My latest probably-never-to-happen fantasy project is a turbocharged small block 1.3/1.4 16v. I like the idea because it should be reasonably frugal (more efficient under daily conditions plus cheap(er) tax), nice and light and hopefully not to difficult to achieve through parts bin engineering. I'm having a job learning about all the small block engines available and would be most gratetful for any information regarding block / head / crank / piston / rod interchangeability, dimensions, deck heights, component strength, which engines were available in which cars etc. A brief summary of what I think I've learned: 1.05 - 1.3 8v engines: - Mostly 75mm bore with stroke altered between 59 and 72mm to change capacity. - SOHC alloy head, iron block. - Some variation in head design; some flat, some incorporating combustion chamber. - Carbed. - Seem to have a rep for being reliable and well engineered workhorses. - Fitted to Mk1 & Mk2 Polo, Mk1 and Mk2 Golf. 1.4 - 1.6 8v engines: - 1.4 has 75mm bore, 1.6 has 76.5mm bore. Stroke also varies. - SOHC alloy head, iron block. - Single point fuel injection. - Apparently no reliability problems. - Fitted to Mk3 Polo (1.4 only) and Mk3 Golf. 1.4 - 1.6 16v engines (Polo 6n): - Assuming same bore and stroke as above engines with different pistons. - DOHC alloy head, iron block. - Multi - point fuel injection. - Apparently no reliability problems - I believe this is what Dogwood runs in his Polo? 1.4 - 1.6 16v engines (Golf Mk4 / Polo 6N2): - Again, assuming the same bore as above. - DOHC alloy head (different to above), alloy block. - Multi point injection - Terrible rep. for piston slap, bore wear, oil starvation, cambelt failure, block warp issues... Ultimately a choice of two 16v heads and various blocks. Looks like the earlier 1.05/1.3 blocks are out (unless rebored) as the smaller bore may cause interference / valve shrouding issues. Obviously the 6n2 block is out as it's basically only any use as a paper weight. Hoping that I might be able to mix and match parts to create a low compression (c.8.5:1) 16v engine of 1.2-1.4 litres capacity (1.6 de-stroked with a 1.05 / 1.3 crank perhaps), but having trouble finding info on engine dimensions. Have tried the polo forums, but they seem to be mostly frequented but 13yr olds who don't really know what they're talking about. Cheers
There are some very good international polo forums with small blocks revving to about 10,000 rpm, probably not with the sort of economy you're looking for tho.... There is also an issue where the crank can't be removed from the block, not DIY anyway. There's a version of this block in the Scirocco with FSI, turbo and superchaging to 120 or 140 bhp.
bigest bore, shortest stroke and shortest rods you can manage without the piston skirts clattering the crank ballance weights... 2.2:1 bore/stroke ratio if you can manage it... have fun...
The engine is codenamed EA111 First introduced in the Audi 50 (aka Polo Mk1), and the Polo shortly after. http://en.wikipedia.org/wiki/List_of_Volkswagen_Group_petrol_engines I used to have a 1272cc one in my Jetta. Same engine was fitted to the Mk1 Golf Driver. 60 brake, solid lifters, easy to adjust. Had 200k out of the bottom end, and it was still going. Solex PICT-7 carb, larger on the 1.3s than the 1.1s Formel E versions were 1.1 litre, with higher compression IIRC, but were the Blue Motion of the early '80s, with a crusing top gear for economy. Oil pump driven off the end of the crank, later changed to chain driven I think when the engine simultaneously went hydraulic (8 bolt cam cover to 3 IIRC). Earlier oil pump design was prone to wearing out the D-shaped location on the crank into a circle. The hydraulic 1.3 dropped 5bhp when put in the Mk2 Golf, reason unknown. Carb changed. The Mk2 Polo GT was 75 brake, again never did find out why, though just stumbled on this. Then of course the top of the 8v tree, the Polo G40, 1?? bhp. Oil breather take off on the back of the block is also the same as seen on Audi 5 cyl 7A blocks, and was also used on the Oettinger 16v big block engines. Then it all seemed to go AFH 1.4 16v, and then Lupo 1.6 GTI, but my knowledge thins out at this point! The engine continued all the way into the Mk4 Golf 1.6, which still has recognisable architecture (exhaust ports at the front, inlets at the back, oil filter I think still on the block front also). 084 gearboxes (Mk1 Golf/Jetta/Mk1&2 Polo), which then evolved to become 085. Lightweight, but not strong. I broke several, but at 25 a pop back then, chicken feed. Some 084 1.1 boxes had a 4.57:1 final drive, which when attached to a 1.3 made a world of difference. Sadly the best 085 final drive was 4.25, and parts swappabilty tricky between the two (I tried). The Mk4 Golfs had 020s in them (as in evolved to 02K spec) with a bellhousing to suit that small block. Mk1 Driver fancied tuning one of these up a long while back, thread here which also links to here
