HRH Posted June 21, 2011 Report Share Posted June 21, 2011 So Joe finally finished my manifold. Still need to hog out the intake holes, may need to add material on the outer edges like we did with the other manifold. Next chance I get I'll yank off the old EFI manifold and fit up the new one. It'll be a while before it's running again. Need to inspect the motor (tear down) and do an in-tank fuel pump conversion, but I'm excited the manifold is getting there. Quote Link to comment
wildmaninid Posted June 21, 2011 Report Share Posted June 21, 2011 +1. Nice Matt! Gonna be great to get that thing on the dime! Quote Link to comment
HRH Posted June 21, 2011 Author Report Share Posted June 21, 2011 Once I get it all good again, I'm thinking this should be a phenomenal increase over the necked down tiny runner 280z manifold. Can't wait myself! Quote Link to comment
Skib Posted June 21, 2011 Report Share Posted June 21, 2011 I'm thinking this should be a phenomenal increase over the necked down tiny runner 280z manifold. ya thats the achilles heal with the stock Z mani, the runners are shit :lol: Quote Link to comment
datsunwizard Posted June 21, 2011 Report Share Posted June 21, 2011 Man, that looks a lot like the manifold I made for CIS fuel injection for a L series. Quote Link to comment
LenRobertson Posted June 21, 2011 Report Share Posted June 21, 2011 Why the switch to in-tank fuel pump? Problem with the external one, or just want to get it out of the way? Or noise? Or (most likely) something I haven't thought of? Len Quote Link to comment
HRH Posted June 21, 2011 Author Report Share Posted June 21, 2011 Man, that looks a lot like the manifold I made for CIS fuel injection for a L series. Hella sweet! Looks like you used the SU manifold ends? I almost wished I would have done that, but didn't want to cut up a good SU manifold. The spacing is wider. Using the Z car ends, you have to port out quite a bit of material to make them match the runners. Your manifold looks quite nice. Len, reason for the internal tank pump is fuel starvation. I need bigger feed and return lines anyway, that's part of the problem. The external pump works fine when under the original Subaru, but an in-tank pump is a lot better idea for performance driving. Insulates the pump for longer life since the fuel is generally cooler, and it is certainly quieter. Plus going around a hard corner, like a 180 degree on-ramp, you won't have the tendency to starve out the pump due to fuel sloshing to one side. You could make baffles or use a fuel cell, but longevity of an in-tank pump is the main thing here. Hell, at 153k, I haven't changed the in-tank pump on the hardbody. It's getting a little weak I think, but still works. Have to leave the key on for a few seconds on hot days if I just shut it off. But it's still the original pump from 1993. Quote Link to comment
Z-train Posted June 21, 2011 Report Share Posted June 21, 2011 Once I get it all good again, I'm thinking this should be a phenomenal increase over the necked down tiny runner 280z manifold. Can't wait myself! What's the size of the ports at the flange on the new manifold and the 280 one? Quote Link to comment
]2eDeYe Posted June 21, 2011 Report Share Posted June 21, 2011 Nice work :cool: Quote Link to comment
HRH Posted June 22, 2011 Author Report Share Posted June 22, 2011 What's the size of the ports at the flange on the new manifold and the 280 one? Right now they're the same size, I haven't ported them. The enlarged opening is close to 1.5" if I remember right. A ping pong ball almost fits inside them. Quote Link to comment
Z-train Posted June 23, 2011 Report Share Posted June 23, 2011 Right now they're the same size, I haven't ported them. The enlarged opening is close to 1.5" if I remember right. A ping pong ball almost fits inside them. Larger ports(increasing runner volume) will move the powerband upwards.You want to be real carefull about hogging them out as the bottom end will vanish. Quote Link to comment
HRH Posted June 23, 2011 Author Report Share Posted June 23, 2011 No worries there. 4.11 gears with a dogleg 5 speed, this thing has so much grunt it's like a diesel. With the lumpy cam she doesn't come alive until 3500. I may raise the compression a bit more also when I tear the motor down. It's fairly high already, thinking about another .030 off the head, but not sure if I want to go high enough to necessitate race gas. Quote Link to comment
