350 troubles

[Silverback85]

Just rebuilt my small block with vortec heads, Edelbrock intake and 600cfm carb, and comp xe262 cam kit. Springs and stuff have all been changed and distributor and plugs are new. Timing has been set everywhere from 18 to 10 degrees advanced. The trouble is when I run it I have what seems to be a constant miss under load and in gear any will not wind up any rpms under load either due to missing and occasional popping out of the exhaust and ideas on what to check or look for? Only thing I know to do new is a new set of plug wires, thanks!

 

[Silverback85]

Sorry for the mixing up of my any/ands there typed it fast and didn’t proof read

 

[wanderinthru]

I'd say your on the right track with plugs and wires, maybe pull them one at a time to check spark, and do a compression check while you have the plug out??

Shakey

 

[Silverback85]

Yea I’ll try that first and see what happens I’ve also heard people say valves not adjusted right but they aren’t noisy or anything but hopefully the wires and stuff fixes it

 

[Shorty81]

Check your firing order and make sure your plug wires are not crossed somewhere.

 

[custodian]

A bad ignition module in an HEI distributor will do that.

 

[Octane]

Sounds like timing but issues can mimick one another

 

[Turbo4whl]

Yea I’ll try that first and see what happens I’ve also heard people say valves not adjusted right but they aren’t noisy or anything but hopefully the wires and stuff fixes it

Valves not making any noise means there is no lash, which is good. But if they are too tight, then they also may not be seating. Best way to adjust those hydraulic lifters is with the engine running. Remove valve covers, plug wires back on, start the engine.

One at a time slowly back off the adjuster nut until the valve starts clacking. Slowly tighten the nut until the valve is quiet. Then turn the nut in 1/2 turn. Do every valve this way. Yes, a little messy as some oil is splashing out, but it will clean up easy later.

Some make a cut open valve cover to catch some oil, but they may be doing more engines. They also sell little clips to keep the splashing down. Don't need them. This is the best valve adjustment procedure.

 

[Turbo4whl]

I should add, the PCV valve needs to be in the hose. Just set it aside away from the moving valve rockers. Every thing should be hooked up, all vacuum hoses etc.

 

[Silverback85]

Thanks for the input will mess with it this evening and see what I come up with and let you guys know hopefully it’ll line out

 

[Clint L]

If your firing order is correct, your valve lash is good, next question is did you do a proper cam break-in? About a decade ago I did a break-in on a cam with conventional valvoline not knowing they removed most of the anti-wear zinc. The engine revved fine with no load but did as you are describing under load. My lifters were mushroomed real bad. Have you checked your oil for metal shavings? I hope this isn’t what’s wrong, just sharing a previous experience.

 

[Silverback85]

I changed the plug wires and ran good for 20 miles and started again the wires were a pain in the butt to get to clip on the plug so I’m guessing I just didn’t get one up on the plug good so I’m gonna recheck them after it cools off but believe that’s where my problem is going to lie. Thanks again for all the help and input!

 

[wanderinthru]

I changed the plug wires and ran good for 20 miles and started again the wires were a pain in the butt to get to clip on the plug so I’m guessing I just didn’t get one up on the plug good so I’m gonna recheck them after it cools off but believe that’s where my problem is going to lie. Thanks again for all the help and input!

"Started again" means doing the exact same thing?