Is this the Ultimate Holden - Waggot Twin Cam head on Grey motor

Sports Car World - January 1954

The evolution of the Holden as a racing sedan has been little short of dramatic. Holdens with twice the manufacturer's horse­power are now common. Enthus­iasts like Lou Kingsley with bored-out, Repco-headed Holdens are talking of 140 b.h.p. But the latest competition Holden is likely to have something like three times the stock power — which, for the record, is 62 b.h.p. at 4,000 r.p.m. (nett) or 70 SAE horsepower. at 4,000 r.p.m. (gross).

Mechanics cluster around Bill Thompson's really fast d.o.h.c. Holden before its debut at Bathurst in Oct­ober. Manifold bother a//owed only a mere 6,000 r.p.m. in top gear

The most powerful Holden con­version to date has been carried out by Mery Waggott of Waggott Engineering, a very active firm of general engineers in Greenacre, a Sydney suburb.

The sedan belongs, to Bill Thompson and there is talk of Jack Myers piloting it in scratch races, with Bill at the wheel for handicap events. For a com­pletely new engine the power unit gave a quietly impressive account of itself at the G.P. meeting at Bathurst. With Jack Myers driv­ing it gained third place in the scratch section of the second race.

Earlier, in practice, clutch trouble was experienced. During the race itself there was also carburettor manifold trouble, and as the race went on the motor began to sound less and less clean. Jack Myers reports that on certain parts of the course on every lap, in exactly the same place, the engine was starving for fuel and he was forced to drive accordingly. A fractured manifold was suspected and Jack could not reach maximum speed.

An engine speed of 6,000 r.p.m. in top gear gave him a road speed of 111 m.p.h. However, maximum engine speed is expect­ed to be around 7,000 r.p.m., although a limit of 6,500 will be imposed on the indirect gears.

After the fuel check at the end of the event the engine refused to start and Mery Waggott found that petrol was spraying out of the carburettor union and the rear carburettor, which was held on by the pipes and linkages alone.

Only two Stromberg carburet­tors were fitted for the Bathurst event as the car was completed just in time for the meeting. For future events, however, six Amals will be used.

Mery Waggott, who has been responsible for both the engine design and machining, is not a man given to guess work. For this reason, he declines to esti­mate the likely power or speed of the engine. But with the specifications before us our guess-is that it will produce about 175 b.h.p. at 6,000 r.p.m.

Most people believe that the .evolution of bored-out special Hol­den engines has reached its zenith. This viewpoint is streng­thened by the decision of Mery Waggott to lengthen the stroke of the engine in his quest for more power.

By doing this he has raised the capacity to 2995 c.c., or nearly three litres. A special seven bear­ing crankshaft has been made to withstand the extra strain and the cylinder head is the well known Waggott "double knocker" with twin overhead camshafts. The compression ratio is 9 to 1 and the induction system will include six Amal carburettors.

The Waggott-Thompson Holden has a power to weight ratio of about 150 b.h.p. per laden ton. This compares favourably with stock 3.4-litre Jaguar, which has 145 b.h.p. per laden ton.

But the engine is not the only major modification. The stock gearbox has been replaced by a four-speed unit from an XK 120; the clutch is a composite unit made up of two Holden clutch plates, a Holden pressure plate, Jaguar centres and a fabricated steel centre plate fitted between the clutch plates.

Mery Waggott, the man who designed most of the unique Thompson Holden's speed equipment, adjusts the distributor before the ear's initial tryout at Mt.Panorama

For the Bathurst meeting a standard pressure plate was used with this special clutch. It failed, however, during the last lap of practice. This was not apparent until Myers went to the line for the start of the first sedan race. Bad vibration occurred and he could not select low gear—a sign that the pressure plate springs had collapsed.

A new pressure plate was fitted for the second day's racing, but Waggott Engineering is at pre­sent modifying the clutch to give positive driving location.

The suspension remains reason­ably standard, apart from stiffer coil springs at the front and more powerful shock absorbers all round. Repco-Holden brakes will be fitted at the front and pos­sibly also at the rear.

The three-litre engine capacity has been obtained by boring out the cylinder bores to 81 mm. (roughly 3/16" oversize) and lengthening the stroke to 96 mm., which is roughly I" longer than normal.

Merv Waggot designed a seven-bearing crankshaft and cradle.  This was fully counterbalanced and took the holden motor out to 3 litres.

