TimZ

That works for me too. So are the flow numbers corrected to some standard pressure, like 25" H2O?

Here's what I did to avoid the problem completely. This was a 4" downpipe to twin 3" ovals on either side. You should should be able to fit a 2.5" oval easily in this manner.

You have a VQ35 in your footwell?

Thanks for the writeup, Joe. I've been thinking that this would be a great way to add power steering for a while now. I was actually looking at whether I could adapt an EPAS system from another car myself, but its been on the back burner. One question that I have is whether the new system retains the collapsible function of the stock column - its never been clear when looking at pics, at least not what I have seen so far. I'd prefer to not get impaled if I were to get into an accident...

Not a dumb question - as I recall the FSM doesn't talk about it at all. The cup-looking thing should be (at lest it is on my 78) a swirl pot. They feed the return line through a small jet pump into the swirl pot to keep it filled with fuel, The pickup line then draws its fuel from the pot, so that it always has a head of fuel over it. The pickup tube has a filter over it, so it _shouldn't_ clog up from stuff in the pot, but its still possible that something has rusted and clogged internally.

St. Louis _used_ to have a pretty strong Z-Car community, but it's been a while since I've lived there. Maybe check with Howard at The Sports Car Centre (great mechanic and honest as the day is long, btw) - if anybody knows where the remaining Z's are in town he probably will...

Okay, so here's an update after considerably less than 7 years I finally got my engine back together and on the road today. First startup was done with conventional 10W-30 oil, and I noticed that I was still getting good oil pressure then, but didn't look into it in any specific detail other than noting that it wasn't stuck at 30psi. Just wanted to run it in first. So anyway, good initial results for oil pressure. Changed the oil and finished putting it back together and got it on the road today. So, with straight 40W conventional oil, stabilized at 180degF here's what I found so far: 1500rpm => 30psi 2000rpm => 40psi 3000rpm => 50psi 4000rpm => 65psi So I think I'm in pretty good shape as far as oil pressure goes. I did go through and ported and smoothed out the oil passages as much as possible while I had it apart, so that may have helped a bit.

Alternate mounting bolt holes for the FI manifold. That is some gorgeous work! You could just about market those if there was a sure-fire way to specify where the new holes in the head need to be drilled and tapped... Am I hallucinating, or is the water passage bore size larger at the rear of the head?

In my case its a moot point, as my rods don't have the squirter holes anyway. However, for someone else potentially doing this mod with stock rods, it might help with oil pressure at or near idle, where the holes in the rods are probably just more of a leak anyway. My worry has been that I'll end up with a sort of plateau or stairstep oil pressure-to-RPM curve that flattens out at ~30psi due to the squirters coming in. This remains to be seen, but this reminder that I have one less thing consuming oil flow from the mains makes me think that it will probably even out. Hopefully.

Thanks again for saving me the typing, Tony One other thing - for the purposes of this discussion and for a given power output, Supercharging is exactly the same as turbocharging (possibly worse depending on the configuration) as far as heat that gets seen by the piston.

I'm already part-way there - I have an external feed from the pan that taps into the pump feed galley in the block. The original pickup point in the block is blocked off. This was done out of necessity at the time as I had an early AZ ZCar cast pan tht did not accomodate the stock internal pickup. My external line is a -12 that runs for maybe 10" to the point where the block was tapped. The internal passage ID isn't too bad, but there are a couple more sharp corners in there than I would like. I've taken a die grinder and opened up the internal, somewhat tortured paths in the front cover, so that should be a bit better, but I suspect a -12 line straight to the pump would still be better. I've seen a mod that involved an adapter block placed between the pump and front cover - is that the mod you are speaking of, or is there a simpler way that wouldn't involve relocating the sway bar? I was thinking of having another look at the front cover to see if it would be possible to mod it directly with a fitting...

Thanks Tony. You always seem to save me a bunch of typing. Now just pray that the oil pump holds up.

