This page is... UNDER CONSTRUCTION
WARNING: I am not an expert on cars, automotive engineering, VW Beetles, beach buggies or anything else discussed in these pages. What I have written is my current understanding of the issues involved in building MY buggy. These opinions are based only on my own research in books and on the web. They, therefore, have no basis in fact, may well be wrong and potentially downright dangerous if taken to be gospel truth. If you intend to use any of this information for any purpose other than pure entertainment, then please get its validity confirmed by someone who knows what they're talking about! You have been warned...
This page contains the following Sections:
The long block is the fundamental basis of the engine and consists of the crank case, flywheel, crank, bearings, connecting rods, pistons, cylinders, cylinder heads, cam, valve gear and valve gear covers, as pictured above.
Whilst choosing a suitable long block for my buggy, I considered the following options:
I didn't consider anything less than a 1600 TP, as smaller engines seem to be less widely available and are no less expensive than the 1600 TP. In fact, I suspect that they are actually more expensive per cc, or per HP, than the 1600 TP. All of the options I considered are designed to run on unleaded petrol. I have not considered any non-VW or non-air-cooled options, even though these can potentially deliver more power and better reliability than an air cooled VW, in order to minimise the complexity of the installation.
My main consideration in selecting the type of long block for my buggy is that it should be as reliable as possible whilst providing adequate, rather than 'ultimate' power. Also, it shouldn't be 'too' expensive (whatever that means?) and shouldn't take forever to acquire (either to build or to save up for).
Further details and considerations on each of the above options are given in the following sections:
Clean up and use the donor vehicle 1600 twin port (TP) as is
Reliability: Poor
Performance: Adequate
Cost: Very Low
Time: Fairly Slow
The engine in the donor vehicle is a remanufactured unit of unknown origin and unknown mileage. I know it runs, as I drove the donor vehicle before stripping it. It sounded OK when it was running but the oil was like treacle with some small metallic particles in it when I drained it. It also has several oil leaks, some broken studs and looks pretty horrible, so that it would take a significant effort to clean it up properly. Work would also be required to replace the gaskets to prevent further oil leaks and to repair the broken studs. Having already spent what seemed like an eternity cleaning and painting the transaxle, I'm not keen to spend that long again on the engine :-(
Refurbish the donor vehicle 1600 TP myself
Reliability: Unknown
Performance: Adequate
Cost: Unknown
Time: Unknown
I would like to rebuild the donor vehicle engine myself, just out of interest, as I've never done it before. However, this is likely to be a very slow option, as I'd need to learn as I go along. The rebuilt engine 'should' turn out to be reliable if I do a good job, which I would, but I'm likely to do this at the expense of speed. The cost could be significant and will depend on the parts and tools required to complete the job. Again, I'm not keen on this option, primarily due to the time it will take and the number of unknowns that are involved (reliability, cost and time).
Buy a brand new genuine VW Mexico 1600 TP
Reliability: Excellent
Performance: Adequate
Cost: approx GBP 1,000
Time: Very Fast
Surprisingly, this is the cheapest of the 'off-the-shelf' engine options and is likely to result in the most reliable engine as it contains only brand new parts, all of which are built to OEM specifications. Keeping the engine at the stock 1600cc capacity will also minimise the loading on the engine components, which should further enhance their reliability. Performance should be adequate if appropriate carburettors and exhaust system are used. Note: These engines do not include a distributor in the price, whereas the remanufactured units below include a '009', centrifugal-advance, distributor. These engines are available for 'next-day' delivery.
Buy a standard remanufactured 1600 TP
Reliability: Very Good
Performance: Adequate
Cost: approx GBP 1,200
Time: Very Fast
The next cheapest 'off-the-shelf' engine option is also likely to result in a reliable engine as it contains many new parts but it is unlikely to be as reliable as the VW Mexico engine. Again, keeping the engine at the stock 1600cc capacity will minimise the loading on the engine components, which should enhance their reliability. Performance should be adequate if appropriate carburettors and exhaust system are used. These engines are available for 'next-day' delivery.
Buy an 'off-the-shelf' performance remanufactured 1641 TP
Reliability: Adequate
Performance: Good
Cost: approx GBP 1,300
Time: Very Fast
The small increase in capacity to 1641cc is reputed to give a significant increase in power, especially when used with appropriate performance carburettors and exhaust system. The additional cost, over a stock capacity engine, is also quite small and so it makes this appear to be a very attractive option. However, the cost is kept down by using 87mm 'slip-in' barrels that have thinner than stock cylinder walls which can lead to distortion and unreliability if abused. The increased power will also put additional load on all of the engine components. Having said that, many people use this capacity of engine for regular road use without any problems. Since reliability is my main objective, rather than performance, and my engine will be required to cover thousands of miles, reliably, in adverse conditions, I don't want to take the additional risk to reliability that this option would present for a small performance gain. These engines are available for 'next-day' delivery.
Buy an 'off-the-shelf' performance remanufactured 1776 TP
Reliability: Good
Performance: Very Good
Cost: approx GBP 2,200
Time: Very Fast
Increasing the engine capacity further to 1776 would give my buggy a major increase in power :-) Unlike the 1641, the 1776 uses 90.5mm barrels, which have the same wall thickness as stock barrels but they require machining of the case and heads to fit. This in turn leads to a significant increase in cost above that of the 1641. Off-the-shelf engines of this type are built to produce high power at high engine revs and are designed for street performance, rather than the low revving, high torque that is required for a reliable off-road engine. In addition to this, an engine of this capacity (and above) requires many additional modifications, like additional oil cooling and full-flow oil filtering systems in order to remain reliable, which will increase the cost further. These engines are available for 'next-day' delivery.
