Formula Ford Kent engine that we built, have since dyno tested and that is now back in car and has completed initial track outing.
A fresh batch of Kent Formula Ford engine (Weber DGAV) large head idle speed screws finished off today and now headed to San Jose CA. We made one of these large diameter head screw assemblies for a Formula Ford engine build we recently completed and observers of that build progression requested we manufacture some more screws.
The large diameter head allows quick and easy temporary idle speed adjustments to be made by hand for elevating idle speed temporarily (and then returning to the previous setting), during pre-race warm up in the pits, without having to go diving for a screwdriver or someone having to stand (idle…) holding the throttle partially open by hand.
VRD recently overhauled/restored/recommissioned two L34 Torana V8 4 Lobe points cam/dual coil distributors for a customer based in Invercargill N.Z. Two distributors and various customer-supplied spares were selected, restored and overhauled to arrive at two complete distributors by repairing various key rare piece parts in the customer's collection of spare items to enable installation and re-use.
One distributor is fitted with a new twin coil post cap we provided by inserting an additional coil post to an NORS brown bakelite standard Holden V8 single post cap.
The customer supplied 3 caps and rotors and all had signs of rotor to cap interference during previous operation. The broken rotor shroud pictured would be the end result of rotor to cap interference. Careful final assembly and clearance checks ensured no interference issues now exist on either of the two finished distributor assemblies.
OEM quality control and tolerance stack-up considerations seemed to be lacking a little with these (low volume) production items.
One cap and rotor amongst the spare parts provided by the customer had clear evidence of electrical arcing/tracking across the bakelite insulating surfaces. As the offset carbon coil post brush that communicates with the "ring" contact on the dual circuit rotor is some distance from the rotor centreline, this carbon brush has a high rubbing velocity inflicted on it my the ring contact, whereas the conventional on-centre carbon brush contact experiences very little relative rubbing velocity. Accordingly, the offset carbon brush experiences a high wear rate and the carbon dust worn from the brush deposits itself on the rotor and cap interior and can lead to cross-firing and arcing in the interior of the cap. To ensure this does not happen, this design trait needs to be recognised, and the distributor maintained accordingly, with regular cleaning of the cap interior and rotor to remove carbon dust residue and to ensure the required insulation integrity exists.
Latest engine build in progress is Formula Ford Kent unit for Sydney-based customer. Some progress shots of bare block with more final assembly pictures to follow.
A few pictures of recent Holden Six BOSCH electronic distributor overhauled using customer supplied core and advance curve modified to compliment customer's other engine modifications. Vacuum advance deleted and pulse generator stator anchor manufactured + fitted. Now on its way back to customer based in New Zealand.
Some recent pictures of Lotus Twin-Cam engine build underway at present. Customer arrived with a ute load of sundry English Ford engine parts, a "Fordised" and knife-edged forged steel fully-counterweighted Datsun L18 crank and a well-used bare twin-cam head for VRD to combine into an engine. Unlike the standard TC engine that is based on the 1500 pre-X-flow block deck height and stroke, this engine will be a "tall deck"/long stroke version based on a 711M Ford Escort block.
Holden Grey six cylinder dual coil distributor development and final rig testing completed this week. This distributor uses a 3 lobe points cam custom ground for Vintage Racing Developments by Clive Cams in Victoria. An additional coil lead post resides in the distributor cap to communicate to the secondary circuit on the dual rotor button track. This design uses 2 completely electrically independent circuits and two ignition coils, such that each coil only serves 3 engine cylinders and accordingly has very desirable dwell/charge soak behaviour for retention of spark energy at higher RPM.
The ultimate points-triggered battery/coil distributor for use in CAMS historic classes that must retain points triggering. Dwell for each 3 cylinder circuit in this distributor is in the region of 56 degrees (compared to circa 38 degrees for a standard single point/single circuit/single coil/6 lobe cam six cylinder distributor). Six cylinder analogue to 4 lobe cam L34 Torana dual coil distributor.
Some pictures of recently completed Renault Gordini engine built by Vintage Racing Developments.
A few pictures of engine oil primer recently completed at Vintage Racing Developments. Uses standard English Ford "Burman" vane type oil pump and draws from large PVC reservoir. In-hex drive is fitted to pump shaft where pump drive gear normally resides when pump is fitted to engine. Male hex drive in hand drill is used to operate pump.
