The history of the Formula Ford engine began with the English Ford 105E engine in 1959. That engine was used in Formula Junior cars and was followed by the 116E, the first five main-bearing version of which was the basis of the Formula 2 engines built by Cosworth. The one-liter Formula 3 versions turned 10,000 rpm typically and propelled the cars of many future F1 stars early in their careers. The original Formula Ford engines were from the Ford Cortina and, interestingly, originally cost under 100 pounds sterling. The later “uprated” or “Kent” engine used a heavier crankshaft, introduced the flush cylinder head and became the predominant engine used in Formula Ford after its introduction in 1971. In the United States, these engines were found in the ‘71 - ‘73 Pinto and also, with some variations, in the Ford Fiesta. As recently as the late 1990's, the 711M Kent blocks from '71-'73 Pintos could be found in choice salvage yards. The Fiesta version - casting number 771M - was made in greater numbers and even today, these blocks can be found in salvage yards and with minor modifications, can serve perfectly well. 

This incredible engine is a simple, sturdy, basic design which, when completely blueprinted and tuned by the best FF1600 engine builders, can typically put out about 117 horsepower. When maximized for use in Caterham cars and other racing applications, this block can be made to yield as much as 250 horsepower. Consequently, as run in a Formula Ford chassis and developing about 115-117 horsepower, there is plenty of reserve strength built in. Properly assembled, carefully balanced examples can turn over 7,000 rpm with no trouble and are bulletproof - as long as the flywheel ring gear doesn’t hit the race track surface! 

Because the engine preparation rules are extremely restrictive - essentially allowing little more than blueprinting - maximum power levels are "maxed out" and are achieved by means of meticulous machining and assembly. Reductions in friction are critical and, as with any racing engine, the machine work must be perfect. High quality balancing of the rotating mass is essential. Ring specs and preparation are also very important as are intake/exhaust port flow, ignition timing and carburetor preparation. High horsepower ratings - in the range of 115-117 hp - are achieved by a number of excellent engine builders across the US who have painstakingly developed preparation methods, modifications, prepared parts and various 'secret' techniques to get every possible advantage. Any racer expecting to make the front of the grid at Nationals or at the RunOffs will have engaged their favorite engine builder to build up and to freshen one or more engines. A complete, new National level engine can cost around $10,000. 

681F6015DA (or 6915) - Tall deck crossflow 1600cc
120E6015  - First five main block 1500cc
2737E6015B - Tall block version of 120E 1600cc
771M6015CA- Fiesta 1600cc
711M6015BA - Tall block, big caps 1600cc
831C6015B34 - Service block - South African casting.

Former block in SVO catalog. Quality questionable.
711M-6015-A-A - 1.3L

Buying a used engine can be tricky but if the appropriate care is taken and the right questions are asked, most pitfalls can be avoided and money can be saved. On the other hand, if there are too many unknowns, you may be in for considerable expense later - either when you pull it apart to see what the conditioon is or when the things blows up first time out!

BUYING FROM AN ENGINE BUILDER

If a reputable engine builder is selling an engine, he will know its history and he will have most likely run through the entire engine to check its condition. He will have magnafluxed critical parts and will have replaced parts that are worn or questionable. Most engine builder run their engines on a dynomometer to confirm their power output and to tune it to maximize output. 

BUYING FROM AN INDIVIDUAL

Buying an engine from an individual is somewhat more complicated because the history of the engine may be unknown, the time on the engine may extensive and it may be in need of a serious rebuild.

DETERMINING THE CONDITION OF THE ENGINE

1 A leakdown test - if the engine's still in running condition - is a good way to determine basic condition as it reveals the status of rings and valves.

2 HEAD - Determine if the engine has an OEM iron head or one of the newer Pierce aluminum heads and who did the preparation work on it.

3 CRANKSHAFT - Find out if it's fitted with a tired OEM crank or one of the new SCCA/SCAT or dave Bean crankshafts. Find out how many hours are the crank and on the engine overall.  

4 PISTONS - Are the pistons original Ford pistons, AE cast aluminum or the new CP forged pistons.

5 LAST REBUILD - When it was last rebuilt, were major parts (crank, rods and cam) magnafluxed? Were new hi-strength ARP or SPS 12 point rod bolts installed?

6 CYLINDER BORE - What's the current cylinder bore? If it's over the limit, the block may need to be sleeved. 

7 CARBURETOR - Has the carb been prepped by one of the major engine builders?

Unless a number of these questions can be answered in the positive, the price will clearly be between the lower end and middle of the range.

FAQs – Formula Ford Engines

Are used race cars always sold complete with everything including the engine?

In most cases, used race cars are sold complete. However, a seller has the option of keeping any part of the car and may choose to do so for various reasons. Cars are also often sold as a "roller", short for "rolling chassis", which means that the engine is not included. Going one step further, if there is no transmission included, the car may be referred to as a "slider". Separate used transmissions are not all that easy to come by so beware if you are looking at a "slider". On the other hand, used or "new" engines can be found without too much difficulty. The installation of an engine into a bare chassis is relatively straightforward but if one is not highly mechanically inclined, the work can be done by a local race prep shop. 

