Ever wondered what was involved in transplanting a 16v engine into a Mk1 Golf? Club member Oil Parker gives you the technical lowdown.
Fitting 16 valves into a Mk I GTI
Be warned, the character of the 16v engine is different to that of the stock 8v - it's a revvier, more energetic engine. If that ain't your style, then consider boring out your 8v block or a G60 conversion. But both of these options are expensive. I initially wanted a 2 liter 8v lump, and started pricing them up at GTI International. The cheapest I found was Grant Motorsport's tall-block 8v 2.0 liter, based on a Mk 3 Gli unit with headwork, etc. But all options would cost a lot more than any 1 6v conversion I could cook up, and actually making less power. 060's are what I dream of, but they are more expensive again. One company quoted me "Around £4,000 fitted" for one of these, a lot of money I guess I could have installed one of these myself for less if I had shopped around for the parts, but it would have still been a lot more than a 16~ as the 060 engines are much rarer second-hand.
Before I start, a word to all you "Keep it original" hacks, who are undoubtedly shocked at the idea that I took the original engine out of an original Mk 1 in favour of a totally different animal .... bear in mind the original Mark 1 Gil had a 1600 engine that Revved like mad. Bit like the 16 valve engine really So, maybe fitting a high-revving 16 valver brings an 1800 Mk 1 back in line with the original GTI spirit VW intended. If you follow the philosophy of "If it ain't broke don't fix it"' then turn over the next few pages ... they won't be of much interest to you. However, we know that there are plenty of Mk 1 Gti owners out there who would really like a few more gee gee's under the bonnet without spending mega-money. If that's you, then a 16 valve conversion is well worth looking at.
Shopping list
Recommended
Optional
Tools Needed
Preparation
A couple of details before the fitting instructions start. Firstly, do something about the brakes. A post-1988 22mm 16v master cylinder & servo make a huge difference (easy to change when the engine is out of the car) but can take some of the feel out of the brakes - they wind up being a bit like a toggle switch -either on or off. I found Martin O'Neill of O'Neill Gil does an excellent 285mm Brembo conversion for the front end of a Mk 1, which leaves you with some nice progressive brakes that really stop you when you want them to. The kit includes new discs, brackets to move the original\ calipers out from the hubs and the necessary bolts to make the whole thing work. Call Martin on (01256) 701975 for up-to-date prices. If you are thinking about them, now is a good time to fit Mk 2 rear discs and braided brake hoses.
Your insurance company will have something to say about a 16 valve conversion, so tell them about it before venturing out onto the road with the new engine. Interestingly insurance companies tend to classify the car in the same way as the vehicle the engine came out of. So, if you get a Golf 16v engine, the insurance grouping jumps to group 16 (same as the 16v Mark 2 Golf), whereas if you use a Corrado 16v engine, your car is then insured as a Corrado 16v, group 17. Make of this what you will, and choose your engine carefully (Editor's Note, some insurance companies may simply increase your premium in line with the percentage increase in horsepower ie 24% more for a 16v, but some may not cover you at all. Whichever, ensure you declare absolutely every mod, uprating the brakes works in your favour and may be insisted on anyway).
Choosing your engine carefully is something worth doing. Expect to pay anything from £300 upwards for the engine from a damaged Mk 2, depending upon engine condition & completeness of ancillaries. If possible, buy a complete engine with everything you need, as then you can be sure that it all works together and you save on the hassle and surprising expense or sourcing little things like distributors, ECU's, HI leads, starter motors, etc.
Find out as much as you can about the engine, eg the car it came from, what happened to it, its mileage and any service history, etc, etc. Don't buy an engine from a car that has been rolled - when a car is rolled, the engine is run upside-down for a while, which starves the head of oil, no prizes for guessing what that does to engine life. The best way of assessing whether an engine has overheated, due to lack of oil or coolant is to take the sump off, remove one of the big end caps and check the colour inside of the shell. If it's grey then all's OK, if it's a bronze colour - avoid it. Don't forget to replace the cap and torque up the nuts correctly (look it up in the manual for the engine).
