RB26DETT into 240Z Beginner Progress

[getoffmyinternet]

Here it is, the 1972 240Z Radiator Wall Diagram (for lack of a better name).

 

So if you trusted my measurements, and you are a bit of an eccentric, you could theoretically get an aftercooler that has a core of 23.75"x13.5" with 5.625" caps on each end that have right angled inlets, and install it without any modifications to the wall--although you'd probably need the use of a rubber mallet to do so. Unless you want to give that core a tiny little 2.625" cap and inlet on each end and add your own 3" tight elbow, or something like that. In application, an aftercooler that size would probable prove to hit the floor attached to the wall and you'd end up having to heighten the holes for the inlets, but over the core you'd have a few inches to spare. Horizontally, you'd have about a quarter inch on each side of the inlets before bumping the hood hinge mounts when you close it. I don't know how far you guys like to space your aftercoolers from the wall, but at this depth, you couldn't space it more than like 2" before hitting the center mount for the grille on the bottom.

 

 

Or you could get an aftercooler with a core that is a little smaller than maximum all the way around, and make sure the overall width is still 34"-35".

 

Or you could just get a huge core and modify the crap out of your radiator wall. I still can't think of the correct name for that thing.

 

I would choose one that has the inlets to the center of each side, or a top inlet and a bottom outlet, although I've never seen one of those before, and have them both integrated into the caps at 90s so that the size of the caps don't suffer. P.S. I forgot to speculate that the larger the caps, the more even the flow. Tiny caps means more air moving across the top and less moving across the bottom. So straight inlets are not such a desirable idea if you're trying to get as big a core as possible. In fact, a core too large that makes you put on smaller caps would probably do more harm than good. I also assume that the area of your core that goes outside the radiator hole is less productive anyway since that section of air isn't going all the way through, but of course spacing your core farther from the hole helps counter act this effect...

 

Realistically, I'm gonna go with the cheapest thing I can find, as long as it fits. Although I don't want the inlets top and bottom because that seems way less efficient by design. Also, same side inlets would just be retarded. Half the reason you go RB in the first place is for the handy cross flow! Even if a double pass would be more cooling, I imagine there would be more pressure drop which sounds like a counteraction anyway. Not that I know what I'm talking about...

 

[getoffmyinternet]

I did get the mafs from someone on the site. Exactly what I wanted too.

 

I think I'm getting a radiator for Christmas, yay! Aluminum RH, double pass 3 row.

 

 

A few things I need to take care of though, other than wiring obviously.

 

Needs to be tested for leaks. I'm crossing my fingers big time.

 

The plan is to drill a hole in the bottom, push out the dent from the inside, and weld it back up.

 

Trying to make heads or tails of all the wires on all the plugs starting with these. I figured out most of them. I think I'll post pictures and pin numbers once I'm done. Many of them will be cut off, but not these two of course.

[Careless]

is that your fuel rail you plan on drilling and welding?

 

BRAAAP's got a source for cheap fuel rail stock. grab some and bring the short manifold to a machine shop and have them spot drill for you.

 

would be cheaper than factory oem rails.

[getoffmyinternet]

Even aftermarket ones don't seem all that expensive. How cheap are we talking here? It actually looks like the rail is silver soldered together, in which case welding it would cause it to fall apart, but I have other ideas for fixing it as well.

[Careless]

Even aftermarket ones don't seem all that expensive. How cheap are we talking here? It actually looks like the rail is silver soldered together, in which case welding it would cause it to fall apart, but I have other ideas for fixing it as well.

 

i think it's like 10 bucks a foot for -6 AN and 12 bucks a foot for -8 AN.

