The V8 Owners Forum -

chodjinn wrote:

Nollywood wrote:^^^Not sure what the Volvo 2,4 I6 TD made, torque-wise, but I would imagine the M47 trans will cope just fine, as long as it's driven with respect.

Well, bear in mind an MGB weighs a lot less than either an S8 or a 740!

How's the wiring on one of these? Lots to mess around with?

True, the MGB's a light weight.

The Bosch Motronic ME.5 is a doddle. I'm pretty used to Motronic, in any automobile. Color codes don't change much, however pin-outs do.

Update 13th November 2012:

I listed the B5 A4 on eBay as breaking for spares, so I can sell off the parts I won't require for this build project.

I have provisionally sold the 01A 5-speed gearbox, and the 2.6 V6 engine has had mild interest. Either way, if the gearbox sells tonight, it means I will definitely have to pull the engine and trans.

Once the engine bay is empty, I'm going to give it the "minimalistic lool." So this means anything not essential to this build will either be binned, or sold. I'm then going to thoroughly degrease the bay, and steam clean. The idea is to have it prepared, rubbed down, and primered. Then apply final coat of satin black. Of course I'm deleting the secondary firewall, so all this work will be done in tandem.

eBay auction for the gearbox ends tonight at 21:29 hours, so we'll see. If she doesn't sell this time around, I still want to pull both the gearbox and motor next week, when hopefully, I'll have more time on my hands.

And further to my previous update, the 2.6 V6 engine sold on eBay. So it's time to yank it out, together with the 5-speed manual. Tomorrow the car will be moved into position - I have to do some manipulation of vehicles, to swap positions.

Picture updates to follow.

Nollywood wrote: Picture updates to follow.

:rubs hands in anticipation

Chris.

Update 17th November 2012:

The buyer of the 01A 5-speed manual called me today, and is coming down to pick it up tomorrow! Which means I've got to work like a trojan, pulling it both the gearbox and engine, then separating them.

Early morning start then!

Update 17th November 2012:

It was an early start for me. By 0830 hours, I was down in the garage. I didn't get much sleep the previous night, as my 4-month-old daughter decided she wasn't sleepy, which meant my 28-month-old wanted to play with her too. Still, it's all good!

The 2,6 V6 engine sold on eBay, and so did the 01A 5-speed gearbox. The gearbox was scheduled for pick-up after 1800 hours, so it meant working fast. The engine and gearbox can be removed as one unit, then separated on the bench. Or both units can be pulled separately. I chose option two, and by 1622, both engine and box were out.

The weather was good, a bit of early morning mist and very light rain, which soon stopped anyway. So I made good time. Engine bay was not as dirty as I thought it would be, but still needs a good steam clean, and preparation for paint in satin black.

Pictures!

More...

...And more...





The outgoing 01A 5-speed manual...





The outgoing 2.6 V6 12V...



And the incoming 4,2 V8 32V, mated to an 01E 6-speed manual...

The next step is to remove the secondary firewall, then prep the engine bay for paint. I also need to run the new battery cable to the rear, as the battery will reside in the trunk.

So is the old V6 a 90degree V6?, does it have a balancer shaft?

Chris.

ChrisJC wrote:So is the old V6 a 90degree V6?, does it have a balancer shaft?

Chris.

Yes, the V6 is a true 90 degree V. No balancer shaft, but they are super smooth, even at high RPM.

Nollywood wrote:

ChrisJC wrote:So is the old V6 a 90degree V6?, does it have a balancer shaft?

Chris.

Yes, the V6 is a true 90 degree V. No balancer shaft, but they are super smooth, even at high RPM.

I wonder how they do that, because it ought to be absolutely shite!

Chris.

One option is that you don't have the rods share the same pins

ChrisJC wrote:
I wonder how they do that, because it ought to be absolutely shite!

Chris.

Balance and smoothness

Due to the odd number of cylinders in each bank, V6 designs are inherently unbalanced, regardless of their V-angle. Each cylinder bank in a V6 has an odd number of pistons, so the V6 also suffers from the same problem unless steps are taken to mitigate it. In the horizontally opposed flat-6 layout, the rocking motions of the two straight cylinder banks offset each other, while in the inline-6 layout, the two ends of engine are mirror images of each other and compensate every rocking motion. Concentrating on the first order rocking motion, the V6 can be assumed to consist of two separate straight-3 where counterweights on the crankshaft and a counter rotating balance shaft compensate the first order rocking motion. At mating, the angle between the banks and the angle between the crankshafts can be varied so that the balancer shafts cancel each other 90° V6 (larger counter weights) and the even firing 60° V6 with 60° flying arms (smaller counter weights. The second order rocking motion can be balanced by a single co-rotating balancer shaft.).