All references to 'Left' and 'Right' are made with reference to looking at the engine bay from the front. Therefore, the left hand side is that on which the driver sits. This article also assumes the original gearbox was removed for the conversion and refitted to the 16v engine, rather than being left in the car for the duration. The engine can be taken out through the top or bottom of the bay dropping it through the bottom is much easier and is the way I did it.
Removing Original Engine
Fitting the engine is much easier if the bonnet is removed first (this is a 2 person job). Undo the two small bolts at each side where the hinge is attached, and then lift the bonnet away from the car. Remove the radiator - undo all the hoses (bottom one first, over a bowl as this will drain the coolant), then undo the two clips at the top of the front panel and lift the whole radiator assembly out of the car. Battery next, then the braided hoses from the metering head to the engine (take care, you will get pressurized fuel squirting everywhere as you undo these), and the air duct to the throttle body Then all the other assorted bits of piping to the different parts of the engine, and the wiring. Don't forget to label the wiring carefully - the different bits all look the same once they have been flapping in the breeze for a day or so, and some good labels save a lot of time. Be efficient in taking everything off the old engine - the 8v lump has a lot of bits that are well hidden around the back and sides, ad they are better removed by hand than torn off when the engine comes out. Don't forget the clutch cable, the throttle cable, the heater cables and the speedometer cable (slightly tricky this one).
Undo the six star-headed bolts that hold each CV joint to the drive flanges on either side of the gearbox, and wrap the Cv's in plastic bags to keep the grease off the garage floor and the grit out of the Cv's. Whilst under the car, reach up & undo the six bolts holding the exhaust down pipe to the manifold. Also reach into the engine bay and undo the various gearshift linkages that fit onto the gearbox - you will have to remove all three of the relay shafts, two with plastic clip ends, one with right angles at each end and clips holding them in place.
By this stage you should have the engine and gearbox in the engine bay with nothing attached to them. Make sure that everything is disconnected from the engine/gearbox assembly When this is the case, you can proceed to remove the whole lot from the car. Make sure that the two driveshafts are well tied up away from the underneath of the engine (better still, remove them).
Engine Mounts
Then remove the front and rear engine mounts both from the car and from the engine (taking them off totally gets them right out of the way). The front mount is removed by removing the starter motor bolts (but replace the bolts when the mount is removed, as they hold the engine to the gearbox, and this joint must be secure when removing the drivetrain) and the rear mount is removed by removing the three nuts that hold it to the gearbox. The engine is fine being supported on the two end mounts, the front and rear ones are only necessary to hold it secure while driving. Place a trolley jack underneath the engine and raise it so that it supports the engine/gearbox lump roughly centrally with as little weight as possible being placed on the engine mounts. (It is a good idea to put a block of wood between engine and jack to avoid bending or puncturing the sump).
Undo the remaining two engine mounts (the bolts just undo and pull out) and carefully lower the jack, while listening for the noise of forgotten wires and pipes being torn from the engine!!! The engine & gearbox should now be nicely balanced on the trolley jack, underneath the car. In practice you may well find that the engine mounts have become seized and need some tugging to make them come off. Do this carefully (not just with a big hammer) and do as little damage as possible. Now, jack the car up as high as it will go with the other trolley jack placed to the rear of the engine underneath a strong part of the chassis (this jack needs to have a tall reach to get the car high enough) and drag the engine out under the front valence, removing the lower spoiler before if it gets in the way
The new engine will fit onto the same engine mounts, but it is advisable to fit (at least) brand new mounts to cope with the extra power - mainly to stop the engine moving in the engine bay and breaking the exhaust downpipe. I fitted a Golf Diesel rear mount (£7.48p from my local URO agent, Simnetts on (01384) 410880) and left it at that. Various people recommended fitting a urethane front mount, but that sounded a little too harsh for me. The front mount is easy to get at, so if I do change my mind then access is easy, it would only take an hour or so to change.
