[Jack P.]

I bought a unfinished car with a 1968 400 [979071] block. I was told it was rebuilt and it was in the car and was ran. I pulled the engine when I got it to check. I pulled the pan and everything was clean so I replaced the oil pump and put it back in the car. I decided to install FiTech EFI at this time. Got it running, ran good for not having 12v tach signal. It was on the oem points but the weak signal caused bouncing idle. I bought a new HEI and installed. Advance blocked off. It runs good with 17.5hg vacuum when the timing is about where it is in the picture. If I move the timing to 10-12deg where it should be, I get 15hg vacuum it is a dog and hard to start. Now the question, why is it happy with timing at about 25-30deg advance? I compared to a new balancer to see if the mark moved, but it did not. That was my last guess.
http://forums.maxperformanceinc.com/...1&d=1575751458

[steve25]

First confirm that the motors mechanicals are ok, as this should have been done way before ordering up a EFI set up.

Confirm that TDC is in the ball park by pulling out all the plugs and baring the motor over to number 1 TDC, you will know your on number one on the Balancer if you feel a pressure build up on your finger tip when placed over number 1 plug hole while baring the motor over, if you do not feel cylinder pressure then your on number 6 TDC.

At this point having found number 1 TDC your Balancer should be reading within 2 degrees of zero if the Balancer outer ring has not moved.
At this point if you measure 2 1/8" clockwise around on the Balancer from the line and make a new mark then that will be 36 degrees of advance and the motor should run happy if all else is as it should be.

This 2 1/8" measurement assumes you have the 1968 and up 6 3/4" OD Balancer.

[ID67goat]

Originally Posted by Jack P.

I bought a new HEI and installed. Advance blocked off. It runs good with 17.5hg vacuum when the timing is about where it is in the picture. If I move the timing to 10-12deg where it should be, I get 15hg vacuum it is a dog and hard to start. Now the question, why is it happy with timing at about 25-30deg advance? I compared to a new balancer to see if the mark moved, but it did not. That was my last guess.
http://forums.maxperformanceinc.com/...1&d=1575751458

Can you clarify your comment about advance blocked off? Is the distributor "locked out" or is the vacuum advance just plugged off? Are you using the Fitech to control timing or the distributor?

I don't think I would focus on the vacuum number so much. Set your base timing with no vac advance etc.....then let the Fitech control timing from there ( but I am guessing that you are not using that feature).....or if just using the distributor for timing plug the vac advance hose into ported or unported vacuum on the Fitech (not sure what it should be on your car) and see how it runs.

[shaker455]

Test to see how worn the timing chain is.
Dist cap off, see how far you can turn the engine CCW before dist rotor starts to move

[Jack P.]

Steve25 I did bump the engine with my finger in the hole to get compression on #1 and installed the distributor there. Are you talking about 36deg total timing, with the vacuum connected and the rpm's up past 3000. I am trying to get idle timing with no vacuum to distributor and that should be about 9deg. The outer ring did not move, I compared it to a new one and they were the same.

ID67goat I have the vacuum port on the distributor disconnected and the vacuum port on the EFI plugged. I am not using the EFI to control timing.

shaker455 I move the crank clockwise till it reads 0deg then moved the crank counterclockwise till the rotor starts to move and it was within 2deg. It is a 6.75 balancer.

If I leave the initial timing about where the picture shows, it runs and starts great and appears like everything is happy. I can just leave it there but I am curious why it is like this. Moving the timing even back to 12deg and it has no power and lower vacuum, so I timed it by ear and this is what I get. This distributor does have an adjustable advance so now at idle, reconnecting it the timing does not move.

[ID67goat]

Jack,

I would try to get a hold of a dial back timing light so you know exactly where your timing is throughout the RPM range. Also, since you are not using the Fitech to control the timing, I would connect up the vacuum advance like it should be instead of plugged off. It should run decent doing it this way...then you can continue fine tuning the distributor curve and Fitech for better drivability.

[Schurkey]

Was the camshaft verified to be properly synchronized to the crankshaft? (i.e., "degreed")

If the cam isn't where it's supposed to be, you'll erase a heap of throttle response and cause poor running.

First (easy) check: Perform a cranking compression test. Excessively high or low numbers on all eight can be a symptom of a cam out-of-time.

Second (not-as-easy) check: Pop a valve cover, put the crank at TDC EXHAUST for #1. Both valves for #1 should be barely open, and open "about" the same amount. If not, the cam is likely out-of-time.

Or you could do the dial indicator/degree wheel process which gives you guaranteed results assuming you perform the work properly.

