Hi guys I'm building up a crossflow 8v engine. The engine doesn't have to be super powerful as its going into a retro mk1 golf. I just want to give it a little more go, and be fun. My first plan was to use an original 1600 8v GTI engine with the crossflow head. I know these engines are revy and fun, I was going to get it lightened and balanced, and rebuid it, and run it with the crossflow head with a set or bike throttle bodies. But I've been thinking recently about using a 2.0l block. If I had it lightened and balanced could I get it to be a little more lively and revy. Or is the a crank and bore combination which would work well for what I want What do you guys reckon. My basic aim is to have a fun revy motor, A little different to the norm. I know I could get more power per pound from other engines but I'm not after massive power. Cheers
2l engine can be made quite revy with lightened components, i have never had a 1.6l engine so couldnt comment on if it would be as revvy, but my 2l with lightened flywheel was better than the std 1.8 in my last car.
A std 8v head on these shores is a counterflow ie inlet and exhaust on the same side of the head. A x-flow head has the inlet on the front and the exhaust on the rear giving better airflow for TB's and or more room for a turbo.
I dont thinkk that there is a massive amount of difference, when it comes to power figures. Wills xflow with ITB's made 170bhp, compared to chrismc's counter flow head running digi injection that made 160bhp, Ian Carvell had 170bhp out of a 2l 8v running on carbs using counter flow head.
Some interesting figures. Cheers for the info so far. I would be interested in hearing about other people's 8v's. And if anybody recomends what cam to use (Guess this will depend on what bottom end I decide) And are there any gains to be had from raising the compression ratio?
You'd need custom pistons to do it on a 1600, or you'd be running very low compression. How about a 16v conversion? They're ALL X-flow, and ready built without any messing around.
Why would it be low compression on the 1600? Could go 16v, but lots of people do that, and it's to easy. I want it kinda original but with a twist, hence the 8v engine, possibly 1600 but crossflow. Should leave me with a nice simple looking engine bay
if you use your 1600 block you will get Low compression as a result of the 1600 gti head having no chamber, if you add a head with a chamber to the block you will get low compression. not a problem on the 2l
Ah ok, I didn't realise the 1600 GTI head didn't have a chamber. Thanks So do the pistons have a big dish for the combustion chamber or is it a combination of the stroke? What about If I fitted 1800 pistons in the 1600 block, but kept the 1600 crank. Would the different pistons increase the compression
Yup... big dish in the pistons As for the piston swap, it might work depending on whether they're the same bore, whether the rod length and deck height is right.. A lot of hassle, for less power than you'll get from a 16v... so why bother???
I believe the bore's are the same but the stroke is different. I think the rod length is also different. Do you know how I could go about working out the compression? I don't find it hassle, it's a hobby, so I find it interesting. I've messed with 16v engines before, but never played with a NA 8V's. So I find it quite interesting what type of engine I can put together. And I little different from the norm. The only 16v I would want to use is a Oettinger, but I gave up trying to find the parts for one of those I'm not building the engine for the most power, I've got a tuned mk2 20vt for that. But it will be interesting what power it gives out in the end,
Work out the compression ratio: by measuring the piston dish (a syringe or pipette) measuring the combustion chamber, and working out the ratio of that to the CC of the engine. You need to either measure rod to piston crown height, or put the bottom end together and see what looks right (aim for the piston coming level with the block deck) You may either need to get the block decked, or the piston crowns machined down. You also need to check the head for compatibility with the block. Check the valves don't hit the block deck, and the water and oil passages will all line up (use a gasket). VR6Will has done an X-flow on a 2.0 block, so he can tell you what machining he had done to make it fit, but because you're going for a different size of engine, you need to do some more investigation. While you're at it, why not rebore the 1600 block to fit some 2.0 pistons in there, and build a big bore, short stroke screamer.
Incidentally, from what I've just seen on Carfolio.com, the bore is different. You need to get that checked before you start, and figure out how much meat is left on there for reboring It's not 100% accurate, but often is. http://www.carfolio.com/specifications/models/car/?car=43054&Volkswagen
