It sounds to me that your fuel octane and Ignition timing where not very happy for you. Detonation in turbo motors kill pistons QUICK!!! If you could here it there was ALOT of detonation, you need to read your plugs. I'll bet you crushed the ring lands in a few pistons and caused the rings to stick causing the blowbye then probably broke a chunk out of the piston top. Make sure the valves are checked for damage from chunks going out the exhaust. How was your timing setup? What octane fuel were you running? You really need to fix this problem before putting a fresh motor in and doing the same thing to the new motor, because oil in the intake from a failing turbo seal won't do it. Please elaborate on your tune/setup. Thanks Nick
Wow Nick.. I missed the whole detonation part. Yeah, if it was pinging like that it surely broke one of the ring lands. Big question is why it wasn't skipping like hell from the broken part or parts hitting a plug? It nearly always closes a plug gap when that happens. That's what happend to Turbo455.. I've seen many SC'd Buick V6 pistons with the same chipped piston problem.. 34* initial and 26* total timing at 8lbs of boost, 12.0 AFR@WOT, and spraying methanol at 6lbs is my setup.. Seems to work really well. Better track times will come.
The timing was locked at 26 degrees without vacum hooked up. I didn't run vacum even before the turbos went on. The spak plug lead that burnt out on the turbo manifold was the last one on the rear drivers side. When the plug burnt out I replaced it and changed the plugs, The plug that came out of the mentioned cylinder with the burnt lead had the gap squashed. The AFR's were great during the 4 days before the plug burnt out and but I found at 85% throttle it started to lean a little to 14 AFR, so I went up in jet size on the secondary and that sorted that out. I installed a brand new distributer and coil prior to running the car with the turbos. The fuel is use is Mobil unleaded 98 octane. I never put the sugar cane meth unleaded mix in her. could the burnt plug have done so much damage?
I meant could the burnt plug lead have done so much damage. The motor now idles rough and when I look at the front pullies the balance seems all over the place. Before the plug lead went I pulled 4 plugs and they were great no oil no greyness no heavy soot. Just nice clean and darkish. The tune was good. However !!!! Now that I think of it, I had the car in getting a custom exhaust built over two days, when I picked her up from the shop it blew white smoke everwhere on the way home, the guys who work there are kind of bike gang types. I wonder if they might have gone for a spin. I don't know? There is no telling how long the plug lead was burning away on the manifold either.
There is only one thing that can close the gap on the plug. Either you ingested a foreign object or chipped one of the weak cast pistons.. ( I guess that was two things) Burning the plug wire and losing a cylinder because the wire is grounding out will not hurt anything on its' own. It will cause a harmless misfire. Keep a VERY sharp eye on the AFRs when you get things back together. Without spraying meth, I would suggest 11.5 AFR at WOT or anything near it. Nothing above 12.. The forged pistons will be more forgiving. http://www.theturboforums.com/smf/index.php?board=13.0 Biggest blow through forum on the net..
Got ya. Just ordered the Flatlander HP kit. The price has gone up to $1100 since last year. The custom forged pistons I ordered are 30 over and 8.8:1 compression ratio. Hopefully the Block and heads are in good shape. I'll get the 73 connecting arms like you suggested from TA. The forged ones are a thousand bucks! I'll post some pictures of the damage next week, it should be a laugh.
The pistons sound just right.. I don't think TA sells the connecting rods, unless they have a used set laying around. I need another set myself.. You will notice a significant difference in the 70-72 to 73 up connecting rods.. It might be a laugh to you, but I would never laugh at you or you situation..
The feed lines are not permanet at the moment but I'm running some blue flexable line off the T piece from Mark. They are 1/4" I.D and I used a 1/8" ID right angle fittings into the feed line at the top of the turbos. I feel that there is still alot of oil going into the turbo and when I take the exhaust down pipe off it sprays a little oil out, I've been restricting it down to 1/16" ID on the passengers side as this was leaking bad both ways into the exhaust and the intake. I did some reading and talked with the drift car guys and they said this happens all the time. I mean there is still a good flow out the bottom dump line and they reckon as long as there is flow it's ok. On the dump lines I drilled and welded into the front of the oil pan with two 1/2" short barbed fittings they stick out only 3/4" from the pan on each side. I connected 1/2" ID hose to these and clamped them for insurance. On the turbo dump line I bought some flanged connector pipes that drop about 3 1/2" inches and connected the hoses to them. I'm happy with the dump lines because they lay nice to the sump but I think Stainless lines to the oil feed for the turbos will be best. I'll post pictures when I get home of it all. The whole set up looks messy yet clean at the same time it's kind of stange cause it's not shiny and colorful like a show car. When I pop the hood the chevy guys where I live are not impressed at all and think I'm flushing money down the crapper, but the import car guys think it's cool and have been a really good help with trouble shooting. It's funny that, I never expected it.