Z-train Posted June 23, 2011 Report Share Posted June 23, 2011 What's the CR now and it's just a L-20b-correct? Quote Link to comment
HRH Posted June 23, 2011 Author Report Share Posted June 23, 2011 This is going to sound bad ;) I don't actually know. I put flat-tops from a Z20 in it and chopped .030 off the head. From power out put, I'd guess anywhere from 9.5:1 to 10:1 or somewhere thereabouts. When I take it apart to check everything I'll probably measure cylinder head volume and actually calculate it out this time. From 0-60 times, seat time, racing other people, we figure the motor probably makes 150 hp right now. But it's all butt dyno, no actual numbers. Been trying to dyno it for a while, just haven't ever gotten around to it, and it goes plenty fast so I don't care all that much. It is an L20B with U60 head. (Same as U67) Quote Link to comment
Rustina 510 Posted June 23, 2011 Report Share Posted June 23, 2011 How much did you pay for that? Quote Link to comment
Z-train Posted June 23, 2011 Report Share Posted June 23, 2011 This is going to sound bad ;) I don't actually know. I put flat-tops from a Z20 in it and chopped .030 off the head. From power out put, I'd guess anywhere from 9.5:1 to 10:1 or somewhere thereabouts. When I take it apart to check everything I'll probably measure cylinder head volume and actually calculate it out this time. From 0-60 times, seat time, racing other people, we figure the motor probably makes 150 hp right now. But it's all butt dyno, no actual numbers. Been trying to dyno it for a while, just haven't ever gotten around to it, and it goes plenty fast so I don't care all that much. It is an L20B with U60 head. (Same as U67) Assuming highest case,you really don't want to go higher for the street.Do your calculations FIRST!Results might dictate the path you'll travel.Too high and all you have to do is dish a couple CC's out of the pistons if the motor is apart. Quote Link to comment
HRH Posted June 24, 2011 Author Report Share Posted June 24, 2011 How much did you pay for that? The motor or the manifold? The motor I probably have $1500 into, built it myself, the manifold was about $300, normally more but we worked out some trade stuff to. Normally they're $400 or more for a custom one from my Datsun guru. Quote Link to comment
HRH Posted June 24, 2011 Author Report Share Posted June 24, 2011 Assuming highest case,you really don't want to go higher for the street.Do your calculations FIRST!Results might dictate the path you'll travel.Too high and all you have to do is dish a couple CC's out of the pistons if the motor is apart. Yeah, compression is fun, but right now I can still run 92 octane with decent advance and I don't have any detonation issues. A little more, not sure. Quote Link to comment
Z-train Posted June 24, 2011 Report Share Posted June 24, 2011 Yeah, compression is fun, but right now I can still run 92 octane with decent advance and I don't have any detonation issues. A little more, not sure. Don't touch it(cr).Play timing games to go any further. Quote Link to comment
HRH Posted June 24, 2011 Author Report Share Posted June 24, 2011 Yeah, I'm not too worried about it. I'll probably unshroud the valves while I have the motor apart too. I ported the head but never cleaned up those areas, so that will remove a little material. There are a bunch of little things I want to do/inspect. I may only cut another .015" off if needed. I seem to remember the cam tower shims come in .015 thickness. Either way I think the 510 will be down for a good bit, hopefully get everything back in order for Canby next year. Quote Link to comment
Z-train Posted June 24, 2011 Report Share Posted June 24, 2011 Take a stone and smooth all sharp points/edges in the combustion chamber-this will reduce hot spots that will cause early detonation. Quote Link to comment
DAW Posted July 18, 2011 Report Share Posted July 18, 2011 Why not use an uncut closed chamber head like a W53 or W58? Much better quench with your flat top pistons and you could get away with a higher cr than U67 chambers. DAW Quote Link to comment
HRH Posted July 18, 2011 Author Report Share Posted July 18, 2011 Harder to find, plus I've already done a ton of work on this head. But you make a valid point. From the original posting of this, I have decided to tear down the L20B for inspection, so I may end up going that route, who knows? Quote Link to comment
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