 

aftermarket pre-drilled and ready to go are around 200 + AUD

[getoffmyinternet]

[scottyMIz]

k i dont get on much but i browsed over the posts and saw talk about fuel pumps and clutches, I'll give my input for what it's worth. I have a gm multi port high perf pump from carquest in mine have had it in my z for about 5-6 years now and it has held great(90 bucks) with low 12 sec runs with both l28et and rb25det. Also i bought a cheapo xtd clutch from ebay for my rb25 "just to get me by" and so far it has taken everything i have thrown at it and more, smileing asking for more. I ran at the track (jitter was there) and i managed a low 12 sec run at 111mph with the bov popping out before the 1/8 mile mark. so it just goes to show that they can handle some power, im not sure how well it will hold in the super long run but with the way i break engines i have the winter season to fix it

[getoffmyinternet]

That's interesting. I was worried that a stockish rb25 clutch would be rated bellow rb26 specs, but perhaps it is fine. That's not too bad for a high flow pump. I'm trying to find out if I can order a bosch one from a wholesaler of sorts which would probably make it about $50. I don't know if I mentioned this but the way I figure it I'll get one that is rated at exactly what the engine requires and then I don't need a regulator to go with it. The bosch just so happens to be perfect from a chart I saw on the right pressure, which I attained from an rb26 spec sheet. Model number 0580254909 if anyone cares to know, says to be 195ph. The Walbros have a big margin in performance, as there seems to be several low flow types that don't cut it, and then one high flow that is far beyond necessary, the GSL 392 at 255lph for $150 or so, plus you would need a regulator, so you'd be paying a bunch extra to jack up the flow, and then a bunch more to knock it back down. Hmm... Will look up the gm ones though.

[Careless]

 

 

http://www.rossmachineracing.com/

 

 

here you is

[synthtk]

http://www.rossmachineracing.com/

 

 

here you is

 

That is where I got my fuel rail extrusion from (Dash10), 2ft was plenty, I then picked up some weld on -10 AN bungs from Summit for cheap and had a buddy weld them on after I had my Dad's machine shop friend drill the injector ports, cut the rail to size and make some nifty CNC brackets which I modified to fit.

 

 

Also, I am running the cheapy eBay IC, 24x12x4" core (31" wide) with 3" top in/outs, I used some 3" silicon 90° bends. It will pass through the stock core support using 3" piping with some heavy modification... I ended up cutting mine out and remaking it since it was bent and twisted from an accident at some point in the cars life.

 

 

More pics can be found in the gallery linked in my sig.

[getoffmyinternet]

So the 31" will fit after all? And the elbows don't hit the hood latches or anything? Or did you move the core support a little when you remade it? Cause if it would work for me, then I'll be damned, that would make it a lot easier since that core seems to be the most common size on ebay and the cheapest for some reason. You had one album with a cooler that had the inlets in the middle, what happened with that?

 

How's the stock radiator working for you?

 

Also, those plastic hoses you eliminated to run the piping through those holes in the core support, do they go to the heater? I don't even know. The popular plan is to get rid of them, but what do you lose as a result?

 

I don't have any friends with a machine shop, so having one made isn't a viable option, since the rates are so freaking high. An aftermarket one would be much cheaper, but I'm still going to try to fix mine first.

 

Thanks for your input!

[Careless]

I don't have any friends with a machine shop, so having one made isn't a viable option, since the rates are so freaking high. An aftermarket one would be much cheaper, but I'm still going to try to fix mine first.

 

 

I doubt it would be more than the price of an after market rail to get it drilled.

 

Go to about 2 or 3 machine shops.. I bet you ONE out of 3 will be like "hey that sounds like a cool project, sure I'll drill those holes... don't worry about it!"

 

and at most you would then buy them a coffee.. Just tell them it's for an engineering project. They like to help out students

[getoffmyinternet]

Yeah, perhaps in your funloving country, but this here is America, and Americans own all the machine shops. We hate everybody. And we charge like $150 an hour.

 

 

But I guess it's worth a try...

[Roostmonkey]

I'm American and I dont hate everybody ( cept for haters ) and my shop rate is $ 80.00 / hr.

[Careless]

Yeah, perhaps in your funloving country, but this here is America, and Americans own all the machine shops. We hate everybody. And we charge like $150 an hour.

 

 

But I guess it's worth a try...

 

 

lol. come on man, don't be so close minded. I'm sure you can find someone to drill the holes and seat cuts for the o-rings fine.

 

If you really want, you can buy the drill bit off ross machine as well.

 

4 feet of -6 or -8, and the 14 or 11mm injector drill bit...

 

you can make 3 of them, and have a lot of room for error. all you need is a drill press and a clamp and patience.

