I've searched around, read as much as I can but want to just make sure I'm on the right path... So, the more and more I look into it, the more I like the idea of turning my mk2 Golf Driver into a 1.8 litre, bike carburettor engined machine. I know I can get power and what not from 1.8T swaps, but if I want power I'll drive my 6R. So the loose general spec I'm building up in my mind is: Mk2 1.8 GTI 8v PB bottom end Mk4 1.6 AKL crossflow cylinder head Mk2 1.8 GTI 8v camshaft Honda CBR 600 bike carburettors Mk2 1.8 GTI 8v exhaust system Mk4 TDI 02J gearbox with hydraulic clutch and cable shift I'm not after record breaking power or performance, just something that sounds good, is better to look at and just has a proper old school vibe to it. The other carburettor options I've been looking at are Yamaha R1's or FZR1000's. The prior is the most expensive with the later costing a little more than the CBR 600's but both the Yamaha ones are for 1000cc engines which I think may be a little overkill for my plans. Some thoughts and suggestions on my spec sheet would be great, although please try and not comment "just do a 1.8T/VR6 swap" as I really don't want that. It's not about cost, performance or the likes, just want an engineering project for some laughs.
Them cbr Keihins are a nice carb. I used them, and gixxer ITBs on 2 projects. The akl head, is that from big block or small block family? Re the drivetrain, AFAIK you'll want a G60 or abf flywheel and clutch. Lightened by GasNGears aka Hotgolf, is a must.
Not too sure, I've only read that the 1.6 litre Golf AKL head is a good option as it requires less modifications to get working with a 1.8/2.0 litre bottom end from a mk2. Yeah, G60 flywheel was my thoughts too, will check out your source for a light one, thanks for that.
Just my personal thoughts from my experience Mk2 1.8 GTI 8v PB bottom end - Ok but why not use the 2.0lrt bottom end, cheap, mor torque, fairly straight swap. Mk4 1.6 AKL crossflow cylinder head - why go to the trouble? (I believe the 1.6 flows less well that the 2.0ltr). Use the DX head, ported/valves flows as well as the crossflow, only at the very top end is there an advantage but you would never notice ion the road. Straight swap, work to do on the cross flow. Mk2 1.8 GTI 8v camshaft - Buy a 283/285 degree one of some sort, use the later DX head with hydro valve for ease. Plenty of good second have piper/kent/tsr cams about for pocket money. much livelier, and your granny could still drive it to the shops. If set up properly it'll tick over like std, don't listen to all the lumpy tickover stories, set up right it will drive/idle much like std. Honda CBR 600 bike carburettors - not had any experience of bike carbs, heard lots good and bad, however some people have had good results like Tristan above, so probably worth a try. Only get advice off people who have done it (and had success), not people who have just read about it or failed!. I always go for DCOE/DHLA or ITB's as they are so much more adjustable, but that's me not being brave enough I guess. Mk2 1.8 GTI 8v exhaust system - be ok, but again plenty of 2nd hand 2.25/2.5" S/S exhaust systems out there for pocket money. Fit and forget and flow better, however with std cam won't be needed from a performance point of view, just possibly noisier. Note: if you like spirited driving, noisy exhausts are not of much use, you get noticed!! if you just like getting noticed then noisy exhausts are perfect! Mk4 TDI 02J gearbox with hydraulic clutch and cable shift - No, no & no. Why fit that? Too high geared if its a diesel, limited ratios available, far too heavy, fly wheel and clutch weigh a ton (even when lightened), gear change will never be as good as an 020, and lots of work to fit. Use the 020 box, get it re built, have the diff bolted for safety, get the fly wheel lightened. Use the 8v gti box ratios of some type and you cant go wrong. Don't believe all the horror stories about them, when built properly they are fine. Only use the 02j if you are going turbo, huge N/A power or rallying of some sort. All other uses the 020 will be fine, and certainly for your use. easier, cheaper and better. Well that's what I think, but of course that just from my experience. Your ideas/reasoning might well be from a different slant than mine, good luck with whatever you decide, hopefully of some help - kept me amused for 10 mins anyway .
Thanks for the feed back mate, very handy. I'll give you 10 minutes of my time with responses... PB bottom end - I already have one, it's not a tall block like a 2E so makes fitting into my mk2 Golf much easier and a GTI 8v exhaust will fit without drama. Mk4 AKL head - Noted! Is there a particular DX head to go for (i.e. do you know the part number)? Mk2 1.8 GTI 8v camshaft - Again, have one which I'm fitting to my 1.6 Driver engine (along with a stock GTI 8v exhaust) so wanted to recycle so that's why I suggested that. But again, a 285 camshaft, even new, is within my budget but more on this in a minute... Bike carbs - Why not, hey? You only live once! All about learning... Mk2 8v exhaust - Again, wouold have it spare but likely I'll get a custom 2.25" full system made and mated to a TSR 8v exhaust manifold for maximum flow. Mk4 02J gearbox - Fair enough, I liked the idea of a hydraulic clutch and the diesel gearing so that it cruised around quietly and comfortably but I will admit the feel of the 020 gearbox is awesome, especially since I've rebuilt all the linkage. Ultimately, I wanted to do the build for less that 1000 initially, just to get it up and running and working well, but the more I research the more it looks like my original plan of tuning the Driver engine first (with PB bottom end, GTI 8v camshaft, air filter and exhaust) will happen to keep me amused, then I'll build up a 2E/DK combination with bike carbs in slower time with the proper parts to get the best out of it and then drop it in. Planning ahead because I know what I'm like and I can't just have a car without it being a project so as long as I have something else on the go to keep me amused, it should stop me ripping things apart through boredom!