Exhaust, Gearbox & Clutch
The exhaust manifold & downpipe have to be changed, as the factory 16v version fouls the steering rack. (Your existing Mk 1 8v manifold can't be used, the pod sizes are too small). Supersprint do a VERY NICE 4 branch manifold for these conversions, but they aren't cheap. Ashley do a more reasonably priced one, a 4 into 1 set up costing about £250. Most VW tuners have stocks of them, ring around for the best price. The alternative is to use a factory Scirocco 16v set up, but these are virtually impossible to source.
Many clutches are available to do the job as required, and there are many stories around concerning the best clutch to use. If you are using the 16v gearbox, then any normal 16v clutch will work, although it is often worth changing the clutch while the engine is out anyway for convenience and peace of mind. If, however, you are utilizing the original 8v gearbox, then some thought has to be given to the clutch arrangement. The 8v and the 16v pressure plates (or covers) are identical - they both bolt up to either engine. The only difference between 8v and 16v clutches are the hole in the centre of the drive plate - one is splined to fit the 8v gearbox, one is splined to fit the 16v gearbox.
TSR assured me that the Sachs 16v pressure plate offers more clamping force than the 8v pressure plate, although Sachs themselves only list one pad number for the plate for both clutches. The fact that they are identical is borne out by several other clutch suppliers, so don't pay extra for a 16v pressure plate over an 8v pressure plate! Instead, I used a standard LUK Mark 2 8v clutch from a local URO supplier. This has done the job just fine, and was quite a lot cheaper than the Sachs pad offered elsewhere (impressive considering that I had the iSv head gas-flowed and subsequently it has been rolling roaded at 169 bhp).
can get at the bolts that hold the brackets to the bulkhead without removing all the skin from your fingers. These will all push the budget for the conversion up, but are well worth it in the long run.
Changing the clutch is easy once you have undone the 5 large bolts holding the engine to the gearbox and separated the two. Undo the 9 oddly-shaped bolts around the edge of the flywheel, and pull it off the engine, along with the drive plate. Release the spring clip in the middle of the clutch, and remove the plate that sits there. Undo the 8 bolts in the middle of the pressure plate, and this will also come off the engine. Refitting, as they say, is the reverse of removal, although it is worth replacing the crankshaft oil seal if it looks at all leaky. This is done by removing the large tin plate that seals the end of the gearbox housing, and then undoing the bolts holding the seal housing onto the engine block. Pull the old seal out, put the new one in (easier said than done). This is also described in the Haynes manual.
Reassemble the clutch, and replace the gearbox (you will find that you need to centre the clutch drive plate in the pressure plate, use a VW clutch centering tool, borrowed from your local VW garage - Alternatively, it is possible to do-it-yourself by measuring to ensure the clutch driveplate is centered within the flywheel). Bolt up the 5 bolts that hold the two units together, not forgetting the starter at the same time. While the engine is out of the engine bay is a very good time to do some work on other things in there. For example, there is a rubber gaiter on the bottom on the steering column that is probably perished & cracked. This is easy to replace while the engine is out, but very difficult when it is in. Same for some of the brake pipes - if they look at all rusty then change them. Same again for the steering rack rubber mounts - now is an ideal time to replace them with some stiffer urethane mounts, as you
Fuel Injection
The Mk 2 16v ECU has to be placed in the car - this is best put into the channel at the back of the engine bay with along the TCI unit. The ECU fits rather neatly onto the back of the TOI housing ,with another small home-made bracket (see photo). The Mk 1 TO! switch can be used with the 16v engine.
