5-Cylinder turbo golf
Posted: Sun Mar 19, 2017 3:47 pm
Ok then, time to share with all of you my project as promised. Sorry its taken so long, my daughter has been showing me how to upload photos to the forum. I'll be needing some help and advice from you decent folk in the future so its fair that I share with you what I'm building.
Its a 150HP NA Volkswagen engine I imported from the USA. It has more or less the same base specification as the 340HP turbo lump found in the Audi TT-RS and RS3.
2480cc
Cast iron block, cast aluminium head
82.5mm bore
92.8mm stroke
10:1 compression
Cast aluminium internals
The Audi turbo engine has forged internals and slightly lower compression but the main difference is that they used FSI rather than port fuel injection as on the VW version. To buy a complete Audi engine would cost anywhere between £5k and £10k. I paid $500 for a complete VW engine then £750 to ship it, so a small saving there. There are some other technical differences which I will explain in detail as I go on.
Engine, stripped of most ancilliaries, mounted to 5-speed gearbox.
Original intake manifold was this big ugly plastic thing. Ditched that for a genuine cast alloy one from Audi. Its a work of art. The plenum is divided internally with charge being forced through a wide slit before entering the runners. This promotes laminar flow, I guess?
Cylinder head removed. It has now been stripped, ready for porting although its worth pointing out that in standard form it flows pretty well apparently. You can see the solenoid for the intake VVT sticking out at the top. The engine is chain driven and the timing can be thrown out by rotating the engine in reverse so it was a relief to find everything straight inside.
The Audi FSI engine has sodium filled exhaust valves which conduct heat better. They are identical in size so I have bought genuine ones to swap out. I weighed them and they are 2.5g lighter each due to the sodium core.
The FSI intake valve heads are 1.5mm wider so I bought some of these too. The head will be gas flowed for good measure.
On closer inspection I found that the lobes on the cams were heavily pitted. The mating surfaces of the rockers were also shot. This engine hadn't been looked after too well by the previous owner(s). The top end of these engines are prone to wear if the oil isn't changed on a regular basis.
Block, completely stripped and ready for machining...
...for these forged JE pistons. I bought them before the engine had arrived so ordered slightly oversize (83.0mm) just in case the bores were scored. I sent the pistons off to Camcoat for ceramic coating of the crowns. They did a fantastic job.
The pistons will be mated to IE forged rods with AGE625+ bolts. I'm hoping to set the rpm limit much higher than standard.
When VW started making these engines in 2005 they used forged cranks. In 2007 they changed to cast ones - maybe for cost reasons as forged cranks are totally unnecessary in a NA engine. My engine came with a cast crank (on the right) so I bought a forged one (on the left) from an early engine. VW also changed the timing chain (see difference in sprocket width).
Light weight flywheel from TTV Racing. I'm worried that its maybe even too light at 2.7kg. The new one is on the left.
Rotating assembly, ready for dynamic balancing. The rods and pistons will also be balanced.
Bosch 1000cc (@ 3 bar) long nose injectors. High impedance of course. I chose these because they have a wide spray pattern. Took me ages to find - most high flow injectors seemed to be of a rotating ball/plate design which produces a thin jet like a garden hose. I'm not convinced that atomisation would be any better with those.
More interesting (in my opinion) photos to follow soon.
Its a 150HP NA Volkswagen engine I imported from the USA. It has more or less the same base specification as the 340HP turbo lump found in the Audi TT-RS and RS3.
2480cc
Cast iron block, cast aluminium head
82.5mm bore
92.8mm stroke
10:1 compression
Cast aluminium internals
The Audi turbo engine has forged internals and slightly lower compression but the main difference is that they used FSI rather than port fuel injection as on the VW version. To buy a complete Audi engine would cost anywhere between £5k and £10k. I paid $500 for a complete VW engine then £750 to ship it, so a small saving there. There are some other technical differences which I will explain in detail as I go on.
Engine, stripped of most ancilliaries, mounted to 5-speed gearbox.
Original intake manifold was this big ugly plastic thing. Ditched that for a genuine cast alloy one from Audi. Its a work of art. The plenum is divided internally with charge being forced through a wide slit before entering the runners. This promotes laminar flow, I guess?
Cylinder head removed. It has now been stripped, ready for porting although its worth pointing out that in standard form it flows pretty well apparently. You can see the solenoid for the intake VVT sticking out at the top. The engine is chain driven and the timing can be thrown out by rotating the engine in reverse so it was a relief to find everything straight inside.
The Audi FSI engine has sodium filled exhaust valves which conduct heat better. They are identical in size so I have bought genuine ones to swap out. I weighed them and they are 2.5g lighter each due to the sodium core.
The FSI intake valve heads are 1.5mm wider so I bought some of these too. The head will be gas flowed for good measure.
On closer inspection I found that the lobes on the cams were heavily pitted. The mating surfaces of the rockers were also shot. This engine hadn't been looked after too well by the previous owner(s). The top end of these engines are prone to wear if the oil isn't changed on a regular basis.
Block, completely stripped and ready for machining...
...for these forged JE pistons. I bought them before the engine had arrived so ordered slightly oversize (83.0mm) just in case the bores were scored. I sent the pistons off to Camcoat for ceramic coating of the crowns. They did a fantastic job.
The pistons will be mated to IE forged rods with AGE625+ bolts. I'm hoping to set the rpm limit much higher than standard.
When VW started making these engines in 2005 they used forged cranks. In 2007 they changed to cast ones - maybe for cost reasons as forged cranks are totally unnecessary in a NA engine. My engine came with a cast crank (on the right) so I bought a forged one (on the left) from an early engine. VW also changed the timing chain (see difference in sprocket width).
Light weight flywheel from TTV Racing. I'm worried that its maybe even too light at 2.7kg. The new one is on the left.
Rotating assembly, ready for dynamic balancing. The rods and pistons will also be balanced.
Bosch 1000cc (@ 3 bar) long nose injectors. High impedance of course. I chose these because they have a wide spray pattern. Took me ages to find - most high flow injectors seemed to be of a rotating ball/plate design which produces a thin jet like a garden hose. I'm not convinced that atomisation would be any better with those.
More interesting (in my opinion) photos to follow soon.