Cos I reckon the 1.8t type bottom end is sweeter than the KR , and I can get my target bhp cheaper from the 16v head. Plus it looks more old skool , which is where I'm at...
or do a complete 20v na set up. one of the 20v heads flows better than a race spec 16v head, are u wanting to use the existing k jet system for factory look. id use a rebuilt 9a bottom end if your looking for bhp. is there any reason why you need a target bhp ie race series power to weight, regulations etc
No ,its for road use. I've spoken to a few tuners who don't agree the 20v head is all that good , for N/A use . The air speed in the ports is too slow , I'm told.
depends which 20v head, there are a few. mad20v who posts on here has a 20v mk1, a 2ltr 16v bottom end with a 20v head its a awsome piece of kit.
I think the max tuning potential of the 20v head in NA form is a bit pants, certainly no massive improvement on the 16v head, but the standard NA cars are pretty good. When Audi introduced the 20V in the A4 they replaced the old 2L 8v and 1.8 8v with a 1.8 20v and a 1.6 engine in the line up as the torque of the 1.8 was as good as the old 2L and the new 1.6 equivalent to the old 1.8. Same went for the Passat and mk4 golf GTI (with the 1.8 20v anyway), although with all the weight of the mk4 that was a bit of a mistake.
The 20v powered Mk1 mentioned here produces 240hp in N/A form (not an ultimate spec race engine either) so there's not a great deal wrong with 20v atmo engines. There arnt many atmo VW 16v engines in the UK making the same or more power (ROBT's is one of the few).
Just my opinion based on experience so I am not having a dig at anybody. But is that feasible. 240BHP from a 1.8 without VTEC or MIVEC @ what revs and what was the peak torque @ revs. And at what budget. Would this engine be smooth to drive in everyday traffic. For the money you will spend to get that kind of output from a 1.8 in N/A it would be best to either fit an OEM larger motor and/or go the forced induction route. Think about it, at 3000revs in a STD 1.8T you are making at least 150lbft of twist. In a well sorted but STD 2.0 16v (ABF) you will make close to that but at 5500revs and at 3000 revs you will be making at least 110lbft . There is no way a STD 1.8 20v N/A. will doing that at 3000revs more like 80-90lbft and with the wrong gearing this will feel gutless. The last engines 20v VW made 1.8 N/A ADR for example were right pigs in everyday performance GTIs as they claim 125bhp@6000revs but were gutless in everyday driving. This is one reason they switched the engine in the MK4 to a 115BHP 2.0 as it had better low down torque for everyday driving (around 2000-3500revs). Horsepower is a result of the work done by torque. I dont know what will be really achieved by taking a 16v head and sticking it on an early 20v block unless you have the parts to experiemnt and you are willing to handle any gremlins that will present themselves from subtle differences the components from different years. I know the chaps in the States make hybrid 20v but for 2.0 applications . So if a 20v head works on a ABA engine which as the same layout as an old KR short motor then I can see why a 16v head can work on a 20v shortblock. Only thing would be piston valve clearance and resultant compression.
It certainly is feasible... The engine in question is a competition spec "2ltr" 20v on throttle bodies. Peak power was around 7,500-8k and peak torque was around 6k from memory. And yes, drivable enough for a comp spec engine. The point I was making was that a lot of engine "experts" (and no i dont mean anyone on here) knock the 20v engine (or at least the head) in atmo form but i wonder how many of them have built one with the power that the ex mad20v car has.
That's what I was wondering too.... I'm only thinking of using the 20v block/bottom end as it should be a nicer better made assembly than a kr ,what with more modern tolerances and machining.
That car is very famous. It was featued in "Golf GTi performance manual" by Tim Stiles which I have and read as well as in, was it Golf Extreem ? and remained there as the HP king for a very long time. Tim says it does 208WHP or 240BHP. He also states "it remains just road legal". A car like this is a one off and must have been made to suit a defined user purpose (track days). Not your average DIY job on a DIY budget. It is also a 2.0 which helps low down torque but carries up the price of the build. Thats why I asked if building an engine like this is feasible especially as Redlexus says "No ,its for road use". I thought it would have to rev to make that kind of output. Thing is you can get the same type of output but with much better torque for road use from a 1.8T turbo. And no need to rev it to 8000revs. Still that Mk1 is a beautiful car.
The torque *may* have been as good, but at what rpm was max torque for the old and new engines? Answer:
mark25, The 1.8 20v N/A had 127lbft@4100revs and rated 125bhp@6000revs The 2.0 8v motor at that time had 125lbft@2400revs rated 115bhp@5600revs. Interestingly the old KR unit does 133lbft@4600revs and 139bhp@6100revs
just a quick note on the 16v vs 20v engine topic, vw motorsport managed to extract 265bhp out of the 2ltr 16v engine in the mk3 kit car circa 1996 and later in the mk4 kit car 295bhp from a 2ltr 20v engine. so the extra 30bhp must have come from some where i say the head as the bottom end in the mk3/mk4 kit cars are of a simular design. the only difference is the ecu's The Mk 3 ran on a Motronic 2.2.1, the Mk 4 runs on a newer (3.x) system with integrated display. apparantly the 20v head looks more like a xe head, mad20vs car ran ADR head i just read a lot
That's what I was wondering too.... I'm only thinking of using the 20v block/bottom end as it should be a nicer better made assembly than a kr ,what with more modern tolerances and machining.[/QUOTE] I see what yr thinking, but I'd be inclined to use a 2ltr 16v (ABF or something) bottom end with yr KR head or even the complete 2ltr 16v engine. Should be as good as an 1800 20v as far as tolerances go but with better power right through the rev range. If age/mileage are also a concern then try and get as late an engine as poss, though even a high miler can be good. Either way, you take a chance with whatever you buy second hand.