To mate up with the Mk 2 Golf 16v inlet manifold you need to move the metering head to the other side of the engine bay - it is best placed behind the left hand side headlight (ie driver's side), moving the windscreen washer bottle to the position behind the battery where the 8v metering head used to be. (The alternative is to use the factory Scirocco 16v manifold top section, talk to BRM on (01926) 451545, but they are expensive). To do this then you have to move the fuel lines around in the engine bay to meet up with the newly-positioned metering head. Moving these fuel lines is not too hard, but great care must be taken not to crack them - otherwise you will have to replace them all. This job is made much easier if you undo a couple of brake pipes under the brake servo and the steering column. The brake pipes are obvious & easy the steering column is not hard. Push the rubber boot back and you will see that the lower universal joint has a pinch bolt securing it to the spline shaft on the steering rack. Remove this pinch bolt, and the two brackets holding the steering rack to the bulkhead. You should then be able to split the rack from the column.
Once the route is clear, then prise off the clips holding the fuel lines to the back of the engine bay and bend them very carefully round to just behind the left hand side headlight. Make a strong mounting for the metering head on the bottom of the airbox to secure it in its new home, don't just leave it flapping in the breeze! (See photos). Plumb the supply and return fuel lines into the metering head.
Mounting the windscreen washer bottle is a little trickier, as the old one doesn't really fit the new location. The neatest option is to use a Mk 2 Golf CTI washer bottle, with some home-made brackets (see photo). If this position is chosen, then the pipe running from the bottle to the underneath of the bonnet has to be moved to suit.
Pipes, Hoses & Cables
The air duct from the metering head to the inlet manifold has to be replaced. The stock 16v one may well work, I didn't have one of these. Instead I used the 8v one with the end cut off with a pipe mounted in the side for the Idle Stabilization System (see photo). I will replace it with a Power Rohr as soon as I can (or maybe a home made version. humm, there's an idea!)
The radiator top hose needs some attention as well. The 8v pipe is longer and bent, the 16v pipe is shorter and straight. With a little cutting the 8v pipe can be made to fit, but a proper replacement is better (my old 8v pipe burst while racing a 240bhp Mk 2 G60 at the Dutch Treffen this year - shame 'cos otherwise I would have had him for breakfast!)
The throttle cable needs to be shortened as the 8v version is too long. This is best done by cutting the end clip off and fitting a small clamp to the cable at the desired end point (to allow it to pull the relevant lever on the 16v throttle body). The clamp I got was designed for a bicycle brake cable, and is ideal (see next photo). However, this could probably be done more tidily with a new 16v throttle cable. The speedometer~ clutch and heating cables fit as before, make every effort to route them as straight as possible.
Replacing Worn Components
Take advantage of having the engine out of the car to replace a few key components. For example, now is a good time to replace the cam timing belt, the timing chain (between the cams, under the rocker box cover) and the timing belt tensioner. Fitting the tensioner with the engine in the car is difficult, if possible set up the timing belt beforehand. The lower timing belt cover is also tricky to remove and replace with the engine in the car (the engine side mount is very restrictive), and the only way I could make it fit was to chop off pad of the bottom pad of the cover (see photo). The new engine is best stripped to some extent to make the fitting easier. Remove the manifolds and all heater hoses, as well as anything else that may get in the way or be broken while the engine is being moved around (dipstick, warm up valves etc). Place them away from the scene of the action, remembering how they all go back together.
Fitting The New Engine
Replacing the engine is not as bad as some people will have you believe. I managed it, with a friend's assistance, in an hour or so. Again, it is easier to put it in from underneath, so jack the car up & support, before placing the re-assembled 16v engine & gearbox on the second trolley jack in order to lift them into place. Carefully lower the car back so that the wheels are on the floor, and raise the engine into a position such that the end mounts can be bolted up (this is slightly tricky the bolt has to be inserted into the captive nut, but the nut is designed to slide in a small groove so it may have to pushed to the right position in order to accept the bolt thread.)
An alternative way of doing this, maybe slightly easier, is to jack the engine on the pulley at the left hand end of the crankshaft, and raising the left hand end to the left hand engine mount, and bolting that one up, before replacing the jack in the middle of the engine and raising the right hand end. This is easier, but risks damage to the pulley which may consequently need replacing. Replace the front and rear engine mounts. By now you should have the engine in the car on the mounts. Now you have to build the engine up again replacing the manifolds, plugging-in the injectors and so on.
