New 440 first drive test

[Durandal25]

Team,

As you guys know, the 383 swap over to the 440 went well enough, and subsequently the drive test also seemed ok also, but after about 5-6 miles or so I started to hear a slight knocking under load. When I got back to the house and in idle you really don't hear it, but I'm I'm sure it one of 5 or six possible issues. Timing? Lifters? Carb? I'm running 750 CFM Edelbrock carb on it and it may be a bit lean, but am not too sure as to why the rattle.

 

[miller]

Pull your plugs, and give them a good look. Running lean would be bad news for a fresh motor.

Get a scope, or screwdriver, to listen for noise from the engine. Might give you a clue where to look.

 

[Durandal25]

.....I'll do that, but at idle and not under load, I really do not hear it. Running lean would run the heat up too right? The engine is not getting all that hot either. I'm wondering if a lifter may be the culprit, and if changing the oil to a 10w 30 or so may help out....

 

[terzmo]

Team,

As you guys know, the 383 swap over to the 440 went well enough, and subsequently the drive test also seemed ok also, but after about 5-6 miles or so I started to hear a slight knocking under load. When I got back to the house and in idle you really don't hear it, but I'm I'm sure it one of 5 or six possible issues. Timing? Lifters? Carb? I'm running 750 CFM Edelbrock carb on it and it may be a bit lean, but am not too sure as to why the rattle.

pull the valve covers and check the rockers for proper adjustment...any loose pushrods..

flat tappet cam? if so...was high zinc breakin oil used ? Roller won't make difference

 

[khryslerkid]

I'm just wondering if you have a down pipe hitting the frame or floor? Check your clearences...

 

[Durandal25]

I'm just wondering if you have a down pipe hitting the frame or floor? Check your clearences...

....got one way close to the torsion bar......

 

[YY1]

Sometimes a knock is really a pop and is just an exhaust leak...

 

[ZR9B]

what octane fuel? a light spark knock will mess with you.

 

[Cornpatch MO]

what octane fuel? a light spark knock will mess with you.

Ditto on the detonation.........................MO

 

[miller]

Every response is possible, to what your hearing. If it was a tappet/pushrod, you would hear it at idle, too.

Best off going through all the basics...fuel mixture, timing (make sure your getting right advance, too), etc.
I've always prefered a slightly rich mixture on a fresh motor, until it's broke in. Only slightly, though. A little easier on the parts.

With the crummy fuel nowadays, tune the motor for the fuel. Motor will tell you what it wants.

 

[Durandal25]

....thanks folks,as always you all have a good angle Defiantly a fuel issue