I finally installed a rebuilt 400/462 engine in my 72 lemans sport. I had the engine builder break in the engine at his shop. after I installed it, it was running fine for 4-5 hours, but then it started blowing what appears to be very light blue smoke out of the drivers exhaust only. It still runs ok, but it definitely was not smoking until after I got down on it a couple times. I'm really bummed out. I'm hoping that I didn't break a ring. If I have to have a head reworked I can deal with that. Do any of you experienced Pontiac engine guys have any ideas about what might be wrong. Thanks Chris
hello;exactly what oil was it borken in with?what oil are you use now?what rings are in it?its possible it is left over oil in the exhaust.remove spark plugs from that side and inspect them.do a wet dry compression test.do a leak down test.if it blows smoke all the time it is likely a ring and the builder better fix ANY eng prob for free...
Thanks, I will do what you said.
10 30 oil not sure of rings, but rotating ass. was balanced. cast pistons, not a super hi po engine. engine builder is a Pontiac guru out of Brookville, fl kept engine for over 6 months. I was not happy with service received and would never use him again. i'd rather start over. Thanks chris
hi;ok cool; but you did not mention what engine oil you or he used.my guess is a bad cylinder.
if it a broken ring. besides a new ring would I have to rebore cause I'm .60 over already.
reelworld72:10 30 oil not sure of rings, but rotating ass. was balanced. cast pistons, not a super hi po engine. engine builder is a Pontiac guru out of Brookville, fl kept engine for over 6 months. I was not happy with service received and would never use him again. i'd rather start over. Thanks chrishello;10w 30 means nothing. is it SYNTHETIC?was it broken in with SYNTHETIC?Is it a stroker?are the pistons hyperutetic or cheapo cast pistons?If your engine has a problem he is not a guru he is a MORON.it took him 6 months because he lives in florida and therefore is most likely a crack head and spent your build money on crack.What is the builder or shop name so others here that might live in florida can avoid him?
reelworld72:if it a broken ring. besides a new ring would I have to rebore cause I'm .60 over already.omg. are you running a stroker at .060"?does it run hot?if a ring damaged the bore you can resleeve it.EXACTLY where does your pcv valve plug in to vacuum?.
As a Pontiac guy I would think you know exactly where the pcv plugs in. In front of the carb in valley pan just like all other Pontiac 400s. Not synthetic oil. you should never use synthetic to break in, but you know that. and yes to get 462 ci out of a 400 you bore .60, but with your experience you know that as well. no it does not run hot. By the way just wondering what your credentials. In my original post I did ask for experienced Pontiac guys to respond. Oh and I live in florida and don't smoke crack. thx
hello;you did not answer my questions about the pistons.the pcv has two ends. i want to know where the other end of it plugs in. the pcv is not always connected in the orig position because these cars are 35 years old and older, and some people often change things for one reason or another over the years and all the pontiac car guys i know are aware that. Also, due to oil splash getting to the pcv in some cases when it is mounted to the valley pan, some pontiac guys change the location of the pcv to a valve cover with a baffle and experienced pontiac guys know that too.if neither the valve cover or valley pan has a baffle, and the pcv is sucking up oil, experienced engine builders recommend using a pcv with a filter that catches the oil. Moroso is one company that sells themyes i know that it takes .060" to get 462 and that a 400 can be bored farther than a 455 but i don't do that because i live where it gets over 100 degrees and unless one is trying to eek out every single bit of hp out of an engine for racing it is illogical to do that on a street engine. it is far better to leave the cylinder walls thicker especially because it is not prudent to bore a std block out to .060" if it will clean at .030 or .040" if one intends to keep the car because you have just reduced the amount of times it can be bored out in the future, but i guess some people don't mind buying another block when theirs can not be bored out any further."By the way just wondering what your credentials. In my original post I did ask for experienced Pontiac guys to respond. Oh and I live in florida and don't smoke crack. thx"part of it is.full time professional auto restorer and high perf engine builder for 25 years. part time for 20 years prior to that.occasional auto and motorcycle tech instructor.sold 3 cars for world record prices.had several national concours trailered gold award cars and gold award driven cars.head of r and d for a major vehicle mfg for several years.professional motorcycle racer and winner of numerous races and and a few championships.you can look up my screen name and also name 70 bird in the search engine if you want to research me. i lost the 70 bird name when the site switched to a new program. many others lost their names too."Oh and I live in florida and don't smoke crack. thx"there is one pontiac builder in florida that seems to have some probs. i can definitely build more than 1 engine in 6 months..
To get a 462 you bore it .060 and stroke it as well.Just boring it wont get you a 462.I live in Florida as well.It does sound like a ring issue to me.Was break in oil used or oil with enough ZDDP in it?I think I already know the name of the shop as there was another guy on here a while back with engine issues as well.Do a compression test on all the cylinders on the side that is smoking and post the results.
Engine builder,self taught auto body guy.Horsepower sells engines and torque wins races
OK, sorry if I sounded a little hot in my previous post, it's just that I have waited so long to get my car back on the road and 2nd day driving it the smoking issue started. In your reply you were using capitals and I was in no mood to be yelled at. So please let me start over. I have read many of your post written under your previous screen name and have appreciated them and your qualifications are in deed impressive. Thanks. I am not sure what kind of cast pistons Ken put in the engine,but here is my story. I had found a 400 YS block that I took to him to build. He told me that it had been bored .30 already and he bored it another .30. I asked and he assured me that that block could handle .60 with no problem. I had previously only had fords (351 clevelands) so I was aware of over boring equals over heating issues thats why I specifically asked. He used all new parts except the rods. I have a 72 lemans sport with the endura front end/ram air non functioning hood so I was very happy to find the YS engine with the correct 7k3 heads since I'm building a gto clone. He knew what I was trying to do with the cloning of the car and that I wanted the engine the correct color, but it was painted the earlier gto engine color so I had to repaint it prior to installing. That took 4 days including stripping the wrong color off. Communication from the shop was poor and it took, as I said, 6 plus months to finally get the engine back. I paid extra for him to run and break in the engine. He told me that it was now 462 ci. to make matters worse I had him send a 72 quadrajet that was correct for a gto to cliff Rugles that I had search for and found. Can you believe that even after speaking personally to cliff about my goals for the car that, the carb he returned 2-3 months later, had all the identifying numbers ground off even though he assured me that the carb I sent was a good one without the typical damage that is common on quadrajet cores. His rebuilds aren.t cheap, but I wanted the best. Sorry for the long windiness, but I want share with you why I am frustrated. Anyway I got the engine back and now 5-6 years later I finally was able to install it. That was 3 days ago. whew! what a month full. I followed your advice and pulled the plugs on the drivers side the # 5 looked wet with oil. I still need to do the other test that you mentioned in your post. I wish it was a valve guide issue and not a ring issue. Thanks to everyone for trying to help.
oh pvc is in valley pan and connected to stock intake manifold on other end. just like stock 400 would be