Whys my initial timing so high? Sbc

Got a quick question

My initial timing is @ 33* with no vacumn (plugged)

My balancer is a new one that the machine shop recommended me putting on (rubber seal was rotten they said).

Shouldnt my intial be in the mid to low teens?!

Whats causing it to be this high!!!!


(Stock HEI Gm distributor, stock weights and medium springs from a mr gasket kit)

I verified the TDC mark on the balancer 1 time before its a pretty much new balancer 10,000 miles on it now maybe)

Whys it so high shouldnt it be like12-15?!

HELP

(350 sbc bored .30 over thumpr cam vortec style heads balanced stock bottom end)

 

Remove the cap and rotor to verify that the advance weights are not stuck out or that a spring fell off.

 

How does it run?

 

Seems to run good,

Ive replaced the weights etc to attempt to get a certain curve. I lubed the underside well.

I put the numbers facing up, this is correct right?

 

What happens when you adj. it back to a more realistic number? If its a correct reading now I don't think you could run pump gas in it. Do you???? Normal Norman

 

Isn't the initial timing manually set?

 

what is your idle rpm?

 

Is replacement balancer timing mark at different location than stock one???

 

Im pretty sure its stock style balancer looks like any other sbc balancer out there

Idle is around 700-800rpm

It runs, but runs like crap at 14 degrees or so

 

A couple of things : First, not all SBC harmonic balancers are the same. I have a '67 327 and a '68 327, and they are different diameters and everything. Second, I had a problem like this and the distributor was installed one tooth off. If you can find the correct manual for you engine, it will have a diagram that will show exactly how the distributor should be installed. If you have a vacuum gauge, here's what you can do. Get the car running and, with the vacuum gauge connected to manifold vacuum, turn the distributor until you get maximum vacuum at idle, Then turn it to retard it just a bit. Check it with your timing light; if its on the marks, you're OK. If you're not, something else is wrong; slipped ring, wrong balancer, or the distributor is installed wrong.

 

Actually, I took the dizzy out today.

I lined the balancer (assuming its correct) @ the zero mark.

Pulled cap off, the rotor was not pointing directly at the #1 firing tower, so I attempted to get it perfect, 30 minutes later I got it right lol

A pretty reputable machine shop did the machine work, im pretty sure its the right balancer..

they go by the diameter right? i'll have to measure it tomorow.

Like I said im happy with how it runs just the numbers are really throwing me off. Ive been tweeking things, i'll keep ya updated guys. thanks

 

when you build a engine put a positive stop on #1 piston and turn both ways mark and then cut a timing mark for TDC in the middle, most are off some
with a cam it aint gonna run without a lot of advance, but tweaking carb power valve and the advance curve and total timeing can be cut back to allow a higher initial timing to cover the cam

best to have a dial back timing lite and check total timing 38 to 40 degrees is what is best for a raceing engine
many run much more on the street

CAUTION THE PISTONS YOU DETONATE MAY BE YOUR OWN COST TO REPLACE

THERE IS A LEARNING curve to do this kind of work once you master it they all will come easy, i had to experiment for hours on stock cars 35 years ago and it still is simple to get most to run decent but costs time and money, you need carb jets and lots of other things to experiment with

 

My guess is the outer ring has slipped - this is common.

The only other thing it might be is that the ballancer is off a van. The van motors' had the timing mark & pointer in a different location (due to viewing access)

 

Like has been said already, you need to know that the mark is at TDC first. If so, (my opinion it probably is), then disconnect and plug the vacuum advance on the distributor and leave it plugged. You say it is a stock bottom end and vortec heads and a thumper cam? Idle vacuum is much different and plays havoc with the vacuum advance. You should just check the total timing using just the mechanical advance and set it about 38-40 degrees at 3000+ rpms and don't worry about initial. Just make sure it doesn't buck the starter when hot (it probably won't being low compression). It will run great like that and won't hurt a thing. Likely need to richen the carb a little and increase the accel pump shot to make it snappy.

At 14 degrees timing and the vacuum advance hooked up it probably either hesitates real bad on accel or even backfires through the carb on initial launch doesn't it?

It isn't stock anymore so you can't assume you can set the timing the same as stock and expect it to run the same. Welcome to hot rodding

 

Somewhere in the late 70's(?) Chevy put the timing mark at 12 O Clock instead of around 2 O Clock. You had to aim the timing lite behind the water pump at the mark to set the timing. If you have that balancer....you will end up having to time it by ear or feel. Or as suggested the outer ring has slipped. I say this because you said it runs fine with the timing showing to be way off. I time a LOT of stuff by ear around my shop. The Brodix headed 406 in my 64 Vette runs really hard and I timed it by ear over 4 yrs ago.

 

Use a piston stop to find out where TDC REALLY is and go from there. All Chevy balancers are NOT marked the same .

 

I'll double check mark in the next day or so and report back.

Turn over till it hits, mark turn other way till it hits, mark. then halfway between the 2 marks is TDC right?

 

Yep , turn gently by hand !!

 

Also realize that if you've modified the engine (especially by changing to a more radical cam), the factory timing marks may no longer be optimum. Then you should "time it by ear" as Groucho says, or use a vacuum gauge as I described in an earlier post.

 

Im using a dial back light from equus.....Ive got it 'timed by ear' to my liking now, Im happy with how it runs but wondering why the initial is soo high???

 

It is so high because there is some marking the is NOT correct. Do the piston stop deal to find the true TDC and work from there. Those dialback lights are not known to be 100% relable or accurate either.

 

Time it by ear or with a vacuum gauge and forget what the light says. Marks are famous for being inaccurate and timing numbers are just a starting point anyway.

 

If you get a new ballancer, be sure mark the hub with the outer ring, so you can see if it moves. A center punch will work - sorry about the crappy pic

 

I'd bet good money that you have a damper and a pointer that aren't matched for each other. As others have said there are a few different versions as to location for SBC. If you really had 33 degrees of initial timing, I doubt the thing would even start - it would just kick back against the starter. Not to mention it would probably ping like a little bitch.

 

If you timed it by ear, it will sound better at more advanced than stock specs, which puts it over the top at the other end (total adv). The correct way is to limit the mechanical advance by modifying the distributor (kind hard for me to explain in print), keep your higher initial advance (idle) and then have the best of both worlds (more advance at idle for crisper response, without going over advanced further up the RPM on your total

 

I thought I was going crazy when I had the same problem with my 348 so I just timed it by vaccume. Same thing happened on the next motor I tried to work on ( sbc 350 ), once again timed it by vaccume. Again third motor, dodge 340, finally figured out the timing light is jacked up. Craftsman adjustable dial on the back.

 

Good thikin lowlife i have another light I can use (non dial back). Still havent checked TDC etc.

tjet-thats a real good idea too

 

Keep us posted, I'm curious now.

 

If you find that the damper has slipped, it would be wise to get it fixed. If it's loose enough to slip, it's loose enough to come apart at speed, with damaging results. I have had them slip on two SBC's I have, with the same results you are seeing. The is a guy in Oregon that can rebuild them for $110. He has done both of mine and they were perfect. www.dalemfg.com.

 

OK. My Timing cover/pointer is the 2:00 position, my balancer is supposed to be balanced with the rest of the engine? (the balancer has a start of ahole drilled in it, i guess to balance it i dunno).

I'll measure the diameter. Im having HECK trying get the TDC measurement its cold and im frustrated!!!

I'll measure diameter and try'n get pix thanks I really think its wrong balancer or something cause it ran good but gave wierd readings.