The Short-Block Build
Our block was in usable condition, so we were able to re-use it just by honing it. The block also needed to be pressure washed and cleaned up to remove all of the “metal” that had run through the engine. Our block is a 4-bolt main, but most dirt track racers look for the four bolt mains but, in all honesty, the two bolt mains have gotten a bad rap. For short track racing, the two bolt mains will easily handle over 500 horsepower with good durability. If you choose a two bolt main, changing to ARP main studs will practically guarantee an engine strong enough to handle 525 horses.
GM 4-bolt Engine Block, Machined to 4.030-inch
Our connecting rods were GM 5.7 inch rods that had been upgraded with ARP connecting rod bolts – a mandatory upgrade for an engine that will rev to about 6,500 rpm. We had good success with the parts used last year, so we got another set of KB flat-top cast hyper pistons. These are 2-valve relief pistons that feature a high silicon content which provides a better ring, piston to cylinder wall seal. Also, the two-valve relief design can help with achieving the allowable 10.5:1 compression ratio without overly having to mill your cylinder heads.
5.7 Inch Rods Upgraded with ARP Bolts
Keith Black 4.030 flat top cast pistons
One thing we decided to upgrade was the crankshaft. Last year we ran a cheaper cast crank and it bit us in the butt when it turned up cracked by the end of the season. In all defense to the crank, we did rev the engine to about 9,000 rpm by accident and keep our foot on the throttle. Yes, we know – not a good idea. The end result was damage to the some hairline cracks due to the stress of the over rev. That’s just what happens when you have a bargain priced crankshaft.
To upgrade for 2010, we talked to our friends at GM and upgraded to a GM 3.480-stroke steel crankshaft. This is the same crankshaft that comes in the GM CT350 crate engine. GM told us this crankshaft would provide us with a increased strength over the cast crankshaft, however it came at a price – weight. The cast crankshaft we were running last year was a full weight design, but it came in at about 50 lbs. The reason is that the cast material is less dense than steel.
GM 3.48-stroke steel crankshaft, 350 Chevy
The GM Steel 3.480-inch stroke crankshaft bulged the balancing scales at 54 lbs, which is 4 more lbs of rotating weight. It’s increased reliability – but the weight comes at the expense of a bit of horsepower loss. And because of the Street Stock rules at Victorville, lightening is not permitted. You must run a full weight crankshaft with no lightening of any kind permitted. It’s a large journal crank designed for 2.100 rods, so you’re dealing with a full heavy weight sucker. The only ways to lighten a crankshaft like this would be special knifge-edging of the crank, but you guessed it – not legal either. So, we have to run it in OEM form.
The GM steel crank is a good option you may want to consider if you’re willing to sacrifice a little power (say 4-7 horsepower perhaps) for an upgrade in reliability.
Another thing we did again was ARP bolts. We used ARP bolts for the block, as well as for the cylinder heads and connecting rod bolts. ARP hardware is really a smart investment. Why would you scrimp on fasteners when they have such a critical job in holding together your engine?
ARP Bolts (Complete Set)
Overall, the short-block was a simple and quick build involving quality parts. But the real power was in the top-end. But, as you can imagine, what is the critical link between the short-block and the top-end? That’s right, the camshaft. Even though we went with the Vortec heads, we were told by COMP Cams that the camshaft we were running – a COMP hydraulic flat tappet #280-AH, was still a good fit for our combination. We also selected the matching COMP hydraulic lifters, double roller timing chain setup, and COMP timing cover.
Oiling, Pans, Pumps & Balancers!
Milodon makes a nice circle track oil pan (Part #31513) that holds an extra quart of oil over the stock pans, and it fits nicely in the engine bay without interfering with crossmembers or tie rods. We have experienced holes punched in oil pans from the zerk fittings on oil pans that were not specifically designed to work in street stock classes.
Milidon 31513 Circle Track Oil Pan
Milidon 18750 High Volume Oil Pump
Milodon has done their homework on their circle track oil pans and we found no fitment problems plus you get other design features line a windage tray and baffles to control oil. We also selected the Milodon high volume oil pump (Part #18750) that is designed to work with this oil pan. The Milodon oil pump housing is a sturdy unit that won’t break. It’s rated at 40,000 PSI tensile strength which will hold up to any track, no matter how rough.
