All, I was hoping to hear some opinions about how they would handle my situation if they were to encounter a simulator problem. Issue: -------- Newly rebuilt 350 Engine with less than 3,000 miles that has a small smoke problem coming from Passenger Side Exhaust and a low PSI Reading in the #6 Cylinder. History: --------- I had a 350 Buick Engine rebuilt back in January 2003 from a Machinist that has a good reputation. Since January, I have been driving the car just to my Auto Body Classes at a local Community College, which is held on Saturdays. I was not driving the car at any other time except an occasional "Around the Block" cruises. One morning on my way to class, about Mid-July with 1,000 miles, I noticed smoke passing by me when I came to a full stop at a Stoplight. I pulled over and observed the small amounts of smoke coming from my Passenger Side Exhaust. From what I remember, I performed a Compression Test later that day and noticed my #6 Cylinder was giving me 90 PSI. The other Cylinders were reading from 110 to 120. I decided to put more miles on the Engine before making a move to work on the Engine. Since July, I have "Days of Smoke" and "No Days of Smoke". Today: -------- Having less than 3,000 miles, I performed another compression test. Here are my results: Cylinder Number PSI -------------------- ---- 1 100 2 120 3 115 4 115 5 105 6 97 (Bad?) 7 107 8 105 Now let me give you some other facts..... 1). I have used the Lucas Oil additive and Havoline Motor Oil (10-40W or 20-50W) since I rebuilt the engine. 2). When I placed oil down the #6 Cylinder, my compression did not increase. (However I remember in Mid-July that I placed oil in the cylinder and it DID raise the compression to 110 PSI. That is when I decided that I needed the rings to break in.) 3). I ran the compression test after I warmed up the Engine. 4). I re-torque my Head Bolts back in Mid-July. 5). I inspected that all my spark plugs are clean! 6). The Buick Factory Shop Manual says to wait until 4,000 mile before doing internal work for Oil Consumption. 7). My Oil Consumption averaged a quart for every 200 miles. 8). This is my 5th 350 Buick Engine that I have had rebuilt and I do not remember have a problem like this before. What should I do? ----------------------- Should I.......... a). Break down my Engine and take the Block and Heads back to the Machinist to rework the Heads and Piston Rings? or b). Drain the Lucas Oil and run a straight Grade. Then after two or three Oil Change, perform another Compression Test? or c). Or does anyone have a suggestion or opinion of what I should or should not do? I would like to Thank in advance for your help and insight. Sincerely, Mark Mantooth
what to do ? firstly, i would contact the engine builder & discuss the situation with him . sounds like a broken ring or at worse a cracked piston . perhaps the ring joints are all lined up vertically , instead of being 90 degrees or so away from each other . my dad in 1966 purchase a new pontaic parisienne (canadian) with a 283 motor . as he drove the car , it would burn a quart of oil every 200 miles or so . dealer pulled the engine & discovered that the ring joints were all lined up in very cylinder .
Mark - Sounds more like a head problem. I agree with Gerry, talk to the builder. Also, do you ever cruise the car at highway speeds? Or is all your driving around town? It will help your break in to vary the speeds over a wider range. Try a few trips on the interstate and after another 500 m recheck the compression. Also, make sure that the #6 stays about the same after adding oil through the spark plug hole. That is key to diagnosing the problem. - Bill
I'd ask why cranking compression is low in EVERY cylinder. Your best is 120, I'd want to see 160 to 180. What compression ratio do you have? What camshaft timing events? Was the battery half-dead when you were cranking it over?
Been there... Before you do a thing, call the machinist. If you do anything to the engine, you may void the warranty. Get you money's worth out of the builder. He ought to be willing to back up his work.
The machinist told me that he be more than happy to stand behind his working. He told me that I ought to put more miles on the engine and not use the Lucus Oil until the Engine has a chance to break in. As far as the compression ratio, I do not know how to measure. But I know that we went back to stock pistons specs. I will admit that I do not like the idea of having my PSI read below 120. Other Engines that I have had rebuilt ran at least 120 PSI. Thanks ALL for your help! Mark
I'll tell you know most likely is rings lined up. been there suffered that. I'm currently rebuilding my Bu 350 for that reason and bad oil pump. thanks to my x machinist builder. thank god i'm doin it now my way.
