from the editors of:
GM High Tech Performance
LOG IN / SIGN UP
GET THE MAGAZINE
tech & how to
engines & drivetrain
Chassis & Suspension
paint & body
Best of the Best
GM High Tech Performance
Horsepower On A Budget - By The Numbers
318 Ponies For Less Than $2,300
Feb 12, 2007
View Full Article »
VIEW FULL GALLERY
Horsepower On A Budget - By The Numbers
All in one package: this 350 engine kit included a fully machined four-bolt main block and virtually everything to make a complete engine. The only things missing before we went to the dyno were a distributor, carb, and valve covers.
The cast crank is ready to drop right in the block. This arm is definitely good to 400 ponies with no problems. The only thing Bob and George recommend doing is to give it a complete cleaning before dropping it in the main saddles.
In today's world of mega-power small-blocks cylinder heads are king. What you get in this package is a basic set of cast-iron heads with 2.02-inch intake and 1.60-inch exhaust valves. Big combustion chambers coupled with flat-top cast pistons keep the compression down to around 9.0:1, which means regular unleaded and no detonation.
To Bob and George, there is nothing more important than cleanliness and attention to detail. Before any part of the rotating assembly gets plugged into the block, the case receives a complete cleaning...
...as does the crankshaft.
With the upper half of the main bearings all lubed up...
...and in the block's saddles the crank was dropped in place. At this stage, there was no grease applied to the bearings in the caps, since Bob wanted to check bearing clearance prior to torqueing the crank in for good. Note that this block uses as two-piece rear seal, which is generally considered more desirable in performance applications.
Unlike most assembly jobs, Bob chose to use readily available Plastigauge rather than set up his dial indicator and calipers to check bearing clearance. The old standby, which has been in every engine builders tool box forever, works just fine when you're trying to keep costs down. For a couple of bucks you'll have enough to do all the bearings and then some.
Once you've laid out a small piece of Plastigauge across the radius of the crank journal the cap and bearing are simply torqued to spec and then removed.
A small part of the Plastigauge's packaging acts as a measure to show what the squished material translates into bearing clearance.
With confirmation of the correct bearing clearance, the next step was to torque down the main caps. Making sure the bearings have enough lube is important prior to breaking out the torque wrench. Note that Bob also applies a little sealant to where the rear cap sits in the block. This helps prevents oil from seeping past the cap.
With a basic engine kit such as this one from Wayne's the ring set is essentially pre-gapped. That's assuming of course that the cylinders are within tolerance after being machined. It probably wouldn't hurt to put a first and second ring into a cylinder and check the gap with a feeler gauge before putting them on the pistons and slipping them into the block.
We did and all looked good here, so in went the cast flat-top slugs with one of the only specialty tools that was used during this build-a tapered ring compressor.
As with the main bearings, a small strip of Plastigauge was used to determine if the rod bearing clearance was within spec. Sure enough, low tech tool does the job again.
With all the pistons and rods in their respective cylinders Bob wanted to determine top dead center (TDC) before the cam was installed. Here, a makeshift tool consisting of a 1/2-inch piece of steel that is attached to a cylinder head bolt hole with a tapped hole and a bolt at the other end was used to determine when the piston was up in the cylinder its highest.
After reading the cam card attached to the box, the small performance cam was lubed and installed straight up. That means that Bob simple bolted it in place at zero degrees. No degree wheel was used, either.
The timing set consisted of a set of steel gears and a double roller chain. Good parts here, for sure. The crank gear did have three keyways cut in so if we had wanted to change he position of the cam by a couple of degrees plus or minus we could have.
Making sure the quality nuts and bolts from ARP and Specialty Fasteners did their job meant using the correct torque specs and a thread locker when necessary. Here LocTite is used to provide a level of security that the bolts holding the cam gear in place stays put even when the engine is revved to 5,000 rpm.
The same theory applies to the high-volume oil pump and pickup that were installed in our small-block.
Bob took the extra step of putting a small tack weld on the tube where it goes into the pump's housing. Otherwise, the press fit may vibrate loose and if the pickup falls off the engine could starve for oil. And once the oil pan, which was included in the kit, is installed, nobody wants to have to take it off, especially if the engine is in the car.
Another high-quality part that is included in the 350 engine kit is this aftermarket all-steel harmonic balancer. Stock balancers have a rubber ring insulating the inner and outer steel rings that can rot and dry out allowing the balancer to come apart. Not a good thing for either you or your car's engine. Using the correct took to install a balancer is a must, as is a correctly torqued bolt and washer helping to hold it in place.
