct? I know the heat gasket is supposed to be thick but the car is going to be sitting a tad bit higher with a spacer and a heat gasket
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[geezer#99]

Like I said. You can use it but it’s not ideal.
You’ve got a thin spreadbore gasket for the base and a squarebore one for the carb so use them and hang the insulating one on the wall.

[GreyGhost85]

Originally Posted by geezer#99

Like I said. You can use it but it’s not ideal.
You’ve got a thin spreadbore gasket for the base and a squarebore one for the carb so use them and hang the insulating one on the wall.

What drawbacks would I have for utilizing them all?
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[geezer#99]

And why would you do that?
Spreadbore bottom, squarebore top!
Done deal!

[GreyGhost85]

Originally Posted by geezer#99

And why would you do that?
Spreadbore bottom, squarebore top!
Done deal!

Did exactly that. Used the thin gaskets and put everything back together. Awaiting distributor and then I’ll set engine timing, then I’ll reset carb and re adjust. Had battery on battery charger as well this whole time so maybe battery issues will be gone as well.
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[68 P.O.S.]

Good work getting it back together. You can hang onto that 9266 if you decide to swap in an Edelbrock intake manifold. Let us know how it goes

[GreyGhost85]

Originally Posted by 68 P.O.S.

Good work getting it back together. You can hang onto that 9266 if you decide to swap in an Edelbrock intake manifold. Let us know how it goes

Ok so I’ll go step by step here:

1. The only line on the harmonic balancer has to be the timing mark. I found tdc using a straw with the valve cover off just to be 100%. Popped my finger in cyl 1 spark hole, found compression stroke and it matched with the line. Straw method marched with line as well.

2. She fires right up connect the timing light and it was way to retarded not even on the scale. Turned the distributor to get the timing mark where it needed to be at 0 and idles at like 1400.

3. Turn off motor, turn back on same thing. I know starternis good because it’s firing up easily every turn now, 3 seconds.

4. Now back to idle, I turned the fast idle screw out a lot and the tpms dropped to a humming 1000 at 0 tdc. For me to set 12 advance, the rpm climbing up there. So I grab some starter fluid and shoot the front of carb and bam 20-40 rpm increase. The bolts holding the space down were suspect upon reassembly so I assume they aren’t tight enough or the gasket is too thin. I will be taking carb off once more and replacing those bolts until I can fix this vacuum leak.
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[GreyGhost85]

Also I wanted to add that with the timing somewhat close, and when I place truck in reverse, the load seems easier and it takes 2-3 additional seconds for reverse to stall which is awesome as I would like to fix that issue at the same time.
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[GreyGhost85]

OK another update:

1. Purchased new space and adapter to get better bolts and a better seal.

2. Let truck run for about 20 minutes, shut it down and it fire right up.

3. Initial timing was set to 8 deg advance with vac unplugged.

4. Plugged in vac advance and it was showing 13 deg advanced at 1200 rpm in park. Threw it in reverse and it stalled.

5. Bumped the timing so that with the vac advance lined plugged in, it is at 0 degrees, idles at 880-912, threw it in reverse and it stayed in reverse for about 5 seconds before stalling. I’m starting to think my tdc line is off? I’m going to try bumping back the timing a bit more just to see.

Any thoughts?
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[68 P.O.S.]

Sounds like you’re making good progress. It also sounds to me like you need to adjust the carb’s transition slots for idle. Check out this thread, it should help you out getting the slots adjusted. http://67-72chevytrucks.com/vboard/s...=765215&page=2

[rechinca]

Can you tell us where you have all the vacuum lines plugged in? Before, your Timed Vacuum port looked to be routed to the vacuum advance and the Manifold Vacuum port was plugged. In the latest picture, they both have hoses running to them, but we can’t see where they are running to. It also appears you removed the vacuum plug in the rear of the manifold. Did you reinstall that and where are those lines routed to if reinstalled?

Also, do you have power brakes?

[GreyGhost85]

Originally Posted by rechinca

Can you tell us where you have all the vacuum lines plugged in? Before, your Timed Vacuum port looked to be routed to the vacuum advance and the Manifold Vacuum port was plugged. In the latest picture, they both have hoses running to them, but we can’t see where they are running to. It also appears you removed the vacuum plug in the rear of the manifold. Did you reinstall that and where are those lines routed to if reinstalled?

Also, do you have power brakes?

3 vacuum lines connected. Pcv, Timing advance, TH350C modulator.

No power brakes. Rear of carb plugged, intake manifold vacuum plugged.

With timing advance connected and engine timing set to 0 degrees, I can stay in reverse for almost 15 seconds with engine wanting to die but it idles up and down during this time. Idle rpm is about 700-800.

When I turned idle screw to increase idle, let’s say 900 rpms, engine stalls in reverse.

So with the base timing retarded and the vacuum advance advancing it to 0 degrees, 700-800 rpm I can move backwards lol. Any other settings than this, stalls in reverse.

