I'm in the process of building a 2.0l 8v using a very low mileage (14000miles!!!!!!!) 1997 Mk3 AGG block and a Mk2 ported head. I would appreciate all your advice and opinions on the best injectors and gearbox for the project. I already have a Magnex stainless exhaust and G60 front brakes to cope with a bit more power. I'm not totally convinced yet whether oversize valves are absolutely necessary, perhaps those of you 'in the know' can give me your valued opinions. Thanks WG
Thanks a lot for your reply Toyotec. Sorry for the delay in replying but I'm an old geezer, I don't have a computer at home (yes, I'm THAT old!!!) and only use a computer in our local library. I intend to use the ECU already fitted in my 1989 PB engined Mk2 and want to see how much more I can get out of the the Mk3 bottom end and ported Mk2 top end with the standard cam fitted and vernier adjustment. If a cam upgrade is necessary it will come later. I would appreciate any comments if you think I'm heading in the wrong direction.
I run a similar engine in my road rally spec MK2. that has a 2.0ltr bottom end and MK2 8v head. The head is ported and running big exhaust valves and a TSR 203 cam but otherwise std, the bottom end has std pistons, rods and a 2E forged crank. The block and pistons have been decked to get the squish right and the compression up to match the cam (about 285 degrees). Its got ARP bolts in the bottom end to keep it all where it should be and has a windage tray and baffled sump. The ancillaries are a 4/1 S/S manifold of some type (this needed a lot of porting to get it right) and a Magnex 3 box 8v system. I didn't like the design of the Magnex back box so skipped that and fitted an ex Formula Renault single seater one that I had lying around. very quite (78dB!!) to comply with road rally rules. It's got a std airbox, obviously stripped out with a cold air feed and a K&N air filter. It has a different chip in the ECU for fuel and the ECU itself has been remapped to change the ignition map and the rev limit (these are not on the chip!) plus adjustable cam pulley to get the cam timing where you want it. It's not been on the rolling road since I rebuilt it but I reckon its between 140>10bhp at the crank and quite quick enough in real world driving, like to rev up to about 6.8>7k happily enough. I took it to the Curby sprint a little while ago and it was just as quick as the 16v and turbo cars even though it is heavier than a std car as the regs dictate it has to have full std interior and it has a full roll cage fitted. I'd suggest this spec is ideal for a fast road car, very easy to drive, smooth and lively enough to make it fun. I enjoy spinning about in it and drive it to most of my events, unless they are too far away as the box is quite low geared and a pain on a long run. As for gear boxes depends on what you want to do. For competition the early 1600 gti boxes have the best ratios then the later 1800 gti boxes. The MK2 16v box has good ratios but a different clutch size, its no better than the 8v box though, I wouldn't bother, far more 8v ones about. They are quite low geared though and not ideal for long runs. If its for more sedate use then I'd go for one of the less sporty boxes, more relaxed. Broke VW's site has all the ratios. 020 box parts are very interchangeable, plenty of ratios and FD's available. For anything sporty you want to get the diff bolted as the std rivets on the FD are the weak link and break easily, often for no apparent reason! Get Hotgolf in Bridgend to rebuild it, it will be fine then. Quaife diff is a good addition for the road as well, but obviously is not a cheap upgrade.
Hi TonyB, thanks a lot for your reply, sounds like you have a properly sorted motor. I hope you don't mind a few questions. Is the standard crank adequate for fast road use and did you decide on the 2E forged crank for peace of mind? Where did you get your windage tray and baffled sump from? How much squish clearance did you achieve? What chip did yopu go for and who remapped your ECU? I know what you mean about the Magnex back box the design of the rear mount is atrocious!!!!!! but it is pretty quiet with the twin silenced tail pipes. I used to have a GTI Engineering Mk1 close ratio box. Wish I had it now! However, I regularly travel from Nailsea to Wrexham so need a box that will suit a fair amount of motorway driving and I want to maintain reasonable fuel consumption. I'll have a gander at the Broke VW site. Thanks a lot.
