Triumph 2500 2.7L fastroad setup.
Hear my car :
Build and mechanical details
The Triumph 2500 2.7L 6 cylinder Lump:
- Fast Road Camshaft reground by Surecam from a standard ‘S’ cam,
- 0.291″ camlift equating to 0.403″ at the valve,
- 224 duration at .050″ camlift,
- Block Overbored to 2.7L,
- Rotating assembly has been balanced,
- Standard (balanced) con rods,
- Hepolite pistons(intended for Mazda 626 engine),
- 6>2>1 Fast road 2-piece Moss TRIUMPHTUNE extractors – with a ceramic coated exterior,
- 2.25″ exhaust re-routed for straight path (right hand trailing links customised for this),
- TriumphTune Spin on alloy oil filter conversion with Valvoline V032 Filter,
- Serck Marston “Speed” 13 Row Oil Cooler on custom alloy brackets. Mounted on front engine cross-member.
- Uprated Oil Relief spring,
- Modified 219015 casting cylinder head with large stainless steel valves, shaved to 9.5:1 compression (kept street-able) and setup for unleaded fuel,
- Double Thrust Washers on Crank,
- Double Valve springs,
- o-rings on valve stems (MG style mod),
- Stag Valve Spring retainers,
- Re-faced cam followers and rocker arms,
- Goodmans Rocker oil feed line,
- Stainless, braided clutch line,
- Magnetic Sump Plug,
- Alloy, finned rocker cover with custom machined nuts (courtesy of Roger King),
- Cold air supply through front mounted K&N Conical Filter (Forward of the radiator),
- Compression Test results for 1, 2, 3, 4, 5, 6 gives 150, 160, 160, 150, 170, 145 psi. Averaging out to 155psi and a worst case reading spread of 8.8% across cylinders. Not great perhaps for a new engine???
- Lucas Mk2 Injection setup (converted for use with unleaded fuel) and running lightly customised (read: brazed in place) linkages ,
- Powder coated intake plenum,
- Re-profiled Metering Unit to suit fast road camshaft. Bench calibrated to my camshaft by Greg Tunstall (then hand tweaked using A/F meter in car),
- Bosch electronic Fuel Pump fed by an old Subaru facet style low pressure pump,
- Twin fuel filter setup with pre and post pump filtering,
- High Pressure in car liquid filled Fuel Pressure Gauge,
- Scorcher Ignition System (with plug-in mapped advance curve module) by Performance Ignition Services – set at 10deg BTDC. Providing 30 degrees advance from static,
- High Energy coil,
- Magnacore Ignition leads,
- NGK Iridium BPR6EIX Plugs with increased gap (debatable as to whether this is a suitable heat range).
- Jacobs Electronics OptoTimer (currently not functioning).
- Lowered by 1.5″,
- KONI Classic RED Struts on all 4 corners,
- Custom built box-steel Front strut tower brace,
- Yokohama A539 195/60/14 tyres on refurbished ‘S’ rims,
- Oversize Whiteline (Selby’s) front anti-roll bar on custom mounts with rose-joints welded into the lower a arms,
- Rear anti-roll bar,
- Rev limiter (ignition cut out type) as part of Jacobs system (currently disabled W0000t!) inc. gear shift warning bell (two stage warning before rev limit).
- Fire extinguisher (under dash mounted).
