Blown 346 cid Stroker 300

[BlownMGB-V8]

Well that was a bit anticlimactic. Cranks OK. but doesn't light off. From my datalog I suspect the injectors aren't firing so I have two tests in mind, aside from the obvious noid light. Look at the fuses closely, particularly the ones powering the injectors, and perhaps squirt some raw fuel into the butterflies. Always something isn't it? But this shouldn't be so bad.

Jim

[BlownMGB-V8]

Ever get to feeling that you could be getting a little ahead of yourself? Yeah, I had this sneaking feeling I was overlooking something... Downloaded the tune to the ECM on the simulator, check. Fired up the VCM Scanner, check. Bundled up the laptop, HPT module and cable, went out and connected and verified it works, check. Looked at oil level and adjusted for fast idle, check. Now what'd I forget? That injector fuse is just fine...

Oh yeah, might want to swap the newly programmed ECM into the car in place of the spare I've been using to check the wiring maybe? Kinda doubtful if that one will even start the car. Yeah. That might do it. So here we go again.

Jim

[BlownMGB-V8]

And..., we have ignition. The engine fired up, smoothed out, started picking up speed and I dialed back the throttle stop to 2000 rpm and let it run until the headers started smoking. Sounds pretty good I think. I'll go back out in a bit and get set up to pull a datalog and let it run long enough to warm up a bit and then back off the idle, check the oil pressure, etc. Being a roller cam it won't need that initial break-in run.

In the end after some fairly intensive troubleshooting that mostly turned out to be duplicative the trouble ended up being those ground wires on the coil packs that I overlooked. Honestly, I meant to do that, I even planned out where they would go. Just slipped my mind. Kinda like finishing the battery end of the new alternator sense wire. All done now though. Looks like the old double-key issue is also gone.

Nothing quite succeeds like success as I always say.

[BlownMGB-V8]

Yesterday I pulled the LS style rockers and ordered new pushrods from Smith Bros. With the .020" orifices (smallest they make) it was a special order and I went with the .116" wall tubes, figuring a few bucks more now was better than a lot more later. Should get those in about a week. Prices have gone up though, they will end up costing me somewhere around $380. For a set of pushrods. Ouch. If you figured in shop time I think we might have passed the mystical $20k engine here. I obviously didn't keep track and don't want to know. The way the numbers work out though, it probably does make sense to just buy the right lifters from TA to start with. As I understand it the choices are Johnson and Morel and the Johnsons are premium with much more attention to detail and of course a higher price. Also a fully shrouded lifter which makes no difference until you get into the higher lift. For awhile there axle failures seemed kinda common on Morel and reports of swarf inside them. But the Johnsons are a couple hundred more at about $900. The pushrods otoh are a quick fix by just pulling the valve covers instead of the intake and do the same job, so the Johnsons when building the engine, the pushrods after it's built. I don't think it really makes financial sense to use the comp cams lifters and plan on using the restricted pushrods.

So anyway I noticed some scraping of the pushrods at the guide plates so I pulled those off and rounded the edges of the notches using the 1" belt sander. Those were punched plates and had sharp corners that were digging in. Now they won't. I'm glad I found that now before they could start adding metal to the engine oil. Those plates are needed with the stud type rockers. Their job is to keep the roller tip centered on the valve stem. Without them the rocker can rotate until the tip drops off, the pushrod hits the side of the hole in the head and the valve quits opening. But that means there is constant contact between the pushrod and the guide plate which is less than ideal. One more box ticked for shaft rockers. Admittedly though the stud based adjustment is quite nice, and is practical to do in an idling engine. WAY easier than the pushrod end adjustment. For that reason alone the stud based rocker can be justified.

I just about have my VCMscanner configured, I was lucky enough to find the most recent (2022) xml file and a math file with the Autometer WB setup and I'll be sorting out the details like sampling rates and such over the next few days. Should be ready to roll by the time the pushrods come in. The initial tune fired up and idled ok if perhaps a little fast on the idle so I may need to block off one side of the PCV vacuum. I have one port on each side using 2L valves but that may be too much. Easy enough to block off one side though. Then charge the AC and go tuning.

Jim