I tested the modulator port on vacuum gauge and it read about 13 hg
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[GreyGhost85]

Also I have not adjusted idle mixture screws at all.
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[68 P.O.S.]

You're getting there man. Good job so far.

If you think TDC is still off, get a piston stop and do it that way to be sure. A piston stop is the only way to be 100% anyway.

So your vacuum readings are low because of your timing and idle mixture screws (IMS). As you advance your timing, the efficiency of your engine increases and it creates more vacuum and rpms. Your IMS effects vacuum as well if not adjusted correctly. You adjust them for highest vacuum using your vac gauge connected to the carb's manifold vac port; the port to the right side. The Edelbrock manual that came with the carb outlines it really well. With the timing right and IMS adjusted, a stock engine pulls around 20" of vacuum +/-.

Almost there with the timing. Do you know how many degrees of advance your distributor has? Also, are the weights and centerplate lubed well? Do you know how many degrees of advance your vac advance has? From your previous posts it sounds like vac advance is 5 degrees, but you need to check it. Since we don't know yet, keep the timing at 8 degrees for the moment.

[GreyGhost85]

Originally Posted by 68 P.O.S.

You're getting there man. Good job so far.

If you think TDC is still off, get a piston stop and do it that way to be sure. A piston stop is the only way to be 100% anyway.

So your vacuum readings are low because of your timing and idle mixture screws (IMS). As you advance your timing, the efficiency of your engine increases and it creates more vacuum and rpms. Your IMS effects vacuum as well if not adjusted correctly. You adjust them for highest vacuum using your vac gauge connected to the carb's manifold vac port; the port to the right side. The Edelbrock manual that came with the carb outlines it really well. With the timing right and IMS adjusted, a stock engine pulls around 20" of vacuum +/-.

Almost there with the timing. Do you know how many degrees of advance your distributor has? Also, are the weights and centerplate lubed well? Do you know how many degrees of advance your vac advance has? From your previous posts it sounds like vac advance is 5 degrees, but you need to check it. Since we don't know yet, keep the timing at 8 degrees for the moment.

I will most likely have to start from square one in regards to tdc because I turned the distributor to retard the engine so that tdc is 0 with vac advanced plugged in for testing and it seems that retarding the engine was the only way to achieve reverse. But that’s still up in the air until I confirm tdc 100%. I’ll grab a piston stop To confirm.
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[68 P.O.S.]

TDC doesn't change with the distributor. It stays the same, you just have to verify where it's at with the piston stop. Do you know how to check it with the piston stop?

[geezer#99]

A little info on tdc.
https://www.crankshaftcoalition.com/...op_dead_center

If advancing your timing increases your idle too much, then find the high idle screw. It might be set to high.

[GreyGhost85]

Originally Posted by 68 P.O.S.

TDC doesn't change with the distributor. It stays the same, you just have to verify where it's at with the piston stop. Do you know how to check it with the piston stop?

I was trying to find a piston stop tool but not in stock locally and didn’t want to drive to summit in Arlington so I made my own with a spark plug fouler, welded a nut to the end and put a 3 inch bolt at the end. I will be rounding the edge of the bolt so it does scratch the piston.

Yea so piston stop you just rotate until it stops, place a mark on the balancer then rotate the crank the opposite direction when it stops make a mark and tdc is right in the middle of it all.
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[geezer#99]

That’s right!
Make sure to. Back off the rocker nuts on #1 when you do it.

[GreyGhost85]

Ok so I I went ahead and plugged the piston stop in, wrapped end with tape so it doesn’t scratch cylinder head, used a reference point on crankcase cover, turned clockwise marked, turned counter clockwise marked. Split the distance between the two and the initial factory line/groove on the harmonic balancer is perfectly at 0 degrees on the scale. So the piston stop provided some insurance in regards to that factory mark.

So let me get this correct.

1. Disconnect vacuum advance again and set initial timing or base timing to 8-12. If I plug in vacuum advance this rpms will be at least 1400.

2. So with base timing set to 8-12 and vacuum advance plugged into carb,I need to reset the carb idle mixture screws and idle screw per manual? In order to accomplish a perfect mix with a perfect idle?

3. Once everything is set, test vacuum on ports? Most of my full vacuum ports are plugged.

Let me know if my method is off. So far battery starting issue is gone. Side notes*** 3 degrees retarded with advance plugged in and idle set to 700 gives me reverse for 20 seconds or so.
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[GreyGhost85]

Almost there with the timing. Do you know how many degrees of advance your distributor has? Also, are the weights and centerplate lubed well? Do you know how many degrees of advance your vac advance has? From your previous posts it sounds like vac advance is 5 degrees, but you need to check it. Since we don't know yet, keep the timing at 8 degrees for the moment.[/QUOTE]

Sorry man I don’t have that info :/ the center plate and weights were lubbed. I’ll test at idle with base at 0 degrees and the connect advance and post the difference.
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[68 P.O.S.]

