Triumph Dolomite Sprint Valvetrain in Motion

Firstly, apologies for the poor quality - this was shot on my digital camera some years ago.

Anyway - after some serious abuse the head gasket on my Triumph Dolomite Sprint gave way - and before finishing the rebuild I thought it'd be interesting to see what the single-overhead cam looked like in operation.

The Sprint was fairly unique in being the first European (I think) production car with a 16 valve engine - yet it only had one camshaft, similar to later Hondas. The intake valves were operated directly by the cam, and the exhaust valves were operated by 'finger' rockers that ran off the cam and onto the valves.

The engine in standard form displaces 2 litres (1998cc) and was factory rated at 127BHP and 122ft.lb. Blueprinted engines with slightly larger carbs easily made 150-160bhp.

After the headgasket was replaced, the car went on to compete in a few track days and several thousand miles later it's still going strong as far as I'm aware! A job well done.....

The engine wasn't harmed by spinning it over like this - obviously it can't fire because the plug leads are out and even if it did, all it would do is spray oil everywhere! You wouldn't want to drop anything into the head, though.

The video is so brief because this was taken on-the-fly just as the engine was almost ready to run again - I was turning it over on the starter to see if it was still timed right and free to rotate, after having turned it over by hand a few times.

Category:

Autos & Vehicles

Tags:

• Triumph
• Dolomite
• Sprint
• engine
• rebuild
• valvetrain
• valve
• train
• operation
• cranking
• head
• gasket
• exhaust
• intake
• rockers
• SOHC
• DOHC
• VTEC
• 16v
• sixteen
• 127bhp
• retro
• classic
• modified
• custom
• racer
• engineering
• exposed
• parts
• track
• day
• drag
• straight
• four
• slant
• timing
• chain

[LashoutUK]

@firehawk400 Rumour has it they did that at one point, and made well over 300BHP on a dyno. You could easily fit one head straight on (spacing and fittings are the same) but you'd have to make a mirror casting for the other head - which obviously is very expensive and time consuming. Doable, though! You could alternatively cut the cam drive off a head and reverse it, re-weld it on the other end. Tricky but, again, possible!

[fleetwoodsucks]

Is it bad running it without a rocker cover?

Mind you it looks pretty well lubed up so I guess not.

[LashoutUK]

@fleetwoodsucks Well, you obviously wouldn't want to drop anything in it! Other than that it does it no harm - all the rocker cover does is prevent anything hitting, or getting into, the valvetrain (dust, debris, fingers) and it also stops the oil that's flung off the cam and rockers getting all over the engine bay.

As an example, really early engines had exposed valvetrains - but you did have to lubricate them by hand to keep them going properly now and again.

[LashoutUK]

@fleetwoodsucks ......and you're quite right - the whole thing had been lubed at reassembly and I'd liberally sloshed oil all over it before turning it over. It already had oil pressure at this point, too :-)

[ACTractionLTD]

Ah Brilliant! love dollys :D

[firehawk400]

If you managed to find 2 of these 16v heads, could they (at least theoretically) be modified to fit a Stag V8? I know they won't bolt up out of the box, but I wonder if they could be made to fit...

[HVdischarge]

Trade it for my 1850 engine? :-P lol

[straylightOz]

what a great vid. thanks

[MidEnginedV10]

this is more interesting than girls!