Problem with a long thread like this and like mine is that you end up with like 6 poeple watching the thing.. When you have a problem like oil blowby on the turbos, if the six people watching don't know why, you don't get an answer. I ran 4an and 3/4 drain and have no issues.. I wonder if you didn't have so much pressure in the crancase that the oil couldn't drain back?? If you were blowing it out the valvecovers how could it drain back??
I think you just found your problem right here. That lean part throttle condition is a detonation killer!!!! Because you make big torque and with that lean condition I'll bet it beat the ring lands to death. You also don't mention what spark plugs you wound up with. You need colder plugs with a turbo motor at least 2 full heat ranges colder then stock. Another thing you need to do is to not fully count on the Wide Band. YOu need to find which cylinder is running the leanest based on plug readings. Once you find that you can use the Wideband along with that one plug to finalize your tune. Then you can use the wideband as a normal gauge after that all as a reference. Don't use the wideband as your only tuning reference. I know its easy to just watch the Wideband, but that will get you into this kind of trouble. When you see the number on the gauge is a combination of ALL the cylinders on that bank....so you might be missing a really lean cylinder. One last thing, I would suggest if you can do a compression test on your motor before tear down to see what the ring seal on all cylinders really was. As a reference my stock 73 motor had 130psi across all 8 cylinders.
A couple things here. First off the white smoke as long as it went away was most likely the coating that is on the pipes to keep them from rusting while sitting around that burns off after a good heat cycle. Next thing with the rough running you might have damaged a porcelin on one or more of the spark plugs. When you pull the plugs make sure to turn them upside down and make sure the porcelin isn't knocked loose this is a common failure that not many people realize with turbo cars. What happens is the porcelin breaks loose and then it falls down on the plug and covers up the tip of the spark plug and causes misfires. So theres a couple things to look into before full tear down so you can learn from all this and not have it happen again. Because forged pistons just last longer before the same thing happens to them.
Thanks Nick, I'm running NGK I think the heat range is 4 but don"t quote me on that as it's been 4 weeks since I've been home. The plugs are about a 1/4" shorter than the NGKs that I pulled out. The timing has been an issue I'll admit it and I'm reading up on the Mallory Hifire VI that Jay is using. I mentioned that I changed the dizzy but The old Dizzy did get some turbo time and the rotar and contacts were worn in it. You are right about doing a compression check, however the plugs take a good 6 hours to take out and put back in I think I could have the heads and oil pan off in that time from memory. That lean condition at the 85% throttle was so hard to get rid off, (Thats if I even did) wether it was a combination of the carb secondary jetting and the timing is hard for me to say but I'm not 100% convinced that my stock HEI igntion system is safe to run with turbo chargers. If I get the engine built right and have the correct ignition system I'll take it down to the Dyno tuner, But I'll only take it in if it has good equipment in it and has the capability to be tuned. This has been a real experience for me. I don't mind the engine being totalled because it wasn't built up for the turbos but I got to see if I liked it or not and I do. It was due a rebuild and now it's time to jerk that engine and throw some serious cash at it.
Yeah the white smoke went away. When I removed the hotter plugs I broke 3 porcelins off becuse of the angle with the log manifolds in the way. So before I put the new ones in I bought some really good friction ball uni sockets, still could of easy cracked one though. I'll check
Your Heat range is a 4, if so that is way too hot. Step up to a 7 or 8 range. That will help with your cylinder temps. As far as the HEI do be concerned with that. As long as you can lock the timing then it will be fine. I was spraying over a 200 shot of nitrous on my completely stock HEI unit with a Digital 6 MSD box.....so the HEI is not an issue here. Good luck with your follow up build and feel free to PM me direct anytime if you like. I've been tuning/racing turbo cars since 95'.
You can forget about doing a compreesion check unless you remove the manifolds.. The spark plus are hard, but not that hard. Just get a big variety of extensions and a swivel.. The hardest part for me is getting the wires off and back on.. Bryon.. What kind of carb are you running?? I'm a little lean at half throttle too. I'm still working on it though..