 

I will agree, the aftermarket ones are nice and easy, but I mean... you can probably do 3 of them yourself and have enough money to have them anodized still.

 

What would be left for you to make? mounts? BAH humbug!

[getoffmyinternet]

I just got the oil pan in the mail today. Waiting on the clutch and a fuel pump. I am also about to buy an aftercooler off ebay, if they are saying that the 31" will fit after all. Perhaps the elbows bend in just soon enough to corner the hood brackets.

 

And yes, I still need mounts. Those pesky little guys are getting on my nerves.

[synthtk]

The hood hinges are close to the 90° bends but you can trim them at angles to make it not hit, the 90° bends I used have been trimmed to fit at the angles I wanted.

 

You will have to do some nice gutting of the stock core support for the 3" piping to pass through but it is very possible.

 

The plastic ducting that is removed is actually for the fresh air vents in the car, they will still work without the ducting there as the hole in the fender/frame still exists.

 

The first intercooler I tried (the one with the mid outlets) would not have worked without doing some modification to the wheel wells, so I just went with the top end tanks instead and removed the fresh air vent ducting.

 

The radiator I am using is a 4 core actually, so far it runs fine with my N1 water pump and Nismo thermostat and electric fan, however I will probably switch to an aluminum doublepass radiator soon.

 

So the 31" will fit after all? And the elbows don't hit the hood latches or anything? Or did you move the core support a little when you remade it? Cause if it would work for me, then I'll be damned, that would make it a lot easier since that core seems to be the most common size on ebay and the cheapest for some reason. You had one album with a cooler that had the inlets in the middle, what happened with that?

 

How's the stock radiator working for you?

 

Also, those plastic hoses you eliminated to run the piping through those holes in the core support, do they go to the heater? I don't even know. The popular plan is to get rid of them, but what do you lose as a result?

 

I don't have any friends with a machine shop, so having one made isn't a viable option, since the rates are so freaking high. An aftermarket one would be much cheaper, but I'm still going to try to fix mine first.

 

Thanks for your input!

[getoffmyinternet]

My stock radiator is the same, but I've heard nothing but bad things about them so I was surprised to see yours working for you. Even a radiator shop told me that they aren't worth servicing because they are cheaply made. Mine doesn't cool the best, it is 35 years old and probably pretty crummy inside. It has one electric fan on it with a thermostat switch jammed into the core, but I just jumped that because it kept overheating so now the fan runs all the time.

 

I just went ahead and ordered an aluminum 3 core double pass. They sure aren't cheap though. Plus having it right hand should make it a little easier. It's funny that the hump in the hood is actually for the radiator cap to snuggle, but I think the side cap will just barely fit because it's slightly lower without the top reservoir. My only regret is that the bottom of the core will be covered by the crossmember and not do very much justice, but I plan on 2 small fans anyway. The more cooling you get, the less power and mileage the engine suffers in daily driving. One day, I will like to go with a water to air ic but the budget is too tight right now and it would be another point of failure since it's more complicated.

 

I went ahead and ordered the 31" aftercooler a few days ago, and it came this morning! I figured that if all else fails, I can get cut off the ends and weld on aluminum 90s instead, but rubber would make it easier all around if I can get it to work.

 

I thought those vents were for the heater or something. Of course if they are sucking from the engine bay, I would think the vent air would be hot anyway. I've never used a vent, and don't plan to start now though. A/C would be a nice luxury...

[getoffmyinternet]

Well my alternator took a dump yesterday. It wasn't in great condition when I first got the car, and now it completely quit and I drained the battery on my way home from work. Perhaps I will start actual work a little sooner than planned. All the major parts are in. I will post pictures, if not here, then on my project forum.

 

http://forums.hybridz.org/showthread.php?t=128243

[Daeron]

actually, it might be easier to simply retrofit the alternator off the RB motor into your 240 as is, if that is a simpler solution to keeping your daily driver on the road before putting it on stands for "the big show..."

 

You can look up info on installing an internally regulated alternator here; the job would be very very similar to the 90 amp maxima alternator upgrade.

 

Honestly, I just read through this thread and wanted to subscribe to it to read anyhow.. when I got to the end I found a tiny spot where my two bits could come in handy. Good luck with this, looks like you're going about it the right way!