Of course, tuning the initial/centrifugal/vacuum advance to your application would be time well spent.

[Jack P.]

I will work on doing a compression check.
How do I find TDC Exhaust #1?
I do not know what cam is in it or do I know if the cam is a tooth off. If the cam were a tooth off would I see anything like I am seeing. With the timing far advanced as shown in the pic, it runs so smooth I could set a glass of water on the air cleaner and it not fall.

[chiphead]

A low compression engine or one with a large cam will want a lot of initial timing. So will an engine with a carb/EFI that is too lean at idle.

What heads are on this engine? Do you know what pistons? Did you verify how timing chain was installed, IE dot-to-dot?

[Jack P.]

I was getting nowhere so I decided to see if it was put together one tooth off.
I found a cam gear that was machined down to far, the dot was gone, and it
was remarked. That is what I am guessing happened. So when I get the new gear
I am kinda hoping it is one tooth different than this, then I will know what is happening.
The heads are #15, it is a stock rebuild. A friend brought over his nice Snap On timing light.
Set it at 38deg and ran it to 3000rpm. When done the mark was at 8deg to9deg idle, as it should be.

http://forums.maxperformanceinc.com/...1&d=1576353821

[grivera]

Originally Posted by Jack P.

Got it running, ran good for not having 12v tach signal. It was on the oem points but the weak signal caused bouncing idle. I bought a new HEI and installed.
http://forums.maxperformanceinc.com/...1&d=1575751458

Do you have 12V to the HEI?

[Jack P.]

Originally Posted by grivera

Do you have 12V to the HEI?

Yes, the engine harness is new and I cut it apart and removed the resistance wire
and replaced it with correct rated wire. When running it only moves around about 50 rpm's.

[ta man]

Originally Posted by Jack P.

I was getting nowhere so I decided to see if it was put together one tooth off.
I found a cam gear that was machined down to far, the dot was gone, and it
was remarked. That is what I am guessing happened. So when I get the new gear
I am kinda hoping it is one tooth different than this, then I will know what is happening.
The heads are #15, it is a stock rebuild. A friend brought over his nice Snap On timing light.
Set it at 38deg and ran it to 3000rpm. When done the mark was at 8deg to9deg idle, as it should be.

http://forums.maxperformanceinc.com/...1&d=1576353821

I don't know if its the picture or my eyes..but the timing chain engagement on the cam sprocket sure looks weird?

[steve25]

What the hell has happened to the teath on that Cam gear???
Timing wise it looks to be ok judging by the locating hole for the fuel pump eccentric.

[Jack P.]

The gear seems ok, maybe just a bad picture view. Here are some better pics.
http://forums.maxperformanceinc.com/...1&d=1576528283
http://forums.maxperformanceinc.com/...1&d=1576528283

[mchell]

Looking at your first pic ......it appears you were lined up at 6 o’clock on the cam sprocket and 12 o’clock on the crank sprocket.... putting you At TDC on #6 cylinder..... doesn’t look off for a dot to dot install..... the cam sprocket locating ^ is somewhat faint ...

Sell that Morse chain to someone looking for a for one... I hear they are hard to find and last forever

[Jack P.]

Originally Posted by mchell

Looking at your first pic ......it appears you were lined up at 6 o’clock on the cam sprocket and 12 o’clock on the crank sprocket.... putting you At TDC on #6 cylinder..... doesn’t look off for a dot to dot install..... the cam sprocket locating ^ is somewhat faint ...

Sell that Morse chain to someone looking for a for one... I hear they are hard to find and last forever

Yea I am at #6 now, just seeing if things line up. Never seen a cam gear without a casted in dot.
Is this chain something good, I did notice it was tight coming off so I only ordered a cam gear.

[mchell]

Originally Posted by Jack P.

Yea I am at #6 now, just seeing if things line up. Never seen a cam gear without a casted in dot.
Is this chain something good, I did notice it was tight coming off so I only ordered a cam gear.

I was joking about the Morse chain ...... Guess they are gold....see this :

http://forums.maxperformanceinc.com/...d.php?t=836187

[Jack P.]

Originally Posted by mchell

I was joking about the Morse chain ...... Guess they are gold....see this :

http://forums.maxperformanceinc.com/...d.php?t=836187

Yea I was reading that the other day, did not really know the difference, oh well
it was going back in anyway.

[mchell]

Originally Posted by Jack P.

Yea I was reading that the other day, did not really know the difference, oh well
it was going back in anyway.

Gotcha.....haven’t run a Morse chain since forever myself....apparently they are alive and well 😂