Unusual sub-assembly containing special seven-bearing crankshaft bearing, bolts to the Holden block, using existing holes. 

The seven bearing crankshaft has been designed and machined by Mery Waggott himself. It was cut from solid 60 ton high tensile steel.

It is fitted to the Holden block by the use of an ingenious "cage"which is bolted to the lower half of the engine. As our photograph shows, the cast iron cage has been designed with seven bearing caps cast integrally.

It is bolted to the block, using the holes normally filled by the four bearing cap studs. The three additional bearings are retained by caps which can be bolted to the cage itself. This means that the crankshaft assembly is clamped to the cage before it is bolted to the engine block.

Initially, standard connecting rods were used. Later special rods will be made in the light of any lessons learned from the early operation of the new power unit. The pistons have been speci­ally cast and were machined by Waggott Engineering.

The contours of the camshaft are half way between semi and full race and the engine will be reasonably flexible. The compres­sion ratio is 9 to 1, so that pump fuel can be used to comply with sedan car regulations.

A standard oil pump is used, as past experience has shown that the gears of the drive shaft are likely to shear if the oil pressure is raised. A full flow Volks oil filter will be used. The ignition will be normal, apart from a Delco twin breaker point distributor.

The cylinder head is similar to that used on Jack Myers' W-M Cooper. The camshafts were machined from the solid by Wag-gott Engineering, but the special valves were made by an outside firm.

Maximum engine speed is ex­pected to be around 7,000 r.p.m., but limit of 6,500 or even 6,000 r.p.m. will be imposed for the indirect gears. Maximum speed will be governed by the choice of rear axle ratio, but is likely to be around 120 m.p.h.

Extra engine cooling has been affected in two ways. First the radiator core has been thickened to help keep the operating teme-peratures of the engine down, and secondly an oil radiator has been added.

So far this unusual Holden is still in the experimental stages. But few men have had more experience with modified Holden engines than Mery Waggott. Jack Myers and Bill Thompson are a formidable driving team.

With this backing the new car should prove unusually fast.

Mery Waggott, the man who designed most of the unique Thompson Holden's speed equipment, adjusts the distributor before the ear's initial tryout at Mt.

Panorama.

Dunstan rotary valve engine

SEACRAFT, September, 1957 ( Pages 50-52 )

This is the engine which may revolutionise speedboat racing

The engine used in the record-breaking skiff Southern Maid is fitted with a "Holden" engine adapted to "Dunstan" rotary valve and fuel injection equipment for which patents have been applied.

Advantages of a rotary valve are: Almost unlimited breathing capacity, freedom of reciprocating motion, absence of hot spots, compact com­bustion chamber, any desired control of turbulence. The results are: High power outputs (limited only by bal­ance and strength of crankshaft, con rods, bearings, etc.), high anti­knock rating and high efficiency. The existing engine at 11-1 compres­sion ratio will run on any fuel from second grade petrol about 75 octane) to pure Methanol and running changes can be made by manual con­trol of fuel pump setting, as no criti­cal jet sizes are involved.

This shows a Holden engine conversion on the dynamometer but with the rotary valve head removed. The engine was later dry-sum _ped by driving the pumps off the camshaft gear. Swashplate fuel injection pump is shown (driven at half speed). This has a distributor to ensure even supply to high or low cylinders whets starting but has no useful purpose under normal running conditions when the jets could be

sprayed continuously and simultaneously.

This is the first Dunstan rotary valve applied to a full sized engine. This version had six separate floating cylinder heads. The fuel
injection is by Dunstan swash plate type pump. Mixture control by swash plate angle is not shown in the view

