yea 4 bottom ends in 4racers need some ansers need to no why

Oil surge? Ask crofty.

Try asking on toymods. But take a while to sort through the crap replies.

Do the 20vs have oil float probs at high revs?

my black top with gt corolla ECU rev's to 8200rpm soft limiter though, with the standard sump no problems

at donald the old girl sits at 8200 for over 1 minute in top down one off the straight's
by the way 2ltr Kombi box's don't like this

use mobil 1 sinthetic change every big race or 2 club rounds

ran whith mod sump more then  6.5 l of mob 1 thinking maby going dry sump with cooler

We ran the 20 valve engines for a number of years with the standard sump and never had a problem with them at all. I can't see why you should have to go dry sump to get them to survive, there are heaps of these engines running without problems so there must be some other cause. Dry sumping a 1600 would hurt power output a bit I would have thought.

What is actually happening? Is it breaking rods, doing bearings, etc?

This was mabye what I thought too.
If the oil is to thin, then at high RPM when the engine is hot there could be an issue.

Evidently the bigport 86kw 4ag had that prob, but not the 100kw or 20valves.

You have to find the common problem with all these motors,
1. do you use the standard sump, or do you have a modified sump and pickup?
2. do you use an external cooler or filter?
3. what rpm's are you revving the engine to?
What damage is happening to the bottom end, spun bearings , melted pistons etc?

find the thing that is consistent with all the engines and you will most likely solve your problem
I ran a 20v racing for 5 years and never had a problem until the thermostat stuck and cooked the rings, but apart from that it was all good.

was 4 drifrent engines first 2 conrod bearings then black top 2 brock rods  last one conrod bearings was a yager engine 

If it is spinning bearings, chances are you are runiing out of oil at high rpm's
if you use the same sump and pickup on every motor i would be checking that there are no holes in the pickup tube ( a pinhole in a weld will be enough) or that it is not blocked or the mesh is jammed up against the tube,
also make sure that the sump is not restricting the return flow of oil to the area around the pickup, some people over baffle the sumps and this can be a problem.
and trekka is correct the blacktop rods are weaker than silvertop!

still looking for a tuff 20 valve engine

I can do them for about $600 but i need the standard windage tray and pickup.
the one in the pictures was the first one that I built, but I reckon I can do a better job with less welds and more folds and If I do a couple of them I will get the sump flanges laser cut so they are a bit neater.

the rings are mahle, the bearings are acl race series, the cams are Kelford cams from NZ ,it has new rear main and camshaft seals and new head gasket, do you need a comlete engine or just a short motor? and what sump do you want on it. I can turn a standard sump around that looks pretty neat.
I have an adapter plate for it to vw.