o.k. to start I have a 84 trans am with 305 carb. engine code "G" and 700r4 trans. i'm on a very tight budget seeing that i've spent more than I planned when my husband bought the car for me. around $200- $600 max. maybe only $300 not sure until after income tax. I've only really started learning and working on this car since summer. anyway, did compression test and cylinder 1 is 125, 3- 80 and 110 with oil put in hole, 5- 140, 7-33 and 40 with oil added, 2-125, 4-120, 6-60 and no change with oil, 8-122.I would much prefer to just change the parts that are wrong and let it be but don't know if that would be o.k doing that. should I go ahead and replace all the parts while the engine is apart or will I be o.k. just doing the parts that need fixing? I don't know how much it would cost to pull engine but I doubt I can afford it. I'm not afraid of the hard work. i've taken some of it apart before. I was told by a friend to get 327 heads to put on the 305. is that possible? how much? and clue how much a 350 would cost still with carb to get and put in? I'm all about more power but on a very small buget. we plan on this being just a temp. fix so later on down the road have more money to get a nice engine. I really want this one running so I don't have to drive my 99 all the time or our vette. any ideas or advice on what I'd need to do to do this or cheapesr route? thanks

 

DEAREST KITT, IM SORRY FOR YOUR UNFORTUNATE LUCK, BUT IM AFRAID THAT YOUR MOTOR IS SERIOUSLY HURT, YOU HAVE THREE CYLINDERS THAT ARE NOT WITHIN THE REQUIRED FIFTEEN PERCENT OF THE OTHER FIVE, MEANING THAT ALL CYLINDER PRESSURES HAVE A FIFTEEN PERCENT TOLERANCE OF THE OTHERS. YOUR ENGINE IS IN NEED OF REBUILDING. DEPENDING ON WHY YOUR PRESSURES ON THREE CYLINDERS IS LOW I.E. VALVES AND OR SEATS, OR PISTON RINGS IS DIRECTLY PROPORTIONATE OF HOW MUCH MONEY YOU'LL SPEND TO FIX IT. YOU OBVIOUSLY KNEW TO PERFORM A COMPRESSION TEST BUT DID YOU PERFORM A LEAK DOWN TEST TO ELIMINATE THE POSSIBILITY OF HEAD FAILURE? I KNOW THAT HEADS ARE INTERCHANGEABLE THROUGOUT ALL SMALL BLOCKS EXCEPT WITH THE 305. IM NOT SURE WITH A 305, I MISTAKINGLY PUT 305 HEADS ON A 350 ONCE AND ENDED UP WITH NOTHING MORE THAN ALOT OF COMPRESSION,PINGING ,OVERHEATING , AND BLOWN HEAD GASKETS, IT TOOK ME THREE SETS OF HEAD GASKETS TO FIGURE IT OUT.

 

how do I perform a leak test? thanks for the imput by the way. I don't seem to get much luck on getting help lately.

 

DO YOU STILL HAVE THE CYLINDER HEADS ON THE MOTOR?

 

yes i haven't taken it apart again. i hurt my hand

 

A LEAK DOWN TEST IS PERFORMED WITH A GAUGE MUCH LIKE YOUR COMPRESSION TESTER WHERE YOU SCREW IT IN A SPARK PLUG HOLE THE CRANK THE ENGINE OVER, IT THEN TELLS YOU HOW FAST THE COMPRESSED AIR IN THE CYLINDER IS LEAVING THE CYLINDER BY WAY OF BENT VALVE OR BURNT OR NON EXISTANT VALVE SEATS.

 

I APOLOGIZE FOR THE DELAYS IN MY REPLYS IM ALSO WORKING ON MY OWN CAR. I WAS LOOKING FOR SOME PARTS WHEN I CAME ACROSS YOUR THREAD AND SAW THAT NO ONE HAD REPLIED.

 

o.k. thanks for explaining.

 

IS THERE ANYTHING ELSE I CAN HELP YOU WITH?

 

yours is the quickest. i usually don't get them that quick. i wish i could get back on mine right now but my hand won't let me and the weather has been too cold and wet.
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do you think that this could have been the cause why the car kept dying after slowing down and in gear idle really bad? oh do you think the camshaft will have to be replaced also?

 

MOST DEFINATELY, THINK OF YOUR ENGINE FOR A MOMENT, YOU HAVE EIGHT CYLINDERS, BUT THREE OF THEM ARE NOT MAKING ENOUGH COMPRESSION TO IGNITE THE AIR FUEL MIXTURE IN THE CYLINDERS (THE REASON FOR COMPRESSION IS TO RAISE THE VOLITILITY OF THE AIR AND FUEL RESULTING IN A MUCH MORE VIOLENT EXPLOSION. IMAGINE A FIRE CRACKER, LIGHT IT AND LAY IT ON A FLAT SURFACE, NOTHING MORE THAN A LOUD POP RIGHT? NOW PUT THAT SAME FIRE CRACKER IN A CONTAINER, MUCH BIGGER EXPLOSION RIGHT?) THE REASON YOU CAR DIED AFTER SLOWING DOWN AND STOPPING IS THAT IN EFFECT YOU ARE ONLY RUNNING ON FIVE OF THE EIGHT.

 

thanks for your help

 

ANYTIME, IF NOTHING FURTHER, IM BACK TO MY CAR

 

I APOLOGIZE, I DID NOT SEE YOUR CAM QUESTION, THE CAM ON 305'S IS NOTORIOUS FOR GOING "FLAT" IF YOUR CAM IS FOUND TO HAVE GONE FLAT IT WILL HAVE TO BE REPLACED. YOU'LL WANT TO INSPECT YOUR VALVE ARTICULATION WITH THE VALVE COVERS OFF IF ALL 16 ARE NOT OPENING AND CLOSING WITH THE SAME AMOUNT OF TRAVEL THEN THE CAM HAS GONE FLAT, A FLAT CAM WILL SOUND LIKE A LIFTER TICKING.

 

thanks, it has had a slight ticking and I noticed when rotating the engine I don't see the lifters or rocker arms moving up or down.

 

THAT'S NOT GOOD, MORE THAN LIKELY YOUR CAM HAS GONE FLAT, AND SINCE YOUR CAR IS AN 84 IT WAS NOT EQUIPPED WITH A ROLLER CAM SO SUBSEQUENTLY THE LIFTERS WILL ALSO HAVE TO BE CHANGED