roninjiro Posted October 14, 2006 Share Posted October 14, 2006 rebuilt the l28 and now she smokes, pulled plug and they have a light tan to them, check compression its equal across the board, checked oil for water, nope; checked for coolant loss with no loss, when rebuilt the rings were staggered like supposed to. whats going on? i know rebuilt motors will smoke for a lil while for new rings to seat but this is weird, i mean she smokes. sure compression is up quite a bit but what the hell is going on. this is a l28 w/ p90 head .09 shave, new rings (gapped em), new flat top pistons, new coil, new plugs, new bearings (primed oil system b/f startup), air/fuel ratio reads good (new o2 also), new valvestem seals (completely reworked the head at machine shop) new everything almost. also running rebuilt dual su round tops with sm's(balanced) <-----dont bash me on my carbs; it is my preference. note: i cant tell the color of the smoke; like a whitish grayish, im running on distilled water at the moment in the cooling system, too lazy to get coolant Quote Link to comment Share on other sites More sharing options...
roninjiro Posted October 14, 2006 Author Share Posted October 14, 2006 help..... Quote Link to comment Share on other sites More sharing options...
big-phil Posted October 14, 2006 Share Posted October 14, 2006 I feal your pain. Check your PVC. If its put in backwards, clogged. It will presure your block and cause it to smoke. Quote Link to comment Share on other sites More sharing options...
roninjiro Posted October 14, 2006 Author Share Posted October 14, 2006 pcv is ok, just went out an checked it. i do have the top valve cover tube open, no smoke shooting out or anything, if anything it has a vacuum Quote Link to comment Share on other sites More sharing options...
big-phil Posted October 14, 2006 Share Posted October 14, 2006 well that means you are one step better than me. good luck Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted October 14, 2006 Share Posted October 14, 2006 white smoke is usually water (steam) did you re-torque your head after first runin? the bolts could have loosen'd up. I know you said you checked the water but Im just throwing out stuff. good luck! Quote Link to comment Share on other sites More sharing options...
roninjiro Posted October 14, 2006 Author Share Posted October 14, 2006 re-torque after first run? nope, should i do that? Quote Link to comment Share on other sites More sharing options...
srgunz Posted October 14, 2006 Share Posted October 14, 2006 Are you using cheapo dino oil for ring break in? You should be. Quote Link to comment Share on other sites More sharing options...
roninjiro Posted October 14, 2006 Author Share Posted October 14, 2006 yes sir... Quote Link to comment Share on other sites More sharing options...
zeiss150 Posted October 14, 2006 Share Posted October 14, 2006 I've read a bunch of times that after break in you should re-torque the head bolts because after the first heat up and cool down it could loosen the bolts. Just a place to look.... If they all still torque to the right specs then you know thats not it. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted October 14, 2006 Share Posted October 14, 2006 How did you break in the engine? What did you do for the first few minutes and miles after you first started it? Quote Link to comment Share on other sites More sharing options...
roninjiro Posted October 14, 2006 Author Share Posted October 14, 2006 didnt quite break it in yet, just drove it around maybe a mile, just smoked alot so i turned around. drove it like a sane person if thats what you mean, no too hard at all. it definitly not fully broken in thats for sure. the plan was to hit the highway for about an hour but the smoking is stopping me , i really dont wanna get pulled over. Quote Link to comment Share on other sites More sharing options...
nienberg.11 Posted October 14, 2006 Share Posted October 14, 2006 Like the others said, retorquing the head after the first startup is a must. Going a pound or two over the torque specs doesn't hurt either. If it smokes a lot while going down the road it's likely to be oil burning. Coolant being drawn into the cylinders happens much more easily when there is high vacuum in the engine, like at idle, and tends to clear when the car is being driven. Quote Link to comment Share on other sites More sharing options...