An 8v motor can be a made to be pretty good road engine if you are prepared to spend quite some effort on it. Be advised that effort would just about deliver the torque of a mildly remapped std ABF motor and the lack of valve area compared to a 4 valve motor would mean it would be short of revs and power. Regardless, if kept on boil, such and engine in the hands of a capable driver could be comparative to a not so capable driver in a 16v car. Over my years of owning an 8v Mk2 from Kjet to Digifant. Digifant 3A 2.0 on standard management to 3A on a stand alone, the engine with the aftermarket ECU was the most rewarding to drive around town due to the torque response at low to mid engine speeds. It was only just more powerful at 5500 rpm. I tend not to state dyno numbers on here as without a correlation they are actual a useless measurement to owner expectation or real life vehicle acceleration. . However a few years ago, I conducted an experiment on Garage Streamline's dyno and tested several configurations of 8v engines on it, comparing the plots with 16v engines that were also tested on the same day. This was shared in the post Validating 8v vs 16v plots. G60KG's engine, 2E, PB head and 272 camshaft was later updated to a SEM ECU and calibrated one night and delivered the torque of a std fully serviced ABF motor was a nice little package to drive. His plot of after/w SEM is >>here<< and needs to be added to the validation thread.
I think at this level of tune, and we are talking fast road here, why go to the trouble and cost of fitting a 16v when a mildly tuned and well set up 8v is just as quick as a std 16v ABF? A half decent 2nd hand 8v performance head and cam can often be picked up for under a 100.00 these days, as they are out of favour. Carefully built with std second hand 8v components, about 100.00 of machine time and you have a good fast road car. Less cost than buying a 16v and ancillaries plus a fair bit of time and fiddling in changing everything over, you essentially use everything else you had, just adapted/modified to the new state of tune. It doesn't sound as good down the pub when chatting about it or looking under the bonnet of course but in the real world its a cost effective and nippy combination. Of course this plan of action is not for everyone as many people don't want to build engines. If you wish to build an engine then I believe the 8v will probably be the most sensible route, if you don't want to then Eddies method above is a better route (but more expensive). In this context though I believe Welshgit is interested in building himself a fast road engine and to a sensible budget. The spec above will give any std ABF a run for its money, tried and tested. Comments: Is the standard crank adequate for fast road use and did you decide on the 2E forged crank for peace of mind? AGG crank is cast but fine, I've never heard of one breaking. I just like the forged cranks found in 2E & ABF's (same) and asI race I like the security of using them. Virtually unbreakable in most situations and level of tune (as long as they have oil!) Where did you get your windage tray and baffled sump from? The windage trays come from many sources. Just do a search, ebay, GSF etc. etc. I have half a dozen if you stuck. How much squish clearance did you achieve? From memory you want about 50>60thou. Machine the bit that sticks up off the piston and then deck the block so the piston are just protruding. Use the ABF metal head gasket. about 11.5:1, suits a 280 degree cam fine. What chip did yopu go for and who remapped your ECU? I used Dubforce tuning in Hampshire, seemed fine to me. He supplied the chip and I sent the ECU for him to map. It had a chip in it but it was just a little flat, once the ignition was adjusted to suit the spec and the fuel it livened up a lot. I know what you mean about the Magnex back box the design of the rear mount is atrocious!!!!!! but it is pretty quiet with the twin silenced tail pipes. Yes, that was one problem! I made a neat bracket with a couple of rubber bobbins, really good. There are some pics on one of my threads. In member cars 'Scruffy red road rally car' I think, have a look. I just had the back box around as the 2" bore wa too small for my race cars but suited the magnex and the 8v fine I used to have a GTI Engineering Mk1 close ratio box. Wish I had it now! However, I regularly travel from Nailsea to Wrexham so need a box that will suit a fair amount of motorway driving and I want to maintain reasonable fuel consumption. I'll have a gander at the Broke VW site. I'm just about to get one of my close ratio boxes fitted with the 5th gear from a 4T or similar to make 5th an overdrive ratio. This will let me use the MK1 for racing at the weekends yet use it as a spare car if I need to go anywhere distant or drive to the events when they are far away. Tim Stiles (TSR) used this idea on their MK1 hillclimb car back in the day. Sounds like it would work with you, or just use a 4T (think that's the carb box). Hope that helps, just my thoughts on the 8v/16v thing. Really depends if you want to modify the car more in the future. The best thing I can say is decide where you want to be and just do that, miss out all the stages in between! The money we all spend on buying bits that we then up grade and change. For example cars will take far more cam than people will have you believe and still be perfectly tractable - especially on modern ECU's etc. On paper, up to fast road 8v makes sense, from there to 175bhp (whatever you would term that as) 16v makes sense, from there to 200bhp 8v is cheaper as there are less of the parts you need to change (just spec the right bits to start with), from there on 8v gets expensive and from a cost point of view 16v makes more sense. Of course turbo makes more sense than both at anything from 175bhp when cams/pistons etc. [cost] are needed! As I say just my thoughts but I've raced this car [engine] two years and come across all sorts and know what it can do, trust me its not high spec or anything clever, just well put together and set up. Lots of supposedly more powerful engines have been beaten on road and race track, even on supposedly power hills It would make a really good road engine.