With the short-block assembled, Bob turned to installing the stock-style cylinder heads. Today, the better the heads, the more power. But that all comes with a price. For a good performing street engine such as this a basic set of small port, big combustion chamber castings are enough. With all new parts including stainless 2.02-inch intake and 1.60-inch exhaust valves there will be plenty of torque to get your car moving fast.
Another area Bob is vocal about is sealing. Many who assemble their own engine forget or don't realize to seal the threads of the head bolts that go through into a small-block's water-jacket. If you don't do this the potential for a leak that will eventually lead to a blown head gasket is pretty good.
Use some sealer then make sure the correct torque specs are adhered to.
This package came with hydraulic cam and lifters. To let the lifters fill up with oil you can let them sit in a tin can filled with 30-weight overnight. But in this case, Bob used an oil pump primer in an electric drill. This gave the oil pump enough time to prime all the oil passageways.
As for making sure the tips of the pushrods are lubed before assembly, a little dab of assembly grease works here.
As critical as making sure everything inside the engine is lubricated properly, is doing your best to prevent leaks. Here, with the intake gaskets in place over the ports Bob uses common RTV silicone sealer in a tube to create the intake manifold's end gaskets.
Proper installation of the manifold is a must and letting the silicone set up is important. The polished aluminum dual plane intake manifold used on our engine was designed for a Holley four-barrel.
Note the trick intake manifold offset washers used. With slotted middle holes for use with different cylinder head combinations, these washer inserts allow the bolts to correctly tighten down the manifold and hold it to the head.
Here it is. This is what you get for around $1,800. This near-complete engine features all new (pistons, bearings, cam and lifters, etc.) or machined parts (such as crank, rods, block, and heads), plus a few aftermarket performance parts like the aluminum high-rise intake, balancer and chrome timing cover. For the money you can't beat kits like this, especially if you want to build it yourself.
For our test engine we added a cool HEI distributor from MSD. This item is a basic bolt in and not only looks great but has the spark to help put down some potent horsepower numbers.
Although this type of engine was pretty non-responsive to carb changes, depending on what application you are going to use it in (manual trans, automatic, heavy car, etc.) you could get away with a number of different fuel meters. For the dyno session Bob chose to use a Carb Shop-prepped 650-cfm double pumper. However, a vacuum secondary 600 would probably be just as responsive and perhaps even save you a little on the gas bill.
When all was said and done, we definitely hit the number. While there was no predetermined horsepower figure we were looking for, we'd have to say that for the money (or lack of) we hit a home run with a best pull of just under 320 hp and right at 370 lb-ft of torque. And when we looked at the dyno sheets and saw low oil and water temps, great vacuum, and low fuel consumption, we could only think of one number-and it was the winning one.
Horsepower On A Budget - Tech Information - Super Chevy Magazine
Good quality on a budget - that was the goal as we build a reliable, street-worthy, small-block Chevy using new parts for less than $2,300. - Super Chevy Magazine
440 LSX Bowtie Iron Block Engine Build - Comp Cams Camshaft - Super Chevy Magazine
Check out this 440 LSX Bowtie Iron Block engine build with a Comp Cams camshaft, a Fast intake manifold, Trick Flow cylinder heads and Mahle pistons - Super Chevy Magazine
Budget LS Engine Build - Affordable Gen IV Small-Block Assembly - Super Chevy Magazine
In this budget LS engine build we mix and match GM Gen IV small-block parts to build an affordable, 6.0-liter L92 powerhouse based on an LQ4 engine block - Super Chevy Magazine
402 Big-Block Rebuild, Part 4 - 1967 Chevrolet Chevelle SS - Super Chevy Magazine
We assemble the top end on our 402 and also discuss how to break-in a flat tappet camshaft in Part 4 of the rebuild of our Real World Street Big-Block! Stay tuned for the install of our 402 on a 1967 Chevrolet Chevelle.
recent how to articles
How to Install a Detroit Speed Inc. Early Camaro Coilover Conversion
1972 Corvette Scarlett Project Car - C3 Column Rebuild
How to Diagnose Cruise Control Problems
Lobe Separation Angle Explained and How it Affects Horsepower
Cam and Heads Add Over 100 hp to Small-Block - Mini Mouse, Part 2
subscribe to the magazine
Subscribe and Save 74% off the Cover Price!