dwwebste

I recently bought an 84 Camaro z28, 305 carb, 5sp manual. I am looking at a vortec 350 this weekend. I am not sure what model year or what it came out of, but my guess is a chevy truck. It currently has a carb sitting on it as well. Supposedly ran 6m ago when it was pulled, and has been on an engine stand since then. My thoughts are if/when I get this engine, before installation, I will replace: front seal, timing chain, cam, head gaskets, and rear main seal. I have new valve covers, intake, and carb I'm swapping over so those are being replaced as well.
What else do I need to worry about and watch for? Anything I need to know before looking at this engine?

Thanks!

8t2 z-chev

If engine is a true Vortec it will be standard production trucks 1996-98 and certain models up through 2002. I would be tempted to do some basic checks on the engine and then install in the car for a proper test run '86-and newer engines have different crankshaft flange,so later model flywheel will be needed.Also ,IIRC,Vortec engine has no mounting for engine driven fuel pump, and Vortec specific intake manifold will be needed because of mounting bolt and intake port location difference vs earlier SBCs. I think the Vortec engines used a plastic timing cover,so that could be a sign engine is a Vortec when you look at it.

sofakingdom

iTrader: (1)

Yes that motor would originally have come from a truck or van. Doesn't really matter too much anymore; motors have no memory of the sheet metal they started out their life wrapped in.

You'll need a different flywheel. Your 84 one won't bolt up. Get one for 87 - 92 305. There might be 2 with different weights, probably around 16 lbs and 22 lbs. You'll probably want the lighter one.

Make sure the distributor you use has vacuum advance on it.

Watch out for interference between the outer edge of the timing chain and the timing cover bolt bosses on the block. You might have to grind a bit off the block, depending on what chain you use.

You might need a different crank damper and timing cover. Depends on what's on the new motor now. You can re-use your 305 ones on the new motor if they're still good. Watch out for mis-matched timing marks on the crank damper vs timing cover if you use ANYTHING that's not a stock matched set.

REPLACE THE VALVE SPRINGS. There are NO ifs ands butts or maybes about this. If they're still stock, they're not really enough for the stock truck cam to begin with, and COMPLETELY inadequate for ANY aftermarket cam. I'd recommend using LS6 ones or even PAC1218 if your new cam has more than .500" of lift, such as from Texas Speed, with the Comp 787 "adapter" retainers and the appropriate keepers and shims to obtain about 1.800" of spring installed height.

Not sure why you're replacing the valve covers, unless the ones on the new engine (the 84 ones won't fit of course) are not stock and you're putting stock ones back on. All you'll accomplish that way is to cause potential trouble. There's no "there" there. Stock ones are just fine.

Tom 400 CFI

Pump flange is there on a Vortec block....the hole for the pump push rod is not drilled.

Correct on the plastic timing cover (w/provisions for a crank sensor).

dwwebste

The Vortec engine is complete other than missing the carb. I plan on keeping all the parts on there (including timing cover) so I'm not worried about that. Thanks for the flywheel info. A lighter flywheel means quicker off the line but the speed falls off more quickly, correct? Since this will be a daily and not a speedster, is the lighter flywheel still recommended?
I have a Summit 1102 cam that I was going to put into the 305, so I can return it or install it in the 350. Thoughts?
I have Edelbrock valve covers that I bought for the 305 but have not installed. So I may be able to return them (if I can find the dang receipt) or if would they fit on the 350, I could use them there.
Thanks!

Tom 400 CFI

Don't over think this, as the difference in real life is marginal at best, -though people will argue one side or the other to the end of time, use hyperbole to make their points, and provide no actual data.
"Flywheels stores more energy! Launches the car better!"
"Makes DD'ing the car much easier!"
-among other claims. Or:
"Less rotating mass = faster acceleration!"
"Gets the engine into it's power band quicker!"
-among other claims (made up, or somewhat real)


I've had both; A CTS-V with a ~40 lb (!) flywheel, my current "Vettes both have ~37 lb flywheels, and I've had an F-Bod with an 11 lb fly wheel. That is quite a large range. The engine will accelerate more quickly with a lighter flywheel. How much more quickly? Depends on the engine and flywheel. SUBJECTIVELY: Both 'Vettes however, have incredible throttle response and dyno'd at the top of their respective ranges (for what they are). The Caddy had soggy throttle response, but I attribute that to the lazy E-throttle and stock tune. A lighter fly wheel will also facilitate engine decel, on clutch-in during shifts. The car I had w/the 11 lb flywheel did this so much, that to have smooth seemless shifts in casual driving required a very slight throttle input (keep the throttle cracked) while shifting, or the RPM would drop off too fast and make for a lurchy (decel) clutch release.

A heavy flywheel will help reduce engine stalling, help "launch", but only slightly. If you don't know how to drive a stick, you can still stall a heavy flywheel car and botch a launch. Knowing how to use a clutch here, is 98% of the "gains", and the added weight of a heavy flywheel would help w/the remaining 2%, or so. I could 1.8 60' my 11 lb flywheel car on street tires....I can 1.9 60' my smaller displacement, 35 lb flywheel same gear/same weight car. Very, very small "gain". ...and my heavy FW cars can still benefit from slight throttle crackage when casual shifting.

After full clutch engagement, there is no point where a lighter flywheel will have a disadvantage to a heavy one. It will always accelerate faster, it will never cause speed to fall off, during acceleration, compared to a heavy FW. How much "faster"? Depends on the combo, but probably an unmeasurable amount. The benefits of the lighter flywheel diminish with increased speed, simply b/c acceleration also diminishes due to higher gear ratios and more drag. With a slow rate of engine acceleration comes less opportunity for the fly wheel (or any rotating mass), to affect a meaningful "gain".

Having shared some objective and subjective comparisons between an 11 lb FW and a 37-40 lb one(s), let's remember that most F-body flywheels are ~20 lbs, so the diff between a "heavy" F-bod FW and a "light" one, is still smaller than the pretty meaningless diff that I just shared. Remember too, that after the FW, you'll still be bolting a ~20 lb clutch PP and disk on to the FW, effectively doubling the weight of the flywheel, anyway.

That was a lot of typing to simply say, "buy the most practical, affordable flywheel available, and it'll be fine."


Personal choice. That cam will work fine, but it's not much more than stock.


They won't fit. You'll need center bolt valve covers.

dwwebste

That was an amazingly thorough and understandable explanation of the flywheel weight and how much it may or may not have an impact. Thank you!
I think I will return the cam to Summit and hope I can find the receipt to AutoZone for the valve covers.

I'm gonna slow down and focus more on the cosmetic work on the car for now and slowly build out this engine, but just as a daily.

David

BBCSwap

If you bought them online both will have a record and returning will be no problem.