The Stovebolt Site Forums The Shop Area Engine Shop Alright inline "experts" need some recommendations here...

Need advice on the following:

Best spark plugs for my engine.
Best spark plug wires for my engine
Timing suggestions for optimum performance.

Many of you know what I'm running but here it is again.

292 engine (Mexican made GM block), bored .060 over, Elgin cam (with .464 lift intake/.490 lift exhaust, 194I/204E @ .050 lift), Dynomax tube headers, GM HEI, Offy 4 barrel intake and Edelbrock 500 cfm 4 barrel. Only reused parts are oil pan and side covers. Head bolts, flywheel bolts, etc., all new GM. 4 speed GM manual O/D transmission.

One other question of curiousity - How necessary are the three dowel pins on a street application vehicle? I just bought three from the local Chevy dealer and rememebered they are a press fit. Since everything's been torqued down, I don't think I'm popping the crank out of my engine to have them pressed in. I'm wondering how necessary they really are.

All suggestions/recommendations/advice/warnings welcome. Thanks guys!

-ftyler

I'd start with an ACDelco plug that is one heat range colder than stock. The NGK U-groove plugs show consistant performance in my Dodge dakota with a warmed over 318 V-8. Gap either to .040"

Plug wire selection depends on whats out there for 292. A good set of silicon 7 or 8 mm wires will be fine. Accel makes a line of good 8 mm wires that are custom fit. Don't know if they have them for 292. Stay away from the u-cut to fit wires. The ends pull off when you try to change plugs. You may have to look at high temp wires or angled ends to fit your application.

Timing- start off with 8 to 12 BTDC. The base timing is about right when you can 'bump' the key and she lights off, without starter kickback. Shoot for a maximum of 32-38 degrees at 3,000 RPM. Get a good recurve kit and adjustable vac advance to custom-set spark curve. Then tune from there to see what the motor likes. I use premium in my car, so I add 2 or 4 more degrees of timing to take advantage of the octane. Connect vacuum advance to ported vac and see how the motor likes it.

Run a 160 thermostat. The motor may show a tendancy to run warm due to the .060" overbore anyway. Running the engine cooler may suck marginally more gas, but it'll have slightly better resistance to detonation caused by improper timing or carb jetting. It could also drop oil temps a few degrees too.

Make sure to read your plugs and tailpipe ends to make sure you're not running rich or lean. If your headers ever glow at night, you're running WAY lean. A really good headers/exhaust system can cause a lean condition by scaveging the unburned gas that was hanging around in the cyl waiting for the next sparkplug party.

Is your engine in car or on stand or what? If flywheel is off, you can sometimes tap the dowel pins into crank flange with a brass hammer and some care.

May I also suggest checking the whole cam-distributor-oilpump thing?

good luck

Chip,

After your experience, I totally understand your advice on the oil pump/distributor. Point taken.

My engine is on a stand. The one thing I wish I had was the bolt boss removed and bolt-in lump ports. Bet that would put me close to 275 HP.

I'm putting it in a '66 c10 - not a big heavy vehicle. Should be a strong runner.

Only question chiphead is why a brass hammer? Will the pins shatter with a conventional steel claw hammer?

All they do is help prevent the flywheel from coming loose from the crankshaft. No need to install them, just plan on pulling the driveline apart every few thou to re-tighten the flywheel bolts, assuming they haven't fallen out, sheared off, gotten jammed into the bellhousing, and/or chewed up the ring gear and starter. As the man said, pay me now or pay me later.

Think about it. The chronic weakness of any inline engine, especially a long-stroke 292, is loosening of damper pulley and flywheel/converter bolts due to torsional vibration, especially if you ever spin the motor at higher RPM than 4000 or so. Especially on a manual transmission vehicle, keeping these parts attached can be a challenge.

Anyone can make overlook something in building an engine, but to realize a mistake and avoid correcting it will always come back to bite you. Do it right the first time. All of the high performance stuff in that engine won't do you much good if you're broken down roadside, or underneath pulling the tranny to fix what should have been done in the first place.

I'd suggest any brand of wires that has the spiral core metal conductor. It's a big improvement over the burnt-string conductor.
I'm at 12 BTDC on my 250, and just on a whim I moved the vacuum advance line from ported to full and the engine is a lot happier, especially on the bottom. I haven't checked full advance numbers and I'll revisit it in the spring. When it's 5 degrees outside, I can get away with more timing and still have no death-rattle.

Reason for the brass hammer is to prevent peening the ends of the pins. Makes it easier to put on the flywheel. Zinc or lead will work, too.

FredT,Chiphead.

Points well taken guys. One end of the dowel pin has scribbling or "scripting" on it while the other does not. But both ends appear tapered the same. Which side goes where?

I'll borrow or buy a brass hammer this weekend. I plan on securing the flywheel with Permatex Red (similar to Loctite Red).

Thanks guys!
-ftyler