TurboGuy

Ususally, the 3/4 grove bearings are considered superior. There is alot of load placed on the bottom to the main bearing and the full grove bearings have less surface area there.

seerex

http://www.d-series.org/forums/showthread.php?t=94973

TTC

I duno how i feel about boring out my oill pump to be honest, im curious yes but havent heard of anyone really doing it on a toyota motor. I've hard of shimming oil pumps, but I already have the higher output pump as it is. Gonna do some more looking around and see what I can come up with. I'm also pretty curious about increasing the bearing holes, IIRC last time i built a 4age the bearing holes were the same as the crank holes as far as oiling goes. I've also found that you can retrofit oil squirters into the block im working with but you have to grind the crank some to clearance for them. That in itselfsounds like lunacy, but i guess if its balanced after its fine.

One side note, there is an arguement that you want more flow and not more pressure, but by increasing flow your dropping pressure. So wouldnt you want to do both? Also wouldnt of honda or toyota have designed the pumps to make more than ample oil pressure ? I wonder how big the bores are on oil pumps on oem turbo cars that are roughly the same size.

Tom-Guy

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In a hydraulic system where the fluid is incompressible, the system is only as good as the smallest orifice. Which is where the oil squirts out around the edges of the bearings, etc. Any increase in flow in the rest of the system doesn't drop pressure - it increases it at the extremities of the system./
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Also, you do realise a lot of the 80's Toyota engines were designed to run 20W50 for no other reason than that's what Toyota got a bunch of for cheap, and sold as their own brand? Yah, now you know why 7M idle at 5 psi oil pressure.

Smith-02

warm a 22r gets dick for oil pressure unless a machine shop re-does the block to their spec

TTC

So you guys recommend people do this? I've heard while using the 7afe block like a 4age it has a tendancy to become oil starved. So these are measures to keep it from killing itself under hard cornering. I duno bout using the expoxy, I think id rather have someone tig it a bit .

Tom-Guy

I dunno about fooling with bearings like that. Everything I'm used to is built off the stock design... ACLs for Hondas where they come in a standard "green" middle of the road size, supposedly targeting the "ideal" 0.0015" clearance. Then the ACL race bearings which target 0.0025" so the engine is loose and wants to spin - if your oilling system is up to it.

Filling head ports, oil pumps, etc with the correct epoxy isn't any big deal. It's done all the time, and if you cleaned the part correctly the epoxy is NOT going anywhere. The biggest hassle with it is selecting the right epoxy (Devcon aluminum epoxy for aluminum, etc) which sure beats the hell out of dealing with warpage/thermal management when welding on something critical like an oil pump.

seerex

Just port and shim it and be done with it.

Tom-Guy

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Alright, I think I'm a little lost by your sentence structure. You're talking about using a 4A-GE head on the 1.8 bottom end, right? I'm about to go chill with my Toyota peeps and drink too much, I'll ask./
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I know from Honduh experience that the guys who run LS/VTECs can have bottom end starvation issues. If you aren't familiar, the LS and B20 blocks don't have the VTEC oil passage, so an external line is run to the back of the cylinder head. Apparently, -3 or -4 is the biggest you want to run, but some people run -6 or bigger, and it starts dropping the bottom end's oil pressure. Yah, not what you are asking about, but it's a very good example of the sort of ---- that can go wrong.

TTC

Yea sorry I wasnt paying attention. I'm putting a smallport 4age head that i built on the 7afe block. Ill be using forged pistons with 7afe sized hbeam rods. What i figure is that with the extra turbo oiling, oil cooler and the mismatched block and head people might be losing a bit of oil flow. This compounded by the 4age's natural tendancy to drop oil pressure under cornering is a concern. It's kind of similar to the b20 problem but its not a for sure thing. There are plenty fo people who run fine like this without problems, perhaps they used a shitty oil pump when it popped or didnt check the oil. Who knows. But im just taking a little bit more time to make sure, so ill port the pump and shim the spring just to be on the safe side of things. I'm also goign to consider putting in those gze oil squirters, but I want to check with engine builders first. You have to clearance the crank since the bump into the squirters, and I dont really want to take a grinder to the crank lol. I have to find out how much it will cost to machine my crank a bit properlly.