Engine Timing/Carb Fine Tuning

[Woobie]

Give us a background on your engine. How many miles are on it? Is it stock?

How much slop is in your timing chain?
---measure this by putting your timing marks on ten degrees BTC, pull the distributor cap off then manually move your crankshaft back and forth with a long extension. From 'end to end' as you go back and forth, how many crank degrees do you get before the rotor starts turning. (This is where your hesitation is coming from.)

As your timing chain stretches, the cam/crank timing slowly retards the cam. Sometimes, your timing light marks will 'jump around' indicating chain slop.

Vacuum comes from the relationship between the pistons and valves. Loss in vacuum can come from leaky valves but more commonly from cam timing. - Dave

Very good advice that deserves repeating. And while replacing the distributor cap it's only a matter of a wrench and turning back and forth. Test completed.

Your new distributor cap may have residual flash on the interior contacts which calls for a careful inspection.

[flyinthermals]

Absolutely. Good advice again. I will systematically go through step by step what I am able to and replace any questionable parts as I go. The carb issue will be a little tricky though, finding the model suggested, or going for a original 4100 or rebuilding my 4160. An simple fit to my car without to much "Macgyver-in" is what I'm aiming for. I will have to see whats in my area and talk to the rebuilder shop and see what he has in stock. So nice driving weather this week. Isn't that always the way.

[Dan Leavens]

The Edelbrock 1406 is the best replacement carburetor in my opinion. Many on the forum use it including myself and I haven't heard any major complaints.

I agree with John.I swapped out the Holley's and replaced them with Edelbrock 1406 on both the 58 & 60 with no issues. Lots of air

[YellowRose]

Engine Timing/Carb Fine Tuning

I am another one with a Edelbrock 1406 carb on Rose and it works great.

[flyinthermals]

Here are some pictures from our email topic. I pulled the carb to have a shop have a look. Your comments are helpful. The intake looks dirty. I have a new filter. I removed the additional inline filter just before the carb a few years ago. Is the the result? The first picture shows the HB /Timing mark setup. Around that timing is where the engine begins to sound good and I start to get increase in vacuum. If I try to retard the timing to the right from this point, the engine stalls. Like I said in a earlier post, I brought the #1 piston up on the compression stroke and at the top of its travel, the white dot was right on "0" degree mark. If anything looks out of the ordinary in these pictures, please point it out. Thanks.

[jopizz]

You could have the wrong balancer. There are no degree marks on the stock '62 balancer. Just a raised dot. Is the white spot where the paint is raised or flat. If it's flat then it's not the correct spot.

John

[Woobie]

flyinthermals, would that be oil inside the intake manifold ?

Lots going on here with your motor. Poor thing.

[flyinthermals]

Yes it looks that way. How excessive is that oil deposit? I have read the gasket can leak and maybe I try to seal with silicone. How to know the health of the engine? What tests can I do at home? Compression test?

[Woobie]

It's difficult to make conclusive recommendations from here.

If that is the pcv system sucking oil ? I'd want to know the hose routing. From the valve covers or a conversion from the road draft tube at the rear of the intake manifold. Then start to determine the cause. Possibly as inexpensive as no baffles in the valve covers.

The intake manifold interior appears to be quite wet with oil so it sparked my curiosity. The spark plugs may need an inspection and cleaning, too.

I don't understand which gasket you are referring to that can leak and require silicone.

Of course compression tests are nice to have a record of. But a smooth running engine, as much as possible, would be a prerequisite for me, before attempting compression testing.

[simplyconnected]

...How excessive is that oil deposit?..

That's WAY too much oil. I'm surprised your plugs don't foul.

If you used a stick in #1 and TDC agrees with your stick and timing marks, you just proved the crank and balancer are together and haven't slipped. You have NOT proved your crank/cam timing.

This is a guessing game now. I don't know why you haven't done the timing chain test. It requires NO money to do.

After that I would have you pull your driver's side (LH) valve cover off for the next test. I'll tell you what it is when you give me the results from your timing chain slop test.

If you haven't got a long breaker bar and deep socket for your crankshaft bolt, I suggest you get one. An engine with 80,000 miles should be very easy to turn. - Dave

[flyinthermals]

Hello Simply Connected,

I was planning on doing that today. I attempted that yesterday but time ran out. I had to meet the school bus. I tried every combination to get the socket on that15/16 nut. It was impossible with the fan and shroud in place. Maybe another set of hands would have helped but I think I will have to remove fan and shroud. I got the carb off and checked out and they assured me it test fine. Someone did comment that I have the wrong spacer. I m a rookie at this so I will go step by step. Thanks for your comments.

[flyinthermals]

Yes the plugs were fouled. I clean them up and re installed. They looked like dry black carbon. They did not seem wet and sticky. I had already cleaned plug # 1 from piston # 1 when I thought it would be a good idea to take a picture. The rest of the photos are from plug (pistons) 2 to 8.

[flyinthermals]

The timing chain test had somewhere between 3 to 4 degrees slop before the distributor rotor began to move. Both directions. I also confirmed again that the HB marks and time pointer are accurate. As Piston 1 on the compression stroke, reached TDC the pointer was at "0" degrees on the pointer.

[scumdog]

Hello Simply Connected,

I was planning on doing that today. I attempted that yesterday but time ran out. I had to meet the school bus. I tried every combination to get the socket on that15/16 nut. It was impossible with the fan and shroud in place. Maybe another set of hands would have helped but I think I will have to remove fan and shroud. I got the carb off and checked out and they assured me it test fine. Someone did comment that I have the wrong spacer. I m a rookie at this so I will go step by step. Thanks for your comments.

Check your carb spacer is actually flat.
Get a piece of thick flat glass about twice the size of the space and some1200 grit sandpaper.
Place the sandpaper on the glass and ‘skid’ the spacer backwards and forwards on top of the sandpaper.
Do this on both sides of the spacer for a few seconds and examine it to see if the sanded surface is even, ie there’s no areas left un- sanded.
If there is you just keep sanding until the whole face of the spacer shows it has been sanded.
And check you have the proper gaskets too, I didn’t and after a wind out in passing gear the 390 had a very high idle speed courtesy of the resulting vacuum leak from the sucked in gasket .!

[flyinthermals]

Thank you. I will look into that. I found a spacer in the P.O. parts box. I'm not sure why it was decided to use the other spacer. It does look to have some slight pitting and corrosion. Would a machine shop due a better job on this to ensure its smooth and evenly flat or would they charge an arm and a leg to do that?