So, I think I might have a bad engine problem. The engine was built by IMM about two years ago. It's a 408 stroker with forged SCAT internals, ICON pistons, 800 Holley DP,-LOL-way too large. about 10:1 compression, Enginquest heads, 1.6 chromolly rocker arms, all new valve train, etc. Everything in the engine is brand new. To this day, I may have a little over 1000 miles on this engine. Mostly street use with 1 track day and 2 autocrosses.-<<These are HARD on an engine, how good is your oil control?
Also what is the camshaft? Just curious. I'm also assuming the engine wasn't on Brian's dyno, was it?
Essentially since November, I have been driving the Dart once a week for about 10-20 miles a day (20-30 minute drive) and it has been babied. For the first 250 or so miles I wouldn't even go above 4000 rpm. The past two times out (probably 30 miles in total) I may have taken it to 5000-6000 rpms twice in between the two trips. The past two times I've driven the car, I started to notice that the exhaust is coming out a little white on start-up and eventually turns up normal; however, the problem is that now there's a black dust/sludge on the ground from those two days. <<Completely normal. Ironically, the last time I had the car out, it was actually quite happy and not as rough as usual. <<What does this mean? Poor cam selection vs expectations? Or poor tune? I'm betting on the latter.
I started it up again today as I've finally had time to do some research on it and the internet is telling me it doesn't seem good (blown headgasket, broken piston, cracked block, etc.). Well, when I started it up today, it sounded like I had a lot more valvetrain noise than usual and some engine knock.
Oil pressure on start-up was 70 psi, but it almost always starts that high. When it warms up and idles, it's usually down to about 25-35 psi. Generally it takes about 5 minutes of running before the engine wants to go. The car consisitently gets 6-10 mpgs despite having a double overdrive (T56) transmission. Around November, the engine was getting some blow-by and the recommendation given to me was to get the carb tuned; however, both IMM and a very well known Mopar Speed shop both tuned the engine last December/January. The second shop didn't change much of anything. Over the past couple months, the blow-by would occur once every 5 start-ups (identified by smoke coming out of the trans tunnel). I checked the oil level today and it's full, granted, the last time I changed the oil was 100 miles after the engine was broken-in (about 1000 miles ago) in January 2017. I don't understand how an engine GETS blowby once every 5 start-ups. Either it has a significant amount of blowby or it doesn't.
Based off of the picture and video, what do you think it is? Is it as bad as I think? Unfortunately, I have literally no time to work on this until maybe mid-June. On top of that, I'm on an extremely tight budget as I've got some major life events coming up.
It sucks that this stuff keeps happening every 3 months, but if anything, I am probably just going to have to wait until June, finish setting up my engine crane and engine stand, and attempt to do an engine diagnostic myself. I'm done with shops.
The video doesn't sound good but that doesn't mean much. Brian knows how to set up piston to cylinder wall clearance so I doubt its anything to do with that. Beg, borrow or steal a much smaller carb-preferably a V.S. , map out your timing, cranking comp test, fresh plugs, fresh fuel and document everything. Change your oil and filter through a paint strainer into a clean container, cut open oil filter as well--actually do this before anything else-if all looks good fill with new oil and proceed to diagnose. Have fun--this is part of the old car culture and I consider it a rite of passage otherwise go get a new Challenger or Hellcat variant and never look back. J.Rob