I just got done rebuilding a SBC. Here is what I have.. 91 Small Camaro roller small block Bored to 30 over Eagle internally balanced crank 5.7 connecting rods Probe pistons OEM roller lifters OEM pushrods Vortec Heads milled to accept .600 lift Stainless valves intake and exhaust Mutha Tumpr roller cam (Dont drill me, I LOVE the sound of this cam) Professional Products high rise intake Quickfuel 650 hotrod series carb Started up pretty easy. Rough idle, but the mutha thumpr is designed to do this. Here is my problem. #1 cylinder header is cold, and the spark plug has fuel on it. Ive changed plugs, and plug wires with no change. I pulled the valve cover, valves are working as they should. I know the dizzy is putting out a spark because I set the timing with the #1 plug. Also, the motor seems to be putting out a lot of smoke. With in minutes of running the whole garage was filled up with smoke. What else do I need to check? Where to go from here? http://www.youtube.com/watch?v=aauvF2aLQh4&feature=youtu.be
Take a compression test,sounds like no compression in #1. If none or low hook up some air to that cyl and see where it's going.
I readjusted the valves. I havent done a compression test, but I know there is compression. I put my thumb on it and turned it over. Blew my thumb off the cylinder. Adjusted valve by putting it on TDC, Tighting the poly lock until pushrod doesnt turn and then turning it 1/2 turn, then locking it down.
Position of the ring gaps might have something to do with that, if they are in line or close to it then that could be it. (or a contributor)
Piston rings were set to book specs. I made sure of that during the build. This is however my first time building a motor and I did it step by step, over several weeks.. I made sure everything was correct. I will do a compression test. With the valve covers off I turned the motor over and the valves seemed to return to seated position. I hope to god its not a broken ring, I will probably cry for several days.
pottsie, here lies what MIGHT be your problem, keep in mind Ive been doing this longer than youve been alive ok. BTW, love that in the video, " have the phone ready to call 9-1-1,", that's priceless!! Now, I teach people to NOT adjust the lifters so that you stop when the pushrod doesn't turn anymore. Listen carefully, adjust them al again so that you cant move the pushrod " up and down " at all, and then another half of a turn, OK. Stick with me I'l even explain why. The newer style lifters do not have the internal spring strength that they used to. The plunger inside the lifter goes down VERY easy, and you turn and turn until it stops right? Well you have collpsed the lifter internally, and now the lifter and valve will be held open once you get oil pressure to assist. This is why you need to closely feel the pushrod up and down and then feel for that slight tension in the rotation that you wouldn't ordinarilly feel by just turning them. I know its hard with the intake on and the engine assembled, but you must try this. The bad news is, is that it could be many other things far worse than the valve lash. But please try and lash them again using my method.
What color is the smoke...If its white its most likely oil smoke.Are you sure #1 has fuel on it and not oil?
Do a compression test, see what's wrong. Sometimes there's a problem with the machine work or assembly, or defective parts, that you don't notice. The smoke might be normal, you're supposed to have the exhaust pipes going out of the garage. A new engine with assembly lube in it will smoke for a little while, also if the exhaust system has fresh paint on it that will smoke too.
Have you actually confirmed that the number one plug is getting juice? I know you said you changed the plug and wires but until you know for sure the plug is firing you are shooting in the dark. Either pull the plug and short it out against a ground while you crank it, or buy one of the $5 spark checkers and find out that way. Sounds to me like a dead cylinder. Don
Now, if you want to be like a engine builder, adjust the sequence like this. When the exhaust valve opens, you adjust the intake valve. When the intake valve opens fully and begins to close, you adjust the exhaust. Just be sure you are turning the engine over in the direction of rotation of running, TR
One broken ring shouldn't totally kill a cylinder. When the guides were cut down for the bigger lift they might have tightened up the guide so it is pinching a valve open. A lot of smoke is pretty normal for a new engine for the first 30 minutes or so. You didn't by any chance use engine assembly lube on the rings when you knocked in the pistons did you? Only pour fresh engine oil on the rings before tightening down the ring compressor. If you did use assembly lube you will probably have to tear it down and wash everything off or the rings will never seat.
