burnt valves?

[RogerDodger]

I go out tonight to put new valve seals into my 318. I remove the rocker arms off one side and hook the air up to the first cylinder and air comes out the exhuast port freely. I continue to check the remaining 3 and I have at least 2 that blow freely out the exhaust and 3 that blow out the intake ports. They all leak a little which I would expect when you put 120psi into it. Some leak very little and others flow freely. Does this mean that I have several valves that are burnt or cracked? I haven't even tried the other side yet.

Part 2: If this is the case and the valves are bad, do I get a valve job done or do I rebuild the entire motor at this time? The motor is out of the car at this time and does have somewhere around 111,000 mile on it. It ran good before I pulled it only smoked a little when starting. My dream was to get a big block but the budget is telling me no. I thought I might do a few things to this 318 to get a couple of years out of it and later go for a big block.

Part 3: If I choose to rebuild everything what kind of performance can I get out of a 318? What can I expect it to cost to rebuild? It is going to be street driven mostly on weekends. Any recommendations on rebuilding to get some performance would be appreciated.

[mikepmcs]

  Sorry Roger, I just want a little education on this as well.  I would say that you have some burnt valves but won't even pretend I know anything.

v/r
Mike

[Charger-Bodie]

if you are gonna have to go thru the 318 you may as well go for the big block

[firefighter3931]

if you are gonna have to go thru the 318 you may as well go for the big block

They both cost the same to rebuild. If the engne was running good and had descent oil pressure.....just have a valvejob done and put it back together. While you've got it out of the car, slap a fresh timing chain on and install new gaskets. That should get you by until you have a 440 ready to go. 


Ron

[RogerDodger]

I hear what you are both saying but to go 440 now there is the expense of the motor and rebuild plus I would need a transmission to bolt up to the big block. And then I need to upgrade the 8-1/4 rear end. So you can see how quickly it adds up. I'de like to start driving this Charger this year. I'm leaning toward a valve job. That gives me a couple of years to get things together and go big block. I've already put a new timing chain and water pump on this block.

[squeakfinder]

Don't the exhaust valves tend to be more prone to getting burnt? Well, you should know for sure after pulling the heads. Who knows, it could just be crap built up on the valves, preventing them from sealing. If everything wears out equally over time, then doing a valve job will put more pressure on the worn an untouched bottom end. Causing the rings/cylinder walls to blow out and it will start smoking.

You could hone the cylinders out and put in new rings. The fix might last a little wile, 10,000 miles maybee before it starts using oil again.

[firefighter3931]

I hear what you are both saying but to go 440 now there is the expense of the motor and rebuild plus I would need a transmission to bolt up to the big block. And then I need to upgrade the 8-1/4 rear end. So you can see how quickly it adds up. I'de like to start driving this Charger this year. I'm leaning toward a valve job. That gives me a couple of years to get things together and go big block. I've already put a new timing chain and water pump on this block.

Yep, that is exactly my point Roger....the 440 conversion is alot more than just dropping in the engine. Trans, converter, flexplate, exhaust, radiator, motor mounts, brackets, suspension....it goes on and on. 

Enjoy the car and wait until you've got all the parts together for the conversion. 



Ron

[phade]

I have the same problem going on in my 440 right now. Best thing to would probably just get a rebuilt pair of heads off of Ebay for less than $200.00. Buy a new set of gaskets and bolt them on. Before you put them on, buy a High Performance intake manifold and port them out to match with a grinder. Then slap a 4 barrell on top and do some willies.

[RogerDodger]

Took a head off tonight. No burnt or cracked valves. Must be carbon. I think I'll get a valve job done anyway. I do have a few push rods that are bent a little. What would cause that? Maybe a timing chain jumped at some point.

[phade]

Not good, might have bent a valve or two.

[Chryco Psycho]

it could be a bad guide not centering the valve , or a bad seat from poor gas quality as well as a burnt valve
small blocks often bend pushrods due to the poor angle between the lifter & the pushrod , that is one of my pet peeves with the small blocks , Mopar should have corrected the angle when the changed from the A block to thje LA block 

[Challenger340]

Leaking air ain't good.
Did you try tapping the valve tip, lightly, with a dead blow hammer, while the air was escaping to see if you could seal it ?

Should hear a "pop", then the escaping air may diminish ?

[RogerDodger]

Took them for a valve job today. Should have them back Monday. It won't cost all that much so I guess its a good idea anyway. The cylinders all look good. Very minimal ridge at the top.