Locating dimple on timing gear

[Nosetime]

My first car was an MG midget, engine was apart in a couple milk crates...I got it together and running at 15 years old. I've owned and worked on lots of stuff over the years and when I came to the Model A a couple years ago, I remember laughing at the simplicity. Why finding TDC is a problem, I find amusing. I guess the point is, we all bring a different set of skills and experience to the table.

[katy]

I guess the point is, we all bring a different set of skills and experience to the table.

Ditto

[erdaviesjr]

I tried all the above suggestions. I found that I was not able to turn the engine easily using the belt even with all the plugs removed. So, I continued to use the crank. I located the dimple before I loosened the rotor so I had a good idea where it should be by watching the rotor. I replaced the lower condenser with a modern upper plate from Nu Rex, and also changed the plugs. I'm still not sure the timing is in the exact right location, but it seems to be at TDC and the car is running really well through all speeds. No stuttering like it did before. Lots of pick up between 2nd and 3rd and I easily got the car up to 55 MPH on a 2 lane road near my house. i can't wait to take it out on the open road and she how she does. Thanks for all the suggestions!@

[katy]

Homemade crank nut wrench:

[30 Closed Cab PU]

I bought a crank wrench form a Model A part venor, is painted green I do not remember who I bought it from. The wrench handle hits the fan belt so is somewhat more difficult to use, so I take the fan belt off.

[wgmatt]

Sponsored Links (Register now to hide all advertisements)

I had trouble finding the dimple also but bought this tool from Snyder's and now it's a breeze.

https://www.snydersantiqueauto.com/P...earchByKeyword

[Patrick L.]

Set point opening [ .018-.022"/ preferred .020"]
Locate TDC with timing pin as you did, good.
Then use continuity meter or test light to set point opening by loosening and turning rotor. Make sure all shaft back-lash is removed when doing this.
It is important to do these procedures in correct order.

[30 Closed Cab PU]

Originally Posted by Patrick L.

Set point opening [ .018-.022"/ preferred .020"]
Locate TDC with timing pin as you did, good.
Then use continuity meter or test light to set point opening by loosening and turning rotor. Make sure all shaft back-lash is removed when doing this.
It is important to do these procedures in correct order.

Also make sure the spark advance lever is fully retarded (up) when setting the timing/points.

[burner31]

I hold the screwdriver in my left hand and turn the motor with my right hand.
The sharp tip of the driver finds the dimple every time
Pull the plugs of course.

[100IH]

Everyone needs to learn a method that is always useful under all circumstances. That means don't rely on the distributor. On a new engine or just after head gasket the dist. has been out and needs to be re-installed in time with the camshaft position so one needs a method that does not rely on the rotor. If the rotor has not been moved, that's OK but often the thin washer underneath dist. cam can get lost leaving the cam able to migrate out of time with eveything else.

[30 Closed Cab PU]

Realize most errors in this post so am editing to prevent possible long strings.


I think I understand what is said below is in cases where there may have been an assembly error and the dimple no longer indicates TDC #1, or a new gear timing mark is incorrectly stamped, an alternate method may have to be used. If all is assembled correctly and parts are correct then no problem. Ideally all you should really have to check is points gap and points timing (at full retard) with the dimple indicating TDC #1.


From what I think I understand, since the distributor is fixed, and only the points plates move, rotor position should be a close indicator for #1 TDC if it is lined up with the #1 position on the dist. body.


So changing the points timing does not affect rotor position, bur rotor position affects points timing. So I do not understand below about points timing affecting rotor position.


Would appreciate comments if my understanding is incorrect.

Originally Posted by 100IH

Everyone needs to learn a method that is always useful under all circumstances. That means don't rely on the distributor. On a new engine or just after head gasket the dist. has been out and needs to be re-installed in time with the camshaft position so one needs a method that does not rely on the rotor. If the rotor has not been moved, that's OK but often the thin washer underneath dist. cam can get lost leaving the cam able to migrate out of time with eveything else.

[30 Closed Cab PU]

Deleted/edited my post above, got confused with what I thought I knew, and was off on a tangent.

[alexiskai]

Originally Posted by 30 Closed Cab PU

So changing the points timing does not affect rotor position, bur rotor position affects points timing. So I do not understand below about points timing affecting rotor position.

I think all he's saying is that one needs to be practiced in a method of setting timing that doesn't rely on the rotor position to get you in the ballpark of TDC, because there are many scenarios in which the rotor gets disconnected from the camshaft or loses its precision over time.

[Synchro909]

Originally Posted by 30 Closed Cab PU

Also make sure the spark advance lever is fully retarded (up) when setting the timing/points.

If there's any chance the engine will be started the engine with the crank handle - ever, I time the engine with the lever a couple of notches down. I run a high compresssion (5.5:1) head so I don't need as much advance as Henry gave us so the slightly less advance this gives me is not a worry.
By doing this, when the lever is all the way up, the spark fires slightly AFTER TDC so there is NO chance of the crank handle kicking back.
Just my safety tip!

[Patrick L.]

Originally Posted by 30 Closed Cab PU

Also make sure the spark advance lever is fully retarded (up) when setting the timing/points.

Ooopps, senior moment.

[katy]

Originally Posted by 30 Closed Cab PU

Realize most errors in this post so am editing to prevent possible long strings.


I think I understand what is said below is in cases where there may have been an assembly error and the dimple no longer indicates TDC #1, or a new gear timing mark is incorrectly stamped, an alternate method may have to be used. If all is assembled correctly and parts are correct then no problem. Ideally all you should really have to check is points gap and points timing (at full retard) with the dimple indicating TDC #1.


From what I think I understand, since the distributor is fixed, and only the points plates move, rotor position should be a close indicator for #1 TDC if it is lined up with the #1 position on the dist. body.


So changing the points timing does not affect rotor position, bur rotor position affects points timing. So I do not understand below about points timing affecting rotor position.


Would appreciate comments if my understanding is incorrect.

"I know you believe you understand what you think I said,
but, I am not sure you realize that what you heard is not what I meant." Author unknown.

[erdaviesjr]

I'm going to get one! thanks!

[Forddan]

I think my question is more or less on the topic.

I want to have a backup distributor. If I time a distributor and take it out to have it as backup:

Will keep the timing ?

Thanks

[30 Closed Cab PU]

Yes, it should keep its timing as long as it is going in the same motor it was point gapped and timed on.

[Railcarmover]

It should be close..but why take a chance? if you drop in the back up distributor,pin it up and check.Its important to master timing your car,detonation (spark knock) is a major contributor to main bearing failure,every time it knocks its akin to taking a sledgehammer to the top of the piston.