Smoke is blue, and reeks of gasoline. So much so that it makes my eyes water. ha. First this next weekend I will re set the valve lash on on cylinders. I will also buy a new spark plug for the #1 cylinder just in case. And I will compression test all cylinders before, and after valve lash adjustment. It just sucks because the motor runs really strong past idle.
are you getting spark to number one and how strong of a spark? How well do you have the engine ground (wierd question, but I have experienced this)? Run a compression test, regardless if your finger is blown off.. It may show you that you have a ring problem. A lot of smoke could indicate the lube you used for the assembly is burning off... If you use too much then this maybe the case. If I were you I would start eliminating systems, first starting with electrical (especially at number 1). Then perform your compression test. Once that has been completed I would then check the valve adjustments again (It wouldn't be the first time that you think you have done something correct and just happened to have the valve lash set so that both are closed at top dead center. At that point you should have found your problem
Your very welcome Jim, the lifters in the last 10 or 20 years are nothing like us older guys remember from when we first started lashing our valves. Especially the new white box chung king lifters, TR
aaggie, I only used engine oil to lube the cylinder walls. Everything else got assembly lube. I am using comp cams oil additive to help set the rings, so they told.
^ waste of money..... swap the plug to a different cylinder to see if the problem follows, if it doesnt, then it is not the plug.
pottsie, what kind of fuel pump and how much fuel pressure do you have? Are you using a regulator? You need to know, ever hear of " washing down cylinders " ? That will surely make you cry, so please be sure about those items too OK buddy, TR
You can put 100 plugs in that cylinder and until you have confirmed you are getting current there you won't know what is going on. Don
What about swapping the plug and wire over to a cylinder that you know is firing to see if that's the problem? That along with re-checking the lash might give you some insight...
I have a quick time fuel pressure regulator and a cheap fuel pump from autozone. I had it laying around but I plan on buying a quick fuel pump as soon as money allows. As far as fuel pressure, I am holding at 5 pounds, and the float bowl sights are at half in the window, per quick fuel manual. Idle mixture screws are at 1 and 1/4 turn out on all four corners, per manual. Base timing is set around 12 to 15 degrees advanced in order to achieve somewhat of an idle.
What I'm going to mention,may or may not contribute to your solution on your current situation. I was under the impression that not all roller camshafts work with factory with OEM lifters. Any thoughts ?
I used another plug from a known good engine and I used said plug wire from same engine. Still cold header pipe. And wet fuel on tip of said spark plug.
I was told by my machine shop that OEM lifters would be fine for my application. Same said machine shop has built a nearly identical engine several months ago with same internals.
You can hear it before you started it it is popping through the pipe 1 are you sure fireing order is right 1-8-4-3-6-5-7-2 and make sure you dont have a wire crossed i am willing to bet thats the problem from here the video didnt make it all the way through so i didnt see the smoke i`ll try again
When you re check your lash, do me a favor start on #1 and pull the rocker arms and make sure your not having any rub or interference with the valve springs or retainer. After all is said and done, you might want to think about checking your valve train geometry, or push rod length. You might have a smaller problem with the stock length pushrods and a cam that steep, or did you check that? Not saying this has anything to do with the current condition, just food for thought so you enjoy your build to the fullest, correct P/R length is very important and often overlooked. TR
Pushrod length - I did deck the heads and block to match. But, because I used a small base circle cam my pushrod length came out to be stock length. I checked the geometry and 7.2 (stock for vortec) came out to be correct. I got hardened pushrods and guides to match. Thanks for all these suggestions, I will spend most the day Saturday morning trying all of these out.
When you do a Compression Test Make sure you take all the Plugs out that way you wil get a Accurate reading and like other guys said Check the # 1 wire to make sure you are getting Spark just my 3.5 cents
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