Is the GT4 (2010) 4.7L engine diff from 4.7L road engine?

[oxf88]

Is there any difference between the 4.7L engine found in the 2010 GT4 race car and the 4.7L found in the 2009-2017 road car?

I know the road engines vary slightly- Vantage (420bhp), Vantage S (430bhp) and GT8 (440bhp) but that's mostly because of remaps?

I found this document:

https://astonmartin.blob.core.windows.net/sitefini...

but it only says:

"Aston Martin Racing 4.7 litre V8 engine"

[AstonV]

This is an interesting video. I sort of answers the question.

https://m.youtube.com/watch?v=srUqoPkn8yU

[nickv8]

AstonV said:

This is an interesting video. I sort of answers the question.

https://m.youtube.com/watch?v=srUqoPkn8yU

Thanks for posting that! Interesting to learn how much was taken from the road car. For example, I thought the race car would have had a different power steering system. Nice to know how good the road car is!

[Jon39]

A great video which I always enjoy watching.

My favourite line is, "We've got some spikes coming out".

[RL17]

Great seeing GT4's with bonnets up at races and great video - thanks for posting.

So 2017 Vantage GTE engines based on 4.7 V8 but either linings or cyclinder head changes it to a 4.5 litre V8?

[RL17]

4.5 V8 500BHP at Silverstone 6 hours WEC 2018

[EVR]

Interesting stuff, both the video and the PDF, thanks for posting.

[oxf88]

RL17 said:

4.5 V8 500BHP at Silverstone 6 hours WEC 2018

Hi, that's the GTE though, not the GT4.

[The Surveyor]

I've a GT4 sales brochure at home, I'll dig it out and if there is anything more than shown on that link, I'll scan the relevant section and post it up.

[oxf88]

AstonV said:

This is an interesting video. I sort of answers the question.

https://m.youtube.com/watch?v=srUqoPkn8yU

I presume you're referring to 3:40 in the video? However, if the engine was purely-standard, Prodrive wouldn't be building it, so there must be some differences from the road car.

Here's a link to same video, but straight to the GT4 engine section:

https://www.youtube.com/watch?v=srUqoPkn8yU&t=...

After watching again, he does seem to keep repeating the GT4 is a standard engine........

Edited by oxf88 on Wednesday 18th December 18:10

[V8V Pete]

Not sure about the Prodrive prepared engines but the BR GT4 engine has some uprated internals, cylinder head porting and is dynamically balanced. One day .............

[KevinBird]

http://cdntb.astonmartin.com/sitefinity/racing/Van...

[Thorburn]

Family friend hillclimbs a 2015 or 2016 (whichever year they started giving the V12 Vantage bonnet vents) Vantage GT4, along with building up a 4.3 based car specifically specced for hillclimbing.

I think the GT4 drivetrain is very close to that of the road-car, I'm sure he even said it had the SS2 gearbox, where as the 4.3 he was building had a proper sequential box.

GTE is a very different animal.

Edited by Thorburn on Thursday 19th December 12:50

[Dewi 2]

Thorburn said:

Family friend hillclimbs a 2015 or 2016 (whichever year they started giving the V12 Vantage bonnet vents) Vantage GT4, along with building up a 4.3 based car specifically specced for hillclimbing.

I think the GT4 drivetrain is very close to that of the road-car, I'm sure he even said it had the SS2 gearbox, where as the 4.3 he was building had a proper sequential box.

Interesting. I have spoken to your friends at a couple of hillclimbs. Their driving is on a shared basis.
I do love my Vantage, but it puzzled me that a brand new GT4 had been selected, to use only for hillclimbing.
A beautifully prepared car, but only driven in anger for a few hundred yards. Nearly all GT4s are race circuit cars.
Wonder if their car has clock up 500 miles yet?
Most British hillclimbs are on narrow roads, so a very light nimble car tends to generally be the best choice.

Look forward to seeing their follow up 4.3 on the hills.
That might be a lower cost way to create a hillclimb Vantage.

[oxf88]

RL17 said:

So 2017 Vantage GTE engines based on 4.7 V8 but either linings or cyclinder head changes it to a 4.5 litre V8?

Not quite. The GTE engine evolved from the GT2. This was based on the 4.3, but the cylinder head changes increased it to 4.5.

At least that's what Wikipedia says:

https://en.wikipedia.org/wiki/Aston_Martin_Vantage...

The Aston Martin Vantage GT2's engine is a modified version of the standard 4.3-litre AJ37 V8 from the road car. The larger 4.5-litre engine retains the road car’s cylinder block, heads and crankshaft, but uses competition components, including cylinder heads, con-rods, valves, camshafts and a racing exhaust system.

[v8vantage]

These were the changes on the 2007 N24 4.3, the 4.7 GT4 is not that much different.

