MG Sports Cars

After owning my 1964 mgb roadster for 25 years I'm going to try and get it finished by end of next year before I turn 50.

The car was largely finished a decade ago, but money and other constraints stopped work.

I have oodles of photos an details, but I'm on holiday right now so can only share the attached photos. I'll upload more in a couple of weeks.

I've used some software called cartest 2000 to simulate how fast my mgb will go when finished. I won't go into any details here as I do need to do a proper build page, but the car was largely finished some years ago so I have basic info.

The car is running a turbo 4l rover and we saw 630hp on the dyno and masses of torque. It's a running a 9" with a 2.75 rear and 18" wheels and a gearbox with a 1:1 fifth.

Using a cd of 0.4 and the normal frontal area cartest shows it should do 190mph. It's a brick, but it has a small frontal area. Even fiddling with a 2.5 rear it will go 200mph.

Of course this is all simulated but changing the cd does have the right effect and less power dies make such speeds unattainable.

In my base config:
- the windscreen will be replaced by a small lexan one
- front spoiler and large splitter
- flat underbody
- small side mirrors
- cabin will be enclosed except for drivers position, this includes behind driver/passenger.
- rear wing (adjustable)
- rear diffuser with cut outs behind rear tyres to reduce pressure
- front guard vents to reduce pressure.
- car is very low
- headlight covers

I'm planning on 2 configurations. One for straight line speed events such as standing km, where the rear wing will be deleted, and the diffuser reduced. I may also try a full front windscreen and roof depending on how it goes.

The other config. will have large rear wing and rear diffuser.

The majority of the work is panelling but I'm no expert so that's isn't as easy it sounds.

I'm happy to answer any and all queries. I'm sure I'll have plenty of my own.

Cheers

Byron

For my first proper post I thought I'd start at the beginning. Bear with me as there is a lot of photos and details and hopefully some of it is interesting.

The car was purchased in 1988 with a 4.4Litre Leyland V8 conversion and a shortened Valiant Charger LSD diff.

The conversion however was unfinished and the motor was in desperate need of a set of bearings.

The motor went in for a rebuild and at the same time it was decided to offset grind the crank and take the motor out to some 4.8Litres. That engine was eventually sold and a 1995 3.5L Rover V8 engine was purchased.

Not long after this I had a change of jobs and had to move interstate and the car was left in limbo up until 1995 when work was started again, with more money and ideas.

Let's start with the engine as that is probably the most expensive component.

ENGINE
The engine is a 1985 Rover V8; for the unitiated the rover V8 is an all alloy engine and weighs in at a mere 318Lbs,
which is lighter than the original 4 cylinder. The engine sits on custom engine mounts and sits as low as possible thanks to a custom wet sump pan. The engine has been moved back as far as possible and now sits wholly behind the front axle.

The engine was dyno'ed in July 2001 on standard 98 Octane pump fuel made a peak of
>850nm@4500rpm@19psi and
>470kw@6000rpm@19psi
Both figures are uncorrected, but given the correction factor for the day was ~0.028% its irrelevant.

RPM Nm Lbs-Ft HP KW Boost
1500 200 148.15 42.31 31.81 ?
2000
2500
3000 500 370.37 211.56 159.07 8psi(held would go higher if allowed)
3500
4000 800 592.59 451.33 339.34 15psi(held as it was overboosting)
4500 850 629.63 539.48 405.62 19psi
5000 790 585.19 557.11 418.88 19psi
5500 725 537.04 562.40 422.85 19psi
6000 740 548.15 626.22 470.84 19psi

19psi is with the boost control valve fully opened (i.e. wastegates fully closed), so the engine is unlikely to make any more power with the current turbos, however intake temperatures were ~85c so I expect more power when the vehicle is moving and I have an intercooler sprayer running.

I have videos of all the runs, and might post them sometime.

Givens:
Number of cylinders 8
Bore 3.5250in.
Stroke 3.1000in.
Rod Length 6.125in.
Piston compression height 1.2800in.
Distance --- "Top of top ring to Top of piston" 0.1800in.
Distance --- "Piston to cylinder @ Top ring land" (per side) 0.01600in.
Piston dome volume - = Dome , + = Dish 27.000cc
Piston valve pocket volume ( must = 0 or +) 0.0000cc
Cylinder block deck height 8.9550in.
Head gasket thickness (compressed) 0.0420in.
Head gasket bore diameter 3.535in.
Combustion chamber volume 37.000cc

Calculations:
Total engine displacement 242.0253 cu.in.
Bore/Stroke Ratio 1.1371
Rod length/Stroke Ratio 1.9758
Compression ratio 7.9560 :1

