Here’s a example of the power loss when a cheap duel valve spring was used as came in a cam, lifter and spring kit, like from PAW when they where around! In this case the inner spring was not made with the right frequency characteristics to dampen the outer spring as needed. note how the power loss does not just take place at the peak rpm the motor was run up to. Now sit back and think about what power loss would take place with your motor if you where to remove those inner springs as your machinist said would be ok.
Just a quick update: I'm thinking to get that dial indicator to check valve wiggle about a half inch up from boss or so to make sure that clearance is or is not acceptable. Also Tim from TA Performance said again today that their builders remove the dampeners all the time and that's why they printed it in the catalog on page 73: "Guides will have to be cut for smaller O.D. seals or dampener spring must be removed" I really think they know what their doing over there. I have the TA 284-88h cam with their stage 1 valves and springs. He added that the difference would be unnoticeable with my setup. With all respect I'm not trying to argue with you knowledgeable people. And I'm not trying to be thick-headed. I'm just a weekend cruiser and not a racer like many of you fellas. I'm just working to get my car updated a bit more from stock setup on limited resources and appreciate your suggestions.
Ron, (oops) You have the oil consumption problem, it is not simply seals and if seals "fix it" it will only be temporary. You might be able to get by changing them every year or so, but if the guide/stem clearance is too much, it will get worse at an accelerated rate, and it will cause valve/seat sealing issues over time as well as there is some side loading on the rocker/stem tip. You also have the detonation issue. There is no such thing as "a little ping" that is acceptable. Ping is detonation, detonation results in rocking of the pistons at the least, hammering on the rings and worse, hammering on the bearings. "Knock" is simply detonation on a larger scale. Silv-O-Lite pistons are Hypereutectic and the pistons can shatter from detonation. Just dialing back the timing is not going to fix detonation, only make it less noticeable. And with the gas quality being all over the place, one tank that has less octane rating than you think your are getting or several other things that can push you into breaking things. We all know the things on the other side of the screen in life. The cost and time you have already invested. The spouse (almost always a biggie on the time and money spent on cars seem excessive to them. Some understand it more than others, but it is almost always a large percent of the tide pushing against the effort. Mark is right, your machinist is blowing you off. A great many do not "know" Buicks, and have a bias whether they admit it or not. There are some machinists/shops that don't know Buicks, but are willing to take the information on things to do, and work with folks. Find one, treat him like a pearl. Having a lack of confidence and knowledge. None of us are born with that, it comes from doing it over time, and often from breaking things, spending money, time, and effort for little or worse, negative gain. You machinist is taking advantage of that, and that is insulting. From reading your "50 year old oil pan surprise" and now this thread, and where I am sitting, you have been working with some less than good parts since the beginning, mostly the heads, (valves/guides). I think you should pull them, get them looked at by a no BS machinist (gotta be someone in the Chicago area), and sort that first. While the heads are off, rotate and measure all the pistons with a dial indicator and see how far each is in the hole at TDC/dwell. That will go a long way to deal with detonation. It is possible, you have lean condition with the carb, coupled with the oil and maybe a poorly curved distributor. (one can hope), but you need to know about the compression/quench and piston/deck height. If the heads are corrected, and you put it together (addressing distributor and carb), you will know pretty quickly if the oil consumption issue is fixed. If not, you will need to do the short block re-work. (And troubleshooting beyond arm's length and blind and deaf, as I am, is a risky thing....) I hope that helps.
I’m stuck on the fact that it’s leaking cylinder pressure on at at least the one hole. Something must be wrong there and it isn’t in the head unless a valve is hanging open. I don’t think he’s trying to be thick headed, he’s just frustrated.
I'd take the heads off, remove all the springs, check the wiggle. Then take them back to the eng shop for new guides done properly for the 2nd time, or a refund. The piston / ring situation will follow. If those silv-o-lites are hypers, they should have had tighter bore clearances.
I'm just thinking out loud. My leakdown test results were strange. The first 2 cylinders I checked had almost zero leak (maybe 3%). The third one I did was about 15% and coming out the crankcase. Then I repeated all 8 cylinders after sitting for a week and all measured 15-19% out crankcase. Just seems strange I guess.
You will be going round & round with this forever and ever unless you bit the bullet and at least yank the head off the bank of the motor that had the 15% leakage when the others tested good. you could then look for scratches in the cylinder walls which would indicate broken rings and or if the piston(s) rock around which would be a due to a cracked piston or once again broken rings. hearing air as you did getting into the crankcase is number 1 not a good sign at all, and number 2 it’s not going to fix itself or really get any better even with the motor fully warmed up and the ring gap greatly reduced as normally takes place. Two weeks ago now you could have had both heads pulled and then not be questioning what’s going on like you still are now!
