hi everyone. i own a 1990 cadillac brougham with the olds 307. i cant really read the block id but this is what i made it out to be 6LR724730
the block cast # on top of the timing chain reads 6509GM5.0L G
on the heads it has 7A stamped on them and yes the A is the same size as the seven. also there is 0142 stamped on the head between the exhaust ports. about a month ago i blew a head gasket so i decide to tear off the heads and replace them. when i separated the head from the block i noticed that my new head gasket matched the old gasket on there and the head itself but it doesnt match the block. some people tell me its supposed to be like that and some say its not. plz help i dont know much about motors except gas and brake. i posted links to the pics since i cant post pics btw i know this isnt the original motor to the car but i dont know where it came from

http://viewmorepics.myspace.com/inde...mageID=8524497

http://viewmorepics.myspace.com/inde...mageID=8524509

http://viewmorepics.myspace.com/inde...mageID=8524521

 

If the new gasket matches the old, you're good to go. Most head gaskets do not exactly match the block (or the head, for that matter) since the castings require additional space to get the sand cores out after casting.

I'd be a little concerned about the amount of sludge in the lifter area, however.

 

ok thanks but is it ok for the head not to match the block. as for the sludge i plan on draining all the oil out and running some type of cleaner in it. how bad does it look?

 

welcome to the site!

 

thx

 

Are they the original heads?

 

Yes. Again, the holes are sized to allow the sand cores to be removed after casting. Besides, wasn't it running for thousands of miles with those heads on it?

 

Once you have your engine back together, change the oil filter, add one quart less of oil than to fill it up and fill it up with one quart transmission fluid. Run the car for 100 miles than drain oil and change the filter again. This should clean the remaining sludge out of your engine as the trans fluid has detergent in it. It has worked for me in the past.

 

I believe he may be referring to how the coolant ports on head gaskets around the piston bores are only 1/8" and the coolant port on the block are big oblong shapes.

 

true i said the same thing about the car running that many miles with those heads. once i get everything put together im gonna need help with making sure everything goes back to its original place. i have a haynes manual but thats only good for torque sequence.again thx everyone for your help
as for the tranny fluid trick i sure will try it, and i was wondering if putting a 10w-40 oil in would help since its an older motor

 

I would get the heads freshened up since you have them off. At least replace the value guides as they will be worn with many miles on the engine. If you can afford it do a complete valve job. Replacing the guides will eliminate one of the oil consuption problems. Running 10-40w with a worn engine is OK. If it is summer you would not need to go as low as 10w. Could go 15-40 if you can find. Is there a big ridge on the top of the cylinders and do the cylinders look oval? A sure sign of too many miles.

 

theyre not oval at least they dont look like it to me. and there is a ridge but i wouldnt know what is considered a big ridge. i know its not as wide as my fingernails. my mechanic said the guides were in good shape.i plan on getting em to the machine shop to get tanked and while they are there ill see what it cost to get the valve job. the seals were shot so i put those brand new, and im putting all new rods and rockers. the guy who had it before me said he took it from victoria tx, all the way to houston like that, so i know some kinda damage had to happen.if it comes down to the point i have to replace the head gaskets again im just gonna go to a junk yard in san anton that said they have a motor for it for 350 and i can crank it on the floor

 

You need an inside micrometer to tell if they are oval. You cannot eyeball it.

 

ok ill have somebody come check it out for me, by the way whats the max they can be bored to?

 

I wouldn't bother boring a 307.
Any benefit you'd get from it would be smothered by those terrible flowing heads.

 

wouldnt they have to be bored just a little because of piston ridge or if they are oval? anyways if this comes out costing to much ill just go pick up another motor and throw that in til i have money to rebuild this one completely the right way.
another ? when i replace the valve stem seals are they all the same size ?

 

ok everyone thx for your help now i need some more. i hate to bother u guys with these newbie questions but i have no one else to ask the shops here wanna charge out the rear just because my car is a cadillac and i tried to tell them its an olds engine and they say it dont matter but anyway i got everything micrometered and they checked out the heads were rebuilt with new parts and cleaned up. i got everything put back together but im having trouble putting the vacuum lines together i need some actual pics i have the diagram but i really dont understand it too good. and some pics of how the brackets for the alternator go would be helpful too. matter of fact any detailed pictures of how the olds 307 looks would be helpful again thx in advance

 

take your time,get the diagram under the hood,and do one line at a time.

