Engine Conversion Muse... Subaru or not Subaru
Posted: 24 Jan 2013, 14:26
I have recently been considering the future for the engine in my 1987 Transporter Syncro, which currently has a 2.1 litre DJ wasserboxer (now getting tired). I already have an LPG conversion on the van so would prefer to go down the petrol rather than Diesel route. Diesels have a number of advantages but petrol engines are much nicer and more characterful. With LPG, they can be pretty much as economical as Diesel too.
After looking briefly at different petrol options I came to the conclusion that Subaru power would be the way to go (there is a very good précis of the pros and cons of different petrol engines on the RJES website (http://www.rjes.com" onclick="window.open(this.href);return false;). Yes, they are selling Subaru conversion parts so have an axe to grind but the arguments merely confirmed my own gut feelings about options like Golf GTI motors, Audi 5s, V6s etc. The Subaru engines are the right size and shape and give a very neat and tidy installation. They also sound good – like the original engine does…
I thus began looking into the Subaru conversions more thoroughly. These are the salient points of what I’ve learned so far:
Subaru engines are plentiful and there are lots of complete cars with good engines in them that can be picked up for £500 or perhaps less. Buying a whole, running, donor car is probably a good solution, to be sure of having all the peripheral bits you need and also because it gives you a chance to properly assess the condition of the engine. Even if doing this, acquiring an engine/donor is one of the ‘minor’ costs of the conversion!
Converting a 2.1 Wasserboxer engined Type25 like mine is probably the simplest of the conversions and needs fewer special parts than almost any other VW to Subaru swap you could name. Despite this, the parts required, excluding the engine but including a stainless steel exhaust, an air filter and the wiring harness conversion work come to about £2k. I long since gave up doing engine swaps myself so add in a donor car and installation by a garage and you come to around £3k. (not including upgrading the LPG system to a more compatible gas injection version) It’s not cheap but you end up with a very nice conversion and a much more modern engine. So, which engine to use?
Any of the Subaru flat fours or sixes can apparently be made to fit without too much difficulty but if investing £3k in the job it would make sense to get a significant advantage in power. For me, this rules out the naturally aspirated 2.0 engines and makes the 2.2s less than desirable. 2.5s are a good bet but the DOHC ones had some head gasket troubles so a later SOHC 2.5 is favourite, if you can find one. These can give you between 150 and 165 bhp and torque to match.
Turbo engines are not recommended. Their chief attraction is their potential for huge power and torque but they add considerable complication to the conversion and the standard VW transaxle can’t cope with huge power and torque anyway (much above 150lb/ft and it starts to get dodgy).
The flat sixes are nice and would sound great. They are apparently not too hard to fit either but they do have the kind of torque that makes the VW transaxle go all weak-kneed. I recently had mine rebuilt so I wouldn’t want to risk it!
Best bet then is a naturally aspirated 2.5, either a SOHC one or a DOHC that has had its head gaskets replaced with the later type. But how does a £3k conversion stack up against the options with the standard lump?
Well, a standard, reconditioned Wasserboxer costs about £1300. If you get a garage to install it that would come to (say) £300. So, for £1600 (or about half of the cost of a Subaru conversion) you can have a ‘brand new’ engine. But, you would still be stuck with 112bhp/128lb/ft (tuning the Wasserboxer is not really worth considering, if you want more power go for a Subaru) and you would still have all your old (possibly ropey) ancillaries. The wasserboxer is a ‘nice’ engine – it sounds good and has pleasant characteristics – but it does lack power and, whichever way you look at it, it is a very old and very compromised design, having basically started out as an air-cooled Beetle engine.
I am still grappling with this question. I love the Type 25 as a characterful design but I have plans to buy a small boat and trailer and the Wasserboxer really doesn’t have the power for towing. I have three options; 1) stick with Wasserboxer power and live with the lack of grunt, 2) bite the bullet and invest £3k in the van to get Subaru power or 3) sell the Type 25 and replace it with a T4 Syncro TDI. Because of the value of the Type 25 Syncro, which is potentially increasing, the latter would probably involve the least outlay, strangely, but I would end up with ‘just another Diesel van’.
