Pacman, an engine builder in Sweden gives additional advice on
16V turbo subject
Originally Posted by Boosted2003 to Turbobricks: Im currently building up a b230ft bottom end with b234f head.
When it comes to building motors what blocks do u guess perfer b230ft or b23ft?
Do you know if the windage tray(crank scraper or whatever you volvo gods call it) from the b204ft/gt will bolt up to a b230ft bottom end?
The strongest redblock to use for high performance turboengines is the late B230FT/FK '97-'98...but all the B230FT/FK '94-> are good.
However, the internal parts are better in the old B23 '83-'84 since both the crank and the conrods are in forged steel. The B23ET also have forged pistons. I dont know about the B23FT since we dont have them here....for abroad sale only.....but its easy to check the pistons. If they are rough inside with typical molding marks and the very typical "Invar"-metalclamps molded into the piston....its NOT a forged one.
The B204FT/GT is a very odd block and differ in many ways from the B230s. I dont really know whether its better than the B230FT/FK or not, but its a strong block, thats for sure.
The most significant differences are the external oilpump and the two balanceshafts. The shafts is mostly taken away when building a serious engine, since they are put there for comfort purposes only...not performance. Some just lose the belt...others take the shafts out and weld/glue/screw the oilchannels...they do wheight some kilograms and adding lightness is one of the best ways to enhance performance ;)
How an oilscraper (direct translation) from the B204 will fit a B230....I do not know! Try!....the bearings should be the same since the cranks are the same, or at least interchangeable. Maybe the internal oilpump will make the swap difficult, but some modifying should not scare the true enginetuner....aight ;)
I make my cranks lightwheight by "axing" it....making the counterwheights look like axes. Then I grind the ends in an aerodynamical correct way to loose some windage. Porsche has done some tests years ago and they won about 10hp in an 200hp N/A-engine by just making the crank aerodynamical.
A few things to have in mind when building a B230/4 hybrid turboengine:
They need to be the dometype w valvecuts since the 4v-comp.chamber is much smaller than the 2v. If buying new aftermarket ones, thats great. Just be sure that the dome is big enough to get the right geo.compression.
If you consider to use the B230FT Turbopistons, thats a cheap way to get it working, but they dont cope that much boost since they are not forged ones.
If you consider to use the B234F pistons.....not good. They make a geo.comp.rate at about 10,5:1 or more, so if you are planning to use some boost, youre in trouble.
-The connecting rods.
The stock ones are fair. They cope the abuse for up til about 250-300hp at moderate rpm and moderate boost. Pinging though will kill them by seconds! I know too many people who have lost track of their boost by loosing a wastegatehose or some other stupid reason, and found their conrods lying on the street along with bits and pieces from various parts of the engine. "Rod Out" is a direct translation from swedish which in few words explain the result if you get ping in a raped stock Volvo engine.
The solution for this is aftermarket conrods! In Sweden there is a single guy who manufactures conrods to almost the whole Swedish Racing society. His name is Stefan Verdi, and his company AutoVerdi has made a name for itself by making H-beam conrods remarkably alike the Carillio H-beams. They are used in engines that output more than 250hp/cyl and revs more than 11000 rpm.....and they do not break!
However...the pricetag is just as much as Carillio's.
-The oilpressure and flow.
The B234 use hydrualic lifters in the DOCH-head. Whether this is the reason why the B234 have an external oilpump or not, I dont know, but one should bare in mind that they do need oilflow. Cranking up the pressure in the internal oilpump by shimming might get you some of the way but not all I guess. I have heard about people who couldnt care less about this, and they are driving their cars....so maybe it works afterall, but I'll wouldnt bet any money on it! Changing to mechanical lifters eliminates the guessing!
-Camshaft pulleys and belt.
The B230 cambelt pulleys are way too small to cope with the double force needed to press twin valves. The B230 belt is also too thin to endure the powertransfer. Changing to B234 campulleys is the proper way, or better...adjustable ones!! The stock B234 crankpulley is too weak though, and here one must find an aftermarket replace made in steel. The stock B230 does not fit when shifted campulleys since the size and number of teeth differ.
And then at last....the engine management system!
The "roof-type" 4valve comb.chamber is all different from the "bathtube-type" 2valve one, and this will make the A/F-mixture ignite in a totally different way.
In practice this will mean that the ignition timing from the 2v-engine will NOT adapt on the 4v-engine....it will make it ping!
Either you must delay the timing using some MSD retard-gadget or something like that, or remap the whole ignition-map.
Again....if using nasty aftermarket EMS....that will be no problem since you'll have to remap it anyway, but if you are considering using the old LH-Jetronic FI....make an effort to think about how to be able to change the timing.