The TCI Harmonic Balancer and new Hi-Torque Starter were included in our build because of reliability and performance. TCI Auto has been manufacturing harmonic balancers for years, including the very popular “Rattler” harmonic balancer. Their elastomer harmonic balancer fit into this build perfectly by giving us a dependable balancer that would offer years of service without problem and was easy on our wallet.
The Top End: Going Vortec
In circle track racing, if the rules allow the use of Chevy’s Vortec heads, it’s a no-brainer and you should use them. Even with a spec head outlined in the rules, the choice of Vortec over the Stock Gen I SBC heads is simple because of the better performance of the Vortecs over the old school GM heads. We got a set of #062 Vortecs from GM new, and at a cost of only a few hundred dollars, that is much smarter than pulling a set of Vortecs out of the junkyard and hoping they work correctly. Remember, those cars in the junkyard are there for a reason.
GM #062 Vortec Cylinder Heads, 1.94 valves, 64cc chamber
The only thing we really did to the Vortec heads was mill them enough so that we would get 10.4:1 compression, slightly less compression than allowed by the 2010 Street Stock rules (max in 10.5:1 compression). That would give us some room in case there was a problem. The cylinder heads started out at 66 CCs before milling. After milling, with zero deck this gave us a compression ratio of 10.38:1
We believe in using components that are designed by the manufacturer to work with each other, so when we ordered our COMP cams camshaft, we also ordered most of our other valvetrain from COMP. The COMP Cams “High Energy” hydraulic lifters, valve seats, valve seals, pushrods, timing chain set, 2 piece timing cover and valve springs were a great fit for this project. These components are a staple for many engine builders, and we know based on the reports from these builders, that all of these parts work well together.
Due to class rules, we were required to utilize GM 1.5 stamped steel stock rocker arms.
GM 1.5 ratio stamped rocker arms
Our rules call for either the stock GM intake manifold or the Edelbrock Performer series manifold. We don’t even need to tell you that this really isn’t a choice. The Edelbrock Performer manifold is the only choice here. Edelbrock manifolds have been doing great on the dirt track for decades, and that isn’t likely to change anytime soon.
Edelbrock Manifold (Part #2116) is a dual plane low-rise design with 180° firing order. Idle-5500 RPM for most manifolds listed. Idle-6000 4-barrel square or spread bore carb flange.
Edelbrock Dual Plane Performer Intake #2116
Finishing the Engine
Capping off our build with Accel Ignition’s Pro Fit Ceramic Spark Plug Wire set and Accel Silver Tip Racing Plugs guarantees that we will still get spark even with the engine on fire. Seriously. The terminal ends on the ceramic plug wire set have been tested to withstand up to 2,000 degrees Fahrenheit. That means the driver can keep going even if the engine is an inferno. We added MSD’s soft touch rev control as cheap insurance against over revving the motor. These components will easily handle the stock GM HEI distributor and add to the reliability of our ignition system.
For our valve covers, we selected Proform Chevy Die-Cast Center Bolt Circle Track Valve Covers (Part #141-139). These are precision fit die-cast circle track valve covers feature a wide flange for a powerful seal, 1 3/8th O.D. vent tubes, and all necessary bolts and washers. Combined with set of Proform air breathers (Part #141-625) – these were a perfect fit for our heads.
We re-used our 4412 carburetor, but mounted a Spectre Performance Air Cleaner to help the engine breathe. The Spectre air cleaner housing is designed to center the air cleaner directly over the choke tower on 2 barrel carbs, and that is how the air flow is improved in our engine build. The Spectre air cleaner is made for 2 barrel carbs and features a high flow filter media that will also keep the dirt out.
We’ve installed this engine in the car and have made several runs on the track with great results. There is a a difference in acceleration in the cars performance down the straightaways with the Vortec heads and when you run through the rpm range. The only drawback to this engine build is that it highlighted areas that we needed to improve our chassis setup. Down the front stretch and back stretch, the car carries more speed than previously which has unmasked our setup for the corners. Aside from the chassis setup issues, the Vortec heads have improved our circle track program by orders of magnitude.
Fel Pro Gasket & Speed Pro Bearing List:
Head Gaskets: Fel-Pro .039 – (Part #1043) Pre-Flattened Steel Wire Ring Head Gaskets, The strength of steel wire sealing with minimum brinelling of aluminum heads. Bore 4.080” Thickness .039” Volume 8.2cc.
