Vantage Turbo: Engine Disassembly

As you all know from previous posts we have bought a spare engine that will be rebuild with stronger internals. Additionally we will replace parts and strengthen the stock design where needed and where possible.

The Aston Martin Vantage V8 engine is based off the AJV8 engine developed by Ford (FoMoCo) for Jaguar and Landrover platforms. The Aston Martin V8 engine however is just loosely based on the Jaguar engine, it has a different casting for the shortblock, uses different internals and has a completely different head. We started taking off the heads. Here is a pic of the shortblock.

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The AM V8 engine has very small cylinder sleeves (liners). These have a wall thickness of 2mm. This should be sufficient for 400HP, but for our goal we will need to have these replaced by liners with thicker walls.

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The main bearing caps are all integrated in a girdle like construction. A lot of engine designers use this system, for example Honda K20 and Nissan VR38 (also in the first picture). The girdle is bolted on the block with a 4 bolt main construction. The inner bolts are M10 and the outer bolts are M8. We are considering tapping the outer holes to M10 as well, but currently no decision has been made. Sidebolts are not needed as the bearing caps are part of the whole girdle / ladder construction.

Last item to discuss for this time is the conrod. The early 4.3 model engines received very good conrods from Aston factory. Later model engines, especially this 4.7 model engine received very weak conrods made out some sort of forged powder metal. These rods are known to be weak and will break with the least amount of boost. The conrods will be replaced with proper aftermarket units.

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In the picture you can see the stock Aston connecting rods. Attached on the top of the rod is the piston. The piston does look decent, however the piston is not suitable for our project. Our project will require a piston that will fit in the sleeve with thicker walls and we will also lower the static compression of the engine, otherwise the engine will knock when boost comes in.

 

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