The major parts/features used in the engine are:

Heads
•Competition Cams - Valve Spring Cases
•Competition Cams Camshaft 264 degree duration, .500 lift and 112 degree lobe center
•Winona - 11/32"Winona exhaust valve guides
•5/16" intake guide solid 5027
•Ferrea - 1.380 " Alloy exhaust valves
•Manley - 1.600" Severe duty intake valves
•Isky - 7 degree titanium retainers
•11/32" machined valve locks
•5/16" machine valve locks
•Valve springs
•Valve seals
•Umbrella valve seals(exhaust only)
•T&D Machine 13/16" rocker shaft assembly with 1.5:1 rockers
•Custom made ARP head bolts.
•Custom rocker arm stands.
•Custom made rocker arm stand spacers.
•Winona bronze - hone custom guides, hone fit bronze guides
•Custom made rocker covers - required as all the valve gear wouldn't fit under the standard ones.
•Sport port
•Machined receiver grooves into heads.

Bottom End
•Custom 4340 4Litre Moldex stroker crank.
•Eagle 4340 Rods
•Custom Wiseco 7.7:1 dished and fly cut(to clear the valves) pistons.
•Custom single lip rear crank seal, needed because the crank end is 8thou oversized.Line bored and line honed block to Chrysler main bearings Clevite#MS-348. These are bigger than standard main bearings. When the engine was originally lined bored, it was bored offcentre by about 4thou. The bigger main bearings allowed us to reline bore on centre.
•Machined centre bearing support for integral thrust bearing.
•Machined spacers to fit between the centre bearing support and the centre thrust bearing.
•Machine main bearing tang grooves into main bearing supports for new main bearings.
•Dowel pinned girdle to block at four points.
•Machine decks to equal deck height.
•Bored and honed cylinders to 3.525in dia. using torque plates.
•O-ringed block.

Intake/Exhaust
•HKS Blow off Valve
•The exhaust dumps into custom stainless (commercial grade) headers that feed 2(two) Garret T3-TB28 Turbos The turbos are the same ones as used on the all conquering Nissan GT-R touring cars. The turbos feature integral wastegates and are water cooled via a small radiator. The turbo's have had their inlet housings changed to give more airflow.
•Each turbo has a 2 inch mandrel bend stainless steel exhaust pipe that meet in a 3 inch custom straight through muffler under the boot floor. The wastegates dump into a 1 inch pipe that is muffled through a separate section in the same muffler.
•A removable plate will allow this to be dumped straight out, prior to the muffler when racing.
•The 6" muffler is packed with exhaust fiberglass, and is a straight through system with minimal damping and has a 3" exhaust tip.
•The whole exhaust system to the rear bulkhead is to be Ceramic Coated to prevent heat getting into the cabin. The ceramic coating is amazing, whilst checking out one of the local V8 touring cars I found that I could put my hand around the exhaust header without discomfort about 3 minutes after the engine had been turned off.
•On the induction side a late model rover EFI manifold is used with a custom plenum chamber and a Holden Commodore 65mm throttle body.
•Air from the turbos is cooled via 2 HKS intercoolers that sit in front of the radiator before entering the throttle body.

Cooling Water/Oil Bits
•The 3 stage Moroso dry sump pump is driven by a belt on the back of the alternator and the oil is cooled by 2 small oil coolers.
•We've had to move away from using a dry sump, due to space restraints, but we are still using the 3 stage pump(as a 2 stage).
•The wet sump is fully baffled and holds about 9 Litres of Redline oil.
•The whole original front cover has been removed and replaced with a Gilmer drive system.
•We ditched the Chev water pump, and changed to a Davies Craig, electric water pump and controller. This enabled us to finally fit in 2 thermo fans, something we couldn't do before. See Davies Craig for more info.
•Fuel from the custom fuel tank is pumped via 2 Holden Commodore fuel pumps and is injected using Bosch injectors.
•2 oil cooler mounts have been fabricated. They sit either side of the intercooler.
•A smaller turbo water cooler has been bought and will sit into front of the intercooler in a horizontal position.
•Due to space constraints the turbo cooling system is now being integrated into the main cooling system.
•A custom 4 core radiator and thermo fan keep everything cool (I hope).

Electric's
•2 Accel DFI Coil packs send the sparks via Magnecor leads to the spark plugs.
•Both spark and fuel are controlled by a Motec M800 engine management system. This state of the art system is fully sequential and incorporates Wastegate control, Traction Control/Launch Control and Data Logging. The MoTeC will datalog exhaust gas temperature along with all normal engine parameters reducing the need for a dash full of gauges.

