Produces Over 105 HP* at the wheels "Out Of The Box". Not bad for a four banger that had 40 HP from the factory.

Several Optional: Side Plates,  Up & Downdraft Manifolds, Crank Pulley, Water Pump Adapter And Much More.

Proudly Made in U.S.A.

Full 30 day Warranty On Parts & Labor. I Stand behind every head built & shipped, Period! Charles H. Yapp

Simply, One Of The Finest Speed Products Ever Produced For The Ford 1928 to 1934 Model A & B

Riley Two Port SPECIFICATIONS

Note: most parts are fully interchangeable with original Heads

The Riley Two Port is a faithful reproduction of the original Riley Dual-Valve-In-Head made from 1929 to 1932 for the Model "A" & "B" Ford. Our new model is the rare 1929 "first version", with the spark plugs on the driver's side. The Riley Two Port is a powerful, efficient and reliable 12 valve OHV "F" head (8 intakes in the head and 4 exhausts in the block) that more than doubles the horse power, runs cooler, gives better gas mileage, accelerates like a motorcycle (sm), is fully oil pressurized, fully adjustable and fits under the hood without modification. Because it is authentic cast iron, you will not have adverse corrosion or expansion problems like you would with a soft aluminum head.

Your Block: For normal road driving and cross country touring, use a stock Model "A" or "B" Ford four cylinder block (1928-1934). The block should be rebuilt. Babbitt bearings are fine, insert bearings will last longer. Use the stock oiling system and rods. We recommend a counter balanced crankshaft and a metal timing gear. Your exhaust valve train, and four intake adjustable tappets must be in place.

COMPRESSION RATIO: All R2P heads are now delivered with a 1/16" deep circular fly-cut above the cylinders. This is to help insure that pistons do not touch the combustion chamber. The fly-cut depth also controls compression ratio and cc's of chamber volume. We offer a 136cc version with a 1/16" fly-cut depth (+ - 7:1CR @ standard bore) and a 151cc version with a 1/4" fly-cut depth (+ - 6.5:1CR @ standard bore). The thickness of the gasket plus the fly-cut should give adequate clearance, but the owner must double check this piston to head fit prior to use. Some engine rebuilds have the pistons higher than flush with deck, which increases CR. Oversized cylinder bores increase CR. Example: our 136cc version is 7.36:1CR @ .080" overbore, with flat top pistons, flush with deck and our gasket. Our 151cc version is 6.8:1CR @ .080 oversize. PERSONALLY: I think the 7:1 is the sweet spot for HP and performance. 8:1CR doesn't show much dyno gain on the street. 6:1 is there for you if you need a physiological edge or have an older engine.

Customers needing higher CR's can order head without a fly-cut and a re-decking up to 3/8" milled off.  Ratios approaching 10:1+ are possible.

Customers needing lower CRs  will need to machine material off each piston's top or obtain pistons with custom pin centers or have rod bearing center changed. 

Combustion Chamber: Roof surface is now partially machined to improve CR accuracy and appearance. Surface is "blanchard ground" for extreme flatness.

Wire Groove: Each head is grooved 2-1/4" between cylinders 1 & 2 and 3 & 4 for a stainless steel FIRE WIRE to improve gasket clamping.

Head Studs: Special length (3 different) studs are grade eight rolled threads. The very best available. Nuts are grade eight. Our studs are custom made in the finest grade 8 materials available.

Camshaft: A Model "B" camshaft is excellent for most touring, near stock idle and fast road driving. Our "Scalded Dog" camshaft special regrind for surprising highway, touring and hill climbing performance. Almost any performance cam grind can be used, but those with stock or just slightly more lift at the intakes and 355 degrees (+ -) of duration seem to work best. Remember the Riley uses two intakes per cylinder, so lift, while very important, isn't as important as in a flathead.

Intake Port Covers:

We supply two per head, aluminum "port cover" that read "RILEY", can be polished. Used to cover unused intake ports on side of the block.

Exhaust Manifold: Use the stock Ford cast iron exhaust manifold or a "flathead" type four tube exhaust header.

Springs: Model A, eight per head. Normal stock tension.

Keepers: Modern 2 pc lockers.

Valve Guides: Modern one pc solid bronze

Valve Plugs:

All heads are now supplied with four billet aluminum Valve Plugs. These are to be press fit into the valve guide and old valve seat of your block. The final installation is usually done by a machinist, at the time the block is decked. The Plug should be either dead flush with engine deck (machined with deck) or "just" below the deck with engines that have already been decked. These optional use Plugs improve oil return and give additional gasket support. When rebuilding the engine we recommend that hardened valve seats be cut for all 8 seats, but installed in the exhaust only. The new Valve Plug is then machined to fit the new valve hole and pressed in.

Our new tooling has the name "TWO PORT RILEY" de-bossed on the top in large clear letters that will not polish off. The gasket supplied is a quality "U" channel neoprene gasket. The covers are 3/8" higher than stock cover to give better clearance to the rockers.

Spark Plugs: Spark plug holes bored and threaded for 14mm, 3/4" reach, flat seat plugs. Not supplied. Start with a cold plug.

Adjustable solid push rods with 1/2" dia. adjusters. We make these from scratch. Our tappet seat bolts are supplied. You must supply "single locker" adjustable tappets.

Water Gooseneck:

Cast 356-T6 aluminum special fit around valve covers. Fits all years.

Distributor:

Each head is shipped with a "RILEY" Distributor Riser part, 356-T6 aluminum, fully machined and a longer distributor driveshaft. This extension will raise your Model "A" or "B" distributor up two inches so the stock "wing" caps and the Model "A" spark advance will clear the valve covers. Mallory, "FS Ignitions", magnetos and many other distributors with Model "A" machined shanks will fit. Distributor Riser must be sealed with silicone sealer between it and the head. No gasket, just a touch of sealer. A thin paper gasket can be fabricated if desired.

Oil Pressure: Each head is "trick" machined to feed low pressure oil to the head and rocker system. Oil returns to the engine block via the pushrod channels. This will effectively oil the R2P valve train along with the low pressure feed to the rocker shafts and rocker arms.

Every Buyer Must Sign a "Release and Hold Harmless Agreement" before head will be shipped. Copy sent on request.

WARRANTY: Yapp Studios, Inc. warrants for thirty (30) days that the workmanship and materials of the Riley Two Port are as represented. If the head is modified in any way whatsoever the warranty is null and void. When you receive your head, inspect it, if it does not appear correct, call us and we will arrange for a full refund, repair or exchange. This product makes increased horse power and is used as an automotive racing product, therefore no other warranty is expressed or implied. The warranty is non transferable. Having said that, be assured that we stand behind all our products and will get you on the road.