CHI Cylinder Head Innovations

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On a Promise

Photos and Article courtesy of Street Machine Fords Magazine


Street Machine Fords article
Choosing Products for an engine build is just the beginning. The real task is making it all work together.

For decades people have been building various engine combinations in the pursuit of more horsepower. Engine builders have developed preferences for modifications, tune and components, and the result has been new performance products incorporating these developments. These parts have made it possible to build powerful combinations using readily available, of the shelf parts.

So can a everyday enthusiast with no specialized experience like porting, assemble a solid high horsepower engine? The answer is yes and no.

It’s just as easy to mismatch parts as it is to build the correct combination. But even when you have the correct parts package you cannot just slap it together. Proper machine work, assembly and lastly tuning, need to be applied to extract the potential of the combination. With that in mind, this combination was built with ease of obtaining results in mind.

As such this large capacity World Products – CHI Windsor small block, requires no trade secrets to produce over 700hp!

Coming on Strong

Starting with an aftermarket block rather than working with an OE factory unit is a good idea. The World Products version we are looking at is both thicker and thus stronger the OEM unit. Additional material in all the critical places ensures these blocks will not distort or move in these high horsepower applications.

Extra material around the bores, allow for increased serviceability, as they can be re-machined a greater number of times if necessary.The only downside to this, is a little extra weight, that is more than compensated for, by durability.

Another feature that makes the World products item superior to the OEM pieces is its priority main oiling system. Furthermore the Man O War comes with four bolt registered steel main caps with studs and splayed outer bolts. To finish it of, the main tunnel is finished to size. Clearances should always be checked, but you can bet that the staff at World Products has got it right.

Now its just a matter of filling the block with all the right parts. To achieve this the bores, which are semi finished from World, need to be bored and honed to their final size of 4.125″ in order to accept the new JE custom pistons. A standard weight Eagle crank with a stroke of 4.00″ is used to create a displacement of 428ci.

Eagle was also chosen for the H beam standard weight rods that measure 6.125″ long carrying the JE Pistons with a pin height of 1.071″. This equates to a deck height of 9.196″ which is just shy of the 9.200″ deck height of the block, allowing for a final deck surface to bring the pistons to the all important zero deck height.

Leave them alone

This package revolves around a pair of unported 3V 225cc heads. The heads as used in this combination have 70cc CNC machined combustion chambers and are fitted as per our website Competition Roller Cam Packages. The Nextek springs are setup at 300lbs on the seat and 800lbs at maximum intake lift of .750″. Compression is a stout 12-1 and runs fine on premium pump fuel with the selected cam timing. Pump fuel was chosen as this is the requirement at the Engine Masters competition, and meeting this requirement when presenting a combination that was easily accessible to customers was important.

To cope with the generous spring pressures T&D Shaft Mounted Rockers were chosen. Double tapered 7/16 pushrods from CV Products were chosen to transmit the cam profile accurately to the T&D Rockers and take the strain of the Nextek springs. The valve train components were chosen to suit the cam profile which is a TK Series Comp piece of around 260 @.050″ on the intake and is available from CHI when purchasing the heads and manifold. Cams are available for all types of combinations to suit all the CHI range of cylinder heads.

True Believers

There has been some controversy as to whether or not this type or size of cam, mated to unported heads can produce over 700hp. Cam selection is a crucial part of any combination and when purchasing from CHI you are drawing on many years of experience with some of the worlds most experienced engine builders. Adjusting the cam was the responsibility of the new CHI Time-Right Small Block Ford Belt Drive system. The unit used on this engine is the test bed for features to be finalized in the production versions.

Fitting Cleveland Cylinder Heads to a Windsor based block requires a few small cooling system changes. The machined 1.000″ diameter water transfer holes on the intake side of the head deck need to be plugged with frost plugs – welsh plugs. The cylinder heads accessory ends come machined with ¾ NPT water transfer holes to suit the CHI water crossover unit, which connects the engines cooling circuit and holds the thermostat.

Although not the cheapest way to build a stroker, the results are predictable and can save you a lot of money whilst experimenting to achieve a similar result. All the best parts still need someone competent to tune this style of engine.

The weight of it all.

The XW falcon that houses this combination has since edged closer to a 9sec time slip. With a best run so far of 10.04 @ 136mph its only a matter of time before the 9sec time slips come.