Originally Posted by GreyGhost85

Ok so I I went ahead and plugged the piston stop in, wrapped end with tape so it doesnÂ’t scratch cylinder head, used a reference point on crankcase cover, turned clockwise marked, turned counter clockwise marked. Split the distance between the two and the initial factory line/groove on the harmonic balancer is perfectly at 0 degrees on the scale. So the piston stop provided some insurance in regards to that factory mark. There you go, glad your balancer matches up with TDC. Makes things a little easier. Read the following links for timing. They're written by a GM engineer and will tell you everything you need to know about timing and vacuum advance and the science of why.
http://www.camaros.org/pdf/timing101.pdf
http://67-72chevytrucks.com/vboard/s...d.php?t=274806


So let me get this correct.

1. Disconnect vacuum advance again and set initial timing or base timing to 8-12. If I plug in vacuum advance this rpms will be at least 1400. Set up this way, can you adjust your rpms down to 750 at idle? If not, you'll have to pull the carb and adjust the transfer slots square. Did you check out the link I posted on doing this?

2. So with base timing set to 8-12 and vacuum advance plugged into carb,I need to reset the carb idle mixture screws and idle screw per manual? In order to accomplish a perfect mix with a perfect idle? Correct, set it up the way you would drive it. Plug your vacuum gauge into the manifold vacuum port on the carb, hook up your timing light so you can view rpms, and follow the procedures in the manual. This will achieve your best lean idle.

3. Once everything is set, test vacuum on ports? Most of my full vacuum ports are plugged. No worries if they're all being used. Using a T, connect your vac advance and vac gauge to the manifold vac port on the carb, then follow the procedures in the manual for setting the IMS

Let me know if my method is off. So far battery starting issue is gone. Side notes*** 3 degrees retarded with advance plugged in and idle set to 700 gives me reverse for 20 seconds or so.
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I responded above in red.

[68 P.O.S.]

Originally Posted by GreyGhost85

Sorry man I donÂ’t have that info :/ the center plate and weights were lubbed. IÂ’ll test at idle with base at 0 degrees and the connect advance and post the difference.
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No worries if you don't know the info, its easy to figure out. I'm not sure why you keep wanting to retard your timing to 0, but don't. The stock "safe for warranty purposes" timing number is 8 degrees advanced. There's no reason to retard it below 8 degrees, or it runs like crap as you're seeing now.

Since we don't know your distributor numbers yet, set your initial timing to 10 degrees with vac advance unplugged. Don't adjust anything else. Plug your vac advance back in to manifold vac and check what your timing is now. Take that number and subtract your 10 degrees of initial...whatever that number is, that's the amount of degrees your vacuum advance provides. What do you get?

To determine how many degrees of mechanical advance your distributor has, take the distributor cap off, remove the two springs for the weights (cover them with a rag so they don't shoot off on you), then replace the cap. Removing the springs ensures the weights will fully extend at lower rpms (so you don't have to rev the engine crazy high) and your mechanical advance will be all in. Hold the engine at 1500 to 2000 rpm and check your timing. This number is your total timing (initial timing plus mechanical advance). Again, take that number and subtract your 10 degrees of initial...whatever that number is, that's the amount of degrees your mechanical advance provides. What do you get? Then put the springs back in.

[GreyGhost85]

Originally Posted by 68 P.O.S.

No worries if you don't know the info, its easy to figure out. I'm not sure why you keep wanting to retard your timing to 0, but don't. The stock "safe for warranty purposes" timing number is 8 degrees advanced. There's no reason to retard it below 8 degrees, or it runs like crap as you're seeing now.

Since we don't know your distributor numbers yet, set your initial timing to 10 degrees with vac advance unplugged. Don't adjust anything else. Plug your vac advance back in to manifold vac and check what your timing is now. Take that number and subtract your 10 degrees of initial...whatever that number is, that's the amount of degrees your vacuum advance provides. What do you get?

To determine how many degrees of mechanical advance your distributor has, take the distributor cap off, remove the two springs for the weights (cover them with a rag so they don't shoot off on you), then replace the cap. Removing the springs ensures the weights will fully extend at lower rpms (so you don't have to rev the engine crazy high) and your mechanical advance will be all in. Hold the engine at 1500 to 2000 rpm and check your timing. This number is your total timing (initial timing plus mechanical advance). Again, take that number and subtract your 10 degrees of initial...whatever that number is, that's the amount of degrees your mechanical advance provides. What do you get? Then put the springs back in.

I have read the article in regards to transfer slots but it specifically mentions holly cards, not edelbrok so the screw at the bottom is not there. Kind of confused me a little. I see the idle screw and how it opens the primary flies , allowing more air therefore increasing idle. I also see the fast idle screw that when at wide open throttle the secondary flies open. I’m sorry I just don’t see this adjustement. I see that they used a feeler gauge to check clearance and I have a set of feeler gauges but overall I’m a bit confused and apologize for my ignorance. I will try to look up more articles. Posted is a pic of my edelbrook 1406.
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