Thanks for the kind words and I'm not taking offense. However I am have trouble following your line of reasoning. This method of stabilizing piston temps is really well established and is becoming pretty much ubiquitous on high specific output engines. Plenty of OEMs use them, not just Honda. And I was having trouble understanding the assertion that they don't have precedence in racing when it seems to me like organized race series that don't have teams that use them seem to be more the exception than the rule. The latest NASCAR engines _do_ use them, btw. As we've already discussed, I'm more interested in the potential longevity aspect of these, rather than trying to get a horsepower gain out of them. I'm already using ceramic coatings on my pistons and they appear to be working, in that I'm not getting any discoloration, coking or sludge buildup on the underside of the crown. However, ceramics are a heat insulator and while they significantly slow the flow of heat into the piston, they won't stop it. This will work great for short bursts, but I have no idea of how long they will stave off disaster by themselves. It seems logical to me that the combination of the coatings with the squirters should allow the oil squirters to remove the heat that does get through pretty much indefinitely, assuming nothing else craps out. My main concern right now is whether the oiling system can accommodate the additional flow required, which should become apparent pretty quickly.

Your suspicion is correct - it's not figured into the torque spec. I always back each bolt off approximately an eighth to a quarter turn, then re-torque to spec. Basically you just need to back off enough so that you will be able to see it turn a bit as it comes back up to spec. Don't back them all off at once - do them in sequence. Back the first one off, re-torque it and then go to the next one. Also, avoid re-torquing while the engine is still warm - you don't want it cooling down and changing temperature while you are doing this. Most recommendations that I have seen say to let the car sit overnight before re-torquing. This way you know that the engine's temperature has stabilized.

...oops -double post

I've seen that bike in person! It's in the Motorcycle Museum in Anamosa, IA...

Maybe I'm misreading what you are saying, but I think there are plenty of examples of piston oil jet cooling being used in performance applications. Are we not counting F1, WRC or Winston Cup as part of the racing world? Also, I'm not running particularly big bearing clearances - I'm right at .002" for both the main and rod bearings. That said, I will be watching the oil pressure pretty closely...

Who says you can't convey tone on the internet?

Ummm, yyyyeeeeaaaahhh... I'll get right on that.

Yes- in the pic above the piston is pretty much at BDC, so plenty of room there. As far as my plans to quantify the results, I don't really have any. I'm not looking at this as a means to increase performance. To me this is more akin to the cylinder head coolant flow modifications - intuitively and directionally correct and should help with longevity, but pretty hard to come up with hard proof that it worked. If something breaks right away I guess that woyld be a different story, or if i (HEAVEN FORBID) end up with oil pressure issues then that's worth reporting. Aside from that, I'm looking at this as something that should be a belts-and-suspenders approach to control the amount of heat in the piston and therefore leave it with a much better margin of safety at 600+ rwhp.

Update - got the bottom end put back together today, and took some pics of the squirters: I aimed (bent) the nozzle out and towards the center a bit, to try to aim it just under (above when it's right-side up) the piston pin at BDC, so hopefully the oil will disperse across the underside of the crown:

Pretty sure it should fit the ET. If you can find a bracket from a ZX, they are made from aluminum and are much lighter than the earlier brackets. The aluminum bracket mounts the compressor a bit closer to the engine so you would want to get the matching idler/tensioner assembly too.

Some may call it blastphemy, but if you are primarily street and you are having wheelspin issues at ~400rwhp, the Mickey Thompson ET Street Radial is available in 275/40-17. The handling is not nearly as bad as you would think, and you will not have wheelspin issues, probably not even in 1st gear.

I guess the main takeaway for the OP was that for 240-250 rwhp there is no reason to go to the trouble and expense of swapping transmissions, assuming the current stock trans is in good repair (and if it isn't just get it rebuilt).

As John mentioned, it depends on how you treat it, but mine didn't give up until I was in the neighborhood of 450rwhp/470 lb-ft, at which point ALL of the teeth decided to leave third gear on an upshift at WOT As I recall Mr Thagard was in the car with me at the time (he's bad luck ) ) I was using MT-90 too, BTW. Assuming that you don't drive it like a complete idiot, a well-sorted stock Z trans should live quite some time with 250rwhp.