355 issues

rustbucketZ28 · 08-02-2010, 06:09:23 PM

Alright I'll get straight to the point, me and my buddy built a 355 a few months ago and it's having a strange timing problem. The thing won't run unless it has over 40* initial timing and it really likes around 78* inital. Totally ridiculous I know. We have checked everything we could possibly think of and checked it again. The car has no problem starting and runs fairly good but seems to be lacking power. We need help!

The ring on the balancer has not slipped.
The timing tab is correct.
The cam has been degreed.
The engine has good compression.
The timing light has been checked.

Engine specs;
bored .030 over
Around 10:1 compression
Edlebrock E-Street heads
Summit headers
Edlebrock 600 cfm carb
Edlebrock Performer intake
Lunati 60103lk;
Duration at .050 227 in/233 ex
Advertised duration 268 in/276 ex
Lift 0.489 in/0.504 ex

AJ_72 · 08-02-2010, 11:15:54 PM

Double check your spark plug wires. Sounds like they're out of order and while you think you're reading off the #1 cylinder, you may be reading off #8, #4, #3, #6, #5, #7 or #2.

I. E. the #8 wire may be going to the #1 cylinder, or the #4, etc.

Seriously, I've seen it done.

Clockwise looking down at the cap.
18436572

Don't overlook the obvious. Happens to me all too often.

496z28 · 08-02-2010, 11:22:10 PM

Quote:

Originally Posted by AJ_72

Double check your spark plug wires. Sounds like they're out of order and while you think you're reading off the #1 cylinder, you may be reading off #8, #4, #3, #6, #5, #7 or #2.

I. E. the #8 wire may be going to the #1 cylinder, or the #4, etc.

Seriously, I've seen it done.

Clockwise looking down at the cap.
18436572

Don't overlook the obvious. Happens to me all too often.

+1

78*, yeah, there is no way your on plug 1. Very common, easy mistake. Check plug wires.

rustbucketZ28 · 08-03-2010, 04:09:28 AM

We're just getting it back together from degreeing the cam(it was right on), so we'll double check when it's at that point.
Thanks

rustbucketZ28 · 08-08-2010, 07:16:32 PM

Ok we got it back together and the same damn thing. Double and triple checked wires, all is good. Runs the best at 78* advance at idle. Checked the timing on my car I just bought with a 355 of about the same build and guess what, same deal. And yes we are reading off the # 1 cylinder. Both cars run good with no detonating.
I guess we should test the timing light again...

BondoSpecial · 08-08-2010, 07:21:40 PM

yeah if you are past 45 degrees mechanical advance you are jumping towers in the cap... so there is no way you have 78 degrees mechanical advance at idle

Chaindrive · 08-08-2010, 07:37:08 PM

What they're saying is to make sure the rotor is actually pointing at Number 1 when Number 1 piston is at the top of it's compression stroke. It sounds like you have the distributor a tooth or two off.

Remove your valve cover on the driver's side, remove your distributor cap, then slowly turn/bump the motor over until you see the #1 intake rocker cycle. Continue to turn the motor slowly in the direction of rotation until the front timing marks line up. (Both #1 rockers should be at rest now.) The rotor should be pointing at the number 1 distributor terminal at this point. If it is not, you need to make it do so, and will probably need to remove the distributor and turn the oil pump shaft a little bit with a long screwdriver before reinstalling it. Remember, the curved gear teeth will rotate your distributor as it seats. Allow for that.

In the end, the rotor must point at the Number 1 distributor terminal when the timing marks are lined up. It will run at that point. You can adjust the advance after it is running.

Pay attention to the direction of rotation of both the engine and the distributor rotor. The next cylinder the rotor must point to is #8, then 4,3,6,5,7,2 as stated earlier. Install the wires accordingly.

sooner · 08-08-2010, 07:57:20 PM

Quote:

Originally Posted by rustbucketZ28

Alright I'll get straight to the point, me and my buddy built a 355 a few months ago and it's having a strange timing problem. The thing won't run unless it has over 40* initial timing and it really likes around 78* inital.

What spark plugs are you running? Using the wrong reach plugs (too short) will cause exactly what you are explaning to happen.

1972L · 08-08-2010, 10:02:09 PM

How did you determine the 78* mark?

Try a different timing light

rustbucketZ28 · 08-09-2010, 06:44:43 PM

Quote:

Originally Posted by Chaindrive

What they're saying is to make sure the rotor is actually pointing at Number 1 when Number 1 piston is at the top of it's compression stroke. It sounds like you have the distributor a tooth or two off.

Remove your valve cover on the driver's side, remove your distributor cap, then slowly turn/bump the motor over until you see the #1 intake rocker cycle. Continue to turn the motor slowly in the direction of rotation until the front timing marks line up. (Both #1 rockers should be at rest now.) The rotor should be pointing at the number 1 distributor terminal at this point. If it is not, you need to make it do so, and will probably need to remove the distributor and turn the oil pump shaft a little bit with a long screwdriver before reinstalling it. Remember, the curved gear teeth will rotate your distributor as it seats. Allow for that.

In the end, the rotor must point at the Number 1 distributor terminal when the timing marks are lined up. It will run at that point. You can adjust the advance after it is running.

Pay attention to the direction of rotation of both the engine and the distributor rotor. The next cylinder the rotor must point to is #8, then 4,3,6,5,7,2 as stated earlier. Install the wires accordingly.

Did that at first but the car would barely run so had to advance it, ran better but still crappy. After advancing it as far as we could it still wanted more timing so we had to move it a tooth to get more advance timing. We have it running the best it has been now with 78* at 1000 rpm.

I have rebuilt a few stock engines and installed half a dozen distributers and never had this kind of problem.

rustbucketZ28 · 08-09-2010, 06:45:48 PM

Quote:

Originally Posted by sooner

What spark plugs are you running? Using the wrong reach plugs (too short) will cause exactly what you are explaning to happen.

The ones that edlebrock recomended for their heads.

rustbucketZ28 · 08-09-2010, 06:48:32 PM

Quote:

Originally Posted by 1972L

How did you determine the 78* mark?

Try a different timing light

Using the fancy digital adjustable timing light that goes to 90*

Tried a regular timing light and the mark on the balancer is on the opposite side of the timing mark.

rustbucketZ28 · 08-09-2010, 06:54:28 PM

It really makes no sense to me it's even running with it advanced as far as it is. What else doesn't make sense is that the car I just bought had that much advance and won't run worth a crap with less.

Like 1977 TPI Camaro said it would be sparking on a different terminal...

ZS10 · 08-09-2010, 06:54:40 PM

Something is way out of wack. Either your timing light, the balancer/tab or what you think is #1 on the cap, #1 wire,or #1cylinder.

But if you can make it run and have some reference point, be it 0* or 78*, its all good. Just don't tell anyone.

1972L · 08-09-2010, 09:20:13 PM

Are you sure you are connected to the front plug on the Drivers side?
Cylinder #2 fires 90* before cylinder #1.
The average sbc idles fine @ 12* before TDC
If you are on the Front spark plug on the Passenger side, that would explain the 78 degrees (90-12=78)

Unless there is some spark jump between the HEI #1 and #2 terminals (inside or out of the cap) or jumping between wires, but I doubt that would be consistant on 2 cars.

A second timing light might not be a bad idea.