Unfortunately during a recent house move I lost the Motec :-( It may turn up, but I'll probably replace with a new Haltech Elite as it's a lot lot cheaper and I can do fly by wire throttle. It also supports racepak SDL3 dashes which are a lot cheaper than motec.

•Wheel speed sensors on the front wheels and the tailshaft will enable the use of traction control and launch control.

Now that's an engine! You can't post too many photos of that one. Welcome to BritishV8.

What is that going in?!

Empressive engine Byron!! I see that it is going in a 64 MGB. Will that fit in an MGB with the those headers and all the plumbing and intercooler associated with the two turbochargers?

Holy Shmaboly!
Now that's a power plant.
Beautiful work.
Uhmm...what part was Rover again?
As far as CD, even if you were driving a sheet of plywood it would still mph.

Cheers
Fred

It fits, but it is tight, I've got oodles of photos I just didn't have time to upload everything at once.

As for what part is rover, it's a fair question, it is a rover 3.5block, intake etc, we just enhanced it a little. Reliability is a concern so speed events will limit the amount of run time, and of course we can fiddle with the boost etc.

The major tasks at the moment is panelling at the rear (tubs etc). The running gear is all sorted, but needs to be checked as it's been sitting around for 13 years.

I'll post more tomorrow and you'll see that it all fits.

More soon.

Byron

A few more engine shots.

Byron

Part 2 - Weight

We did weigh the car at 1490lbs with a nice 25% split at each wheel. Not ideal for racing but I'm sure I can tweak that. Things like the turbos, battery and part of the fuel tank are on the passenger side to even up things for a solo driver. Also all weights except for radiator and intercooler are inside the axles. The car is effectively mid front engined.

I'm hoping for a wet weight of ~1750Lbs all up. We shall see.

The roll cage has to be redone (or parts of it) since 4130 is no longer allowed in Australia and what was compliant 15 years ago is no longer. I can retain bits. I will need to do that this year as I need to enclose the mid mounted full tank from the cabin, and I need the roll cage done before I tackle that. Not super expensive. Just a bit annoying.

Byron

Some more pics!

Byron

Part 3 - fuel tank

The fuel tank's been custom designed to fit behind the seats and just in front and partly over the differential to give the best weight distribution as well as capacity(65L) The design gives room for the spare wheel, and can now be installed from the top (no need to remove the diff). When it was a road car this was true. Now it's a track car I have to seal the tank off so now it has to come out underneath. This means the diff carrier has to be dropped. A little painful but not that much extra work.

The lower section holds about 20 litres, which is perfect for sprint stages etc.

Byron

Part 4 - Drivetrain

The horses are transmitted by Ford Falcon GTHO (351ci V8 Australian car) single plate clutch that fits the original Rover flywheel, and is rated at 550lb/ft of torque which should be enough. Ideally a smaller clutch (say 7 1/4") would be better, but then it would have to be twin-plate. I'll roll with the single plate for now and perhaps change to a twin plate if it fails. Clutches have come a long way in the last 15 years when we sourced the original.

Billet steel flywheel that weighs in at about 4kg. This lives in a custom bellhousing made locally by Dellow. I need to make a scatter shield for it.

A Getrag 5 speed gearbox from a Ex-Dick Johnson Racing Sierra passes power to the custom tailshaft. These cars ran around 580hp/500ft-lb for 8 hours around Bathurst on 10" slicks and as far as I know never failed. The MG is lighter and a little more power.

A custom shift mechanism that gives shorter throws and has no play. The Getrag 5 speed uses a custom gearset with a 1:1 5th gear.

The 9" differential was shortened by Harrop Engineering and has Harrop full floating hubs. A Strange Alloy Carrier holds a Detroit locker and a set of 2.75 gears. Top speed with this gearing is about 190mph.
The 9" is heavy but I was concerned about breaking anything smaller with a full power launch.

Byron

Part 5 - Suspension/Wheels/Brakes

Suspension
•The front suspension is a custom designed double A-arm arrangement using Porsche 944 Turbo magnesium front hubs. Coil-over TraxSpax shockies take the bumps with 1000Lb springs. The suspension is a rising rate design as used on most modern cars and hence requires heavy springs. The suspension was all CAD designed for the car.

•The rear suspension is a 5 link arrangement with a panhard rod setup as used on Australian Group A touring cars. Adjustable Coil-over Spax Aluminum TraxSpax shock absorbers take the bumps and 265Lb springs keep everything in place.

•It appears the bump stops have rotted over the last decade and need replacing. I'm hoping the shockies are ok. Given they've done nothing and a shock can last a decade on a car they should be fine.

•All suspension components use high quality rod ends and all tubing is 4130 chrome moly.