z-ya Posted October 14, 2006 Share Posted October 14, 2006 Did you bore it, or just put new rings and pistons? Did you use the proper hone for the rings you used? Did you remove any ridge? Head re-torque is not required. I built a bunch of L28s and have never done it. Never had a problem. What color is the smoke, white ore blue? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted October 14, 2006 Share Posted October 14, 2006 Sounds to me like the rings just haven't seated yet. Take it out and don't hit the freeway. Accelerate and decelerate is the key. Find a windy road or drive in trafficky areas. You need that accel and decel to seat the rings. You don't have to take it all the way to redline, but I wouldn't stop short of 5000 rpm. Quote Link to comment Share on other sites More sharing options...
srgunz Posted October 14, 2006 Share Posted October 14, 2006 FYI. Back when I worked for a Datsun dealer the heads were only re-torqued when the customer brought the new car back for its 1,000 mile inspection. The break-in oil was changed at that time also. Quote Link to comment Share on other sites More sharing options...
roninjiro Posted October 15, 2006 Author Share Posted October 15, 2006 so do i retorque or dont retorque? i didnt bore it out, had the machine shop hone it out, gap rings, measure bores, i just put it all together according to manual. onlything majorly done was the head shave of .090 smoke is more whitish, than bluish. (new headgasket, all new seals, all new gaskets) everything was torqued when put back together key thing: i havent been able to drive it around as i should, too smoky. BUT keep in mind there is plenty of power (much more than it was b/f rebuild) , no hesitation-not a hint, idles perfect. as far as jmortensen was saying, you need to the engine to heat up then cool down so the block makes a fingerprint on the headgasket and so forth. is this what you mean? so nienberg.11 said its coolant possibly, like how when you replace the freeze plugs and it leaks a little and later it stops due to heat expansion? Quote Link to comment Share on other sites More sharing options...
nienberg.11 Posted October 15, 2006 Share Posted October 15, 2006 If the smoke doesn't have a hint of blue to it, you're probably right to think it's coolant. I'm not sure what goes on after freeze-plug replacement, but I was referring to the fact that as you're driving the car, coolant won't be drawn through leaks into the cylinders as readily because of the higher manifold pressure. If the leak is big enough it wouldn't make much difference, however. I was burning coolant due to a rotted H.G. and it would only show at idle when the engine vaccuum would draw coolant past the weak spot on the gasket. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted October 15, 2006 Share Posted October 15, 2006 There's probably no issue with retorquing, although I don't think modern head gaskets for Zs require it. The Felpro's I've used says "No Retorquing Necessary". Once, before I took the head off, just to see, I tried retorqing. I had to exceed the spec in order to get the bolts to turn at all, so I think you can take them at their word. From everything I've read, your best chance to seat the rings is in the first 50 miles or so after a rebuild. From you description I can't tell how you've been driving it, but to Jon's point earlier, you need to get on it, not WOT, but accelerate hard, and then decel, over and over again. Idling is not good at this stage. Before I broke my last rebuild in, I did a lot of research about how to break in motors. I must have received more than 40 replies from a bunch of different sources, including HybridZ. The general concensus was: - Start it up and keep the revs above 2500 for at least 10 minutes to get everything up to temp and check for leaks. - Then go out and drive it hard, but not abusively, and with constant acceleration and deceleration. Avoid steady light throttle driving - that's the worst at this point. - Change oil after 50 miles (some said after 10 minutes) - Continue to drive it as above as much as you can through 500 miles and avoid steady light throttle driving as much as possible. - There's no problem with using revs, just don't go to redline at WOT. - Don't lug the engine. There were a few times in the first 100 miles or so where I saw smoke out the back when accelerating hard. It wasn't as much as you are describing, and only occasionally. Now that it's broken in there's no smoke at all. I understand your concern about driving it while it's smoking, but I think you either need to find a source of the smoke without running the engine, or follow a proper break in procedure. It sounds like you're kind of in the middle right now, and that's not a good thing. Quote Link to comment Share on other sites More sharing options...
badjuju Posted October 15, 2006 Share Posted October 15, 2006 I'd listen to Z ya, he and Braap are the ♥♥♥♥ (in a good way guys, lol) when it comes to heads. That's not downsayin anything about anyone else, just that everytime i've asked either one a question on l28s they've come through for me. Might try pming Tony D too. Quote Link to comment Share on other sites More sharing options...
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