i have a rebuilt new 355 and i have some questions. This is the original motor out of the car and i reused the orig. block, crank,rods, balancer,covers etc. new parts are iron eagles,cam, weiand stealth, summit HEI 750 vac secondary. 9.3-1 comp.


1- for some reason to get the car to run properly i have to set the initial timing to 21 deg. with the dial back timing light, even then it doesn't have any difficulties starting when 180 deg. ??


2-the pcv valve is in the pass valve cover and to the back of the intake to a port ( manifold), it's always clattering, or actuating. when i pull it out and cover the bottom up with my thumb it slows the motor down ? Is this normal ?

the cam is 224-234 @.050 112LSA. it has 14" of vaccume at idle.

Any suggestions ?

I'm open to any ideas ?


wnat causes a pcv valve to surge back and forth at idle ?

Could the ring have slipped on the balancer ?

what kind of injection is used on this engine?

dual plane weiand stealth and a 750 vac secondary.

I have learned a faulty pcv valve will act as a vaccume leak, i think this is my problem there.

It would be a good idea to use a piston stop and make certain that your TDC mark is really TDC.

A bad PVC could definately hurt your idle.

thanks eric.

congrats on your new time.

How many of you run pcv valves as opposed to a push in breather ? I would only be able to run one breather, but the engine is fresh.

Isn't the pcv valve supposed to be hooked to the pcv port in the front of the carb? I've never heard of anybody hooking it to a manifold vac source :confused: Try plugging it off and see if your timing requirements go back to "normal".

Travis, I always thought the port on the back of the carb was the same as a manifold source. It just goes to the plenum right under the carb instead of an individual runner.

Someone pls enlighten me if I've been missing that one over the years ;)

I would think it depends upon manf of carb, Holley & the lookalikes, puts theirs in the rear, everybody else, Carter & Rodchester, is up front.

PCV is hooked to full time vacuum. It is a controlled vacuum leak. By pulling it out and plgging the inlet, engine rpm will drop, this is normal. The symptom of the PCV making noise is the idle is alittle slow.

As for 21* of initial timing, I would suggest plumbing the vacuum cannister to manifold full-time vacuum vice ported. This will allow less initial timing, hence, better starting due to the fact no vacuum at startup.

thanks,

i have the pcv valve plugged into manifold vaccume and the vac to the dist to manifold vac as well. With 21 deg of initial timing the car never labors to start, and the batt is in the back with the stock starter. It has to be at like 40 deg initial for it to labor to start. I'll look into it this weekend, i think something is not right with the motor ?

Check piston TDC with the harmonic balancer mark vs. timing pointer.

Are you pulling (and plugging) the vacuam advance hose when you check the timing? 21 would be "reasonable" for a normal amount of initial timing PLUS full vacuam advance.

with 21 initial only, there is no way you could crank that thing

yes, this is the reading without the vac adv. I can set it at 12 initial, but it's a dog and runs hot, all the simptons of timing being retarted. I plan to work on it this weekend and i'll report back on Monday.

Mike

your timing marks must be off... easy enough to happen, 'specially if you have a non-stock cover or pointer... if it runs happy and cranks easy, the timing "HAS" to be somewhere between 8 and 14....

Originally posted by Eric68:
Travis, I always thought the port on the back of the carb was the same as a manifold source. It just goes to the plenum right under the carb instead of an individual runner.

Someone pls enlighten me if I've been missing that one over the years ;) That goes to show when the last time I messed with a square bore holley was redface.gif My q-jets, edelbrocks, and holley spread bore all have the pcv port on the front base of the carb. Just ignore me...I'll be ok
graemlins/clonk.gif

it has the stock cover and balancer. The car is running great now, thanks to a friend of mine helping me out. We just worked off the total mechanical and ran the car then adjusted the carb and timing according to the plugs. So the final is 30 deg total on the balancer ( this produces a 0-60 of 5.25 on the g-tech) and to get the part throttle stumble out i had to go to 76 primary jets and 76 secondary with the long yellow spring, the car runs perfectly now.

thanks for all the input.