New here and I need some help. This is my second car but my first Classic. Little introduction, I bought a 1987 Buick Regal off auction which was listed to have the origanal V6 non-turbo. Once I got the vehicle home and opened the hood, I noticed it had a Chevy 305 in there with no valve covers. Cranked the engine, it will crank but won't start. Checked for spark and I'm good there, checked for fuel and wasn't getting much so I replaced the pump and it works fine, set initial timing to TDC#1 set the distributor and was getting good blue spark. Now I was clueless, Crank, Fuel, and spark should turn the car over. Now I took the compression tester out and found it had low compression, took off driver side cylinder head off and Head Gaskets were blown. Cleaned them and changed both sides, reset Valve lash to Zero. I was thinking I would be dead on the money now, before I put the intake and exhaust back on I tested compression on Driver side Cylinder head. Cyl#1: 60psi Cyl#3: 90psi Cyl#5: 120psi Cyl#7: 90psi Can anyone please help? I can send pictures if anyone would like
Welcome Al from Washington State! When you set the valve lash did you make sure each cylinder was on the compression stroke?
those are low numbers but it should still run. have you checked to make sure the distributor isn't 180 degrees off? that's a common mistake. any idea what the motor is from?
Did you do the compression test at WOT or with the throttle closed? You need to crank the starter for 3 to 5 revolutions of engine with the throttle wide open so air can enter to create pressure(PSI), without any air to be compressed, the engine can't create pressure. After you redo that test, do a wet compression test if you're are still getting the low readings. A wet compression test is when you spray oil down the spark plug hole, I like using WD-40 with that red straw that comes with it. Make sure you hold onto the red straw though when you spray into the cylinders so that thing doesn't launch off of the spray can into the spark plug hole! Count to ten when your spraying the WD-40 in the cylinder you're getting ready to wet test, then test. If pressure goes up with a wet test that tells you that your rings are shot, if hardly no changes are observed then your heads and or rings can both be bad. A valve job could fix your problems if no changes when wet testing if its only the heads bleeding pressure. And like mentioned above, make sure you setup the valve lash properly, there is a sequence to follow when adjusting valves that hopefully you followed. If its a hydraulic cam you can't just set the lash to zero, you need to go an extra at least 1/2 turn to set the preload. GL Derek.
No I adjusted the valves like so at TDC #1 Exhaust: 1-3-4-8 Intake: 1-2-5-7 And TDC #6 Ex: 2-5-6-7 In: 3-4-6-8
As of the moment I had taken off the intake off, water pump, and also exhaust headers. Because I had just redone HeadGaskets
Yeah after I set the valves I did half a turn. I also mentioned above how I set them. I apologize I'm used to more modern engines and this is my project car, I'm trying to learn as much as I can
I usually pick a cylinder, and rotate watching the intake rocker. when it closes and before the exhaust opens, rotate each pushrod between two fingers until it stops spinning, then give it your extra half turn. Next cylinder, repeat...
Update : I have done all the valve adjustments to Zero-Lash and did 1/2 turn for pre-load. Now this is where I'm worried and confused I began the compression test and I'm still getting 60psi in Cyl#1 so I took an air chuck and plugged it tight and blew air in through the spark plug hole. I got air out the intake, I backed the nut off the intake valve to fully close it and blew air again. Still air coming out?! I suspected maybe a bad Intake valve. So I have the Driver side Cylinder head off and put oil on Cyl#1 Valves but after 30 minutes the oil was still at the same level
Could be a number of issues with the valve train. Bent valves, bent push rods, bad valve seats, etc. Remember, air is thinner than oil and it will leak much quicker. I applaud you on the work you've done so far. This is real mechanical inspection. Most guys just throw parts at a problem and pray!
I appreciate it! I'm taking out the cherry picker and taking the Engine out and sending it to a machine shop to check the block, heads. I will be ordering new Valves if that's the case.
Yep, good job so far. Sounds like someone threw that engine in for a quick sale? I agree with pancher, good diagnostics..
If it is actually a sbc 305, just scrap the thing. If you're going through the trouble to remove the 305, it would be a waste of time and $$ to put it back in because the results would be disappointing. If you want to stay with the sbc platform, there are thousands of runners on craigslist for next to nothing. There are also sbc 350 cores for sale out there that you would be better off taking to the machine shop than a boat anchor 305. Junkyards have many Vortec 350 engines ready to rebuild, a really great way to go for a sbc build. You can get a 383 stroker crank for the cost of what it would be to have the 350 crank reground! And aftermarket rods for less $$ than it would cost to recondition the factory rods. Forged pistons for a sbc are as cheap as the better sbb cast pistons as well, super cheap to do a performance build, but it won't be Buick powered if that matters to you. Or do a me too swap(did you swap in an LS, me too!) and install a junkyard LS engine in your car, not as cheap as it sounds but they do get good fuel economy while running really good. On the other hand, you have the opportunity to convert back to Buick power as well. But you may need other parts for the swap back like a Buick trans or an adapter to bolt to a chevy trans , among other things that may be needed. GL Derek