Yep! Experience and knowledge I firmly believe comes from trying new things, stuff breaking on you, and figuring out how to fix it I’m an auto painter by trade…40 plus years, I screwed up a lot, with that came “experience” from your “experience” you know the outcome of most everything your going to do, and then decide if that’s the right path. I worked with a way younger than me painter, he was fast, he thought he was a hot shot until “Mark, your awesome at sanding runs out. Mark, why did the base coat or clear do this? Mark, my blend looks like ****” We were all flat rate, but I never hesitated to help out. 69 Wild, pull your heads, take your time, and ask us questions if you have any, most all of us on here share experience and knowledge, there’s nothing too secret
I've been grain harvesting all month working 15 hours days. The only thing I had time for was to remove springs from #one cylinder so far and found those chewed up umbrella seals. So I sit in my tractor all day and brainstorm about eventually fixing my motor with you guys. Thanks again for all the advice and keeping my mind occupied. I appreciate it.
Keep on farming great job! The Buick will be there when you get back first things first. I am having same trouble getting everything ready in yard for winter which includes getting wood ready for wood burner and working on car at same time.
Thanks. I can see the light at the end of the tunnel........but it could be a derailing locomotive. jk
Huh... lots of advice here.. Let's try this to get an idea where the oil is coming from. Real basic stuff.. Before you take anything out.. Take the plugs out.. if your getting oil past the valve seals, the plugs will have a brown residue on them, only on one side. It's really obvious. Next Get ahold of a bore scope.. buy or rent one. Look thru the spark plug holes.. at the piston tops. in all cases, with no exceptions, if you see a shiny ring around the outside of the top if the piston, then oil is getting past the rings. Looks like this.. This motor was leaking oil past the rings for about 20K miles, since it was built back in the 80's. Hence the carbon buildup. That's cylinder number 6 on this engine..now compare it to cylinder number 4 and 2 on the same engine.. 4 shows just a slight ring on the piston, number2 is solidly sealed up. The next question is was a torque plate used when the cylinders were honed. Buicks, because of the thin wall casting, as well as the head bolt count, pull the cylinders out of round when the heads are torqued in place.. worse than many engine do.. the honing plate attempts to mimic this distortion, so the cylinders are round with the engine assembled. We leave them .005 under the desired bore size, so we are sure to be able to straighten the cylinders out, after the torque plate is installed. I once did an overhaul on a 70 455 for the vehicle I used to tow my race car trailer.. Just a de-glaze hone and the same series rings that you used. Cylinder pressure seals rings, and this engine was dynoed, as well as for at least half the time it was running, it was under some serious load, as it was pulling a heavy trailer. So it saw a lot of high load, high cylinder pressure work.. probably a bunch more than your engine has, just pulling the car around. Took this engine, with it's factory, out of round cylinders... Buick did not use hone plates... ( bores were in spec during the overhaul, and really looked great) and big 5/64 moly rings, almost 1500 miles of hard use, before it quit using oil. I was so used to adding a quart of oil at every fill up (2-300 miles) that when it quit, I was shocked.. I had resigned myself to the fact that it was just going to use oil, and regretted not boring it over, and honing it with a torque plate.. but it was just so nice, I thought it was a waste of money.. it was a motor that had just 60K of light use, taking the farmer than owned it into town once a week.. for the 25 years of it's life before I owned it.. So let's see what you got there, no heavy disassembly required.. At least not yet.. JW
You can get an Endoscope for about $20.00 or so. Do a search I'm sure you'll come up with something in the price range. When I go to my garage I will post the part number I got. Tom T.
Thanks Jim for chiming in on my problem. I posted pictures of some plugs earlier and here are some more. Seems to me plugs are pretty uniform across the board. I think I do have access to a scope and I'm not quite ready for disassembly yet anyway until I move the wildcat to winter storage for more room to work. She's a big girl I have to ask if a torque plate was used during the hone. I would hope my machine shop would answer truthfully. Thanks again for your brainstorming.
I had a torque plate made for the 300 (also fits 350) and left it with DAM (Dustin's Automotive Machining) in Culloden, WV. Stamped my name in it, told him he was welcome to use it. Jim
Oil on the threads usually indicates rings......... a look at the piston tops will verify that. Were it mine, I would insure it's not detonating, and then I would drive it hard for 500 miles.. If it's detonating, then it's rocking the pistons and loosing ring seal. JW
