New Motor High idle

[geraldtson]

You sure you don't have a dummy converter installed?

[GARY C]

Are you getting the engine to full operating temp before trying to do all your settings?

If the converter is tight then you need it to idle low enough that it doesn't load the engine.

[F-BIRD'88]

You don't check piston tdc with a indicator.
You check it with a piston stop (head on)
Or a piston stop strap and bolt across te cylinder deck.
With piston stop in turn crank by hand in one direction till
Stop. Note degree on degree wheel. Then rotate crank by hand in the other direction till stop. Note this degree reading on wheel. Tdc is right between these 2 stop points.
Stop deg reading A + stop deg B. Divided by 2. Move the degree wheel to correct wheel.
Do the tdc check using a piston stop again just for grins.
Before installing the piston stop in #1 cylinder. Looen off both rockers so valves are closed so stop does not hit valves.

Hole in bottom of tunnel ram port wall flange.
Faulty weld repair in manifold
Other air leak..
Check tachometer rpm accuracy.

[RD_Racing]

You don't check piston tdc with a indicator.
You check it with a piston stop (head on)
Or a piston stop strap and bolt across te cylinder deck.
With piston stop in turn crank by hand in one direction till
Stop. Note degree on degree wheel. Then rotate crank by hand in the other direction till stop. Note this degree reading on wheel. Tdc is right between these 2 stop points.
Stop deg reading A + stop deg B. Divided by 2. Move the degree wheel to correct wheel.
Do the tdc check using a piston stop again just for grins.
Before installing the piston stop in #1 cylinder. Looen off both rockers so valves are closed so stop does not hit valves.

Hole in bottom of tunnel ram port wall flange.
Faulty weld repair in manifold
Other air leak..
Check tachometer rpm accuracy.

You can check TDC with an indicator too. Rotate the motor in both directions and go past TDC, making sure to note TDC in both directions on the balancer and then split the difference and you will have true TDC (My family are all machinists).. I also used a piston stop strap to verify as you can see in the below photo.. But I didn't have the screw installed during this picture

[RD_Racing]

You don't check piston tdc with a indicator.
You check it with a piston stop (head on)
Or a piston stop strap and bolt across te cylinder deck.
With piston stop in turn crank by hand in one direction till
Stop. Note degree on degree wheel. Then rotate crank by hand in the other direction till stop. Note this degree reading on wheel. Tdc is right between these 2 stop points.
Stop deg reading A + stop deg B. Divided by 2. Move the degree wheel to correct wheel.
Do the tdc check using a piston stop again just for grins.
Before installing the piston stop in #1 cylinder. Looen off both rockers so valves are closed so stop does not hit valves.

Hole in bottom of tunnel ram port wall flange.
Faulty weld repair in manifold
Other air leak..
Check tachometer rpm accuracy.

You can check TDC with an indicator too. Rotate the motor in both directions and go past TDC, making sure to note TDC in both directions on the balancer and then split the difference and you will have true TDC (My family are all machinists).. I also used a piston stop strap to verify as you can see in the below photo.. But I didn't have the screw installed during this picture because I was checking cam specs

[RD_Racing]

Hole in bottom of tunnel ram port wall flange.
Faulty weld repair in manifold
Other air leak..
Check tachometer rpm accuracy.

You can check TDC with an indicator too. Rotate the motor in both directions and go past TDC, making sure to note TDC in both directions on the balancer and then split the difference and you will have true TDC (My family are all machinists).. I also used a piston stop strap to verify as you can see in the below photo.. But I didn't have the screw installed during this picture

Its very possible there could be a warp from welding the manifold. They fly cut the surface afterwards and I didn't use a felpo 1206-s3 which is a little thicker but it is possible the surface may still have been warped..

[RD_Racing]

Hole in bottom of tunnel ram port wall flange.
Faulty weld repair in manifold
Other air leak..
Check tachometer rpm accuracy.

You can check TDC with an indicator too. Rotate the motor in both directions and go past TDC, making sure to note TDC in both directions on the balancer and then split the difference and you will have true TDC (My family are all machinists).. I also used a piston stop strap to verify as you can see in the below photo.. But I didn't have the screw installed during this picture

Its very possible there could be a warp from welding the manifold. They fly cut the surface afterwards and I uses a felpo 1206-s3 which is a little thicker but it is possible the surface may still have been warped..

