I have a 71 cutlass supreme with 395558 2 block and #7 heads 4 bbl with ac. Shows now 19560 miles but i cant back those numbers up i have paper work from the late 80' early 90's in 93 it had 11230 miles when the nexted oil chage was due. So hear is were im at. The car has sat since 2004 untill this summer i have got the car back on the road now have clean the tank replace fuel lines and pump plugs wires cap points belts hoses water pump flused out the coolent. The engine runs good dosent smoke or nock. I havent even turn a screw on the carb it runs that good.

BUT im worried about the head. So i want to pull the engine out and reseal it, but what head gaskets should i use that wont drop the comp on the engine i have read that the newer ones are thicker. Im also going to change the oil pump and timeing chain if i dont rebuild it. I rater fix it one time and be done. I have built alot od sbc 350 but this is my first sbo 350 and i see i have alot to learn about then.

Should i go ahead and rebuild the engine and put flat tops in it since im going to be that far in it. Maybe a new cam and head work or just leave it alone i would like for it to have a lil more power but im ok with how it runs now. What should i do to the engine when i have it out like build tricks or something that will fail after i get it back together if not redone.

I know sometimes you can be opening up a can of worms. I dont want to do that. Just need a little help on what i should do that will be best for me. All i plan on doing is driven the car. My lil boy loves rideing in it.

I have not run the comp yet on the engine but what i have read and seen should be 8.5:1 if im right.

Sorry for it being so long

 

If it ain't broke don't fix it... drive it as is and enjoy it. save your $$$ for repairs when they are needed.

 

If it ain't broke don't fix it yea i know but the head gaskets just worry me im going to have it out of the car to clean up the engine bay i really do not want to pull the motor out twice. Are the olds head gaskets bad about blowin when there that old.

 

The original head gaskets were stamped steel shims and unless they rust out, they last forever. If you change head gaskets, what about the surfaces, valve job, valve seals, etc? As the manager of an auto machine shop told me about 40 years ago: "there is no end to concern." While you could make improvements, you could also bring on a lot of problems if your knowledge is insufficient, or the machine shop does a poor job. If you want to race, then a rebuild and upgrade of many things is good, but it sounds like you just want the car to run reliably.

 

Then don't.

Do a compression test, change the valve cover and oil pan gaskets, check the timing chain (if it's got 11,000 miles it won't need to be changed, if it's got 111,000 miles, it will), and be done with it.

- Eric

 

Defiantly look at the timing chain! If you do remove the heads, mill them, and reseal with thinner head gaskets. Keep in mind this might also require milling the intake side of the intake to get everything to line up again.

 

Yeah, take NO CRAP from that timing chain!
Refuse to obey, you rebel!

But seriously, you can get thin head gaskets nowadays, they are just a bit pricey. But, if you crackalack the heads off that motor, the $100 bills are gonna hemorrhage pretty good anyhow, so what's one more c-note, right?

Three paths lie before you, young rebel:
1) IIABDFI - No touchee! [If it ain't broke, don't "fix" it]
2) Do the BARE MINIMUM- timing chain, F&R main seals, *inspect* main bearings, replace oil pump (maybe) & freeze plugs.
3) Do it -all- $Hundreds and $hundreds on heads, machine work, bearings, crank work, new everything, assembly time, etc. It'll drag on for weeks and months at the least. Not at all like TV where the frame-off "restore" a car in 6 days.

If you go route 3, be sure to read and consult folks with Olds experience, so you don't pull the Chevy Mechanic errors like replacing the LH aft oil gallery plug with an unholey one.

I vote for Plan #1.

 

Why do the head gaskets concern you? Do you see a coolant leak, or an increased antifreeze usage? If no, why worry about something that isn't causing any problems.

 

Really it is just the age of head gaskets that concern me. They are not leaking i keep a check on the coolent i havent lost any since i have been driven it. I KEEP tellin myself there ok but since i had it out then i should just go ahead and change them. But i could be opening up a can of worms. Im going to run a compression test on it tonight to see where it is at. If it checks good then im not going to pull the heads off, but as far as the rest of the gaskets and seals i am going to replace them the and the timeing chain and oil pump. A gasket set ant the high so why not then i can get this little voice out of my head about the head gaskest. I am also going to put a set a mechanical gages in the car so i see the temp and oil psi. I know that the lights work made sure of that but you cant alway trust them that they will work right. Thanks for the help. Keep yall posted on what i find.

 

This is what the compression is on the engine i was the same on each cylinder not sure how great my gage is its been around a long time.
So it might be off a lil bit going to get a new one and recheck it.

http://i1303.photobucket.com/albums/...psa317c9ba.jpg

 

Leave it alone, drive it. I'm pretty sure you can tell the difference between 11k and 111k, if you pull the valve covers and drop the oil pan. In turn, you can figure out if you should change the timing chain and the other basic gaskets. I've always been a SBC guy, and I'm starting to learn about these Olds motors and apparently the timing chain is always a concern with high mileage. I never really heard of head gaskets going bad due to age though.

 

The issue with the timing chains isn't wear as is the stupid nylon coating on the gear chipping off and clogging up the oil pump pick-up, starving the engine of oil. When that happens the cost of a timing chain just cost you a few thousand in engine machine work and parts.

 

Oil pump and the timing chain that is a given to change out. I was trying to find out what should be the compression psi on my engine was not able to find out what it should be. I ran in on my car and was around 120 to 125 psi. What should it be? Just trying to find out as much info about the engine befor i pull it out. Then i will know if im just going to reseal it of rebuild it. Eather way dont matter to me just want it to be right when i put it back in and not slaped together.

 

1971 Oldsmobile Chassis Service Manual, page 6-C4:



- Eric

ps: nominal compression ratio on that car is 8.1:1.

 

Rule of thumb is first full rotation of the engine the gauge should read 1/2 of the final reading.The engine should be at operating temp. Remove all the plugs, wire the choke and throttle wide open, and test each cylinder for a equal amount of time. Make sure the battery is fully charged or use a big battery charger to ensure the starter spins the engine fast enough. As long as all 8 holes are within 10% of each other the final reading isn't really important. If the timing chain has a lot of slop in it the readings will be low, but should still be fairly close to each other. If the first rotation reading is low, that is a indication of worn rings and/or sloppy ring seal.

 

Beat me to it!

 

Well i have to go back and recheck. I done it one at a time pulling a plug out checking it and putting it back in then moveing to the next one. The throttle was close. So there is no numbers out there to check it to. Where do you think they should be at. Just trying to get a game plane on what i need to do the engine,

 

Did you not read our helpful posts, man?

"The lowest reading cylinder should not be less than 80% of the highest,

and no cylinder reading should be less than 100 pounds."

• Lowest cylinder no lower than 100psi
• Lowest reading no less than 80% of the highest.

- Eric

 

Yea I read and thanks for the information. All I was wondering if there was a base set of numbers to go by on what it should be from factory. On a all stock motor.

 

The timing chain WILL effect your readings!!
If it was me, I'd change the timing chain and water pump, and don't worry about the rest, as long as all the readings were the same.
Maybe change the VCG's, but forget the rest - unneeded!

 

I agree, if you have good compression & no noises may as well stick with the simpler stuff like just seals. Water pump & timing chain absolutely. I took my 72' (200000 miles on it) apart this past fall & found the timing chain a tad loose .