Hi We just bought a 70GS with a fresh 71 Rivi 455 in it. (about 500 miles on the engine) I was told that it has great oil pressure when it's cold, but it drops as the temp rises. He said it drops to about 10 PSI when totally warmed up. He said he sent the timing cover out to be "ported and polished" by a "good Buick guy" before installing it. He also told me the crank was cross-drilled. 67 430 heads with SS swirl polished valves Lunati 501/245 cam, SP1 intake, Speed Demon carb, 3" exhaust, 2800/3200 TQ (didn't ask about gears) That is literally all I know about it. I felt the deal was too good to pass up regardless of what I find out about the engine, so I had to act quick to get it. (less than 5 minutes from seeing the ad, to buying it!) Heck, maybe even someone here is the one he sent the cover to. The guys name is Matt Johnson in Kentucky. Ring any bells with anyone? I won't have the car until next weekend, but thought I would get a conversation going about it now.... I would guess there's a few things it could be: 1 - Bad timing cover? 2 - Bad oil pump? (or just not shimmed correctly?) 3 - Too much slop in some of the engine bearings? 4 - Crank shouldn't have been cross-drilled? 5 - All of the above? Any suggestions as to what steps I should take to troubleshoot the problem before I start foolishly throwing money at it and buying parts that I don't need? I'm not afraid to spend the $400 for a TA Perf reworked timing cover if I knew that was the problem, but I'd hate to do that and find it wasn't the problem. We're definately strapped for cash after our last 2 Buick purchases within one month. :gt: I'd also like to leave the engine in the car if possible. So hopefully the first couple troubleshooting steps can be done "in the car". But if it has to come out, so be it. o No: Thanks in advance!! :beer
Rick, 10 psi in gear at idle is not so bad. I've seen plenty of motors get down that low, and be just fine. You want to see what happens when you step on the gas and bring the revs up. If you have 11-12 psi/1000 RPM, and the motor is quiet, it's probably fine. Lots of guys get hung up on oil pressure #'s, it's like a competition sometimes. It may be large pump clearances, or looser bearing clearances. I'd make sure it had an accurate oil pressure gauge, check the engine temperature, and idle RPM. Then I would look at oil viscosity, and maybe step up a grade and see what happens. Last thing I would do is check the general condition of the pump, and end clearance. You can do that with the motor in the car and the TA oil pump shim kit, and booster plate. Just make sure to assemble the pump with vaseline and prime it with a drill. Good luck.
Rick, I saw that one on ebay, and while I'm not a fan of the 70-72's that looked to be a good deal. Start with the easy stuff first, 1)be sure the pressure reading is accurate 2) drain the oil through a filter paper and see what you have, if it looks good, 3) Try a fresh oil change and good filter use 20w50 to see if that helps, if not, 4) pop the cover off the oil pump and inspect the pump cavity. If the cavity is good check the clearances/shim and install a booster plate and adjustable regulator. If the cover is bad you already know the deal. See how you do from there.
Thanks for the replys guys. You've given me some hope. :grin: I just got off the phone with the seller a little while ago, and he said at hot idle it goes to around 10, but if you're driving or rev it a little it will go up to around 20-25. Still seems a bit low to me. I'll try your advice on the first things to check out and go from there. He did tell me again that he sent out the cover and had the ports all opened up and polished, and had a new oil pump, with an adjustable regulator put in it. So I would start to doubt that it's the cover, but who knows. o No: I'm still trying to line something up for this weekend to go get it. On a sad note.... I just found out it has a one legged rear end with highway gears. :gt: ou: This should be a 12 sec streeter with some gears and a posi wouldn't you think?
That's real low for an engine that was just assembled, especially with a booster plate. Who knows they may have just shimmed the pump cover wrong and it could be an easy fix. Guess we'll have to wait until you get your hands on it to see. I don't know nothing bout no 12's, I'm building an overweight ragtop.
Rick, Ask him what the main/rod clearances are, and what weight oil he has in it.. If it has .0025-.003 or more on the mains/rods, and 10-30 oil in it, then I would consider that "normal". If the mains are at .002 or less, and has thicker oil in it, then I would be concerned that there is some reason it's bleeding off the oil pressure. JW
Jim I didn't ask about the oil, but I did ask about the bearings. He couldn't remember, but he thought he had it in his notes somewhere and was going to search for it. He does remember that his "engine guy" was real happy with how they all turned out, for what thats worth. I'm convinced now that the first thing I'm going to do is give it an oil change and a new filter, and hook up a different gauge to double check. I assumed that he's played with the adjustable oil pressure regulator to see if that will do anything, but I didn't specifically ask if he did. Oh yeah.... I also just confirmed that I have a truck and trailer lined up to borrow for Saturday!! So I'll definately be looking into it on Sunday. :Brow:
Got her home last night! I have a few other tuning issues that I will be starting another thread about in a minute... But regarding the oil pressure.... I just got back from Autozone with 20W50 oil and a new filter. I'll be trying that in a few minutes. Where's the "crossing fingers" smilie. :gt: :beer
Success! (I think) First.... I found a half empty 10W40 bottle under the seat. (Maybe he was using 10W40?) That would be my assumption. Anyways.... I put 20W50 in it, with a new Fram filter: At 190 (took forever <small>(20 miuntes?)</small> to warm up to that, and I didn't feel I needed to get it any hotter than that anyways) At 190 - at 1,100 RPM Idle = 25 PSI oil pressure Bring her up to 2 grand, and I have about 45 PSI Drop it in gear, whch maybe drop RPM to 1000 = about 24 PSI Sound good enough? o No: The gauge is kinda crummy (very small, and goes all the way up to like 120PSI) so it's kinda hard to read accurately, so I'm going to drop another gauge in its place to see what happens then. But so far, I think the oil pressure just might be taken care of! :TU:
Rick, You really need to drive the car to bring the oil up to full temperature. Idling it won't do it, even if the gauge reads full operating temperature. Even if it gets down to 10 psi at idle, if you have 11-12 psi/1000 RPM as you rev the engine, and the engine is quiet, you'll be fine. Get a good Autometer mechanical gauge on it, that way you'll be sure of the readings.
I wouldn't use a fram filter, I heard they had brittle filter elements that can break apart and do some nasty things to a engine. I run AC or WIX. Just trying to help
.....and to answer another of your questions..... My crank is cross-drilled and chamfered. I run a mix of 2 quarts 20w50 and the rest 10W30 mobile one. Start-up cold pressure is just under 60. Hot, heat soaked pressure at 850 idle in gear is ~18psi, and just touching the throttle brings ut up almost to 40 psi. Cover and Pump are TA's older ported stock assembly/pump/plate Jim - Whats your thoughts on straight 20W50 ??? BTW - Ditch the Fram on your next filter change Congrats on the New Ride !! :TU: :TU:
