Kent Formula Ford Large Head Idle Speed Screws

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.

P1010001.JPG
P1010004 (2).JPG
P1010002 (2).JPG

L34 Torana V8 Dual Coil 4 Lobe Points Cam Distributors

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.

 

Completed L34 Distributors Ready for Dispatch 

Completed L34 Distributors Ready for Dispatch 

Temporary tags on caps denote distributor (as opposed to engine) firing order.  Provides ease of installation for customer who can reconcile distributor and engine firing orders to ensure correct lead placement.

Temporary tags on caps denote distributor (as opposed to engine) firing order.  Provides ease of installation for customer who can reconcile distributor and engine firing orders to ensure correct lead placement.

Twin coil post caps with original on LHS and item on RHS of picture being newly "manufactured" cap

Twin coil post caps with original on LHS and item on RHS of picture being newly "manufactured" cap

Freshly lubricated and assembled centrifugal advance mechanism and 4 lobe points cam

Freshly lubricated and assembled centrifugal advance mechanism and 4 lobe points cam

Broken centre shroud on one dual circuit rotor with secondary crack also visible

Broken centre shroud on one dual circuit rotor with secondary crack also visible

Remnants of broken shroud machined away, crack ground out and new black bakelite shroud ready for bonding in place. 

Remnants of broken shroud machined away, crack ground out and new black bakelite shroud ready for bonding in place. 

New shroud epoxied in place and crack void potted with epoxy.

New shroud epoxied in place and crack void potted with epoxy.

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.

4 lobe points cam, dual points, dual condensers of the two completely electrically independent ignition circuits.  45 degree distributor firing intervals = 90 degree engine firing intervals.  With each circuit serving only 4 cylinders of the V8 engine and the engine firing order successively  alternating from one circuit to the other, the dwell behaviour of each circuit and coil saturation time is akin to a 4 cylinder engine, so high RPM spark intensity is far superior to a standard 8 lobe cam/single coil V8 distributor.  Due to the independence of the two circuits, careful setting of the 45 degree firing interval between each circuit during final rig testing is crucial to ensure all engine cylinders see the same spark advance during engine operation.  A now well outdated, but still clever and interesting design.

4 lobe points cam, dual points, dual condensers of the two completely electrically independent ignition circuits.  45 degree distributor firing intervals = 90 degree engine firing intervals.  With each circuit serving only 4 cylinders of the V8 engine and the engine firing order successively  alternating from one circuit to the other, the dwell behaviour of each circuit and coil saturation time is akin to a 4 cylinder engine, so high RPM spark intensity is far superior to a standard 8 lobe cam/single coil V8 distributor.  Due to the independence of the two circuits, careful setting of the 45 degree firing interval between each circuit during final rig testing is crucial to ensure all engine cylinders see the same spark advance during engine operation.

A now well outdated, but still clever and interesting design.

Modified Holden Six Distributor

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.

P1010025.JPG
P1010028.JPG
P1010051.JPG
P1010053.JPG
P1010054.JPG
P1010055.JPG

Lotus Twin-Cam Engine Build

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.

 

Lotus Twin-Cam Cylinder head on VRD Flowbench

Lotus Twin-Cam Cylinder head on VRD Flowbench

Simple (but accurate) template/slave centre made for marking inlet manifolds to increase size to suit 45DCOE Weber carbs   

Simple (but accurate) template/slave centre made for marking inlet manifolds to increase size to suit 45DCOE Weber carbs

 

Post modification

Post modification

Death by Heli-coil...

Death by Heli-coil...

Rectification of damaged/smeared head bolt washer spot face surfaces as a result of previous use of incorrect washers at these sites.

Rectification of damaged/smeared head bolt washer spot face surfaces as a result of previous use of incorrect washers at these sites.

Increasing depth of LHS engine mount attach threads in freshly bored, decked and line-bored 711M block after removal of 0.450" from LHS engine mount pad to bring transverse block width in to line with that of earlier 120E, 116E, 691M et al pre 711M blocks.

Increasing depth of LHS engine mount attach threads in freshly bored, decked and line-bored 711M block after removal of 0.450" from LHS engine mount pad to bring transverse block width in to line with that of earlier 120E, 116E, 691M et al pre 711M blocks.

One of several mock assemblies to check various fits and clearances including valve to piston and valve to valve clearance prior to final assembly.  VRD dummy tensioner plunger allows tensioner quadrant to be loaded to set chain tension during mock-up without needing to fit front cover

One of several mock assemblies to check various fits and clearances including valve to piston and valve to valve clearance prior to final assembly.  VRD dummy tensioner plunger allows tensioner quadrant to be loaded to set chain tension during mock-up without needing to fit front cover

Clay blobs waiting patiently to be squashed during valve to piston clearance check...

Clay blobs waiting patiently to be squashed during valve to piston clearance check...

CCing combustion chambers with burette

CCing combustion chambers with burette

Fine adjustment to camber volume to equalise CC with slave second-hand valves fitted to protect freshly cut seats

Fine adjustment to camber volume to equalise CC with slave second-hand valves fitted to protect freshly cut seats

VRD combination drilling/welding jig fitted to sump along with VRD windage tray.

VRD combination drilling/welding jig fitted to sump along with VRD windage tray.

Windage tray attach brackets manufactured and fitted with floating and self-locking anchor nuts waiting to be welded to sump interior.  Microstop countersink tool in background used to countersink brackets to accept anchor nut attach rivets.

Windage tray attach brackets manufactured and fitted with floating and self-locking anchor nuts waiting to be welded to sump interior.  Microstop countersink tool in background used to countersink brackets to accept anchor nut attach rivets.

Pre weld

Pre weld

P1010038.JPG
Don't forget the dipstick access hole when making the windage tray....

Don't forget the dipstick access hole when making the windage tray....

Oil suction tube skirt

Oil suction tube skirt

Oil temp sender port and lockwire tab for sump plug and temp sender added to RHS of sump

Oil temp sender port and lockwire tab for sump plug and temp sender added to RHS of sump

Bespoke Holden Grey Dual Coil Racing Distributor

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.

Engine Oil Primer

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.

P1010003.JPG
P1010009 (2).JPG
P1010011.JPG
P1010015.JPG
P1010017.JPG
P1010013.JPG

Custom Hybrid BOSCH HEI Distributor (Ford 4 Cyl Pushrod Engine)

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.

Holden V8 housing modification

Holden V8 housing modification

517.JPG
525.JPG

LUMENITION Electronic Kit to Holden Grey Distributor

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...)

 

IMG_20160628_225452[1].jpg
012.JPG
004.JPG
001.JPG
002.JPG

Holden Grey BOSCH Hybrid HEI Electronic Distributor

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.

    

 

 

Vintage Renault Powered Racing Boat

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.

 





Modified Holden Grey Distributors

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.

Dual Point Conversion for Group Lb Special

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. 

002.JPG
024.JPG
029.JPG
031.JPG
034.JPG
036.JPG
64-PD-C30864-042-Cropped.jpg

1947 MG TC Holden Square Rigger

 

Background

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.

 

Competition History

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.

 

Engine Specifications:

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.

  • Ross balancer.

  • 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.

Ford Electronic Distributor to Suit Early Ford Six Cylinder

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.

005.JPG
006.JPG
007.JPG
008.JPG
009.JPG

Holden V8 Racing Distributor

Holden V8 BOSCH Distributor

P1010019.JPG

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

P1010017.JPG
P1010021.JPG
P1010028.JPG


Valiant Slant Six Dual Point Distributor

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

020.JPG


001.JPG
012.JPG
015.JPG
018.JPG