Tony, I am not at all suggesting to swap to an ABF 16v motor. However on the basis of tuning, testing and owning 8v motors in all sorts of combinations and engine sizes, it is a lot of work ( hardware modifications and then a proper ECU calibration) to get them to begin to match the torque and power of the equivalent sized valver. The empirical data gathered at Garage Streamline and the road testing done with a G meter supports that theory. That aside G60KG's 2E 8v 'cammed' motor was a nice compromise as a road car. Much more torquier and excellent driveability that could outperform well serviced KR 16v, once it had a refined calibration on the SEM. That was a road car that did long distance on the OEM AUG/ACD gearbox.
Hi TonyB and Toyotec thank you SO much for taking the time to reply to my queries, very interesting and thorough. I posted a reply some time ago thanking you both and explaining how I got hooked on Mk1/2 Golfs and Jetta's but some how it seems to have been lost in the ether and I don't have too much time at the moment. Mum passed away a couple of months ago and there's still a lot to sort out but the engine upgrade takes my mind off things and keeps my feet on the ground. I'll certainly be back. All the very best. WG
No problem. 8v motors are not that bad and you could have a pretty punchy little car if you choose the right bits.
Hi there. I know its a 2015 post. But any advice on building a 3a bottom end engine for my golf would be appreciated.? 270 cam pb head. Etc. Any advice on finding a suitable ecu...? Using dizzy from 3a engine. And injector choice once find a better chip or ecu for fueling.
Hi Mark. Depends on your base car system....k-jet, Digifant etc. With your mention of PB head, ecu chipping etc i'd guess you have a later MK2 GTi? Or is it a carb car your upgrading? As for the engine itself, a 270-ish degree cam will make for a nice tractable conversion and the idle should be ok once the final set up is complete. A standard head will work to a point but will run out of breath over approx 5000rpm depending on the final spec, cam, cam timing etc. A ported std valve head will help a great deal overall and extend the usable rev range to around 6k The bottom end condition will dictate what needs doing and how far you go if it comes apart. If it came from a known good running car with no rattles or smoke and you can see the bores are in fair condition then you could run it as it comes, like wise with the current head, apart from a new gasket, bolts and belt. Once you strip either your committed to doing the job thoroughly if you want it right and to last...guides/seals, seats cut (maybe valves) and a skim as a minimum in the head (all std work in ported head so one job can become the other at the same time), rings, hone, bearings, big end bolts in the bottom end etc. There is a lot more you can do, but it all depends on what you want from it and the budget you want to put in
Cannot use "chips" on a Digifant effectively. Been there and done that. There is a link in this thread to a chap "G60KG", with a 2E+ PB cylinder head and a 272 cam, that was fitted with Megasquirt at the time. I tuned that car. It was tested with the engine hardware above on a stock Digifant also on the same dyno. I also drove it, before and after. Subjectively, with a calibration that matched the hardware, the car had significant torque from as low as 2500 rpm ( much more than a stock ABF) and felt much stronger than some of the good KR cars coming to the top end. Compression was still stock 2E at 10:1. What ECU you can use? DTA, Emerald, OMEX. They all will allow the same experience.
