did some more research on thermostats and operating temps, and decided the 195 thermostat stays.

so I have nothing to do this weekend so I took the suggession that was left in the old fourm, to advance camshaft by 4 degrees, I did this twice, first time I made a mistake, the rollmaster have advance key way on the crank gear, 2 degrees each, I retard the crank 4 degrees, that gave the cam 8 degrees of advance, I didnt realize it till I have everything back together, coolant and all... lets just say I was not happy





anyway today I put it in the right one, 2 degrees crank retard, so 4 degrees of cam advance, compression up from 125 to 150 psi, but, it runs like crap, I don't know whats wrong with it, I think it sounded like the ignition timing is too retarded, I timed with to 20 BTDC with the timing light. any suggessions?

20° BTDC initial timing?  What's your total timing?  I'd suggest 8-12° initial and 36-38° total as a starting point.  Did your idle speed increase significantly where you had to slow it back down?  If so, then there's the chance that your vacuum advance to the distributor was activated at idle with the old cam timing and with the new cam timing it's not.  You may want to see if this is a player and hook up the vacuum to the distributor to a 'direct' source on the carburetor and see if your old idle characteristic returns.

Just food for thought.

Lorena, Texas (South of Waco)

Total is 40BTDC the vacuum advance is not activated at idle.

Just couldnt get it to run right at advanced cam timing, Guess my engine dont like advanced cam timing. so I put it back to origional.



my be the 4000lb car with 3 speed stick and the highway geared rearend prevent me from having what i wanted lol.



mybe when I put the T-10(off a 66mustang 289) will help.



anyone know the ratios on the T10 and the 61 3speed? --- Found it T10-H 2.73 first, the 3 speed is 2.78, I guess that wont help on dead stop accel and burnouts hahah



the accelerator pump nozzles and cams is here I guess i will tune them tomorrow after my job interview..

HoLun,

Were you using a degree wheel and dial indicator to verify that moving the crankshaft sprocket was moving the cam timing the desired number of degrees?  Although the increase in cranking compression up to 150 psi sounds right, there's the chance that the cranking compression was already past its peak and had come back down to 150 psi meaning too much camshaft advance.  Idling characteristics are normally improved by advancing cam timing which leads me to believe that there is more going on in your particular circumstance than meets the eye.  Did you happen to check the idle manifold vacuum while you had the camshaft advanced and if so, how did that value compare to the old manifold vacuum value?

Lorena, Texas (South of Waco)

I dont have a degreeing kit, so I cant check exact degrees on the camshaft.



when the cam was advanced, the idle vacuum was about 1"Hg Higher, and flucturated less, but cruising vacuum seem to dropped about 2".

did some more tuning, back the timing down to 16btdc, delay the advance curve max advance from 2500rpm to 2800rpm, played with the accelerator pump nozzles, and cams, changed from .035 to .031.



dont seem to change much. when doing quick revs in neutral, it have a slight hiccup at about 2300rpm, the vacuum gauge shows thats when the vacuum starts to climb back up, only hiccup at WOT revs and hard acceleration at low gear.



changing the accelerator pump cam seem to effect how bad the hiccup is, but I can't eliminate it. any thoughts?

For trying to resolve a flat spot or hesitation in the acceleration, I'd suggest trying the extremes in fuel shooter sizes to first determine if the engine is either getting too much fuel or not enough.  Pump cams will not have the immediate effect that the shooter sizes will.  I've seen those instances where too much 'shooter' fuel will create a hestitation just as well not having enough.  I'd suggest trying the #25 shooter size first just to get a feel for what the smallest shooter size does and then if necessary, work from the other direction.  If using a #25 shooter helps, then work with the pump cams to further reduce the accelerator pump shot. 

Other players also includes the fuel float level, primary fuel jetting, and idle mixture.  All these also affect fuel delivery at the intermediate rpms.  The secondary side float level is also a player as that affects the 'fixed' idle mixture on the secondary side which ultimately affects the primary side.  And don't forget about vacuum leaks; these will make you run in circles trying to work around them and a vacuum gauge will not necessarily pick those up if they're small.

Lorena, Texas (South of Waco)

Holun - Did you get a timing card with the cam you put in your engine? I couldn't find any mention in the threads - but I did go through pretty quickly. I'm curious whether it is symmetrical or has a "Dual Pattern" with exhaust timing modifications. If its symmetrical, I was thinking that you might take off the right hand valve cover and find the approximate "split overlap" point of the cam by following the #1 rockers with a couple of dial indicators. Set the lash equal and then with the exhaust closing and the intake opening, find the spot where the lift is equal on both lobes. That point should have a definite relationship to the TDC mark on your crank dampener. Advancing the cam as Ted suggested - should have worked. Over-advancing it would make the engine feel like it belongs in a tractor - massive torque and not want to rev at all. Retarding it makes the engine struggle to get up to speed then smooth out as the revs rise. You said it ran bad - which was it?

Another carb tuning item you might fool with, is the spring on the accelerator pump actuator. Crushing it down to "coil bind" isn't always best - if it has some travel, the "cushion" continues to stroke the pump after movement of the throttle stops. This has a relationship to the shooter size, but it does offer a little different behavior of the pump shot. 

 
 Steve Metzger       Tucson, Arizona