It will give it a little longer life that's about it if your putting expensive after market parts in it a good idea to do it.

 

do it. If you don't, you might wish you did but by then its going to be too late to pull everything back apart and get it done.
I only built one engine I didn't balance, that was a 289. it did have a very slight shake to it at idle, but it smoothed out as it speeded up. With a bigger engine or a longer stroke it might be a lot worse. remember a 298 stroke is only 2.87"
Every other engine I have balenced and they were very smooth.

 

Its worth the extra money for the peace of mind that your engine isn't vibrating itself to pieces. It helps alot with the longevity of the engine.

 

$250.00 is a small price to pay for a smooth long lasting engine. Do it for sure.

 

Okay, I told him not to on Friday, but I'm thinking that I should probably reconsider that. We don't have the heads worked out yet at this point, so we haven't even ordered the pistons yet anyway. One of my buddy's just put a terrible idea in my head though; is ballancing something I can do myself? Isn't it pretty much just making sure the opposite piston and rod assemblys are of equal weight? Never having done that before it seems like one could easily do that with a ballance and a sanding drum.:shrug. Like I said, probably a terrible idea. It can't be that simple, can it?.:scratchhe

 

I think balancing a crank is like balancing a wheel, you need to rotate it quickly and a computer tells you where to add (for a crank remove) weight. I don't think this is a do it yourself job, but I've been wrong before...

 

Do it, you'll be glad you did.

 

It takes a machine to spin crank..Like stated above.

 

Okay, you guys have convinced me. I was unsure of what was involved, but spinning the crank never occured to me. Thanks for your help guys.

 

You will need the whole rotating assembly. The crank, with the flywheel and balancer bolted on and torqued down. Last time I did it the machinist also wanted the crank pulley and timing sprocket, but they have only asked me for that once

 

You might also want to consider a windage tray. If you're going all gonzo on the motor, may as well do it right all the way. I'm not trying to spend your money for you, but it's worth it. IIRC, they're not very expensive.

 

Okay, while I'm showing off my ignorance I may as well go for broke...what the hell is a windage tray?:brownbag

 

Its a metal plate with a type of screen in it that seperates the crankshaft from the oil in the pan. It keeps the oil from splashing back on the crank and creating resistance.

If you are building a moderate to serious motor or have a big budget, then go for the tray. If it is just a basic rebuild I would save the money for something else. The real benefits of a windage tray are with high rpm motors.

 

The real benefits of a windage tray are with high rpm motors.

Have you seen videos of his wheeling??? :rofl:

 

I think the windage tray might cause more problems than good on a wheeler where its possible to have the truck angled so far up or down that oil could be on the crank.....I don't know...seems like it might trap it up in there for a second instead of letting it run back down

 

When they balance it, they don't need to balance it to within a gram (or whatever ridiculous tolerance the racers have) They will weight balance your pistons, weigh the rods with a special machine, and remove material to make them the same weight at both ends.

Other tips/thoughts/suggestions
Have cylinder walls torque plate honed. The reason for this is because the process emulates cylinder wall distortion that the heads being bolted on causes. I've heard this can be good for up to 15 HP.
Wrap crank and rod journals with duct tape, Grind off any casting flash. The casting flash is a location that cracks tend to happen. Grind the area flat, it wont crack there (or so the theory goes) Don't hit your journals(hence the duct tape protecting everything.)
Chamfer the oil drain back holes in the intake valley, and head
Epoxy a thick wire mesh screen over any holes in the intake vally to catch anything that doesn't belong in the lower end. (this keeps crap out of the oil pan if something fails)
Specify ARP wavelock (or better) bolts when you have your rods reconditioned. Never re-use old/stock rod bolts.
Get your rods shot peened, and polished (grind off the casting flash on the sides)
having main studs will help your bottom end stay together better. You will have to get your mains line honed/bored. Supposedly it causes some sort of distortion???
Have your valve pockets blended to your seats
Use good quality stainless steel valves
Specify chromoly spring retainers, and 10* valve locks
An upgraded billet oil pump shaft is a definite bomus, a hardened shaft is a minimal, but important upgrade.
If your crank oiling holes are not already chamfered, have the shop do that as well.

 

Epoxy a thick wire mesh screen over any holes in the intake vally to catch anything that doesn't belong in the lower end. (this keeps crap out of the oil pan if something fails)

All good points, but this one I have always disagreed with

 

2000 miles a month?? Yeowsa, you must be rich to afford that much fuel. I would imagine that driving it that much would def. not cause gumming up, as hot oil/long trips does not leave crap everywhere like oil would on short trips. 100 highway miles are alot easier on a rig than five 10 mile trips. Nothing has a chance to burn off...

 

Not when you're pulling down 18+mpg :toothless

And truthfully she was driven as a DD for 7 years until the speculators gouged the crap out of us during Katrina.

Now my mileagemaster is my 90' Lincoln Town Car

Sixlitre

 

I work on fleet vehicles oil change every 3000 miles i see engines with 150k miles fords Chevy Dodge even detroit's. There clean a whistle inside 3000k that's the magic number.

 

Thats a dino oil interval. I go 5000 on synthetic.

 

I was thinking the screen thing was a chevy thing, I've also read to do that.
I would also get it balanced for all of the reasons listed, 250 sounds kinda high though it is only around 150 here.