Hello all, Seeing as these engines have been around for a while I assume this has been done but can't find any info on the topic. Which makes me speculate that it might not have been done regularly for some particular reason? Or perhaps rather the aluminum blocks are hard to source and the iron ones are tried and proven to hold up very well so most people don't bother? I don't know the engine codes, but talking about the later style blocks which have an internal water pump and chain driven oil pump, as opposed to the earlier (058) style blocks which were external water pump and intermediate shaft driven oil pump. Some of the NA 2L 20v engines came with aluminum blocks. The water pump is different (larger) than the iron 06a blocks, but other than that, all the "bolt ons" appear to be the same. The weight savings aluminum vs steel is apparently close to 50lbs, which would be a significant savings from the front. Was just curious if anyone had experience building/ boosting one of these. Cheers all, Isaac
Basically there is the 20V ALT and the N.A FSI engines...and are very similar to eachother > waterpump The fact that VW / Audi go for a steel block for Turbo engines gives already an indication … but for a road car, it has to last long time ... In motorsport,we see upto ca 300 hp in N.A form....and being pretty bullet proof with alloy blocks. but tbh i think its more fuzz than its worth to go alloy block ….
Hello HPR, thanks much for the info and the very helpful pictures! I heard the stock cylinder sleeves are nickel as opposed to steel, do you happen to know? My machine shop has some of the alloy blocks on hand including the correct water pumps, and I need to buy a block core from them to build anyway. The core pricing between the allow vs the steel was hardly different, so I thought for the little extra, I might as well save the weight (47lbs is what I was told) in the front for a better handling car, as long as the block would hold. Regardless the iron vs alloy block, it will get machined to fit 83mm pistons. In the case I went with the alloy block, they'd put steel sleeves in to increase the strength. Aside from that, everything else seems to be pretty much the same. I do have an alloy oil sump too though. Perhaps a steel girdle would be necessary to keep the block in check. The engine should be good for 500hp.
Indeed fit steel sleeves is the proper way to do it and the alloy block get its strenght by its cast in steel liners and the oilpump/ balanceshaft assembly… A bare Alloy block weight ca 20 kg while steel blocks are ca 40 kg
Thanks much HPR! May just give it a go and seen where that takes us. The machine shop needed to see if my 95.5 crank would fit, they suspect it will be too tight. At any rate, if we do go for the built alloy block I will update for the sake of anyone who may be searching in the future.
Indeed its all tight ...with the std liners / sleeves the top 6 mm are alloy … and with 95.5 mm stroke, the top piston ring would come onto the alloy…. Anyway its not something you would have to deal with, once new full lenght liners are fitted !