With all the talk = about main bearings color codes I think I can clear the air on this subject. = It has been suggested that the difference in size of the blue verses red is = .004 ths. The measurements I have taken show that the difference is .00025 ths. that turns out to be a 1/4 of .001ths. Why they would bother = to make two different bearings sets with so small a = clearance change baffles me. The clearance for the main bearings is important and = hard to measure I have spent thousands to be able to do this = accurately every time. Plastagauge is nice but not the cure for knowing the = clearances of the main and rod bearings and it has let me down to many = times.

I have never found = the case measurements or the bearing clearances listed for the1.9 or = 2.1 engines and I am not going to offer them today. what I = will say is that I have found the need to align bore most 1.9 blocks. = the reason is they loose the crush on the bearing over time In layman's terms = the hole is to big.

As for the 2.1 block some are fine and some need to be align bored and there is only one way to tell. That = one way is with a top of the line bore gauge and a couple of hours = to get the block clean at the mating surface and bolted together. I can say that if = the middle bearing web is out of round then it needs to be align bored the = other thing you need to know is that the crush is greater on the 2.1 main = bearings because they are a thinner walled tri metal design bearings.

The clearance = for the main bearings to the crank on the # 3 and # 4 bearings is = .002 to 004 ths. as taken from the type 2 Bentley book yes its a different = engine but the basic requirements of main bearing clearances are the same = and the journals dimensions are also the same. the # 2 splitshell = bearing is not the same in the WBX 2.1 engines as the type 4 = or the 1.9 engines. the type 2 book says the min clearance is .0012 ths to = .0035 ths. As for the WBX 2.1 I would not want any less than 0015 ths on = this split bearing to be safe. The # 1 bearing next to the = flywheel calls for .0019 to .004 ths I have found most cases with bearings = installed to measure close to the high limit of new spec. the wear limit is .0074 = ths. WOW

As for the rod = bearings I like my rods to have .0015 ths between the rod bearing and the crank journals the type 2 book lists .0008ths to .0027 ths as the new = spec this is for both the 1.6 and the 2.0 air cooled engines.

I'm really pleased with the = increase in power. I had some concerned about the injection system but the exhaust = gas tests showed everything is a go. I did have to back off the main spring for = the air door in the air flow meter to get the mixture set right. The mixture = adjustment was much more sensitive than any I have seen I think the big = valves are the reason. The flow bench showed a 20% increase in air = flow threw the heads at all valve lifts we tested.

Because of the past shortage of WBX = main bearings I used a set of used main bearings in this engine with no problems the = clearances where right where I wanted them and no oil light at hot idle