[RD_Racing]

You can check TDC with an indicator too. Rotate the motor in both directions and go past TDC, making sure to note TDC in both directions on the balancer and then split the difference and you will have true TDC (My family are all machinists).. I also used a piston stop strap to verify as you can see in the below photo.. But I didn't have the screw installed during this picture

Its very possible there could be a warp from welding the manifold. They fly cut the surface afterwards and I used a felpo 1206-s3 which is a little thicker but it is possible the surface may still have been warped..

[F-BIRD'88]

Was the balancer and factory timing cover timing tab correct ? Or needed adjustment to correct?

Yup possible air leak at bottom of a or 3 intake port(s) at the head. Ported heads that have been decked too and 1206 gasket can be a pain to seal at the bottom.
Sucks the gasket in at the bottom.
It seems it is getting extra air , from somewhere.

[RD_Racing]

Was the balancer and factory timing cover timing tab correct ? Or needed adjustment to correct?

Yup possible air leak at bottom of a or 3 intake port(s) at the head. Ported heads that have been decked too and 1206 gasket can be a pain to seal at the bottom.
Sucks the gasket in at the bottom.

I have an aftermarket adjustable pointer that I had to set.. That's about the only thing left is pulling the intake, I think I have pretty much checked everything else.. The 5" autometer tach is the same one that I used with the 355 I pulled that idled at 1000rpm and I can hear this motor RPM is definently above 1000 so im going to say its accurate

[RD_Racing]

Was the balancer and factory timing cover timing tab correct ? Or needed adjustment to correct?

Yup possible air leak at bottom of a or 3 intake port(s) at the head. Ported heads that have been decked too and 1206 gasket can be a pain to seal at the bottom.
Sucks the gasket in at the bottom.
It seems it is getting extra air , from somewhere.

You can see the pointer I used in this picture

[F-BIRD'88]

Besides the intake manifold mods and welding were the cylinder heads flat milled or angle milled?
Lack of gasket crush at the bottom of intake ports flange. This is always a pain on big port sbc heads that have been ported and heads (and block decks) milled too.
May have to glue the gasket to the manifold...
Annoying.

[RD_Racing]

Besides the intake manifold mods and welding were the cylinder heads flat milled or angle milled?
Lack of gasket crush at the bottom of intake ports flange. This is always a pain on big port sbc heads that have been ported and heads milled too.
May have to glue the gasket to the manifold...
Annoying.

They are flat milled 23 degree Promaxx 225cc Shocker heads.. I should of just purchased a new intake that was already matched to a 1206 but instead I tried to make mine work and sent them to a company in Ohio that specialized in welding and porting intakes (forgot the name)

[F-BIRD'88]

The head pics on the web site look like the bottom of the intake ports has a very thin bottom flange.
(Intake opening ported too big at bottom)
Now any milling of head and block decks kills the alignment snd ctush at this critical gasket point.
The street tunnel ram was intended fir a stock like 1205 ish gasket size at the head flange.
Pesky very thin flange contact at the bottom with lack of gasket crush. Very annoying.. The gasket flange must be thicker than the gasket is . I always leave the intake flange opening undersize on both the head and manifold just to ensure gasket sealing .. 1205 ish size.
Hopefully this is the air leak fault.
Still not 100% convinced that the timing pointer is located correct... (I know, you don't want to hear that)

[F-BIRD'88]

A basic "cylinder balance" ignition diagnostic test will detect the leaking weak cylinders also.
Disable each cylinder's spark 1 at a time while noting relative change in rpm or manifold vacuum change.
The cylinder that changes the rpm the least is the weak cylinder. Can be more than 1 cylinder leaking weak.
Rpm drop of each disabled cylinder's spark should be all the same. Don't get zapped, doing this.
Insulated pliers, gloves to handle spark plug wires.
Only one hand touching car. Other hand behind your back, not on fender... Ha ha
Be sure plug wires are fully re-seated in diz cap after test.