I still have more learning and pondering to do before I can make a decision.
Any opinions?
After looking briefly at different petrol options I came to the conclusion that Subaru power would be the way to go (there is a very good précis of the pros and cons of different petrol engines on the RJES website (http://www.rjes.com" onclick="window.open(this.href);return false;). Yes, they are selling Subaru conversion parts so have an axe to grind but the arguments merely confirmed my own gut feelings about options like Golf GTI motors, Audi 5s, V6s etc. The Subaru engines are the right size and shape and give a very neat and tidy installation. They also sound good – like the original engine does…
I thus began looking into the Subaru conversions more thoroughly. These are the salient points of what I’ve learned so far:
Subaru engines are plentiful and there are lots of complete cars with good engines in them that can be picked up for £500 or perhaps less. Buying a whole, running, donor car is probably a good solution, to be sure of having all the peripheral bits you need and also because it gives you a chance to properly assess the condition of the engine. Even if doing this, acquiring an engine/donor is one of the ‘minor’ costs of the conversion!
Converting a 2.1 Wasserboxer engined Type25 like mine is probably the simplest of the conversions and needs fewer special parts than almost any other VW to Subaru swap you could name. Despite this, the parts required, excluding the engine but including a stainless steel exhaust, an air filter and the wiring harness conversion work come to about £2k. I long since gave up doing engine swaps myself so add in a donor car and installation by a garage and you come to around £3k. (not including upgrading the LPG system to a more compatible gas injection version) It’s not cheap but you end up with a very nice conversion and a much more modern engine. So, which engine to use?
Any of the Subaru flat fours or sixes can apparently be made to fit without too much difficulty but if investing £3k in the job it would make sense to get a significant advantage in power. For me, this rules out the naturally aspirated 2.0 engines and makes the 2.2s less than desirable. 2.5s are a good bet but the DOHC ones had some head gasket troubles so a later SOHC 2.5 is favourite, if you can find one. These can give you between 150 and 165 bhp and torque to match.
Turbo engines are not recommended. Their chief attraction is their potential for huge power and torque but they add considerable complication to the conversion and the standard VW transaxle can’t cope with huge power and torque anyway (much above 150lb/ft and it starts to get dodgy).
The flat sixes are nice and would sound great. They are apparently not too hard to fit either but they do have the kind of torque that makes the VW transaxle go all weak-kneed. I recently had mine rebuilt so I wouldn’t want to risk it!
Best bet then is a naturally aspirated 2.5, either a SOHC one or a DOHC that has had its head gaskets replaced with the later type. But how does a £3k conversion stack up against the options with the standard lump?
Well, a standard, reconditioned Wasserboxer costs about £1300. If you get a garage to install it that would come to (say) £300. So, for £1600 (or about half of the cost of a Subaru conversion) you can have a ‘brand new’ engine. But, you would still be stuck with 112bhp/128lb/ft (tuning the Wasserboxer is not really worth considering, if you want more power go for a Subaru) and you would still have all your old (possibly ropey) ancillaries. The wasserboxer is a ‘nice’ engine – it sounds good and has pleasant characteristics – but it does lack power and, whichever way you look at it, it is a very old and very compromised design, having basically started out as an air-cooled Beetle engine.
I am still grappling with this question. I love the Type 25 as a characterful design but I have plans to buy a small boat and trailer and the Wasserboxer really doesn’t have the power for towing. I have three options; 1) stick with Wasserboxer power and live with the lack of grunt, 2) bite the bullet and invest £3k in the van to get Subaru power or 3) sell the Type 25 and replace it with a T4 Syncro TDI. Because of the value of the Type 25 Syncro, which is potentially increasing, the latter would probably involve the least outlay, strangely, but I would end up with ‘just another Diesel van’.
I still have more learning and pondering to do before I can make a decision.
Any opinions?