Thanks gents, some good info I know the little b*ggers like to rev As you say though; not great for economy. Looking to build something with plenty of poke if neccessary, that will be frugal if driven grandad-stylee. 10k would be all good if it was sufficiently tractable lower down the range, which I suspect without VVT won't happen. Would like to go to about 7-7.5k; although ultimately this will be dictated by the cams.. the 1.4 16v fitted to the lupo/polo makes 100bhp, so probably gets to about 6.5k in stock form. I believe the engines that can suffer from block warping upon crank removal are the alloy blocked 1.4 16vs (AHW etc); apparently the 1.6 16v is alright; not sure about 8v alloy blocked equivalents. Almost Would love to build an over square rev-monster; most extreme possibility on stock components would be the 76.5mm bore of the 1.6 block with the 59mm crank of the 1.05 engine. Not sure if these would physically fit, or what to do about rods and pistons. I'd have thought longer rods would have been better for a higher revving engine myself.. Thanks Chris - some good links there I did a fair bit of digging on ETKA last night and now understand a bit more.. so due to the oil pump issues etc, it seems reasonably to rule out the mechanical lifter engines for a start. Good point about the 'boxes; this did worry me. I know the 085s have a rep for dropping to bits. The thought of an 020 with a small block bellhousing appeals, but I think the 02k gearbags also have an apalling reputation for reliability (Polo Gti owners seem to consider a gearbox rebuild in the same inevitability as a 60k cambelt change ). I wonder what makes them so inherently sh*te..? There must be some fairly large weakness since they can't seem to cope with 115lb/ft for more than 60k without disintegrating. It would be nice to think that the guts from an earlier / beefier 020 could be transferred into an 02K casing; however if this was viable I expect the Polo boys would already have cottoned on. I've begun the construction of a mammoth spreadsheet (there seem to be millions of small block variations) will host it for all if it turns out to be of any use. Cheers again chaps - any more info much appreciated; I'm off to trawl the internetz to see if any info can be gleaned from those crazy europeans
The 02K contents are swappable with 020 we think, either Danster or rubjonny commented a while back. Don't worry about spreadsheets. Use the Table function. To get it in table format, all you need to do is put a "|" between every row. Easiest way to turn it into text format by using this sort of formula to put it into 1 cell, ready for cut/paste: =A1&"|"&B1&"|"&C1&"|" etc Cut and past the results in between table brackets for instant win.
Cheers Chris, the gearbags are something else worth of investigation, then Regarding the spreadsheet; I've already started it and it is rather epic in scale.. not sure I have the patience to stick it all in a table format, but will have a look when it's finished
Just email it to me. Five min job and a million times better if directly accessible on a web page, and comes with free Polo territory ownage
nope short stroke and short rods are the way forward, it reduces the torionals no end which stops crank flex and although the larger bore creates more frictional losses because the mass of the crank, rods and pistons is closed to the rotational centre of the crank then the need to balance is greatly reduced thus making for a lighter crank too!
Yup.. but transplanting one would be a) expensive and b) a nightmare from a management situation, I suspect. Bit too new to be pilfering bits from too, I imagine, which is a shame as I bet it has some nice pistons. Work still in progress Agree about the large bore / short stroke; however I hear longer rods are generally better from a loading perspective (slower peak acceleration and smaller component of force on the bore wall) which I think would be important in a ghetto build I've got up to 2002 with the spreadsheet, but it still has plenty of holes. A couple of things I've learned on my travels: The earlier engines do seem a lot better built; just about all 1.05 and 1.3 engines (including the G40) use the same conrods, which suggests they should be plenty strong enough. They have 20mm gudgeon pins too, which is large for an engine so small. Calculated deck height of the earlier engines is 201mm, the 1.05 engines have pistons of greater compression height to account for the engine's shorter stroke. It appears that all the 1.4/1.6 varients got weaker rods and a 17mm gudgeon pin, so none of these bits are interchangeable with the earlier engines. This is a sod as I think I'll need a 76.5mm bore to suit the 16v head. Also, it appears that the oil drains at the rear of the block changed at some point; meaning the 16v head isn't a straight swap onto any of the iron 8v bottom ends. Despite their w*nk bottom ends, the 1.4/1.6 16v heads look to be of promising design - decent looking valve angle and valve size (getting on for twice the valve area of the 8v engines). Also roller rockers instead of bucket tappets; hopefully meaning high, short duration valve lift which should be good for forced induction. Some 16v engines use the same cam for inlet and exhaust; pointing to interchangeability and possible scope for variation using stock cams...
Bump. I have been giving myself a hands on tutorial on the blasted modern 16v sheit small block engines. 1.4 AXP code with an oil pressure issue. Had the sump off, pickup pipe clean, removed the bypass valve from the oil pump (not meant to but I am uber skilled so no great shakes ), it was fine. Still would not lift oil even with pump primed with oil. Crappy design means you have to strip off the timing belt to get to oil pump. Did this earlier and hoped to find something that would be a sign as to the problem. Internally the drive gear to the crank is fine, there is no obvious scoring or drastic play anywhere. The only thing I can see is it looks like there is a gap at the lower part of the pump and cover plate denoted by the brown area on the sealing face. I just wonder if it is drawing air at this point, or leaking out oil so the pump is not full of oil to prime on each restart.
It's that branch, I had one in my sump once and it would NOT pump oil. Had the skanky old black rag as well - blocked the pickup in no time.
