Not making power

[Johnnyz453]

I have a 83 chevy k10 with a 350. Recently it was rebuilt with all new parts. Running like 1:9 compression on 89 pump gas. Got it timed perfectly but something still isnt right. It starts right up and runs great at idle and revs up normally. When you take it for a drive it doesnt pull very hard and it feels like its pulling a heavy trailer. Doesnt want to get past 4000rpm and takes awhile to get there. Has brandnnew msd distributor, msd plug wires, new spark plugs, edelbrock 1405 600cfm carb that was just rebuilt. The valves are adjusted perfectly and i had a mechanic check them over and he said they were right.

 

[CSFJ]

I had an '84 that acted similarly. Ended up being I was a tooth off on the timing chain from when I had replaced it.

 

[1987 GMC Jimmy]

What are your timing numbers?

 

[74 Shortbed]

One tooth off will make it lazy as hell..

 

[Johnnyz453]

Had it timed at 12BTDC idle at 750rpm runs perfect at idle and sounds mean when revved up but sucks when driving. I just dont know how the timing chain could be off. Chain and gears are brand new and the dots were perfectly aligned when it was put together.

 

[CSFJ]

Had it timed at 12BTDC idle at 750rpm runs perfect at idle and sounds mean when revved up but sucks when driving. I just dont know how the timing chain could be off. Chain and gears are brand new and the dots were perfectly aligned when it was put together.

I thought the same thing when I did mine, too. The only way to be sore is to pull the cover and double check.

 

[Johnnyz453]

Yea. Guess i will have to. Couldnt it also be the secondarys not working?

 

[CSFJ]

I'm not familiar with the eddy carbs. Are they mechanical or vacuum secondaries?

 

[Johnnyz453]

I'm not familiar with the eddy carbs. Are they mechanical or vacuum secondaries?

Not quite sure. I know there are two flaps and the bottom one opens by the throttle cable but I'm pretty sure the top flap won't move unless the engine has load.

 

[CSFJ]

Sounds like mechanical, but again, not familiar with that carb. From what you decsribe in your original post, it sounds timing related, not a fuel/carburetion issue.

 

[Johnnyz453]

Checked the cam today with a degreeing tool. Valves opened and closed right where they should according to the cam specs. Checked timing again. Starts up right away and idles fine. Goes into gear and runs fine and cuts right off. If you rev it while sitting it sounds like it should but as soon as you take it for a drive it just goes slow and has barely any power. Im ghinking the only thing left would be that the secondaries arent functioning right.

 

[Rusty Nail]

A 1405 is NOT a 600. That's a 1406.
Just sayin! I think 1405 is a 500?
Before I pulled the timing cover, I'd look at that carburetor.

 

[74 Shortbed]

A 1405 is NOT a 600. That's a 1406.
Just sayin! I think 1405 is a 500?
Before I pulled the timing cover, I'd look at that carburetor.

Slight correction here.

1405 is a 600 calibrated for performance

1406 is a 600 calibrated for economy

1403 is a 500

http://www.edelbrock.com/automotive/mc/carburetors/performer.shtml

 

[Rusty Nail]

Cool. More for you! I ain't mad, trying to help...
I'd still start at the carburetor, it says
edelbrock for cryin out loud!

 

[74 Shortbed]

Had it timed at 12BTDC idle

What is the total and when is it all in by???..