turbo intake manifold webbing is heatsoker or radiator?

[BRAAP]

looks great!

how much would u sell a fuel rail like that for?

o-ring im guessing.

 

mike

 

 

Mike,

Yes, that fuel rail is machined for the O-ring injectors, not the barbed Datsun style.

I bought the bare fuel rail extrusion in bulk, (8 foot stick, enough to do my L-6 race car, my V-8 Z car, and few others as well).

 

If I were to build a fuel rail using this extrusion for an L-6 that would use the OE style barbed injectors, I’d charge $100. That would give you the fuel rail itself, cut to the customers length, both ends tapped for 3/8 NPT fittings, and 6 injector ports drilled and tapped for either 1/8” NPT, or ¼” NPT whichever the customer so desires, lined up to the OE Datsun manifold injector spread. I would even include another drilled and tapped port or even two, if the customer needs it for a fuel pressure gauge, extra injector, etc. This price does not include machining/modification, etc for mounts. (If you supply dimensions, specs, I could machine whatever you need for mounting into the fuel rail, price based on time needed to machine). This also does not include any of NPT fittings, just the fuel rail machined for those fittings. Add another $20 for six 5/16” barbed brass injector fittings. I could also supply the 5/16” or 3/8” barbed brass inlet/outlet fittings in straight or 90 degree, add another $10.

 

This fuel rail has a pretty thick section across the bottom which allows for some creative mounting solutions on the part of the installer. You could build a pillar style mount, “C” channel style, what ever your imagination can conjure up.

 

 

 

 

Now for an O-ring style injector, like what I did for the race car, it would cost a bit more as the injector bores have to be VERY precise and smooth to get the O-ring to seal. Also, The customer would have to have his/her manifold modified to accept the O-rings as well, then getting the fuel rail mounted exactly perfect so as to locate the injectors “straight” and get the O-rings sunk to the proper depth within the fuel rail and manifold, is bit of work as well. In short, to build a duplicate the O-ring fuel rail to what I built for the race car, easily $200 and that is only the fuel rail, no mounts or manifold mods.

[BRAAP]

Do you have a pic of the underside of the intake?

 

Thanks

 

 

 

Here is a picture of the bottom. Nothing special here. No customizing other than the addition of three vacuum ports. One for the brake booster' date=' (has the 90 degree fitting already installed), and 2 small 1/8” NPT ports at the rear of the plenum, one for the EFI MAP sensor, the other for the fuel pressure regulator.

 

[img']http://i17.photobucket.com/albums/b81/BRAAPZ/Pearl/DSC_7693Medium.jpg[/img]

[DemonZ]

Just went out and checked and Yes, in deed, the Turbo intake manifold runners ARE larger in diameter than the N/A Runners!!! I couldn’t get a real good measurement as I was just checking, not really measuring, but approx .080†to an1/8â€th larger ID!!!

 

The intake runners of all L-series EFI manifolds are on the small size, so every little bit of runner diameter we can get helps and being as the Turbo intakes have larger inside diameter Runners as cast….. hmmmm….>>>

 

 

 

 

 

Being a rough casting and not perfectly round, I measured the smallest port, and the smallest distance of the port (not including the hump opposite of injector hold down). The smallest port:

 

 

Horizontal 1.227", Vertical 1.250"

 

 

The other ports were around 1.260". The vertical was always wider than the horizontal for all. (YMMV considering slight production variances) I used telescoping gauges along with a dial caliper.

 

 

RE: O-ring injectors

 

 

Do you have to do anything to the manifold side bung to use the O-ring style?

[DemonZ]

The purpose of the webbing is to keep as much heat away from the fuel as possible.

The purpose of the heat shield under the manifold is to keep as much heat away from the manifold as possible.

 

I would not go with a non-webbed intake unless it came on the car. Meaning I wouldn't go out looking for one if I had a Non-EGR webbed manifold. I like my P82.

 

 

 

Guess that's what I ended up with... plasma surgery postponed.

[BRAAP]

 

 

RE: O-ring injectors

 

Do you have to do anything to the manifold side bung to use the O-ring style?

 

 

Yes. I had to open up the bores for the injectors in the manifold slightly to accept the new style injector O-rings, I went ahead and punched that bore all the way through so that I could bury the injectors till they come almost flush with the head mating surface. I then countersunk a slightly larger hole to clear the injector body itself and cut that counter bore just deep enough to give the injectors the penetration I wanted.

FWIW, The injectors I’m using have the 14 MM O-rings, so the fuel rail injector bores were machined out to .540”, and the manifold injector bores are a little oversize at .550”, (I was testing one of my valve guide reamers for this purpose), though it should seal just fine as I still have .025” O-ring crush at that size.