Update Here's an update. Today I decided to tear-down the Motor (1968 Block with 1972 Heads) and took them back to my Machinist. We BOTH torn-down the engine and found the following: 1). Metal shavings at the bottom of the Oil Pan and Oil Screen. 2). All Pistons had a heavy concentration of Black Carbon. Kind of odd for an engine with 3,000 miles. 3). A heavy smell of Gas within the Crank Case and below the Compression Rings of each Piston. 4). The Crank will need to be turned again or will need to be replaced. 5). Oil was "sticky" from using Lucus Oil Additive. 6). Piston Rings gaps were properly offset as expected. 7). My Heads on Cylinders #6 and #8 did not pass the vacuum test. This was due to excessive carbon on the exhaust valves. My machinist told me that I had two things against me. 1). My Quaderjet is run TOO RICH causing what called a "Wash". Since the Gas was too rich, it slipped threw the compression rings and worked its way into the Rod and Crank Bearing, which stripped the protective coating. I ran my fingers on each of the parts and felt grooves that concern me. 2). Second, I used the Lucus Additive on a newly rebuilt engine. He told me that he would rebuild the Engine at no charge. But I told him that it seemed that I was at fault and I should at least pay for the gaskets, rings and bearings. Now I need to figure out what to do about a carburetor. The previous Quaderjet was a newly rebuilt carburetor from NAPA. I thought about getting a new carburetor and I was eyeing the new Holley Avengers. Well...Does this make sense to anyone? Does anyone have any solutions to my carburetor problem? Thanks again!!!
I doubt a rich running carb would cause that much damageuzzled: But I've been wrong before. At least he's not leaving you out to dry.
what ? too rich a carb should not groove the bearings & crank . most likely the "excess metal shavings" are the cause . someone did not properly wash all the engine parts before installation . if the engine was bored , were the proper oversized psitons installed ?
I assume that the Cylinders were bored to the correct size. It may not have been properly cleaned for metal shavings. We did not find nicks or chunks missing from the Rod and Crank bearings. Nor did we see broken Pistons Rings. However, the crank did feel worn. As Samtrin mentioned, the Machinist is not leaving me out to dry.
Mark Not to divert you from your 350 questions in this post ,but when you get a chance we would like to hear about your 70 GSX project.
I remember tearing apart a freshly rebuilt race engine (350" SBC) that had been severely 'gas washed'. All the cylinders were horribly glazed!!ou: Rings were quite sharp, needless to say. Plenty of gas in the oil....don't recall any bearing damage though. Mark - If your machinist is willing to fix or 'go halves' with you on the price - consider yourself fortunate. Not all shops will warranty a bad carb or throttle body.
Thanks for asking "flynbuick", The GSX Project involves taking my 70 Skylark and converting it into a Clone. If the funds were available, I would run down to a dealer and buy one. :grin: Currently I am dropping a 350 into the car until I finish the Body. When done, I will have a 70 Saturn Yellow GSX with a 455. (But I am thinking about going with a richer yellow like the 2000 Corvette Millennium Yellow.) I have ALL the parts to make this a good clone. 1). 455 Engine. 2). Newly rebuilt 3.42 Posi Rear-end 3). Bucket Seats. 4). Center Console. 5). Steering wheel 6). Hood and more. The thing that I lack is the Numbers and GSX Dash. :ball: I have been working on this car, at my Auto Body Class, since January 2003. I am doing a TOTAL Restoration by taking the paint completely off and fixing ALL trouble spots. I am luck to have an instructor with 25 years of Auto Body experience. By the way, I purchased a Quarter Panel Skin from Tabco Body Parts for a total of $169.75. That price included Freight!! Their link to the Quarter Panel is: http://www.tabcobodyparts.com/html/810.htm Right now, the car's Hood, Fenders, Roof, Deck Lid and doors are primered. Once I finish the fixing the Quarter Panels, I will be near ready to Paint. Since I was 15 yrs old, I have always dreamed of having a 1970 GSX. My first car was a 1969 Skylark. My second was a 1971 Skylark. My father had a 1972 Skylark Sun Coupe when I was a teenager and I brother had another 1971 Skylark. Now that I am 33, I have the ability to pursue my dream car. Again, us pros would be able to identify a clone, but the average man will enjoy glazing upon the car. I have enclosed a picture of where it stands now. Again....Thanks for asking and everyone's help. I am still open to other peoples opinions and experiences with problems that I encountered.
Very nice. When you say GSx dash are you talking about the little GSX tag that goes on the dashpad? Are you going to install a hood tach? Do you have a 70 GS grille?
Yes flynbuick. The GSX Dash Tag that goes on the Dash Pad. I will be ordering a Hood Tach from Year One or Original Parts Group. However, I already have the 70 GS(X) Grill. :grin:
