Im wanting to build a 489 big block shevy and had a few questions. I have a stock 454 that is already bored .030. i was wondering what rod length i would need and would i have good valve clearance with the stock flat top pistons with the small valve releifs? Any info would be appretiated thanks
09-14-2012 08:28 PM
I was also wondering should i get a internal balanced or external balanced crank
09-15-2012 01:36 AM
Internal balanced cranks are usually preferred.If the power is reasonable then let your budget decide what route to take.Piston to valve should always be checked when assembling an engine.The HD 7/16 GM rods are pretty good.If you need better than stock, then check with carillo or crower or any other good manufacturer for rods.
09-15-2012 04:10 AM
Most stroker cranks require 6.385 rods. External balance is ok for a street/strip type motor. Otherwise it gets real $pendy quick, at balance time. As for valve clearance. Not knowing any specs on your motor.. Check on assembly.
09-15-2012 06:53 AM
I recommend that you buy a complete kit (crank, rods, pistons, rings, bearings).
But first, you need to know what size heads you have and what compression ratio you need.
09-15-2012 07:01 AM
Building a 489 stroker
When building a stroker motor it is usually best to purchase a rotating assembly. One first things to do is checkout your heads,(post your casting numbers)to know your combustion chamber size. Knowing the chamber size you can purchase your pistons for the compression ratio you want. Make sure the valves are at least 2.19 intake and 1.88 exhaust. You will not use your old pistons because the compression height is different on a stroker motor. Purchasing a rotating assembly is cost effective too. Here is an assembly from Summit Racing. Eagle Specialty Products B18021030 - Eagle Street and Strip Rotating Assemblies - Overview - SummitRacing.com. You will need to find a machine shop to do your block and head work. If you need help choosing a camshaft or any problems that come up you can discuss it with your machinist. It's a good idea to know if this motor is going to be a daily driver or a street/strip motor or strictly race. Know what kind of vehicle it is to be used in.