Build a custom performance engine myself to my own specifications
Reliability: Unknown
Performance: Very Good
Cost: High
Time: Very Very Slow!
This option would enable me to build an engine of 1776, or above, that is designed specifically for reliability and high torque at low revs, rather than street performance. However, the amount of research that I'd have to do to ensure that I used the right combination of parts would be huge! Building this type of engine also requires a considerable amount of machine work to be carried out and I'd have to pay someone to do this, as I don't have the facilities to do it myself. Mistakes on an engine of this type would be very costly and I wouldn't want to attempt it until after I've built at least one stock engine.
Get a professionally built custom performance engine to an agreed specification
Reliability: Very Good
Performance: Excellent
Cost: Very High
Time: Fairly Slow
This is the ultimate air cooled VW engine option and could give me a powerful bored and stroked engine of, say, 2007cc, designed specifically for smooth running and longevity with lots of torque at low revs. However, at this stage, it's out of the question due to the very high costs involved :-(
So, having considered all of the above options, I've decided to buy a brand new VW Mexico 1600 TP long block as the basis of the 'Phase 1' engine for my buggy, with a view to replacing this during 'Phase 4' with a professionally built custom performance engine, of around 2007cc, when (and if!) funds permit. I'll buy the long block from VW Heritage at a cost of GBP 995, inc. VAT, delivered 'next-day'. Note: This price includes one-way shipping charges and there is no 'core charge' or requirement to supply an old engine, as this is a brand new engine, so I'll be able to retain the long block from the donor vehicle to rebuild at a later date.
Having chosen the VW Mexico 1600 TP long block, I now need to choose a distributor, as, unlike the remanufactured long blocks, the Mexico long block doesn't come with a distributor.
There is a wide choice of distributors available for the VW Type 1 air cooled engine, ranging from stock to high performance. Some of these options are listed below, in increasing order of (approximate) price in GB Pounds:
The major choice to be made between distributor types is whether they are of the centrifugal or vacuum advance type. With the former type, the ignition timing is advanced, as the engine revs rise, by centrifugally operated weights within the distributor body. With the latter type, the vacuum in the inlet manifold is used to advance the ignition timing via a diaphragm on the outside of the distributor body. Of the above listed options, only the ACN SVDA Distributor is of the vacuum advance type. Note: Stock VW distributors are normally of the vacuum advance type but since the donor vehicle engine is a remanufactured unit, it has a reproduction Bosch 009 centrifugal advance distributor.
The choice of distributor type must be made in conjunction with the choice of carburetor, as some carbs are designed for vacuum advance distributors and have vacuum take-off points for this purpose, e.g. the stock VW Solex PICT carbs, whereas other carbs don't have vacuum take-off points and must, therefore, only be used with centrifugal advance distributors.
It is possible (but sometimes not advisable, depending on the carb type) to use any type of carburetor with a centrifugal advance distributor but impossible to use a vacuum advance distributor with a carburetor without an appropriate vacuum take-off point. Using a vacuum advance distributor without a proper vacuum feed will result in an engine that will only run properly at tick-over :-(
The choice of carburetor configuration is also linked to the choice of exhaust system, in that many after-market off-road exhausts don't have the necessary manifold heat riser ports for use with a single centrally mounted carburetor, which means that you must use dual carburetors with this type of exhaust system in all but the hottest of climates.
Since I want to use a 'bobcat' style off-road exhaust system, without the heat riser ports, I will need to use dual carburetors. My choice of dual carburetors are Dellorto DRLA 40s, which although they do have vacuum ports on them, these are meant to be used only to balance the carbs, rather than to work with a vacuum advance distributor. This in turn means that I need a centrifugal advance distributor. Further details about the choice of exhaust system and carburetors are given in their respective sections.
Having chosen the type of distributor that I need, the choice of make and model is basically one of price vs. performance/sophistication. You pays your money and makes your choice :-)
The Bosch 009 is probably the most widely used distributor on VW replacement and performance engines and whilst it isn't the 'best' quality unit available, it is generally considered to be adequate for most applications, provided that it is timed dynamically, with a strobe, rather than statically with a timing light, due to its erratic advance curve. Bosch have recently stopped making the 009 distributor and, whilst they are still available (at time of writing - Oct '06), stocks are now dwindling.
In order to obtain a reasonable compromise between price and quality, I will use a genuine Bosch 009 distributor on my buggy. This will initially use the standard points ignition system, with a view to upgrading it to use an electronic ignition system in future.
The fuel pump draws fuel from the fuel tank and supplies it to the carburetor(s) at a suitable rate and pressure. A fuel pump is required unless the fuel tank is high enough in relation to the carburetor(s) to supply fuel by gravity alone. Since the fuel tank will be in the front of my buggy, at a similar height to the carburetors, a fuel pump will be required.
The basic choice with fuel pumps is between the stock VW mechanical fuel pump and after-market electrical fuel pumps.
The stock VW fuel pump is both simple and reliable and supplies fuel at a suitable rate and pressure for the most commonly used off-road carburetors. The stock VW fuel pump is driven by an eccentric cam on the distributor drive shaft.
Electrical fuel pumps, on the other hand, are typically able to deliver more fuel at a higher pressure and so tend to be used in very high performance engines. However, since they require an electrical supply (by definition!) they are likely to be less reliable than their mechanical counterparts and will not work with a flat battery. Also, electrical fuel pumps are not self regulating and so are generally used with a separate pressure regulator between them and the carbs.
Since reliability and moderate performance are my goals, I will use the stock VW mechanical fuel pump in my buggy.