- Master Electrical overload / cut-out switch 150A,
- Fuel System Cut-out switch,
- Oversize Aussie version of 2500 radiator,
- Thermostat controlled 350mm Davies Craig electronic cooling fan,
- Front Spoiler (ex Dolomite 1850),
- Sound-deadened Under-body,
- Sound deadened, heat proofed interior (floors, inside doors, under seats and over rear wheel arches)
- Boot, engine bay and body over top half of doors, door surrounds and around front grille has been resprayed in black,
- Power Steering (standard)
- Reconditioned Steering Rack (3rd time now in 15 years.. sigh),
- Bosch 60A Alternator with custom-built bracket and rose-jointed tensioner, attached to a front engine plate bolt using a 1155mmx11mm belt (hanging out wide away from plug #1 for a change)
- Custom loom in various places, particularly the engine bay,
- Halogen Main beams with relays on all white lights,
- Halogen Driving lights (mounted on spoiler),
- High-torque Light-weight IMI Custom Gear Reduction Starter Motor (essential – would not start when hot with standard starter),
- Remote control Central Locking and engine immobiliser,
- Powered O2 sensor fitted at extractor y-piece collector and connected to an air/fuel ratio gauge in car.
- Electronic oil pressure Gauge by AutoGage,
- Rear battery conversion (heavy duty cable inside flexible conduit – routed to rear right boot area and contained in a marine battery box),
- Customised Dashboard with Smiths Manifold vacuum gauge and electronic oil pressure gauge.
- Beige carpets and furflex (was bloody horrible chocolate brown).
- Late model pale cream coloured TC seats (part cloth / part vinyl) – better wearing than the all velour ones of the ‘S’.
- Customised center console with cherry wood (more like that of the Stag i.e. mostly wood with a black leather gear shift gaiter rather than the vinyl stuff).
- Standard Lockheed calipers and Drums with harder pads,
- Vacuum Booster Tank on brake servo,
- Reconditioned (for the third time so far) 4spd gearbox with J-Type overdrive (operating on 2nd, 3rd and 4th),
- Lightened Stock Flywheel,
- 4.11:1 Differential
- 1.7/8th Inch Clutch Slave Cylinder (up from the 1.3/4 standard),
- Breather line fitted to gearbox,
- Rebuilt Dif, hubs and half shafts,
SO WHAT’S IT LIKE:
The current motor was installed at 77,315km.
It’s seen 7200RPM at short bursts but we’re limiting it to 6500 as this is still a standard crank and don’t want any surprises. Even though it will rev right through the factory red line I don’t see any point in going much harder than about 6700.
There’s been some trouble with rough starts and rich idle due to an incorrectly configured metering unit (and linkage trouble), but it’s a reliable piece of fun now. I still have had the occasional 4 or 5cyl only starts when hot and need to rev it for about 30sec to make it even out. Someone mentioned something about dodgy banjo bolts…. In truth I think it was the dodgy injector I found a while ago – see the blog for comments.It goes much harder than the standard S motor but not as hard as I would have hoped. I was aiming for 180-200 BHP but compared to other cars I think it would be more realistic to say that it puts out 160-180 BHP.
I plan to install a roller rocker kit – hopefully will get away with an increased ratio kit without putting a valve through a piston crown or binding up the valve springs (fingers crossed).
It pulls strongly from about 1500 upwards in any gear – but below that it can be rather lazy. It’s too lean down low and I’ve had trouble sorting this out – although it now seems good.. I think the min-fuel setting on the metering unit is to blame but have also had trouble sorting out a good linkage setup. I have trouble with part throttle operation unless the choke is out a bit. It comes on song near 3500 RPM and keeps going effortlessly up past 6 – and if you’re keen it will wind right off the tacho but the power curve starts dropping off a little after 6 anyway. It feels like peak power is somewhere up in the mid 6’s which is strange as the cam profile suggests more like 5800. I’d also guess that peak torque was somewhere around 2500-3500RPM. Compare all of this to the original motor which felt like it was going to fly apart as it hit a brick wall at 5650RPM (power also fell off steeply after 5000). I don’t think I’ve lost any of the low RPM torque of the original motor.
The handling mods have resulted in something very chuck-able, very reliable and predictable, but it has resulted in greater under-steer than the original setup – especially with the addition of the rear bar. Flexibility over nasty humps on curves and steep driveway entrances is terrible given the reduced wheel travel – but on the street and HWY it is a treat to drive – being very very direct in hand and stable to boot.The Bosch pump is noisy – and the increased strain on the alternator often left me with a dead battery (after night time driving) so I recommend an alternator upgrade if you’re adding more ‘always-on’ electrical items as I have.
