Engine - Valve/Timing Question

[manchildau65]

Here's the situation:

1) Fresh engine (406 SBC, hydro cam, and other goodies)
2) New 1407 Edelbrock Carb (750 CFM, Manual Choke)
3) Engine does start... but it's a major pain in the butt to get running
4) Sounds like it is missing on one or more cylinders (shakes like a ba$tard)
5) Verified plug wires
6) Checked to make sure that I'm pointing at #1 at TDC (zero on timing mark as well)

So now to my questions:
1) Is there a possibility I'm 180* off? and if there is, how can I verify this?
2) I may have the valve train too tight, if this is the case, can I simply back them off and readjust? or do I have to do something else because they are hydro lifters (like prime the engine or something)?

I brought the engine up to operating temperature with no problem, it holds 50lbs. of oil pressure at 190*. I started to adjust the rockers while the engine was running but wasn't doing it justice because of how loud everything was (couldn't really hear the 'clicking' when I had them backed out).

Thanks for any help... I'll post up more engine specs. shortly.

 

[manchildau65]

More engine specs... I'm shooting for 400 ponies, but I'll need to obviously get it tuned right.

Block
Serial Number: 330817
Bore: 0.030" over
Main Caps: 2 Bolt
Crank/Connecting Rods: Stock

Heads
Serial Number: 14014416
Intake: 2.02 SS (hogged out chamber)
Exhaust: 1.60 SS (hogged out chamber)
Rockers: 1.6/1.9
Push Rods: Stock
Valve Springs: Doubled
Valve Guides
Tapped/Studded Rocker studs - Double locked nuts
Combustion Chamber: 64CC
Camshaft
SUM-1107
Cam Style: Hydraulic flat tappet
Basic Operating RPM Range: 3,000-6,500
Intake Duration at 050 inch Lift: 234
Exhaust Duration at 050 inch Lift: 244
Duration at 050 inch Lift: 234 int./244 exh.
Advertised Intake Duration: 292
Advertised Exhaust Duration: 302
Advertised Duration: 292 int./302 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.488 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.510 in.
Valve Lift with Factory Rocker Arm Ratio: 0.488 int./0.510 exh. lift
Lobe Separation (degrees): 114

Pistons
Ring dimensions 5/64, 5/64, 3/16
Dome shape: .135 dish; 4 valve reliefs
Compression dist 1.560
Deck Clearance .025
Skirt Clearance .0015

 

[76zimmer]

I think I would confirm you have true TDC/firing on #1, by checking piston position, and valve motion, then make sure your firing order/plug wires are correct. If you've had it running, I would back off the rockers, and adjust by rocker lash....i.e. tighten the nut til the movement of the rocker arm is gone, then an addtional 1/2 turn. They are too tight if you don't hear any clacking when you back off the nut while running.

 

[manchildau65]

I plan on adjusting the valves 'cold' tonight and trying again.

Will the engine still run if it's 180* out? (I had it running for 5 minutes... extremely rough and missing but I wanted to try and adjust the valves warm)

 

[4X4HIGH]

Did you use the external balanced harmonic balancer AND flexplate/flywheel for a 400SBC? This would cause severe shaking if you did not.

 

[manchildau65]

yes

 

[76zimmer]

I plan on adjusting the valves 'cold' tonight and trying again.

Will the engine still run if it's 180* out? (I had it running for 5 minutes... extremely rough and missing but I wanted to try and adjust the valves warm)

as in crankshaft degrees or cam degrees?
It takes 720 crankshaft degrees to turn the cam over 360 degrees, so if your thinking timing mark on your dampner, then that would be the bottom of the stroke, either way, I doubt it would run at all.

Are you positive that true TDC on the #1 piston is the same as what your reading on the timing indicator on the timing chain cover, and that cam timing is correct?

 

[fmstruck]

Did you use a 3 keyway timing set? If you did, you may have got confused on the timing marks.

 

[76zimmer]

Did you degree the cam?

 

[folkenheath]

Here's the situation:

6) Checked to make sure that I'm pointing at #1 at TDC (zero on timing mark as well)

So now to my questions:
1) Is there a possibility I'm 180* off? and if there is, how can I verify this?
2) I may have the valve train too tight, if this is the case, can I simply back them off and readjust? or do I have to do something else because they are hydro lifters (like prime the engine or something)?

When you put the dist in did you make sure you were at #1 with the rotor pointing to #1 plug wire (or barely before) AND on the compression stroke?

Also, you can set the valve lash easily without the engine running. Just start at #1 with both valves closed, adjust them to zero, when you will feel resistance to rotate the pushrod, and then go another 1/2 turn. Then rotate the crank 90 degrees, and do #8, then 90 more degrees and adjust #4, then 3..6..5..7..2. (Verify you are back to 0 when you get to number 6 so you don't get way off in your crank rotation).

Also, if you get them close (1/4 - 3/4 turn past zero lash, but be consistant), the lifters will adjust themselves the rest of the way, but it may run rough for 30 seconds or so until they do since you may have had them too tight before.

 

[manchildau65]

Guys, thanks for all of the replies and help!

Last night, I found two main contributing problems 1) my valves were WAY too tight 2) I ended up being one tooth off with my distributor

After adjusting the valves the truck still ran like crap, so I checked that I was still pointing at one at TDC. It appears that I was pointing towards one but a little more towards 3, so I rotated all my plug wires one spot. Low and behold the truck ran great! So I pulled the distributor and moved it forward a tooth and replaced the wires in the proper location. Truck runs like a champ! I'm going to figure out how to post a video... atleast I like hearing a high torque starter and lopey cam

Trucks not togethor so the wife took pics of me driving it while sitting on a bucket (only a cab and running gear at this point). She said I'm the poster child for REDNECK

 

[Yo]

Dude one of the best parts of my day is hoppin in my Blazer, cranking the high torque starter on my zz4, and listening to that fat, juicy idle as it warms up.