Oil Pan Gasket: Fel-Pro (Part #1881) H/P Oil Pan Gasket PermaDryPlus
Distributor Gasket: Fel-Pro (Part #70165) They are made of a unique composite material that works with cast iron and aluminum intake manifolds.
Water Neck Gasket: Fel-Pro (Part #2202) Water Outlet Gasket SB/BB-Chevy 1/8″ plastic/molded rubber.
Exhaust Mainfold Gaskets: Fel-Pro (Part #1444) Stock, steel core laminate gasket material. 1.380″ port height and width.
Rear Main Bearing Seal: Fel-Pro (Part #2912) 2 piece Rear Main Seal, Fluorolastomer
Timing Cover Gasket: Fel-Pro (Part #2335) Timing Cover Gasket, Rubber with Steel Core.
Vortec Intake Gaskets: Fel-Pro (Part #1255) Composite, 2.110 in. x 1.08 in. Port, .120 in. Thick, Chevy, Vortec, Set. Most Fel-Pro Performance intake manifold gaskets have Printoseal construction, which puts beads of special elastomers around the ports for extra sealing power. They also feature a non-metallic, rubber-fiber base material that resists gasoline and alcohol, while allowing engine builders to precision-trim around the intake ports.
Valve Cover Gaskets: Fel-Pro (Part #1648) cork with steel core. Thickness 0.250″ Cork-Lam construction utilizes a metal core with a cork-rubber material chemically bonded to both sides.
Cam Bearings: Sealed Power (Part #2100M) Solid Cast Aluminum high performance cam bearings. They feature high embedability and conformability and a special “sacrificial” design that enables the bearing surface to deform under extreme loads, preventing any wear and damage to the camshaft.
Rod Bearings: Sealed Power (2.1 journal) (Part #87100CH) Constructed of H-14 alloy . Duroshield coated bearings feature a micro thin unique enhanced molybdenum disulfide in a polymer base, the coating’s hyrdophilic matrix becomes part of the bearing, absorbing oil for high lubricity and low friction.
ARP Hardware List:
Main Bearing Studs: ARP Main Stud Kit (Part # 234-5601) Main Studs, 4-Bolt Main, Large Journal, with Windage Tray. These ARP main studs are made from 8740 chromemoly steel and have a 190,000 psi tensile-strength rating.
Rocker Arm Studs: ARP Rocker Arm Studs, High Performance, 3/8-24 in. Thread, 1.75 in. Effective Stud Length, Chevy, Vortec, Kit.
Rocker Arm Adjusters: ARP Perma-Loc Rocker Arm Adjusters (Part #300-8241) Rocker Arm Nuts, Stamped Steel Rockers, 3/8 in.-24 Thread, .620 in. Outside Diameter, Set of 16.
Thermostat Housing Fasteners: ARP (Part #130-7402) Thermostat Housing Bolts, Black Oxide, Hex. These ARP thermostat housing fasteners are designed to properly secure your water neck. They are available in black oxide chromemoly steel or polished stainless steel. The fasteners also come in your choice of hex head or 12-point and include washers to complete the installation.
Torque Assembly Lubricant: ARP Ultra Torque Assembly Lubricant (Part #100-9911) Assembly Lubricant, for Engine Assembly and Fastener Installation.
Distributor Stud: ARP Distributor Stud Kit (Part #130-1701) Distributor Stud, Steel, Black Oxide, 12-Point
Flexplate Bolts: ARP Flexplate Bolt Kit (Part #200-2902) Flexplate Bolts, Pro Series, 7/16 in.- 20 RH, .680 in. Length, Chevy, Ford, Set of 6.
Harmonic Balancer Bolt: ARP Balancer Bolt Kit (Part #134-2503) Harmonic Balancer Bolt, Chromemoly, Black Oxide, Square Drive, Chevy, Small Block, Each. 7/16-20 RH in.
Spark Plug Wires: Accel Pro Fit Ceramic Spark Plug Wire Sets – (Part # 9001C) 90 degree 5/8″ Hex plug boots w/ terminals for male and female tower caps (Universal, cut to length). The ceramic boots will withstand up to 2,000 degrees Fahrenheit.
Spark Plugs: Accel (Part #526) ACCEL Silver Tip Racing Plugs.
Story Courtesy of www.onedirt.com