Engine & Transmission
Cylinder heads re-profiled, smoothed inlet & exhaust ports and optimised compression ratio
Crankshaft, conrods, pistons and flywheel lightened and balanced to race standards
ITG cylindrical foam air filters
Reduced cell density primary catalysts
Revised engine calibration (97 RON fuel)
EGR & secondary air system removed
Simplified oil breather system with catch tank
Weight reduced rear muffler without by-pass valves
Air conditioning system and compressor removed
FIA approved ATL bag type fuel tank with twin fuel pumps -100L capacity.
Filling point built into the right hand C-post with facility to accept a quick fill 'dry break' arrangement
Standard 6-speed manual transmission – fitted with breather catch tank
Valeo twin plate cerametallic clutch (215mm) with lightweight flywheel

Lots more details here: http://www.v8vantage.com/n24spec.html

[Dewi 2]

oxf88 said:

RL17 said:

So 2017 Vantage GTE engines based on 4.7 V8 but either linings or cyclinder head changes it to a 4.5 litre V8?

Not quite. The GTE engine evolved from the GT2. This was based on the 4.3, but the cylinder head changes increased it to 4.5.

At least that's what Wikipedia says:

https://en.wikipedia.org/wiki/Aston_Martin_Vantage...

The Aston Martin Vantage GT2's engine is a modified version of the standard 4.3-litre AJ37 V8 from the road car. The larger 4.5-litre engine retains the road car’s cylinder block, heads and crankshaft, but uses competition components, including cylinder heads, con-rods, valves, camshafts and a racing exhaust system.

I am puzzled by the capacity of the GTE engine.
At a Prodrive factory visit a few years ago, they said the base for the 4.5 litre engine was a 4.3.
At that time, the 4.3 was not in production.
The capacity of the engine cannot be changed by the cylinder head, because the capacity represents displacement.
The change must be to the bore or stroke. I suppose a bore change would be simpler.
Does anyone know what the changes were ?

[8Tech]

Dewi 2 said:

I am puzzled by the capacity of the GTE engine.
At a Prodrive factory visit a few years ago, they said the base for the 4.5 litre engine was a 4.3.
At that time, the 4.3 was not in production.
The capacity of the engine cannot be changed by the cylinder head, because the capacity represents displacement.
The change must be to the bore or stroke. I suppose a bore change would be simpler.
Does anyone know what the changes were ?

Quite correct. The capacity is directly linked to the bore and stroke so the heads would only be able to alter the compression on their own. They will undoubtedly be ported if the regulations allow it in the class they are being entered. If torque was the most important feature of the engine power delivery, then the stroke would be retained and the bores altered to suit. If power was more important, then the engine would rev more freely with the larger bore and a slightly reduced stroke.

A shorter stroke reduces piston and rod loads and reduces piston ring travel (friction) leading to a free revving engine whereas the longer stroke increases the rod angle to increase torque on the crank. A short stroke engine is often described as "over square" when the bore is greater than the stroke, whilst a long stroke engine is referred to as "under square" and uses a stroke greater than the bore. Reducing the stroke would probably require using longer connecting rods unless the block was shortened, unlikely as the block needs to be unchanged.

The inlet manifold tract length is also a great influence on power and torque and this is why the Le Mans DBR9's used the longer manifolds from the DB9 rather than the shorter manifolds from the higher powered DBS. F1 cars use the best of both worlds with variable length inlet manifolds, also moving the fuel injector positions variably to suit.

8Tech.

Edited by 8Tech on Thursday 19th December 19:54

[oxf88]

Dewi 2 said:

I am puzzled by the capacity of the GTE engine.
At a Prodrive factory visit a few years ago, they said the base for the 4.5 litre engine was a 4.3.
At that time, the 4.3 was not in production.
The capacity of the engine cannot be changed by the cylinder head, because the capacity represents displacement.
The change must be to the bore or stroke. I suppose a bore change would be simpler.
Does anyone know what the changes were ?

My apologies, I took the "cylinder head" comment from the person I quoted.

[oxf88]

v8vantage said:

These were the changes on the 2007 N24 4.3, the 4.7 GT4 is not that much different.

Engine & Transmission
Cylinder heads re-profiled, smoothed inlet & exhaust ports and optimised compression ratio
Crankshaft, conrods, pistons and flywheel lightened and balanced to race standards
ITG cylindrical foam air filters
Reduced cell density primary catalysts
Revised engine calibration (97 RON fuel)
EGR & secondary air system removed
Simplified oil breather system with catch tank
Weight reduced rear muffler without by-pass valves
Air conditioning system and compressor removed
FIA approved ATL bag type fuel tank with twin fuel pumps -100L capacity.
Filling point built into the right hand C-post with facility to accept a quick fill 'dry break' arrangement
Standard 6-speed manual transmission – fitted with breather catch tank
Valeo twin plate cerametallic clutch (215mm) with lightweight flywheel

Lots more details here: http://www.v8vantage.com/n24spec.html

Thanks. However, even if we assume the GT4 is same as N24 above, is this different from the 4.7 road car?