The alternative option is to use the PB bottom end, a cross flow head and twin Weber carburettors on a DCOE manifold for 8v engines... This is slightly more expensive but should be far easier to get going, right?
Car carbs...Weber or Dellorto...are easier to tune as access to the jetting is via the top of the carbs, unlike most (if not all?) bike carbs with jet access at the bottom, which makes tuning them a pain when you can see them let alone hanging over the back of the engine over a hot exhaust manifold. Some like as been said above have made bike cabs work OK on front mounted installs like a 16v, so access with a crossflow head would be easier but there's still breather hoses and an alternator in the way...I've done a crossflow install on a customer 8v with an underslung throttle linkage on itb's which taught me a whole new dictionary of swear words due to lack of space. The 2ltr crossflow head flows much better than the 1600. The above mentioned project has one with only minor valve seat & throat work and makes 160hp on itbs with a mild 272 hydro cam on a std bore DX block 1800...pretty quick in a full road trim mk1. Also need to think of radiator location at the front...don't mount it in front of any carb whatever you use and don't have air flow direct into weber's or dellortos or you'll get high speed mixture lean out/misfires when it was fine on the rollers setting them up.
Webers and dellortos are a pain in the ****, vike carbs are a lot more dependable, the dellortos that my dads old elan had needed tweaking regularly to keep it happy. More modern bike carbs will stay as you set them. (My old Chevette had a 1600 zetec se engine on mikuni zx6r bike carbs and they did the trick) though they are expensive throttle bodies and fuel injected is far superior to carbs
Pardon me, but that's nonsense. Properly set up carbs, jetted correctly, using a good strong throttle linkage centrally mounted, and running proper filters, are very dependable and simple. Most (all?) carb problems I've encountered have been down to incorrect install, or people never setting /balancing them, running with fuel filters or dodgy fuel pressure and / or running open trumpets. Set them up right and there is almost nothing to go wrong. I only used bike units from a cost point of view, as I could make manifolds and bracketry myself.
I know that from experience, and from what I've been told by people who know what they are doing, dave walker and Richard lepley have both explained it to me, I've owned a car with bike carbs, I've grown up around lotus elans, and historic rally cars (mostly mk1 and 2 escorts) and kit cars. My experience with webers/dellortos they are dependable if you check they are doing what they should regularly, bike carbs seem to just stay set up and fuel injection is fit and forget. Anyway I'm not having an argument over it, you have your opinion and i have mine. Agree to disagree.
As Tristan...car carbs don't go off tune unless worn or set up with a worn linkage which is then a moving variable. I never touched my Weber's in several years of competition and it was still class winning when I stopped using it...same with my current customers on carbs. Dave Walker is a top man...but sells and sets up ecu's for a living........I've never seen in print a Microsoft salesman say "what you need is an old zx spectrum". As said some get good results from bike carb's...I've always found a power gain changing to car carbs and never found a night and day difference between correctly set up Weber's or Dellorto's vs throttle bodies (not old knackered carbs vs new tight itbs) when comparing like for like sizes and tune....it's the mappable ignition that makes the most difference.
Dave Walker, who I have recently met and spoken to, used to be an old skool engine tuner, and natural progression led him into EFI and when ultimately the business he does now. His understanding of engine features from basic principle is also implemented into the Emerald engine control functions. He still knows a hell of a lot about carbs trust me. I worked on lots of Japanese (Asian/Nikki,Mukuni Keihin) 2BBL, 2BBLx2, 1BBL, 3BBL, Solex/Mukuni twins, S.U and Stromberg carbs and they all go out of tune as the jets pick up deposits over time. I have been around long enough to see carbs also pick up electronic controls to improve robustness. Ulimately they are still a carburettor. When I say "out of tune" they will still run the engine in most cases, but the critical window to deliver LBT fuel control will be slowly shifted over time. With that downside taken into account, you can get any carb variation to run an engine, provided it is sized and jetted to suit the airflow requirements of the engine.
Cheers for all the information here guys and girls. Ultimately I'm looking to stay with the carburettor rather than fuel injection purely for the sake of it. If making my own manifold for bike carbs out of the original manifold is a cost effective means of achieving my goal then I'll likely go down that route. Back to the question in hand, will the set up I've listed likely work well enough for a smooth drive? I'm not interested in power or performance, just nice running and sounding engine that is period correct for the age of the car.
The other thing to think about is fuel pumps and pressures, if your car is a driver or GL which I suspect it is, it will have the block mounted pump, which if you switch to a PB you will lose.
Ah, interesting. I had seen that people also purchase a matching CBR600 fuel pump and use that when converting to bike carbs, along with a fuel pressure regulator on the fuel rail. Am I on the right lines with this thinking? Also need to start thinking about making up an inlet manifold, probably just going to fit them to my 1.6 EV cylinder head for now as I have plans already forming for a future engine upgrade... Anyone have any tips for making a custom bike carburettor inlet manifold (i.e. chopping the stock manifold and removing the solid metal between runners)?
I work on bikes for a living and personally find the last of the carbed r1's was the best of all carbed bikes imho. I would say a set of r1 carbs mated to a KR16v would make a very potent combination!. Efi is a lot easier to tune, either way you should invest in a wideband with datalogging if tuning yourself.
Missing the point, this isn't about top power potential, just throwing something cheap together as a project for a learning exercise. Not looking to mess with EFI at this stage, but thanks for the suggestions. Maybe a later project...