 

i tried that way but theres some thing i dont understand like a efe valve and vac tank and theres numerous other ones. i got a friend with a car just like mine same motor and all but there is still one line i cant figure out where it goes. is there a link on here that has actual pics of everthing or did someone else already start a thread about it??

 

ramos7, take a look at this site it may help. I would advise you that next time you disassemble something that you first take MANY digital pictures so you know how to put it back together.

http://performanceolds307.tripod.com/

 

i got it down to one vacuum line its a big one that connects to the tower shaped thing that the smog pumps connects to via the short fat hose from the back. also the air pipe that connects to the pass. side exhaust manifold connects to the same thing. well the line im trying to connect goes to the back of the intake manifold and i dont see a connection.

and yes i learned a hard lesson this time about taking pics. everyone warned me and i went ahead and did it anyway. next time i do something this extensive i know to put that digital camera to use

i used as much info off the site u provided as possible but now im at a stand still. thx for all ur help again

 

The vacuum diagram under the hood on the 307 cars leaves a lot to be desired. The "tower" on the A.I.R. pump is the air divert/air switching valve. There should be two places on that assembly that get vacuum hoses. The two hoses tee together and need to be connected directly to a manifold vacuum source. It is not critical that the attachment be in exactly the same location as factory, but it must be full manifold vacuum.

 

ramos7, If you are still having a problem take some pictures of the engine and post them. Maybe if we can see what you are talking about we could help.

 

ill have some posted tonight but theyll be links again cause i cant figure out how to post pics

 

well thanks everyone for your help, but i found the easiest way in the world to fix this. i found this guy that had a car exactly like mine with the same motor so i gave him ten bucks to come to my house and let me match my wires to his it turned out the hose went right behind this big plastic circle on the pass side of the car, not on the intake. but when i was taking of my thermostat housing i broke the head off the bolt that is on the side that the cruise control thing bolts to. i tried a screw extractor and some trick where you drill the middle of the bolt then use this drill bit in reverse to back it out but no cigar any suggestions???

 

There is another way but you must be VERY careful. First you take the smallest drill bit you have and drill straight down into the bolt, use some 3 in 1 or other oil to keep the drill bit lubed. Then move on to the nest larger bit and drill the same hole a little bit larger, then the next larger bit until all you have is a very thin bolt with a big hole in the middle of it. You can then pry the threaded edges between the bolt and the housing and the bolt will collapse and you can pull it out with a needle nose pliers. As I said be VERY careful or you will destroy the threads in the block and then you will have to rethread the hole. Good luck.

 

thanks for the tip ill try it tomorrow my father in law said he knows a few tricks well try out as well. another question i have is i need the direction of rotation for the distributor. i called a few different places and they gave me different answers. the book says counterclockwise but it only goes to an 87 yr model so i wanted to be sure just in case. and what is the recommended gap for a high mileage engine??

 

Oldsmobile distributors rotate counter clockwise.

 

points????

 

Thanks Jeff, seems I am getting my threads crossed and getting too old.
rokit

 

you had me paniced for a minute that I have neglected my points in all my cars

I actually said outloud WTF?????

then I woke up

but I do miss my points in this long gone mistake

 

points???

 

ramos7, Just ignore the points comment as I had posted something about points by mistake then deleted it when Jeff caught it. How is it comming with the broken bolt?
rokit

 

man i tried to use an ez out on it but it snapped in half and now any drill bit that i try to drill through it with snaps in half also. im running out of ideas to try i soaked it in wd40 and ill try again tomorrow

 

i need to post pix but myspace isnt working now can anyone help me out????

 

Photobucket.

 

X2. Go to http://photobucket.com set up a free account, upload your pics then copy the address in the "IMG Code" box and then paste that address in your thread response.

Works like a charm and looks better than thumbnails.

64sideview.jpg

 

i need to know where this plug hooks up to



and right under my finger there is a thin black vacuum hose that i cant seem to figure out where it goes. u can see where i had stretched across to make it more clear. i couldnt find these on my friends car.



and these wires were connected to the far rear bolt on the pass. side of the intake manifold im wondering if it was grounded and if it was can i just ground it somewhere else. thanks for your help guys

 

just for ***** n giggles does edelbrock make a set of heads i can use for this engine

 

No on the heads.