Any Way To Cheat And Find The Right Timing Tab?

[BRL]

I put this 350 SBC together and didn't bother to set a tab on the timing chain cover before bolting on the heads.

Of course the crankshaft and harmonic balancer line up together with the key, but I'm hoping that there is the right tab as an aftermarket piece at the auto parts store without having to shove something in the spark plug hole.

Or am I just out of luck.

...yes I'll clean all the gunk off either way.

[HO455]

Why of course you can "cheat" and bolt something on as a reference to make changes and monitor your timing. But the number you come up with means nothing to any other engine. This is one reason so many engines run the same with different timing numbers. Most people don't spend the time to properly zero the tab after degreeing the cam or the tab has been damaged or is the wrong one. So by all means get a handle on your timing.

[BRL]

Originally Posted by HO455

Why of course you can "cheat" and bolt something on...

Well you started off good enough...

I timed it by ear, and its been doing pretty good all these years, but it also has an Accel "Blueprint" distributor with some adjustable vacuum advance and some aftermarket advance spring setup on the counterweights, so I have no idea where the timing is...surprised the thing runs at all and doesn't "ping".

Thank you for the reply HO455.

[demian5]

https://www.summitracing.com/search/...ab+small+block

[BRL]

Originally Posted by demian5

https://www.summitracing.com/search/...ab+small+block

Cool Thanks!

[ZEKE68]

You could make a piston bump stop out of an old spark plug and bolt and check top dead center to set the timing tab. You would have to be able to turn the engine over by hand though, both directions. The ones I have bolted on and checked have not been off by much. A degree or two.

[Mike C]

There are two location for timing tabs. But 99% user the common bolt on tab. If you have an aftermarket balancer that it looks like you do then just bolt on and move down the road.

The other guys are right that you could check and verify etc. But if you aren’t a max effort build the bolt on should be “good enough”.

[LEEVON]

Any tab that's not zero'd to TDC won't help you.

[cleszkie]

Remove the driver side valve cover. Manually rotate the engine until neither valve on the No.1 cylinder is moving while the cam slowly rotates (both exhaust and intake are closed). This is top dead center. Stop rotating the engine. Now find the timing mark on your harmonic balancer. Whatever timing tab you add, make sure the 0 degrees BTDC mark lines up with the timing mark on the harmonic balancer. Done. You may have to slowly rotate the engine forward and backward a few times to truly zero in on the point at which both valves close. But its as easy as that.

[jocko]

I think that method is generally used for finding ballpark tdc just to get a starting point good enough to get a vehicle running, after which it can be fine tuned with a timing light - but that fine tuning requires a good known TDC and already valid timing pointer... so kind of a catch 22. In other words, both exh and int lifters are riding the cam base circle (closed) for much more than 1 single degree of rotation - so I believe this method could induce some error if the goal is to find the exact TDC for the purpose of a timing pointer confirmation.

[CaptRMW]

Originally Posted by cleszkie

Remove the driver side valve cover. Manually rotate the engine until neither valve on the No.1 cylinder is moving while the cam slowly rotates (both exhaust and intake are closed). This is top dead center. Stop rotating the engine. Now find the timing mark on your harmonic balancer. Whatever timing tab you add, make sure the 0 degrees BTDC mark lines up with the timing mark on the harmonic balancer. Done. You may have to slowly rotate the engine forward and backward a few times to truly zero in on the point at which both valves close. But its as easy as that.

And with this method you will be somewhere in the neighborhood of 180 degrees of TDC. If the intake valve stops moving near TDC the combustion created by this scenario wouldn't be enough to blow your nose.
Go to your local parts store and buy a timing tab for a 7" balancer and get on with life.

[Killer Bee]

^ agree with most of the above.. unless you know the engine had a unique timing scale, start with any of the standard SBC units from some place like summit..

zeroing to TDC is smart and necessary to duplicate a published timing value from a reference but absolutely NOT necessary to set your timing, advance curves, etc..

a scale of any kind to give you a reference from base idle to part and wot will be of value even if the numbers are all off by what difference the scale is from zero..

good luck!

[demian5]

1. Look where #1 plug wire is located on distributor cap.
2. Pull the cap off and rotate the motor for rotor to line up with where #1 plug wire is located on distributor cap.
3. Look at balancer on driver side of motor like the picture you have.
a. I can see mark and it looks like its at about 2 O'clock to 2:30 on the balancer - Get a generic pointer for the size balancer you have and bolt it to the cover using the cover bolts.
b. I cant see a mark - Rotate motor 360 degrees for rotor to line up with where #1 plug wire is located on distributor cap. Can you see it now?
NOW i can see a mark - Get a generic pointer for the size balancer you have and bolt it to the cover using the cover bolts.
I still don't see nuttin - Look for it on the top (12 O'clock) or bottom (6 O'clock). You could have a van or older G body motor or balancer. If this is the case, they make pointers for these too.

[cleszkie]

Originally Posted by CaptRMW

And with this method you will be somewhere in the neighborhood of 180 degrees of TDC. If the intake valve stops moving near TDC the combustion created by this scenario wouldn't be enough to blow your nose.
Go to your local parts store and buy a timing tab for a 7" balancer and get on with life.

You've obviously never watched your valves before. Its very clear when you are 180 degrees out. One of the valves is always in motion. Don't knock it until you try it. Simply buying a timing tab for a 7" balancer does nothing for verifying TDC on a particular engine.

[GASoline71]

Gotta say... I've never seen machine screws used to hold a timing cover on.

Gary

[Killer Bee]

Originally Posted by GASoline71

Gotta say... I've never seen machine screws used to hold a timing cover on.

Gary

OE Corvette in the 50's

[jocko]

Originally Posted by Killer Bee

OE Corvette in the 50's

Interesting, learn something new every day. Looks like they were used on the whole timing cover.

[lowbucktrucks]

So this is the corvette engine option??

[BRL]

Originally Posted by jocko

Interesting, learn something new every day. Looks like they were used on the whole timing cover.

I did place them on the whole cover, really don't need a whole lot of force to tighten up the tin timing cover, just like OE tin valve covers, if you over torque the bolts you stand a good chance of warping them and having a leak.

[hjewell2]

Originally Posted by GASoline71

Gotta say... I've never seen machine screws used to hold a timing cover on.

Gary

I spotted that also.

[GASoline71]

Originally Posted by Killer Bee

OE Corvette in the 50's

Originally Posted by jocko

Interesting, learn something new every day. Looks like they were used on the whole timing cover.

I am in the same boat jocko.

Originally Posted by BRL

I did place them on the whole cover, really don't need a whole lot of force to tighten up the tin timing cover, just like OE tin valve covers, if you over torque the bolts you stand a good chance of warping them and having a leak.

I agree that many a pan has been warped due to over tightening of fasteners. Good way to put your over tightening in check!

Gary