Hi all,

I am a 17 year old kid trying to get my '73 dodge dart swinger up and running. I bought the project for 1200 dollars from a friend, it originally had a vynl top and the whole roof was practically gone/rusted through. I tore the car down and put a new roof and redid the interior. I bought the car having two main mechanical issues, 1 it shifted into gear with a delay, and 2 had a spun bearing.

So i realize now that i probably should have focused on engine and drivetrain before body work.

I have been on a very small budget for this project, went on a whim, and found a 318/727 pair on craigslist for 300 dollars. drove a couple hours and found the motor to be in decent shape, it was a '85-86 block that ended up being rebuilt, bored .30 over and internals unknown to me. The cynlinder walls looked to be in good condition and the bearings were not thrashed either. I know this now because i tore the motor apart after i got it home. The cam was flattened on 1 lobe and one lifter was entirely cupped. I used the valvetrain (cam, lifters, rocker arms etc) from my old motor as they were in good condition and worn appropriately to eachother.

I have the motor assembled now and painted but have growing concerns of the integrity. I have done a finger test for compression on the cylinders and 2 cylinders on the left side are not building pressure when i plug with my finger, you can hear the air escape if i put my finger covering 3/4 the spark plug hole. But on the other cylinders you can feel the pressure and a pop of air when you pull the finger. My compression gauge does not read anything on any of the cylinders and i have read that I won't be able to get an accurate reading until the motor has been run in the car.

If anyone has any insight into what steps I can take (should i maybe try the heads from my old motor and see if there is a difference? - which the water galleys do not match up completely to the new block) or did i just completely screw myself over buying a craigslist motor. Should I just pop the motor in and cross my fingers in or are there any tests, checks I can do to see before hand.

I have a suspicion that it could be the valves not closing all the way, I am using hydrolic lifters and non adjustable push rods.

Thank you very much in advanced
-Corey

 

Corey... Hats off to you for jumping in a project this large... You are a very smart young man to jump rite in and grab the bull by the horns!!!! Welcome to the school of hard knocks... But do not get down on yourself... You will never get stung like this again after you complete fixing your ride....


Let me ask.... Did you have the heads off the motor you picked up and check to see if the valves where in good shape?

Starting in 1980 you have to look out on those 318 or (Teens) as I call them. Part swapping can get you messed up, in the Mopar world.....

Hope this was not a roller cam engine you picked up? If it was, all the cam parts are what is wrong....

just my 2 cents

 

The engine does not have a roller cam, per the cast number (85-86) it said it would. but i suspect that when they rebuilt the motor they put a different cam hydrolic flat tappet lifters in. (because that is whats in the motor now.)

as for the heads off the motor i bought, i only checked the combustion chamber and cleaned the deck surface I did not tear the heads apart to check internals of the head or valve seats etc.

I am thinking now to try the old heads (which i know are good) on the new '85 block. Although the water galleys don't completely match up.

IF a different set of heads alleviate the problem I am seeing, then I would be able to narrow it down to the heads as the issue.

Thank you for your reply Racerhog, do you have any other tips or things I could check before trying to start this motor? Is it worth another tear down?

 

Get yourself a compression gauge. Not expensive at Harbor freight Another possibility is that the lifters are pumped up from the other engine and not adjusting for the replacement engine and holding the valves open.

 

I have a compression gauge, but it does not read anything on on any of the cylinders when i crank the motor over on the stand (by hand), could this tell something too? The gauge works, i just did a compression check on my friends 76 ford truck. IS there anything i can do to check or drain the lifters?

Thanks for your insight.

 

You need to crank it with the starter !

 

I agree... You need to be able to spin it faster....

 

Ok great. As of now I'm going to put the motor in the car and get it wired up. I will crank it and see if it builds anything, depending on the results I can always swap heads with the motor in my car. Cross my fingers and pray. If this motor is a bust, the only thing I'm out of is 300 dollars and a bit of time to save up for a rebuild. Hopefully the motor at least runs and is drivable with some care. I am planning on getting my old 318 block rebuilt and built up. Having 2 318's is somewhat of a blessing. Thank you so much you guys!

 

Dont forget to oil prime the engine.....

 

Kudos on the project! Yes, you’ll find the pressure is much different when the engine is turned faster. keep us posted!