Hi All: Spent the holiday buttoning up my Skylark with my rebuilt 455 to get her back on the road. Had everything all done, started her up, and I get a wierd sound coming from the driver side, lower front of the block (near the fuel pump and oil pan). Sounds like da-ga-da-ga-da-ga and is in time with the idle. Ran fine on the engine stand beforehand. Pulled the valve cover, getting oil no problem. Pulled the #1 plug, it is fouled (new plugs, obviously). The #3 was fine. I know this is a pretty tough problem to diagnosis without seeing it firsthand, but any advice or possible direction anyone can offer would be greatly appreciated. It is a 73 455 from a Centurion that I put in a new cam, cam bearings, water pump, 4 core radiator, hydraulic lifters, intake, carb, headers and 2.5" exhaust. It's in a 72 Skylark with a rebuilt TH400 and new driveshaft. Thanks in advance....has me and my father in law stumped, so I figured this board would be the best possible reference point (as it has helped immensely during the rebuild process). Thanks again, Dan
if it ran good on the stand a guy would come to the same conclusion as you. should run good in the car. make sure you didn't maybe tip the motor around putting it in and have some oil top side that would foul the plug out and couse over comprssion on that cylinder. maybe make sure if you might have pulled the distributor before putting it back in that its not off a tooth maybe. how about follow through from the back of the motor. tourqe converter matched up wrong or not bolted tight to the flywheel just throughing things out. good luck Greg o No:
Thanks for the quick response Greg! I did have the engine/tranny at some wierd angles getting it in the car with those hooker headers. If I do have oil on the top side, how would I compensate for that? I checked the timing and with it set at 10 degrees advanced from TDC, the noise is still there. How would I ascertain if the distrib is off a tooth? Good thought on the torque converter. I'll check that out. I think it is seated ok, but i'll pull the flywheel cover and double check. If anyone else had similar problems I would love to discuss. All my car nut buddies had been riding me for months (almost years?) to get this sucker rolling and I am almost there. Just want to make sure it isn't something catastrophic that might have given way on the bottom end (didn't do any bottom end work, heads etc because it looked like a fresh rebuild (blown cylinder, hence a new looking piston). Thanks again Dan
pull the plug and the coil wire to the cap and turn the key over. if oil comes out of that cylinder it was tiped to far. had the with another motor i put in . the motor would not even start and made sloping sounds as well. guy told me it was from over compression in a cylinder. alot of oil came out of 2 of them on me. without being there and listening to it, it is hard to figure out. hope someone else jumps in here as well and gives other ideas as well. did you have the timing cover off? was the a oil pick up on the cranck that maybe isn't lined up right. there is alot of varibles here. let me know how it turns out Greg :3gears:
Thanks for the follow up Greg. I will check those out and let you know what I find. I did have the timing cover off to do the rebuild, but not since. It definitely sounds like a rotating assembly noise as an increase in throttle makes the sound increase. Can you describe the sound you were getting fro the over compressed cylinder? Mine sounds oddly like a piston hitting on something (or like the fuel pump arm hitting on the gear it attaches to?). As you said, there are a lot of variables here and I know it is next to impossible to diagnose without witnessing the problem. I will disconnect all the plugs and spin the starter and see if the sound is still there. If so, I will then disconnect the fuel pump and see if that is the culprit. If it is spitting oil out of the spark plug chambers, how long should I spin it....until the oil stops coming out, or otherwise? As an aside, where are you located in Wisconsin? I am now an 'official' California guy, but originally grew up in Milwaukee. Gotta say I do not miss the mosquito's, humidity nor snow. Plus, I get to take my car out 365 days a year (when it is running, that is)!
i live 50 miles north of milwakee in plymouth. straight up. that oiling arm will sound like that as well that conects to the front of the cranck. if assabled wrong might be making the noise. good idea on the spinning over without it starting as well. should be able to hear it better without the motor running if its something in the front or back of the motor. let me know what you find Greg
Quick thought... Could it be the fuel pump arm contacting a double-roller timing set? You may want to pull the pump and see if there is any wear on the inboard side of the pump arm (assuming you used the double roller setup).
Hey Guys: Thanks for all of the feedback. I will be checking the pan, flywheel connection, plugs and fuel pump this weekend and will let you know how it works out. Hopefully this thread will help out someone else down the line with similar issues. I've said it before, but this site is amazing. I wouldn't be near where I am now without all of the assistance and thread reading that I have gotten from this group. Cheers, Dan
Is it possible the crank is hitting on the oil pump pickup tube? I had a bent one in a fird once that did the exact thing you're describing. :bglasses:
I would like to chime in on this. My 73 engine was also recently rebuilt and is in the car. I have a noise coming from the same area, giving it a solid lifter cam sound. The engine runs very well, and plugs are OK. I have a double roller timing chain installed, and a new Stage 1 fuel pump. While I shaved off a little of the metal ( on the fuel pump arm) for clearance, I'll bet that is the noise we are hearing. Good call on the chain being the likely culprit! Russ Waters 1970 Skylark Convertible 455 :3gears:
