Y-block 292 Timing question

[smtichy]

I have a '55 Sunliner, with a 292 (casting no. shows it as a '59)

This weekend I did a tune-up and hit a bump when checking the timing. The timing pointer on my car is different than that shown in the shop manuals. [See thumbnails attached at bottom, double click to enlarge].

The timing pointer has 4 points marked clockwise 10, 6, 3, 0.
Anyone familiar with this type of pointer on the Y-block?
If so, which point matches the standard pointer and should be used to set timing?

The damper is stamped TDC followed by 6 marks. The timing light shows the point on the pointer labled "10" between the 4th and 5th marks on the damper.

FYI in doing the tune up, I checked points, plugs, idle, dwell, vacuum, etc. None were within proper specs but now they are sorted.

I've had this car for about 6 months now and have been getting it into good shape thanks to all the knowledge you all have shared with me.

Have a great weekend!

p.s. - a picture of a similar pointer below:

[Y-Blockhead]

There are two different "sets" of timing marks used on Y-Blocks.

One has the pointer with the scale on it like yours with only one mark on the damper. This is the early style.

The other has a single pointer and graduated marks on the damper like yours. This is the later style.

Appears to me you have a combo of each "set".

I would use the "0" on the damper as your TDC and time to 10° BTDC on the tab. Make sure that the "0" is a true TDC. Sometimes the damper spins in the pulley, throwing off the mark.

Hope that helps...

[Y-Blockhead]

Or you could use the "0" on the tab as TDC and the scale in the damper. either way you need to establish TDC. Or locate the correct pointer.

[Ole Don]

Where you want the initial timing depends on the grade of fuel you get. Here in the US, we have several grades. The more you want to spend, the better grade you get, and the motor will respond to each. The best way to time an engine is with a vacuum gauge, with the fuel it will be using. With the vacuum gauge reading manifold vacuum, advance the ignition to the maximum reading, then back off just a bit, maybe 1/2 inch of vacuum. Test drive, lug the engine and if it pings, retard a bit more.

[scicala]

Originally Posted by Y-Blockhead

There are two different "sets" of timing marks used on Y-Blocks.

One has the pointer with the scale on it like yours with only one mark on the damper. This is the early style.

The other has a single pointer and graduated marks on the damper like yours. This is the later style.

Appears to me you have a combo of each "set".

I would use the "0" on the damper as your TDC and time to 10° BTDC on the tab. Make sure that the "0" is a true TDC. Sometimes the damper spins in the pulley, throwing off the mark.

Hope that helps...

I recently worked on a '54 Mercury 256 Y Block, and it had a pointer mounted to the engine, and the TDC with notches up to 10 degrees was on the damper ring. Maybe they were all over the place.

[Y-Blockhead]

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Originally Posted by scicala

I recently worked on a '54 Mercury 256 Y Block, and it had a pointer mounted to the engine, and the TDC with notches up to 10 degrees was on the damper ring. Maybe they were all over the place.

And lotsa things get changed by all the "Mekeniks" over the last 60 years...

[smtichy]

Thanks everyone, your input set me on the right track. I pulled the #1 plug and made a quick check with my finger where TDC is.

It looks like it is close to the timing pointer marked 0°, just a little off. Anyway, that means the current timing is at about 12° BTDC vs. the specified 3°. I'll give a go at timing with the vacuum gauge, and then after seeing the result try and find the precise TDC later.

Ole Don, the fuel here is generally pretty good. I use the mid-range Euro Natural 95 which is equivalent to about 85-86 octane US (similar to that available in '55). At the better fuel stations such as Shell, OMV, and Agip it contains about 3% ethanol. I've had that car sit for a couple weeks and fire right up with the fuel in the bowl.

[Y-Blockhead]

Steve, Y-Blocks like a little advance. I wouldn't set it at 3°.

With the cam I have in my 318" I also set it with a Vacuum gauge. When I check mine with a light after setting it with a gauge it is ~16° BTDC so don't be surprised if it is advanced a bit.

Not saying yours will be 16°, that's just where my engine likes it.

[smtichy]

Once again thanks for the tips. Here are the results. Top vacuum was around 24 in.Hg and over a range of about 10°. I put it on the lowest advance in that range and then retarded by about 1/2in. Hg. Took it for a drive, and it was sluggish and missing so advanced a bit further. Did some tests, lugging on a steep hill in 3rd at about 20mph, no pinging, so fixed it there.

End result is an estimated 14-16° advance, which surprised me for a stock setup. We'll see how it goes. Thanks again.

[Hot Rod Reverend]

Ditto on the Y blocks and giving them a little more initial advance than normal... wakes 'em up quite a bit.

[Ole Don]

Where I live in the corn growing part of central US, our fuel is 87, 89, or 91. If my car is tunned for best performance, it requires 89. It all has about 10% ethanol. It evaporates out of the carb in about three days. I have mounted an electric fuel pump near the front of the tank, with a relay and a swich under the dash. If the car sits more than a few days, I run the pump for several seconds prior to trying to start it. Neither fuel pump seems to mind the other one in the system.

[smtichy]

Pardon my dragging out this post, but I took the car out for a good drive today, slower speeds, with some starts and stops, plus hotter weather. Note I have a manual transmission, and I noticed that in 1st it would loose considerable power, almost stutter, at higher rpms, and backfire more letting off the throttle in mid-range speed in 2nd. I'm assuming I might need to back the advance off a bit. Any thoughts are appreciated. [It might be the timing on the car was fine as it was , oh well that's how you learn].

Ole Don, I grew up in Nebraska and remember back in the late 80's we too were running 10% ethanol. The higher octane from the ethanol sure squeezed more power out of the Ford turbo 4 banger I had in those days.

Also Ole Don, coincidentally my car had a mystery toggle switch below the steering wheel that some "mekeniks" installed. I traced it to an electric fuel pump that is mounted on the frame by the rear axle, but seems to be frozen-up and non-functional. It's been Ziebarted over so I haven't been able to figure out what era it came from but I think it was before a general restoration done on the car in the 80's. Surprisingly the non functioning pump doesn't seem to obstruct the fuel line (ie. same situation as you have).

BTW, I'm sure I don't need to tell you all this but never Ziebart a classic car, it makes a nice sticky mess to manipulate around!

[Y-Blockhead]

Steve, check your total advance. When you have 16° initial advance you may be over advanced at higher RPM. I had to limit my mechanical advance for 38° total advance.

[Talkwrench]

You will be over advanced . If you want higher initial advance you will need to modify your timing slot [shorten it] I don't think you should be going over 35 degrees total, but then I don't know your corn fuel.. I would say for your engine [manual trans]everything being in tip top condition you should be idling on 21 Hg. This info without Vacuum advance hooked up.

[Ole Don]

The racers in the Y block magazine say to time the engine at 3600 RPMs for a total of 36 to 38 degrees. I ran about 37 - 38 with 100 LL fuel for one mile at Bonneville.

[smtichy]

Considering the comments on vacuum / mechanical advance, one thing occurred to me that I need to research.

My motor is a '59 and the dizzy appears to be '57-59 as it has a 12200-B type rotor in it. The vacuum advance is hooked up to a "ported" pickup on a '55 Holley 4000. Some research a friend of my forwarded to me seems to indicate that the "newer" dizzy has a different advance system and might need the vacuum hooked to a non-ported source . With the other stuff I've found, I would be surprised it the old "mekenik" got it wrong .

Let me know if you think I'm on to something here with the ported vs. non-ported pickup? Tomorrow evening I'll try to get over to the garage and see if I can identify the type of distributor I have to be sure.

[Y-Blockhead]

The '55 carb is set up for the Load-o-matic distributor and visa versa. The later distributor will not work properly with it nor will the Load-o work with a later carb.

Later Holleys (AFB's, Edelbrocks, etc. have ported vacuum for the vacuum/mechanical distributors ('57 up).

Some have run with manifold vacuum with success but it is best to run the correct combo.

[scicala]

Originally Posted by smtichy

Considering the comments on vacuum / mechanical advance, one thing occurred to me that I need to research.

My motor is a '59 and the dizzy appears to be '57-59 as it has a 12200-B type rotor in it. The vacuum advance is hooked up to a "ported" pickup on a '55 Holley 4000. Some research a friend of my forwarded to me seems to indicate that the "newer" dizzy has a different advance system and might need the vacuum hooked to a non-ported source . With the other stuff I've found, I would be surprised it the old "mekenik" got it wrong .

Let me know if you think I'm on to something here with the ported vs. non-ported pickup? Tomorrow evening I'll try to get over to the garage and see if I can identify the type of distributor I have to be sure.

There is a procedure for making the Holley 4000 work using ported vacuum from the carb instead of using the loadomatic (AKA: BS system) distributor.

I can try to dig it up if interested. The Holley 4000 does have a ported vacuum hole in the right front bore. Just need to block off the part that uses venturi suction for the loadomatic system.

[smtichy]

Originally Posted by scicala

There is a procedure for making the Holley 4000 work using ported vacuum from the carb instead of using the loadomatic (AKA: BS system) distributor.

I can try to dig it up if interested. The Holley 4000 does have a ported vacuum hole in the right front bore. Just need to block off the part that uses venturi suction for the loadomatic system.

Hi Scicala, hold up on the digging, you're note gives me a lead and I will first flip through my Holley manual, and get an ID on the dizzy. My vacuum advance is hooked to a ported vacuum hole, if I follow what you noted above, maybe it is set up right?

My confusion / question is related mainly to the dizzy. Do the '57 - '59 distributors with centrifugal advance need to be connected to a ported vacuum source or a manifold vacuum source?

[Y-Blockhead]

Ported, but the ported vacuum in not the same on later Holley as on your Holley 4000 unless you modify the 4000 as scicala suggests. That's where a lot of guys get confused.