I'm in Saudi Arabia, have a 85 Buick Le Sabre Collectors that was fitted with a 403 from a cadillac a year ago... Engine was always overheating and now the main/big ends have gone. When i dismantled the engine i found that only 2 of the 16 available water ports were open because the wrong? head gasket was fitted. That explains the overheating! Problem is I don't have any torque settings to rebuild the engine. Head bolts must have had 200 ft lb on them when I took it apart! Any info on main/crank bearing loads much appreciated. Also timing information, I did paint mark the timing chain/gears. Also, when should the big, carb butterflys open, only the small ones seem to work, even with full throttle( in neutral), when I jammed them open and then revved the engine the whole car seemed to rotate ... much more torque! Could the butterflys be stuck? Never tried to work on a rochester before. Read the comments about the gearbox, mine has Odrive but I have broken all the mounting bolt holes so will be fitting a replacement. A recon 350 chevvy 3 speed box is cheap will it be Ok? Thanks...
Torques for Olds engine fastners While I do not have the specifications for the 75 thru 79 403 Oldsmobile small block engine, the following is for the Olds 307 which has the same stroke, but smaller pistons: These should be in the ball park. Main bearings: # 1,2,3,& 4 - 80 ft-lbs Main bearings; #5 (back) - 120 ft-lbs flywheel to crankshaft - 60 ft-lbs Crankshaft balancer to crankshaft bolt - 200 to 310 ft-lbs connecting rod nuts - 48 ft-lbs cylinder head bolts - 130 ft-lbs intake manifold to cylinder head - 40 ft-lbs The overdrive transmission in the car is a 200 4R with a bellhousing pattern for Buick, Olds and Pontiacs. The Chevy transmission will not bolt up without an adapter plate and you will lose you 4th gear. If you go to a BOP style TH 350 you will need to change out the crossmember as the mounting location is closer to the engine.
Loyd, Thanks for that, I was beginning to think that unless you had a 455 you didn't deserve a reply..... Got the torque settings and I recon I will stick with the old gearbox, I will just use some big washers to hold it on, The struggle I had getting it off means it ain't going to go anywher anyway! Engine now back from the machine shop, all out to +40 thou so that's it! Still about the carb! The new gaskets only have 2and half openings for the water to get between the block and the head.... Less than the holes in a 307, that's got 3! Can that be correct, I think I'm gonna drill through a few more holes to try to increase the flow over the heads. It gets to over 50 degrees C here 4 months of the year Harry:bglasses:
Harry, As far as the Rochester Quadrajet is concerned, the butterflies on the top of the carb are called air valves. Their purpose is to adjust the air flow to the engines demand. They are supposed to "tip in" gradually as the engine demands more air flow, which will not happen at low engine RPM. The primary choke diaphram(passenger side front) has a linkage to the air valves and will hold them closed at idle. The secondary throttle valves will open mechanically when you floor the gas pedal, but the airvalves will remain closed until the engine needs the additional flow. If you disable the choke diaphram so that the air valves flop in, the engine will bog. When you floor the gas, vacuum goes to zero, relaxing the choke diaphram, and allowing the valves to gradually open. With the engine running, if you open the throttle very suddenly, you may be able to see the airvalves operate, if the RPM's rise fast enough. There is nothing wrong with the carburetor. There is also a spring on the airvalve shaft that is adjustable. the shaft is slotted(to be held with a screwdriver), and there is a small allen screw(from underneath) that locks the spring adjustment. If you push the airvalves down with engine off and they spring back, I would say they are working correctly, leave them alone. As far as the head gaskets are concerned, not all the holes are supposed to be open. The coolant should flow in one direction. I would make sure my fan clutch was working correctly,make sure you have a fan shroud in good shape, use a 160 thermostat, use the biggest radiator, aluminum if possible, and use 100% distilled water with just a anti corrosive additive(Like Red Line water wetter). That should help your overheating. Hope that helps and good luck.
Not the case at all Harry! It's just that users here won't clutter up your post with useless replies, if they don't have any helpful information for you. Truth is, MOST users here on V8BUICK are running cars older than your 85 LeSabre, and run 455's or 350's... not all, but MOST. Looks like you're getting some of the help you need. Welcome to the V8 board! :TU:
Yep, Thanks for all this stuff, has helped a lot and all now getting rebuilt... Thought that might raise a few replies! No offence meant! :Brow: Yep, and having realised what older buicks can do for you I'll be keeping my eyes open from now on..... Harry :bglasses:
Harry-in-sa To day I registerd myself in this forum. You probably don't have any problem with your Lesbre transmission, however you can buy one (200 4-r) for SA 2000. And if you still have the original one it cost you SR. 1200 for a complete rebuild.