Prior to fitting the oil cooler the pressure was fairly inconsistent and gave 80PSI at 800RPM cold, 20PSI at 800RPM hot and 60PSI at 2500RPM. After oil cooler installation pressure figures changed to 65, 28 and 60PSI respectively so as you can see the pressure stays much more consistent and the extremes have been chopped off. I am not yet running a thermostat on the cooler so I will comment on that later. I’m concerned about winter operation being too cold.It idles with 9-10inHg of manifold vacuum and although a bit cammy it will idle suitably as low as 500 if you were so inclined. I leave it at 7-800RPM idle for smoothness sake. However, given my lean fuel low RPM issues I’ve noticed the engine a lot nicer to use if the idle is set at about 1000RPM. I’m not sure why this is.
- 1.6:1 Alloy Roller Rockers + increased valve lift ratio.
- BMW vented brake rotors on front.
- Volvo four pot calipers on front.
- Datsun Roller Half-shafts.
- Finned alloy brake drums from Datsun 240/280 OR a custom rear disc brake conversion.
- Brake ducting for cooling of front discs.
- Electronically managed Water Injection.
- Ducting to cold air intake to give positive air pressure at the filter.
- Alloy water pump pulley and housing.
- Alloy radiator.
- Baffled Sump.
Nearly finished… crappy old wheels though… (04/01/2017)
Just ironing out the final bugs in the rebuild before the big reveal. Still to do:
- new wheels and tyres
- minor electrical bugs (reverse lights)
- some clear skin barrier to cover damage prone areas
- one more good polish to be sure...
Audio Gear (04/01/2017)
- Pioneer DEH-X4650BT Bluetooth CD Head Unit with phone mic mounted on steering column
- Pioneer GM A6604 760W 4 channel amp in bridge mode running rears
- Sony XM-N1004 1000W amp running fronts and mids
- Pioneer TS-A6965S 6×9″ 3-way speakers rear-mounted
- Pioneer TS-G1645R 6.5″ 2-way speakers front-mounted
- Pioneer TS-G1345R 5.25″ 2-way speakers mid-mounted
- All cables routed underneath sound proofing
Special Interest Projects
I've tried quite a few different guns mostly suction but recently got a gravity feed and love it. I reckon I'll try and get some more HVLP gravity fed guns and drop the suction stuff. They're too tricky to get all the paint out of and I tend to waste stuff. Easier to clean gravity fed too.
Stag – 2500 S Alloy Wheel Refurbishment
I'll post full details here when I get the other photos processed. Basically: 1. Paint stripper. 2. Lathe down the edges to be clean OR 2. Hand file any marks out using fish oil as a lubricant for the file and regular cleaning of the file. 3. Work down to a smoother finish using various grades of wet/dry paper with water or fish oil. 4. Polish using a buff wheel on a high speed rotary tool. 5. Mask with loads of tape and use a razor blade to strip back the tape to be the exact shape of the areas not to be painted. 6. Etch Prime the surface. 7. Spray loads of coats of a gloss black that isn't so hard that it will take some beating. 8. Remove masking tape. 9. carefully File/Smooth any paint edges that are stuck up and capable of being caught and flaked off. 10. Touch up any damaged / missed areas using a fine brush (gloss black). 11. Wipe off overspray using thinners. Make sure the inner area is clean and smooth so that tyre will seat properly and not leak air.
Kienzle Clock repair
The clocks in the 2000/2500/dolomite saloons always seem to be busted. Mine ran fine but gained at least 10 minutes every couple of days. I pulled it out of the dash with the plan to adjust the speed and as usual the white plastic ring which holds it in place got busted. After fiddling around and then plugging it back in it made an electric pop/click and failed to function. Now my plan is to work out why it is dead and get it running.