When a new camshaft is fitted to an engine, especially with high load valve springs in a modified/competition engine, it is undesirable to wind the engine over on the starter motor with the spark plugs removed to build engine oil pressure prior to initial start. For optimum camshaft run-in and subsequent camshaft longevity, it is desirable to immediately bring the engine to 2500 to 3000 RPM as there is then a sufficient supply of "splash" oil released from rotating components to adequately lubricate the camshaft.
Use of the priming pump immediately prior to initial start (along with the usual filling of the oil filter before fitment) provides instant oil pressure upon initial start and allows the requisite camshaft run-in process to be carried out without potential bearing starvation.
Initial start and camshaft run in procedure this week with high ZDDP content oil. 11:1 compression ratio, 45 DCOE carbs, Wade Camshaft, and various Vintage Racing Developments bespoke modifications.
Bespoke distributor made using components from 2 different BOSCH V8 electronic distributors, one BOSCH 4 cylinder electronic distributor and original LUCAS points distributor. Uses 4 of the original 8 plug locations on Holden V8 cap and Holden V8 housing. Supplied to customer to use on Ford 1500 pre-crossflow engine in Group S historic sportscar. Uses companion low resistance ignition coil and electronically controlled variable dwell.
Some pictures of recently manufactured small bespoke adaptor plate used to fit English-made "LUMENITION" P/N OS50 eye and chopper to original Holden Grey Motor BOSCH distributor. LUMENITION make many kits to fit the generic OS50 eye (which is the trigger component of the wider LUMENITION system) to a large range of distributors (but not this one...)
This distributor is a development that along with modified internals marries the top half of a BOSCH electronic HEI distributor with the lower half of an original cast iron BOSCH Holden Grey Motor points type distributor. Uses original BOSCH control module (which is usually mounted on the integral "balcony" on the side of the electronic distributor housing) but is now remote mounted for use with the hybrid distributor. Remote mounting is primarily for packaging reasons, but also has the advantage of removing the module from close proximity to direct engine heat and vibration. Companion low resistance coil is used and distributor provides variable/active dwell control and high energy spark.
Allows use of 0.060" plug gaps and provides a fully functional true electronic bolt-on HEI system for Grey Holden engines. Not to be confused with simply fitting an "electronic points" module to a standard distributor which maintains an essentially fixed dwell and points type coil.
Ignition package is for customer in NSW running Holden Grey engined nostalgia drag car.
VRD carried out some engine modification work for the owner of this vintage Renault powered racing boat a little while back. The boat and highly modified engine were built in Melbourne during the 1950s and at that time the builder had bespoke pistons cast for the engine. The boat set various Australian Water Speed Records in period and the speed record for the 50 cubic inch class that this boat set in 1960 still stands! The pistons have very large crown intruders and the current owner noticed during routine engine teardown that the edges of the piston intruders were showing evidence of picking up in the bores of the piston sleeves in the direction parallel to the piston pin. VRD modified the piston intruders to relieve this area with minimal reduction to compression ratio and also measured and selectively matched various pistons and liners the owner had (this is a wet sleeve engine), before "Flexhoning" honing the liners ready for re-assembly. VRD also manufactured a simple ring lapping tool to allow the owner to lap slightly thicker new piston rings he had obtained to suit the original ring groove widths.
Following the VRD piston modifications and careful engine re-assembly by the skilled current owner, the engine has since performed reliably at various vintage racing boat meetings throughout Australia.
Two more cast iron BOSCH Holden Grey engine distributors off to customers in Western Australia this week. Both re-curved to suit customers' supplied engine specifications. Single point unit has typical 6 cylinder 38 degrees dwell and dual point has 48 degrees dwell. Both retain these dwell readings to beyond 7000 crankshaft RPM under rig test. Both units have vacuum advance deleted and fixed breaker plate assemblies.
Recently completed dual point conversion and re-curve of BOSCH distributor for use on Group Lb historic MG-based special. Distributor has advance curve tailored to engine, circa 50 degrees dwell and consistent dwell behaviour beyond 7000 crank RPM. Some details of the car and pictures of completed distributor below. Vehicle is based in South Australia.
1947 MG TC Holden Square Rigger
The car has the following summary technical specification:
1947 MG TC – (original engine number XPAG 3306, chassis number TC2675)
Registered Number Victoria RZ 685
Square rigger style T series MG body.
Cycle front guards.
Fitted with a modified Holden Grey engine in the 1950’s with triple SU’s and other engine and mechanical modifications (unknown if any competition history).
Fitted with both 16” and 15” x 5” wheels in the period up to 1965.