What do engines cost?

The current cost for a complete “new" top National engine from one of the FF1600 engine builders is in the range of $10,000 - less so for what might be termed a "Regional" engine. Since there are no new blocks available for the Kent engine, any such engine will be built up using a reconditioned block – one which has probably been sleeved and line honed, etc. And since there are many new aftermarket parts being made for this engine, most of the remaining parts will be new. (see “Engine Parts” below) Professional engine builders will typically run the completed engine on a dynamometer to assure everything is as it should be and also to tune it for maximum power output. Complete running Kent engines can be found at prices ranging from $2,000 (tired and in need of a rebuild) up to, say, $5,000. If the engine is well used or if its internal condition is unknown, then it is wise to have the engine taken apart and "freshened" or rebuilt. The engines and their parts are by no means inexpensive but anyone seeking to join the Regional racing ranks need not spend a fortune to get on track and run respectably quickly.

Where can I obtain Kent engine parts?
Parts for the Kent engine can be purchased from almost all of the well known engine builders – Ivey, Loyning, Quicksilver, Elite, Butler, Cricket Farm Motors, MWE, Farley and Williams among others. Parts suppliers such as Dave Bean Engineering, Pegasus Auto Racing Supplies and BAT also sell all the parts you will need.

Which parts are the new, aftermarket parts?

Aftermarket parts include crankshafts, camshafts, aluminum cylinder heads, flywheels, distributors and valves – all of which are equal or, in most cases, better parts than the OEM parts were. Secondary parts which are new include rings, bearings, timing chains and rocker towers.

How long does a fresh engine last?

Assuming most of the new parts listed above are used when the engine is assembled and also assuming first rate machinework, balancing and assembly, the bottom end of a Kent engine can now be considered to have a life of over fifty hours. Typically, the head would be rebuilt at about ten-fifteen hour intervals or when a leak down test shows leakage at the valve seats.

How reliable is a FF engine?

In the past, several gremlins plagued the Kent engine. In particular the crankshafts, rods or rod bolts were prone to breaking - especially of the flywheel was "run aground". But these issues have been entirely overcome, for the most part. New rules lowered the flywheel weight and allowed stronger aftermarket parts to be used. The new crankshafts manufactured for the SCCA by SCAT as well as the new crankshafts made for Dave Bean Engineering are extremely strong and can be considered to have a useful life of over ten years. High strength 12 point ARP or SPS rod bolts should be used to avoid failure in that area. Standard rods are bullet proof if properly prepared, carck checked and balanced. The bottom line is that catastrophic failures are quite rare assuming the use of high quality parts and their careful assembly.

What kind of engine modifications are permitted?

The FF engine preparation rules allow blueprinting, balancing and some tuning. For example, cam timing can be modified. In addition, distributors and carburetors can be modified within limits and heads can be “ported” within very strict limits. The rules specifically allow what you can do and if it doesn’t say you can do it then you can’t. This set of very restrictive rules keep everything relatively equal. Read through the engine preparation rules in the SCCA’s GCR which can also be accessed on the SCCA’s website.

Do club racers usually have more than one engine?

A Club racer running Regional events on a limited budget can certainly operate with only one engine. Obviously, if something goes wrong with it and it needs to be worked on, then you are out of commission. Regional racers with substantial budgets may have a spare short block available or perhaps a complete engine. National racers may also survive quite well with only one engine but if they are going for Divisional or National Championship wins, then they will undoubtedly have two engines on hand.

What does an engine rebuild involve and what does it cost?

An engine rebuilt involves complete disassembly, machinework, possible sleeving of all four cylinder bores and the replacement of all worn or out-of-spec parts such as pistons, rings, bearings, timing chain, valves – and perhaps the crankshaft. After everything is reassembled, the better engine builders or machine shops will then dyno tune the engine to assure it is putting out maximum power. A rebuild which involves disassembly, crack checking and a minimum of parts will cost about $2,000 while a rebuild involving a large number of new parts can cost between $3,500 and $5,000.

What is a Cortina? An Uprated? A Fiesta?
The original engine used in all FF1600 cars was the “Cortina” and it was sourced through Ford which used the engine in the English Cortina. This engine had flat top pistons, combustion chambers in the head and assorted other differences. It is now usually fitted only to vintage cars which would have used the Cortina engine when first run. The “Uprated” Kent engine which was used is Formula Ford from about 1974 onwards is known by its casting number starting with “711M” and is the predominant engine used in FF1600. It is distinguished by its stronger lower end, dished pistons and flat head surface. The same block was used in the Ford Fiesta which was sold in great numbers in the US. The Fiesta block can also be used in a Formula Ford and has no deficiency relative to the 711M block. There are minor differences in the casting but the block is as strong or stronger than the 711M.