•Custom adjustable front and rear sway bars are made from hollow chrome moly tubing.

•A standard MG steering rack is used in conjunction with a custom steering column. We did modify it to increase the steering ration. A removal MOMO steering wheel helps access.

•A custom cross member provides radiator mount points as well as joining the 2 chassis rails together at the front of the car.

•The Chrome-moly roll cage joins all four shock absorber top mount points to ensure maximum chassis stiffness, in addition the front shock absorbers are laterally braced at the top and the bottom.

Wheels and Tyres
•Simmons FR18 Wheels are used, they are 9inches wide on the rear and 8 inches on the front. They are pretty darn light for a largish rim.

•I'm adding flares to the car (courtesy of Paul Trevathen) so I can go wider. Clearances were very tight so this gives me plenty of room and of course wider rims means wider tyres. I have external rim halves that allow me to jump and inch front and rear. But I think I can go 2 inches (11inch rear and 10 inch front). The front wheel nuts (3 piece rims) are rusted and need removing/replacing anyway. Simmons went out of business but came back and still make these rims so I will need to get that sorted before they disappear again

Brakes
• The front brakes use Porsche Big Red Calipers and discs. I need to get a radial mount to allow these to be mounted on the 944 hubs (common in the US).
• The rear brakes were some basic brakes and I need to sort something out for this. I was chasing some rare 911 GT3 calipers to go with the original front discs (12"), but that might be too hard. There are a lot of aftermarket options to explore.
•A Tilton balance bar in the custom pedal box ensures that the car stops as quickly as possible.

Byron

More pics.

More pics.

More pics.

Part 6 - Interior

•The very obvious chrome moly roll cage ties the whole car together from the rear suspension to the front shock towers. This ensures that car is incredibly rigid whilst providing real safety (and proper side intrusion bars).

•A Stack 8130 Instrument cluster incorporates all normal instruments in one convenient display that provides threshold alarms for things such as oil pressure, oil temperature etc. Switches to control the stack are in easy reach without needing to take your hand off the steering wheel. This will probably change to a Racepak dash. I'm not sure the cutout is the same size which means i'll scrap

•Various warning lights and a shift light are mounted off a single piece carbon fibre dash.

•Sparco Pro 2000 Fibreglass seats are bolted to a custom floor pan. The floor pan incorporates the seat mounts and allows the exhaust system to sit above the chassis rails. A box section replaces the normal gearbox cross-member, and holds the gearbox from the top.

•The floor pan is custom folded mild steel, and incorporates mounting bolts for the seats(using a captive nut setup). This means the seats sit as low as possible in the car.

•Bar work has been added to hold the spare tyre and the muffler.

Byron

Part 7 - Exterior

• The external body panels(except bonnet) are largely original (apart from flares). The guards are rusted and need repairs which will be fun.
•The underside of the car will have aluminum sheets fitted, which not only protects things, but it also ensures that the underbody is perfectly flat. This in conjunction with a venturi style boot floor helps airflow under the car. This also means that the lowest point on the car is the chassis rails, which enables a 100mm ride height to be used legally and without fear of bottoming out.
• Ford Falcon GTHO mirrors
•The original aluminum bonnet got the flick in favour of a fiberglass one. This made it easier to integrate the intake and extraction scoops.
•The scoop at the front of the bonnet is to extract hot air from the radiator/intercooler.
•Another scoop feeds air directly into the new intake system. This needs a hole cut into it to be complete.
• 2 Ford Cosworth Sierra scoops will sit in the rear corners of the bonnet to extract hot air.
•The spoiler needs a bit of a tidy up, and since this one gives us about 75mm of ground clearance.
•The spoiler is flared at the sides to ensure airflow is not interrupted by the tyres.
•A splitter will also be fitted.
•Not shown in the photographs is the bottom of the spoiler that has an integral venturi to provide a small amount of downforce.
• A rear wing has been sourced from an RX7 sports sedan.
•This is not some poser wing and will provide noticeable downforce. It will most likely be mounted from the centre of the boot, via an adjustable mount (TBA)
•Ends will added to the wing prior to painting it in the same colour as the body

Byron

More pics

Very very impressive. I really like that you have been able to get the ground clearance by keeping everything above the chassis rails, this is something I will be going back to fix on mine. I didn't see the fender flares in the pictures but I know that can be another sticking point on the ground clearance. It was for me so I'd say go big, especially with those wheels. Rear clearance was tough while trying to keep the monocoque together under the flares. I really like your watts link in the rear, very clean. I'd love to see more pictures of it all together, this has got to be one of the most impressive and well engineered MGB builds I've seen.