edit: i was proven wrong
is this a direct bolt on?
would you run a 16v ecu?
edit: i was proven wrong
Last edited by HYPNTK; 27th January 2009 at 02:29 PM.
Yes it fits (from what I've heard/read, unfortunately not first hand yet). I don't know if they become interference, given the 5 valve reliefs and 4 valves.
You should be able to run it on the 16V ecu. The main change will be slightly higher CR, so you'll have to keep an eye on things. And also make sure you fit all the 16V sensors to the bottom end (knock sensor is all that springs to mind, but I'm sure there are more).
Hen
wouldnt u go the other way around
NO way!
16v head is not a direct fit onto 20v bottom end !
Because the inlet valve reliefs are in the wrong place in the piston crowns.
You would have to get a proffessional to dummy up the combo and check
piston to valve clearance and get the inlet reliefs machined in the right spot.
As for the ECU it might run it if your lucky but don't waste your time get
an aftermarket one.
the ecu will run it no problem. there are alot of small ports running on big port ecu's ect. the CR is going to be similar to that set up. there just isnt that much difference in chamber volume or piston crown.
the fly cuts are the issue, but i would be very surprise if there were any issues under normal operating conditions. you might end up with an interference engine. but it will probably not contact under normal operation.
having said all that. while the engines apart, a hone, some fresh rings on some 2nd hand small port pistons would be a little bit nicer way to go. thats the set up ive run a few times. typically i guess youre looking at $60 for a hone, about 50/60 for rings from memory. and 2nd hand pistons usually go for about $50.
was a passing thought. as i can get a smallport head cheap and saw a cheap 20v block. ill get a roady then figure it out
^^^correct
smallport heads have an external oil drain from head to the block, the 20v doesnt. this could be an issue.
besides i wouldnt bother with a combo like this, as the silvertop and 20v bottom ends are VERY similar in strength. obviously the pistons are different, and the silvertop rods are the same as GZE, but its not worth it.
just a buy a complete smallport, or complete silvertop, save yourself the hassle of combining the two.
just my 2c.