Im not sure what this could be but i dont seem to have any power at all under 1750RPM. If im racing off the line i have to mash the brake to the floor and get the RPMs up to about 2500 to get a half descent launch. If i just sit with no brakes and mash the gas to the floor im very lucky if i get a little bark out of the tires anymore but around 1750RPM it puts you right back in your seat and takes off like a rocket.

I have set up the timing according to the tech articles for my non cc HEI. I have found my best setup to be without vacc advance and the mr gasket mech advance curve kit #929g w/1 light & 1 med spring. I have noticed setting initial advance wayy up to g0d knows where (line on balancer is a couple deg to the passenger side of the top) it gives me a bit more bottom, i can kindof chirp the tires but this is a crazy ammount of advance compared to what edelbrock tells me to run (14*) but with that much advance i have no top end and it barely starts.

Sorry for the long @$$ post but i want to be able to have some off the line power!

Specs on engine:

70-74 350 block
Edelbrock performer cam,EPS intake,600cfm carb,14" K&N open element. non cc HEI new plugs/cap/rotor. running hedman long tube headers with straight dual lakers.
Th-350 trans w/ 410 rear.

 

What are the cam specs?

 

im not 100% sure... whatever the edelbrock performer is.

just got a few specs off the site
Lift: .420''/.442''
Duration: 278°/288°
RPM Range: Idle-5500

Im not sure where but somewhere along this build i lost all power under 1750RPM. I used to be able to just mash the pedal and smoke the tires...

 

The cam seems relatively tame for a 350. That duration shouldn't be causing that kind of lower RPM problems.

Having said that, the cam installation could be an issue. I've had similar symptoms from one of these:



That's an 18° difference in timing per chain/sprocket tooth. That can cause what you are experiencing.

This is more like what you should have:

 

That's an 18° difference in timing per chain/sprocket tooth. That can cause what you are experiencing.



Missed it by that much

 

What exactly are we looking at in these pictures?

I don't see the difference other than the angle/straight edge.

I exhibit these symptoms in my car.

 

To me it looks like it's off a tooth in one picture.
Maybe you could be off a tooth on your distributor installation?

 

The Cam timing is dead on, i checked and double checked because i didnt want to take off that damn leaky chrome front cover again! But i did use a brand new but OEM style single roller timing chan could this maybe cause this?

Dist timing is kindof weird though... edelbrock reccomends 12-14* but it runs alot better at something like 30* initial. Its hard for me to tell exactly what * i have as the mark on the dampener is about straight up and way off the tab.

 

As for the previous photos, it was on one that I "inherited", and was indeed off by one tooth - 17.75° to be precise. It exhibited the same lethargic symptoms at lower RPMs. The engine ran better with about 30-35° ignition advance (to match the valve events better, and not the piston position) and still made poor power. I'm not the only one who has found this.

As for the issue at hand, NOW we start to get some details.

That "chrome front cover" could be part of the problem. The timing tabs supplied with them are typically wrong. Verify the actual TDC and timing mark alignment. The bolt on timing tabs are often based on an 8" damper, and the TDC marks are often way off.

First, verify that the timing groove on the damper has not slipped. The woodruff keyway milled into the crank snout should have been machined exactly at the TDC position of the #1/#2 crank throw. The stock position of the timing groove on the balancer outer damper ring should be 7° retarded from that keyway.



If your timing groove is different, you'll have to compensate with the timing tab position or paint a new timing line on the outer ring in the correct position. (Note the chrome cover and Chinese timing tab in the photo)

Next, once you have established a reliable timing mark on the balancer outer ring, rotate the engine to TDC on the #1 cylinger. You will not be able to use the timing tab to find TDC. You'll need to use the same degree wheel and piston stop that you used when you degreed the cam on installation. Find the piston stop angle in both directions, divide, remove the piston stop, and set the crank at 0°.

Finally, you can compare the position of the installed timing tab to the actualy 0° position of the crank. Don't be surprized if there is a difference. That difference could easily account for the "excessive" advance you apparently need.

 

I think i might just rip it all apart and put in the double roller setup i have on my new block, or just live with it for the next few weeks of summer we have left up here.

That OEM single roller chain i have in there now probably stretched enough to get me 20* out lol

 

Just a bit of clarification:

The photos of the timing set are from ME, not from 84Z.

Yes, the timing was off on that installation. It caused performance problems and one bent valve.

The timing of a distributor does not rely upon the orientation (insertion position) of the distributor gear relative to the camshaft gear. As long as the wires can be position in the proper sequence and the distributor can be moved, adjusting timing should be easy.

This is a better representation of being off a tooth (or more):



BTW - If you see ODB, tell him I asked whassup.

 

I think hes skipped a few teeth, at least 180* out... lol

I know for sure the cam was installed straight up, Im guessing my el cheapo timing gear & chain must have jumped a tooth so my cam is probably out 18* or whatever because it did have good low end for a bit after the cam change.