350 chev, poping thru exhust

[lakeview]

i just built a 350 chev and now i have a poping thru the right exhustut,so far i tried a diff. carb, replaced wires,cap rotor(MSD) adjusted valves 3 times , sprayed starter fluid around manifold to check for leaks,but still have a poping around 2000 rpms but then it goes away! HELP :confused

 

[G Winter]

A valve set to tight or a lobe on the cam going bad.


Glenn

 

[lakeview]

i addjusted valves 3 times , rocker motion looks good? would it run very good if the timming gear was a tooth off?

 

[G Winter]

If cam timing was off you would think it would effect both banks. Maybe two plug wires crossed ?
Check eight and four they are next to each other on the distributer and are both on the passenger bank.

Glenn

 

[lakeview]

If cam timing was off you would think it would effect both banks. Maybe two plug wires crossed ?
Check eight and four they are next to each other on the distributer and are both on the passenger bank.

Glenn

firing order looks good but number 1 on the cap is towards the fire wall on passenger side not towards the carorator drivers side? does that matter?

 

[Bobsvette]

Maybe something as simple as a cracked insulator on one of the plug's on that bank.

 

[lakeview]

i am on my second set of plugs ,platiumn this time
:confused

 

[G Winter]

Where number one is on the dist. really doesn't matter as long as you installed the dist. accordingly but can get confusing if someone else would work on it.
Anyone ever have a dist. 180 deg. off? Been a long time since I had that happen and don't remember how they act.

Is the cap new? a crack in the cap could give you a crossfire especially if the weather is damp. I am sure this is going to be something simple.

Glenn

 

[lakeview]

new MSD cap, rotor,wires, switched back to old carb. no change? running some marvel mstry oil in fuel in case of sticking valve! ran it up to 4,000 RPMS seemed to flaten out use to rap to 6500 easy, new fresh motor so trying to stay out of it only 50 miles on it.

 

[Bobsvette]

Did you take a compression test?

 

[lakeview]

i did not put new valve springs in to match new cam , i wonder if i have a week spring? just replaced distributer no change, and compression is 175 all they way!;help

 

[GerryLP]

firing order looks good but number 1 on the cap is towards the fire wall on passenger side not towards the carorator drivers side? does that matter?

I would say that perhaps it would not matter if the dizzy ROTOR was also relatively on the same location as the BODY of the dizzy while the crankshaft is at the TDC on the #1 piston.

So, assuming that the cam sprocket is aligned correctly with the crankshaft while the #1 piston is at TDC, and your rotor is pointing to the left-front portion of the engine, BUT your dizzy's body is 180 degrees off, then that could explain the popping.

The key point is not the body of the dizzy, but the location of the rotor when firing the #1 spark relative to the #1 electrode on the cap. If the body of the dizzy is 180 out from its typical location, but the rotor would as well be 180 degrees out of its typical location, then this would NOT cause a problem.

clear as mud, right?

 

[lakeview]

well it turned out to be a weak set of springs ,cam to big for stock springs!! thanks for everyones help