Engine Timing question

evintho

Dirt-Old 20+Year Member
Nov 12, 2003
607
189
73
Santa Rosa, CA.
Set base timing at 13* BTDC with SPOUT out and with SPOUT back in it runs about 22*. Does that sound right? It also has a lopey sound to it but it's the factory roller cam. Open headers if that makes a difference.

Also, what's oil pressure supposed to be at? My SW electric gauge pegs at 80psi and stays there as soon as I fire it up. I don't let it warm up much 'cause no radiator installed just yet. New Melling oil pump......not hi-volume.
 
  • Sponsors (?)


What rpm?
Is the oil pump a hi pressure pump?
Install a cheap mechanical gauge to check the accuracy.
Open headers may be a problem because of the location of the 02 sensors but I think the 02's don't play a roll in cold startup but not sure.
The computer controls the timing with the spout installed, disconnect the battery for 15-30 minutes to erase the codes so the computer starts fresh.
 
Sounds about right except for the 13* part..Timing is 10* unless you specify in the tune..Even 3 advanced changes the timing events between Injector and valve..

When I want to advance /retard my timing on the fly I use one of these...They sell units that work with and without MSD ignitions....

IMG_20221028_162944.jpg


Open headers isnt too good and will make your engine run rich..............

The faster the 02's heat up the faster the engine cleans up and running an engine even in short bursts isnt good as you need to put a proper load on the rings asap to properly seat them plus running rich just gaswashes away the protective oil...

Even with flattappet hydraulic and solid camshafts I drive them straight away as the 2000 rpms sitting still is only a myth..

What kills flattapppet and hydraulic camshafts is the improper use of the thick assembly lube then allowing it to sit in engines too long not allowing the lifters to properly spin......For roller camshafts it stops the roller wheel from spinning right

I know you have a factory roller thats why driving the vehicle straight away and keeping it under 1/2 throttle varying engine speeds is very important at getting maximum ring seal...

Screenshot 2022-12-15 011617.jpg




Adding a wideband 02 controller to the EGR port wire #27 on the EEC plug helps out alot too

My Melling HV HP pump in my 410runs at 70-75 psi cold..In my 351w with regular oilpump it goes to 60psi cold
 
Last edited:
What rpm?
Is the oil pump a hi pressure pump?
Install a cheap mechanical gauge to check the accuracy.
Open headers may be a problem because of the location of the 02 sensors but I think the 02's don't play a roll in cold startup but not sure.
The computer controls the timing with the spout installed, disconnect the battery for 15-30 minutes to erase the codes so the computer starts fresh.

In order for the O2 sensors to operate properly with openheaders they must be at and stay at a minimum temperature. If you place the HEGO O2 sensors farther away from the head than the stock location or you may have the sensor too far away to keep it hot enough to read correctly due to the cooled exhaust gases.

This causes the EEC to richen the fuel mixture and may cause plug fouling. Header wrap is strongly suggested.

The EEC has a timing table used to time the sampling of the O2 sensors to coincide with the arrival of the latest cylinder exhaust pulse from each bank and when ipen doesnt give a good pulse resonance also meses with proper engine scavenging..

Moving the HEGO sensor further away or letting it operate too cool may result in an mis-timed sample which could also cause improper air/fuel mixtures to occur due to the O2 sensor not sampling when the pulse passes the sensor.

One way to compensate for the additional time needed due to adding length in the Long tube headers is to change the timing table or the FN1351 table values or just put the exhaust back in before starting it any further or ready to drive..



1671085501389.png
 
Last edited:
@CAMTWO1070
Too much technical information, we don't have a dial on the dash, not gonna move the bung for 02 sensors for optimum exhaust sampling, or have the ability to change the FN1351 table, I don't even have a dinning table :doh: I have a patio table but I ain't change'n that :nono: oh, and my mustang ran just fine at 13*, far more spunky than the pedestrian 10* the factory sets them at and still ran the crappy 87 octane junk they call gasoline today.
You obviously have extensive technical knowledge but the average member that seeks help here does not, hell, most are like me and can barely change a spark plug with the 139 piece Craftsman tool set they got for Christmas years ago and most of those tools are at the neighbors house down the street.
I came here seeking help with several (self inflicted) issues with my stang years ago and now I can diagnose most issues that arise with my stang, I can even change the spark plugs now :D
 
X2 on the cheapo AutoZone mechanical oil pressure gauge. Attach the white tube where the current sending unit is and put the gauge on the cowl where you can see it.

Melling makes high volume, high pressure, and stock replacement pumps. If you knew the part number on the pump that would help.
 
  • Agree
Reactions: 1 user
I believe the oil pump is a Melling M68 which is standard volume, standard pressure pump. I have an older SW mechanical gauge, some cap tube and fittings laying around. I'll hook that up and see what it reads.
But, why would the brand new electric gauge peg? Oil too thick and cold? I ran the motor for maybe 10 minutes with no coolant and it was pretty warm to the touch. Just using Castrol 20/50 and it's a quart low.
 
I don't understand the no coolant and a quart low thing but I understand the 'need to hear the 5.0 rumble'.
I would guess the sending unit for the gauge is outta wack, call the tech line for the manufacturer and they can give you the volt variations to see if the sending unit is wacked. I got a temp gauge that the sender had the wrong values, always read 30* hotter than actual temp.