When spending your hard earned $$$ on cylinder heads and engine combinations, going with a well proven engine combination or cylinder heads and cam selections for your new motor from a company that tests and proves its products makes good financial sense.


A well thought out World Products based combination will make over 700hp on pump gas
Photo 1: Assembled correctly, a well thought out World Products based combination will make over 700hp on pump gas.
A World Products Man O War 9.2" deck block
Photo 2: A World Products Man O War 9.2″ deck block, provides the basic building block for this combination. The Man O War Block includes many superior design features over other aftermarket blocks. Notably, the oil galleries are.500″ as a standard feature.

These high density iron blocks feature siamese bores for increased strength and rigidity
Photo 3: Another great feature of the Man O war block is they are pre-notched from the factory to clear wide rods, allowing the possibility of 4.250″ stroke crank and 470ci!
Photo 4: These high density iron blocks feature siamese bores for increased strength and rigidity. The coolant jackets did not go without attention either, and they feature increased coolant volume as well as flow capacity for improved cooling.
Photo 5: All these features come in a very attractively priced package when you consider the Man O War comes with Steel Caps, Studs and splayed outer bolts.

CHI 3V 225cc Cylinder Heads
Photo 6: 3V 225 Heads have been proven time and again at the Engine Masters Competition since 2002. For the purpose of this exercise the 3V 225cc units were used as they would be supplied to the end customer.

CNC chambers are supplied with all cylinder heads
Photo 7: CNC chambers are supplied with all cylinder heads and these come in at 70ccs for a final compression ratio of 12-1. Although high for pump gas this works well in this combination.

Complete Roller Assembled Heads
Photo 8: Valves are 2.150″ on the Intake and 1.650″ on the Exhaust. Complete Roller Assembled heads come with Nextek springs, Manley Titanium retainers, Manley 10 Degree Locks, hardened spring locators and Viton seals.

ARP fastener
Photo 9: ARP is the fastener of choice for this build.

1.8 Intake rockers were chosen with 1.7 for the exhaust
Photo 10: 1.8 Intake rockers were chosen with 1.7 for the exhaust. A check of valve geometry required a different pushrod length for the intake exhaust. These options do not affect the price of either the rockers or pushrods.

The 4500 series manifold is designed to compliment the 3V 225 heads
Photo 11: When ordering a cam from CHI the cam will come with valve an intake closing event that will ensure the engine builds good dynamic compression. Although this event can be dialed in with chain set, the CHI Time-Right Belt Drive Unit, makes for easy timing adjustments when chasing the very best result from your combination.
Photo 12: The water pump was a electric unit from CSR
Photo 13: The 4500 series manifold is designed to compliment the 3V 225 heads and like the heads have been tested time and time again at the Engine Masters Competition since 2002.
Photo 14: Custom JE Pistons are the choice for this combination and CHI can organize your next set of JE custom order pistons for you.

The Eagle rotating assembly
Photo 15: The lifter bores have bosses cast into the block between each pair of lifters for extra plumbing in highly stressed combinations. The Man O War blocks have all the features you could want from an aftermarket block.
Photo 16: The Eagle rotating assembly is made up of a standard weight crank and rods. Rods were ordered with a rod bolt upgrade. The block will handle even more stroke for those looking at larger cubic inch Small Blocks
Photo 17: There is a number of 4.000″ stroker Kits available for these combinations. Eagle was chosen for their consistent sizing and quality control.
Photo 18: The engine is internally balanced and utilizes an ATI balancer to keep things in check.

custom Pro Systems modified 4500 Series Holley
Photo 19: Mellings Select oil pump was chosen for distributing slippery stuff.
Photo 20: An appropriate sump maintains a ready supply of the vital fluid. This ones is a locally made Russell unit.
Photo 21: This package made 740hp and 638ft/lb of torque. The engine needed a 2.000″ spacer that was made by CHI. Without the spacer the figures were down a little. This will vary between different combinations.
Photo 22: A custom Pro Systems modified 4500 Series Holley was the choice of carburetion.

this combination has run 10.0 @ 136MPH whilst hauling 3540lbs
Photo 23: Awaiting fitment into the XW Falcon, where this combination has since run 10.0 @ 136MPH whilst hauling 3540lbs.