Most of the running has been with a standard Holden 6 volt coil ignition system with 12 volt applied. However, between raising the 135 cubic inches restricted hull class record from the previous holder's 53 m.p.h. to 60.624 and our latest 63.015, we fitted a Lucas magneto which is undoubtedly preferable to coil ignition at speeds over 6000 r.p.m. Most of the racing is done on stan­dard or super petrol (about 80 octane) with addition of A pint 0/two-stroke oil per gallon for valve lubrication; 1 pint for touring. Methanol fuel, because of its high latent head and rich mixture, increases output about 12 per cent, over petrol and this fuel is used for special occasions. About 2 per cent. of castor oil is added to the Methanol to lubricate the valve which incidentally never shows any sign of wear or scuffing. A few foreign bodies such as jet tubes have in fact been through the valve and cylinders without affecting seal or perform­ance. This is of course not recom­mended operation procedure. It is possible of course to fit a metering lubrication system of low consumption to eliminate the need for adding oil to the fuel. Although with self-mixing oils now available petrol/oil is no bother. A cleaned up version of this design is being put into production for the Holden engine and this will be sold to speedboat, road and track racing car enthusiasts or private car owners on the basis of valve head only, or head plus enclosed front end drive for valve and accessories, plus fuel system if required, or complete dynamometer tested engines suitable for oars or boats. Many orders and interested inquiries have already been received and efforts are being made to expedite completion, testing and manufacture of the new model. Such a valve could be fitted to any type of engine, using one valve for each bank of cylinder in the case of a Vee engine. However, all present efforts are being concentrated on "Holden" which is readily available at low cost and fits into competition classes very well and also stands a remarkable amount of "hotting-up" for a production car engine. The valve is of grey cast iron and runs the full length of cylinder block and is hollow for water cooling. It runs at a quarter of engine speed and has two opposed pockets at each cylinder station. These pockets work on succeeding cycles. The original engine has six separate lower heads in floating contact with the valve. The new version has one aluminium head, split on centreline of valve, with six floating inserts which main­tain valve contact and seal. The new head could be fitted in lieu of the ordinary overhead valve head in about an hour. Arranging a drive for the valve is, however, more in­volved, especially if a front end drive is required to leave flywheel and clutch available for normal use. Valve diameter is approximately the same as the cylinder bore (3") as this gives reasonable proportions of ports over a range of useful tim­ing diagrams and also gives a satis­factory balance of pressure areas to ensure valve seal without scuffing. The heads have main ports about 1" ;" wide by 21" long and 1" or more deep depending on compression required. These ports are also the combustion chambers. Compression ratios of up to 12 to 1 can be achieved with standard flat top pistons. We might mention that the original set of standard pistons are still good after 12 months frequent racing, although the cylinders were recently linered as the bores were tapered and ridged and were breaking rings. The spark plug is 10 mm. and because of space problem in the original engine the points are i" down, a 5/16" diameter hole, but fire perfectly. Because of the shielding of plugs, plus cooling of the alumi­nium heads most of the racing has been with K.L.G. ten L30 plugs which are quite "soft" for such an engine. Recently we have used K.L.G. ten L80. Plug trouble is unknown. The latest engine used K.L.G. 10 L100 for racing at 7000-7500 r.p.m. The inlet and exhaust ports are approximately horizontal and on op­posite sides of the valve and are about t" x 2,i". The valve pockets connect these with the main central port or combustion chamber accord­ing to the timing desired. The edges of the combustion chamber port and the edges of the valve ports control the exhaust opening and inlet clos­ing points and the lower edges of the exhaust and inlet ports control ex­haust closing and inlet opening or the overlap timing. Valve timing can be adjusted in detail by machining or filing port edges and the timing can be moved bodily by means of slotted setscrew holes in the main chain wheel. Valve timing of present engine is approximately: exhaust opens 70 degs. before bottom d.c., closes 30 degs. after top d.c.; inlet opens 20 degs. before top and closes 60 degs. after bottom. This is not necessarily ideal as this is about how the original cast­ings cleaned up and no changes, apart from bodily varying timing (which is not very critical) have yet been made. The motor (132.5 cubic inches stan­dard Holden bore and stroke) has de­veloped 200 b.h.p. at 7500 r.p,m. The rotary valve will, of course, not give greater torque at any given capacity and compression ratio than poppet valves at moderate speeds. It does, however, enable higher compression ratios to be used with ordinary petrol and this raises torque and efficiency. It also can be made to give breathing capacity adequate for any desired speed such as 7000 r.p.m. and to 10,000 up to even 15,000 r.p.m. if the crankshaft, rods, bear­ings, pistons, etc., were designed for such speeds. I have a design on which I am working, of a 139 cubic inches engine weighing 225-250 lbs., which is much more compact than a Holden and which would run safely at 12,000 r.p.m. with 15,000 r.p.m. over-runs. This is eight cylinders 111 two banks with two rotary valves. The stroke is quite short and there-foie piston speeds are low, as are the inertia loads. In racing conditions, such an engine would (IrnsuperchargerVi de­velop 300-400 b.h.p. The design allows for a moderate change of capacity between say 2,000 c.c. to 2,500 c.c. by varying stroke or bore.