A 90° V6 can use almost the same technique that balances an even firing 90° crossplane V8 in primary and secondary order. A flatplane V8 is in primary balance because each 4-cylinder bank is in primary balance. In a crossplane V8, balance is achieved at each cylinder pair, since the primary imbalance of a 90° pair is a special case that can be cancelled with a crankshaft counterweight. Secondary balance is achieved by the staggered arrangement of the crossplane crank. A simple 90° V6 with crankshaft counterweights achieves good balance for similar reasons, although the uneven firing intervals will be perceived as roughness at low RPM, making this an unpopular solution. Therefore, designing a smooth V6 engine is a much more complicated problem than the straight-6, flat-6, and V8 layouts. Although the use of offset crankpins, counterweights, and flying arms has reduced the problem to a minor second-order vibration in modern designs, all V6s can benefit from the addition of auxiliary balance shafts to make them completely smooth.[6]

When Lancia pioneered the V6 in 1950, they used a 60° angle between the cylinder banks and a six-throw crankshaft to achieve equally spaced firing intervals of 120°. This still has some balance and secondary vibration problems. When Buick designed a 90° V6 based on their 90° V8, they initially used a simpler three-throw crankshaft laid out in the same manner as the V8 with pairs of connecting rods sharing the same crankpin, which resulted in firing intervals alternating between 90° and 150°. This produced a rough-running design which was unacceptable to many customers. Arguably, the roughness is in the exhaust note, rather than noticeable vibration, so the perceived smoothness is rather good at higher RPM. Later, Buick and other manufacturers refined the design by using a split-pin crankshaft which achieved a regular 120° firing interval by staggering adjacent crankpins by 15° in opposite directions to eliminate the uneven firing and make the engine reasonably smooth.[7] Some manufacturers such as Buick in later versions of their V6 and Mercedes Benz have taken the 90° design a step further by adding a balancing shaft to offset the primary vibrations and produce an almost fully balanced engine.

Some designers have reverted to a 60° angle between cylinder banks, which produces a more compact engine, but have used three-throw crankshafts with flying arms between the crankpins of each throw to achieve even 120° angles between firing intervals. This has the additional advantage that the flying arms can be weighted for balancing purposes.[7] This still leaves an unbalanced primary couple, which is offset by counterweights on the crankshaft and flywheel to leave a small secondary couple, which can be absorbed by carefully designed engine mounts.[8]

Six-cylinder designs are also more suitable for larger displacement engines than four-cylinder ones because power strokes of pistons overlap. In a four-cylinder engine, only one piston is on a power stroke at any given time. Each piston comes to a complete stop and reverses direction before the next one starts its power stroke, which results in a gap between power strokes and noticeable vibrations. In a six-cylinder engine (other than odd-firing V6s), the next piston starts its power stroke 60° before the previous one finishes, which results in smoother delivery of power to the flywheel. In addition, because inertial forces are proportional to piston displacement, high-speed six-cylinder engines will suffer less stress and vibration per piston than an equal displacement engine with fewer cylinders.

Comparing engines on the dynamometer, a typical even-fire V6 shows instantaneous torque peaks of 150% above mean torque and valleys of 125% below mean torque, with a small amount of negative torque (engine torque reversals) between power strokes. On the other hand, a typical four-cylinder engine shows peaks of nearly 300% above mean torque and valleys of 200% below mean torque, with 100% negative torque being delivered between strokes. In contrast, a V8 engine shows peaks of less than 100% above and valleys of less than 100% below mean torque, and torque never goes negative. The even-fire V6 thus ranks between the four and the V8, but closer to the V8, in smoothness of power delivery. An odd-fire V6, on the other hand, shows highly irregular torque variations of 200% above and 175% below mean torque, which is significantly worse than an even-fire V6, and in addition the power delivery shows large harmonic vibrations that have been known to destroy the dynamometer.

^^^ Wow. That lot made me dizzy.