Timing trouble on my 283...I don't get it.

[jdhcth]

When I first got the 67 Chevy pickup the stock 283 would stay about 30 deg advanced to run good, the closer ya get it to 0 the worse it runs until dies all together.

I recently rebuilt it and I think I did everything right. Bored out new pistons, new cam 282/292, timing chain, I lined up the timing dots, just like the book said. Well, now it like like brand new and it STILL stays around 30deg advanced to run. I even tried a different distributor...NO CHANGE! Two different timing lights! AHHHHH!!!!

Whats' the deal? I set my dwell at 30. I have a Holley 650 on it. Edelbrock Performer intake. Can anyone tell me why this is happening?

I would really appreciate it.

JD

[67_C-30]

The ring on your balancer has probably slipped. This is a common problem with old balancers.

[krue]

Yeah, I was gonna ask if you used a new harmonic balancer. I couldn't time mine with a light for anything, new hb and it's right on the money with the light.

[Longhorn Man]

Couple other posabilitys;
Could be the wrong bablancer/pointer combo
Are you unplugging the vac advance hose?



I've had a couple engines that ran like crap when set at the normal timing. One was a 300,000 mile old 350 with asmall cam 305 head (mega compression) and a performer intake... it liked running at about 2 degrees BTDC, I replaced the Harmonic Damper, double checked the pointer/damper combo, finally, said screw it, it wants to run there... i ran it there. Got 11 MPG @3500 RPM all day long. Then the next 350 had way too much cam for the rest of the combo, (stock bottom end, mild port on the heads, 9 to 1 compression, 1900 stall converter, 3.07 gears, and a mystry cam that wanted a 2500 stall or so before it would idle properly in gear) I finally ended up with light springs on the weights, base timing set at about 12 BTDC, and no vac advance. Ran like a raped ape as long as I tossed it in neutral at stop lights, and it got a constant 10 - 12 MPG on the freeway at 2500 RPM.
If it doesn't want to be set per stock numbers, then set it by ear or with a vac guage, then record the numbers for the next time you take it apart, and you can set it with alight to YOUR numbers.

[shifty]

you need to plug up your vacuum hose any time you set the timing. i usally pop off the hose from the carb and put a rubber plug on the advance.

[jdhcth]

Thanks all. Never thought of the balancer slippin'. And I tried every combo with the vacuum. Seems like I woulda noticed it not bein' at TDC when I was building it. It is my first rebuild though. Maybe I'll try a new blalancer.

Thinking about gettin' rid of the points and going with an HEI also.

JD

[krue]

HEI is WAAAAY better IMO.

[JMac11]

Best way to check....... Find TDC on plug one, see where your marks line up.......... Paint stick the true mark......

[Longhorn Man]

Originally Posted by JMac11

Best way to check....... Find TDC on plug one, see where your marks line up.......... Paint stick the true mark......

As soon as it gets fired up, it may slip again, so marking it is pointless ... plus, there's damage being done if the damper is slipping.

[Billla]

Originally Posted by JMac11

Best way to check....... Find TDC on plug one, see where your marks line up.......... Paint stick the true mark......

This is the place to start.

[Billla]

Originally Posted by Longhorn Man

As soon as it gets fired up, it may slip again, so marking it is pointless ... plus, there's damage being done if the damper is slipping.

I've never had this happen, but I've always replaced my dampners. I guess I hate to replace a part unless I *know* that's the problem. How about:

1. Find TDC and mark on outer ring
2. Scribe a mark across the inner and outer ring
3. Attempt to time
4. Inspect mark that crosses rings to determine if the outer ring is slipping.

I agree that if the ring is slipping that's a VERY dangerous condition, I guess I'm just thinking you can chase that ghost or just be SURE that's what's going on...

[Longhorn Man]

I'm just saying if it has slipped, it's junk and needs removed pronto.

[VetteVet]

I wonder if the plug wires are not advanced in the cap. I would try moving them counterclockwise one terminal and see if the timeing comes in. Did the balancer come on the engine when it ran before. There are different timing tab locations. 12:00 and two oclock and the balancers have to match.

[jdhcth]

It's the original balancer. I should have changed it out but didn't know. The crank nose is not threaded and the I had to tap the balancer on. That was easy on the stand, now it's in the truck.

I'll try to rotate the wires.

Thanks Guys.

JD

[67_C-30]

Make sure if you're going to tap the new one on to make sure you do not make contact with outer ring. Make sure all of the force is applied to the center hub part of the balancer.

[jdhcth]

Is it possible to thread the hole in the crank nose? When I pounded the original balancer back on I did only contact the center. I marked across the balancer so time will tell if it's moving.

Thanks,
JD

[Green Machine]

I'm pretty sure that the keyway for the crank should line up with the timing mark on those balancersif nothing has slipped, might be worth a check.