Hydraulic telescopic shock absorbers and axle restraints front and rear.
Holden grey banjo differential centre and modified axles in TC rear axle housing.
Cut down Morris Minor rack operating as a steering box across to the original position LHS steering arm (common modification in the era).
Larger twin leading shoe 10” x 2 ¼” front brakes in one off cast iron finned brake drums.
Modified finned Monaro Motors 9” MG TC rear brakes.
The car was built in the 1950’s as a MG Holden (triple SU’s and modified engine) with modified front brakes, telescopic shock absorbers etc, The car has a confirmed ownership from 1959 and an identified racing history in the period 1963 to 1965:
Used as a road car from 1959 to 1963 by Vern Barlow in Victoria as a grey Holden engined MG TC special (triple SU’s, modifications, etc).
Sold to Peter Mahony in 1963 in Victoria (entered under BP Heidelberg).
Competed at Lakeland hillclimb, Calder and Templestow hillclimb.
Sold on then to Rod Cooper, Victoria (entered under SAAS) at some point in late 1964.
Competed at Lakeland hillclimb, Calder and Hume Weir.
The subsequent ownership history is unknown until 2013. No history of competition has been confirmed before and beyond the dates above, and its competition history appears to have ended in 1965, due to the car quickly becoming uncompetitive.
The car was then in storage in a semi disassembled state since 1966.
The car is currently under restoration to Group Lb specifications in its early 1960’s configuration since 2014.
The following are the key specifications in progress:
EJ Block. (early low number block)
Capacity 2350cc (thin wall sleeved).
Main bearing straps and girdle.
Vauxhall E Model crank (stroked to 3 1/8”). – MGB main bearings / modified rear seal arrangement.
Mitsubishi Starion con rods and bearings.
Lightweight billet flywheel (8kg), Holden heavy duty 8.5” single plate clutch assembly.
JE 3 ring domed pistons (21mm gudgeon diameter).
Modified water pump and head outlets.
Vintage Racing Developments special twin point distributor.
Modified camshaft grind – approximately 235 degrees @ 0.050” and 0.3” cam lift.
Modified head with 1.48” and 1.25”’ valve sizes and relieved chambers – LS1 beehive springs.
1.7:1 rocker ratio.
10.5:1 compression ratio.
Triple 30 degree SU 1 ½” (internally modified) on 1960’s Sonic short inlet manifold and common cold air plenum chamber with rolled edge short ram tubes.
One off exhaust manifold – 1 3/8” primaries, 1 5/8” secondaries into a 2 ¼” system.
Genuine BOSCH full electronic distributor with housing modified in region of clamp flange to allow installation on earlier Ford six cylinder engines (221, 250 etc) originally fitted with points type distributors. Original oversize non-circular flange machined to be of like dimensions to original points type distributor. Standard housing shown for comparison.
Holden V8 BOSCH Distributor
Advance mechanism modified by TIG welding and then precision machining points cam stops to provide 9 distributor degrees of internal advance. Advance mechanism lubricated with CASTROL "Premium Heavy Duty" blue Lithium-based grease.
Converted to dual-point configuration with single piece breaker plate and two sets of brand new heavy duty genuine BOSCH (P/N GB752) L34 Torana points fitted for much improved high RPM dwell behaviour
Vacuum advance deleted, vac advance can attach boss machined from housing and closing plate fitted
Custom advance springs fitted to provide single slope advance curve with onset of advance at 1200 crank RPM and full advance at 3200 crank RPM
Built to suit well-modified engine with significant camshaft overlap
Will allow increased static advance to be used as required by high performance camshaft and companion modifications without dangerous over-advance at elevated RPM
Consistent and correct dwell behaviour under test beyond 7500 crank RPM
Some recently completed standard Holden Grey Motor BOSCH distributors.
Red oxide housing = VJU6AR17 (OEM fit on FJ Holden); Black Housing = VJU6BR30 (OEM fit on FE Holden); Blue Housing = U-VJU6BR54 (OEM fit on EJ Holden)
One for the Valiant fans!
Re-engineered OEM fit BOSCH distributor (converted to Dual-Point Configuration).
Built to provide 9 distributor (18 crank) degrees of advance commencing at 1000 crank RPM and "all in" @ 3750 crank RPM
Individual points set to 38 degrees dwell provides 48 degrees combined dwell for significant coil saturation and spark strength improvement over standard single-point distributor particularly at elevated RPM
Sound and consistent dwell behaviour beyond 8000 crank RPM
Suit high performance Slant Six engine