Distributor Cap
There are a couple of other pads needed to make the conversion work, The iSv's side-exit distributor will foul the Mk 1 CTI brake servo master cylinder, making it impossible to connect the HT leads. The solution to this is to use a foreign distributor cap - a Bosch 03.041 (or equivalent) from a 1.0 liter Renault 5 (72-81) or 1.3 liter Fiat Strada works fine (see photo). This has the HT leads exiting at a 90 degree angle to normal, and keeps everything from fouling, but only just! (Editor's note, there is also a Talbot Samba dizzy cap of a similar spec if you're desperate). However, these 'foreign' dizzy caps don't work with the connectors used on Vw 16v HT leads, so others that suit the cap have to be acquired. Hotwires do a set that are reasonably priced, and suit the head. Talk to your local decent motor factors about these parts. NB, if you have fitted the Mk 2 16v master brake cylinder then clearance or compatibility of connections isn't a problem. The Mk 2 16v dizzy cap will fit with a Mk 2 master cylinder in place, particularly if the reservoir is mounted backwards).
Wiring Loom
The wiring is best left to the experts - there are companies offering ready converted wiring looms for this conversion 'off the shelf'. I ordered a custom-made loom from TSR, although after 2 weeks waiting around for it to arrive I gave up and ordered one from BRM, who had it with me at 8.30 am the next morning. Fitting it isn't quite the breeze it is claimed to be, but BRM was very helpful on the 'phone and talked me through the process. What you also need if you buy the BRM loom is the 16v ECU wiring loom. You can find one of these at a good breakers, although you may have to buy all the 16v looms to get the one you want. The ECU needs a vacuum feed, best taken from the brake vacuum line.
Turning The Key & Setting Up
Setting up the engine to run is not too hard, if the timing marks all line up (on the top cam pulley and the bottom fan belt pulley i.e. with number 1 piston at TDC) then the rotor arm should point at a small notch in the rim of the distributor. If this is so aligned then the engine should fire up, but will need tuning as soon as possible.
Don't forget simple things, like make sure that there is oil and water in the engine before you try running them. If it doesn't fire up immediately then keep trying - you may find that the fuel lines need to have the pressure built up in them. If it still doesn't fire then check what is wrong methodically - pull out an injector and check it is supplying fuel, and check for a spark at the spark plugs. Check the pipework, especially from the metering head for leaks, and don't forget (as I did) to plug the brake servo pipe into the back of the inlet manifold .. without this then the engine will suck all the air it needs through this little hole, and not lift the metering flap at all.
Once running, check the fuel system for leaks - the banjo fittings on the fuel lines need two copper washers EACH to work properly, otherwise they leak. Don't just try doing them up a little tighter as they break quite easily. Check the newly repositioned fuel lines for cracks as well, and make sure that they are held away from the adjacent fan belt, having one of these break and squirting petrol under pressure over the exhaust system doesn't bear thinking about.
And that's about it. Don't forget to get it tuned properly (you will be rushing down to the local rolling road as quickly as your 16 valves will carry you anyway to get a nice new high power figure I guess) and enjoy the car The new engine has totally different characteristics to the old 8v unit, and will feel totally different. Below 4,000 rpm it is miserable, above there and it takes on a new lease of life. Anyway I wish you better luck with the new engine than I had, 3 weeks after I fitted mine one of the inlet valves broke and ruined the gas-flowed head, knocked a big hole in the piston, puffing aluminium filings into the oil system, scoring the bores and wrecking the big ends. Hang on a sec, I'll just get the C&R catalogue and price up a 2 liter rebore
Very Many Thanks for the help with the conversion go to Bal and Mark from the Wolverhampton and Shropshire Regional groups respectively without whom it wouldn't be running. Oh, and 'Daft Question Of The Year' award goes to Mike Page, Club merchandise manager, who was heard to utter the immortal words "What'ya doing this for Oh?" shortly after I'd got the old 8 valve lump out. 'Nuff said!
