This evening we spent some time working with the brand new forged crankshaft that's just become available for the Big Block Ford. The lack of a moderately priced forged crankshaft has been a problem for these engines until very recently and this crank is designed to fill that void. It's designed to be a basic solid piece for moderate racing applications. It does not feature any radical lightening, knife edging or any custom features but it does have all of the rod throws drilled with lightening holes and counterweights designed for easy balancing. The forging will work in a production block with no clearance issues and it has elliptical shaped counterweights that will clear with a 6.700 or longer rod with no interference what so ever.
Wes Littrell's 557 was originally built using the Scat 9000 series cast crankshaft with Big Block Chevy size(2.200) rod journals and a 4.500 stroke. His engine uses a Venolia piston and aluminum rod(6.700 length Venolia) and has a bob weight of 2112 grams. The engine is fitted with a set of TFS A-460 heads and it produces 900 horsepower at 7000rpm. Knowing that the 9000 series crank while quite strong is somewhat marginal at this power level, Wes decided after a season or two of drag racing to replace the cast crank with one of these new forged pieces. This crank is forged and machined in China and is available from several sources here in the the United States. Wes bought his crankshaft through Brian Adams at AD Performance in Shamanish WA.
The crankshaft was carefully inspected after it arrived, it was checked for journal size, roundness, taper etc. after which was trial fitted into the engine crankcase where it fit without any interference problems, clearing the piston skirt and wrist pin at BDC easily. The crankshaft or at least this example is sized within spec but slightly on the "high side", this would be fine with normal bearings for more moderate power and rpm levels but for this application the bearing clearances were a bit on the tight side so a set of "X" bearings were purchased. These bearings are available from Clevite, Federal Mogul and others and are designed to give an extra .001 of bearing clearance for performance, racing and high rpm applications.
In the above picture you see three different Big Block Ford crankshafts, all 4.500 stroke. The crank on the left is the new forged piece available through AD Performance(Ph# 877-273-0005) and other sources. The crankshaft in the middle is a billet piece from Scat and finally the crankshaft on the right is a Scat Series 9000 cast piece that had been used previously in Wes Littrell's 557.
Balancing proved to be quite easy with this crankshaft and bob weight. The Scat 9000 series crank we're replacing took 3 pieces of heavy metal, 2 in the back, 1 in the front in order to balance with the 2112 gram bob weight. With this new forged crankshaft no heavy metal was needed saving time and money. The counterweights had no drill holes when we started and they are placed correctly for easy balancing.
This crank was the 4.500 stroke version that had been trial fit in Wes' 557 production D1VE block engine. This crank fit without problems in the production block but there have been some minor reported problems with using it in the SVO A-460 block due to that block having slightly wider main webbing at the bearing housing bore. This can be fixed easily by milling about .010 off of each side of the main saddle. Measuring each of the crank we had on hand at the shop in this problem area shown in the above pictures with a snap gauge produced the following widths. Forged crank 1.126", Scat 9000 Series cast crank measured 1.140", and Scat billet 1.225" width. From what is known, the Scat 9000 Series cranks fit the SVO A-460 blocks without interference, having .015 more width at the journal is all that's needed so taking a very small amount off of the block is an easy fix for the problem. It is not known if there are any clearance issues on the IDT Eliminator blocks at this time.
Now the finished crankshaft is balanced and ready to go into Wes' 557 inch drag racing engine. LINK TO EX-514 headed 557 Ford Engine Buildup