[Tony D]

What I was getting at with my statement was that the webbing keeps exhaust manifold heat from transferring up to the fuel rail, and is a SECONDARY blockage after the heat shield under the manifold itself. The heat shield keeps the heat out of the manifold, and hte manifold is a heat dam for the fuel rail. They work together, so yes---you will have BOTH on a factory equipped car. It's not an either-or situation. The earlier non-webbed manifolds had the heat shield ONLY, and did have some hot restart heatsoak problems. So they put in the webbing, and added vents to the hood.

 

Then came the ZX, and another manifold altogether!

 

I have measured those runners, and UP IN THE RUNNER the size measures the same from what I found. (This includes the LD28 manifold, too.) At the HEAD, the runners may be slightly larger, but up the manifold say 1" measured with a snap (telescoping) gauge you will find a different story than at the head/manifold juncture.

[DemonZ]

What I was getting at with my statement was that the webbing keeps exhaust manifold heat from transferring up to the fuel rail' date=' and is a SECONDARY blockage after the heat shield under the manifold itself. The heat shield keeps the heat out of the manifold, and hte manifold is a heat dam for the fuel rail. They work together, so yes---you will have BOTH on a factory equipped car. It's not an either-or situation. The earlier non-webbed manifolds had the heat shield ONLY, and did have some hot restart heatsoak problems. So they put in the webbing, and added vents to the hood.

 

Then came the ZX, and another manifold altogether!

 

I have measured those runners, and UP IN THE RUNNER the size measures the same from what I found. (This includes the LD28 manifold, too.) At the HEAD, the runners may be slightly larger, but up the manifold say 1" measured with a snap (telescoping) gauge you will find a different story than at the head/manifold juncture.[/quote']

 

 

 

 

 

I should have been clear that I am using the heat shield in place. The ZXT had vents, heat shield, webbing, and a blower. The webbing would seem to be a radiator for whatever heat got past the shield for the blower to act on. The heat has to go somewhere, better to let it escape through the hood?

 

 

 

Tony, that's where I measured, from about 1" down. I just verified my earlier measurements, and all check out as before. #6 being the smallest (go figure, isn't #6 bore always the one with the problems?). The surprise is I found that at 2" down the ports got BIGGER, at least 1.252" Horiz. 1.282" Vert.!! The smallest portion seems to be AT the head.

[510six]

http://pg.photos.yahoo.com/ph/sss510six/detail?.dir=63ef&.dnm=4002.jpg&.src=ph

 

A pic of a non EGR N42 that has been cut apart ported , welded back together and ceramic coated to provide a thermal barrier.

[BRAAP]

.........I have measured those runners, and UP IN THE RUNNER the size measures the same from what I found. (This includes the LD28 manifold, too.) At the HEAD, the runners may be slightly larger, but up the manifold say 1" measured with a snap (telescoping) gauge you will find a different story than at the head/manifold juncture.

 

 

 

My “checking” that I did was also with my machinist snap gauges and I checked from approx 2” till I couldn’t reach, +-5” or so, and the Turbo intake was consistently noticeably larger by approx .100” in that entire region that I checked. I did not measure the head port area as both intakes I used for the comparison have been port matched.

Now being as you measured no difference between the Turbo and Non turbo intake, (which non turbo intake did you use for the comparison), this begs the question; Which intakes did Nissan, (or Hitachi) cast with these larger runners? My comparison was an ‘82 Turbo intake and that gray ’75 N-42 intake.

I have a few other intakes around and at some point I just may go out and pull them off my parts cars and get a little more serious about investigating this intake runner size thing. (For the life of me I can’t believe I didn’t do this in the past).

[BRAAP]

........ A pic of a non EGR N42 that has been cut apart ported , welded back together and ceramic coated to provide a thermal barrier.

 

 

 

So did you cut the plenum apart so that you could reach the runners from both ends?

[SHO-Z]

Heat travels from high to low. If the air going into the manifold is at a higher temp than the under hood temp. the webbing will cool the air. If you have an intercooler on the car your air temp will probably lower than the under hood temp so the webbing will heat the intake air.

[Mack]

waitaminute... so turbo manifolds DO actually have larger runners? I thougth tis was a nasty myth circulation around the internet for quite some years now. Man, I wish you people would make up your minds! I've got a few turbo intakes laying around, is it a year casting difference? Im very curious.....

[Tony D]

I will have to go check some more now, as I can't remember the runners I checked. There may well be a difference in size between castings and years.

Basically, the runner sizes you guys are mentioning are around 32mm. Which when you split the plenum off the LD 28 manifold is what you find at that juncture (roughly), though if you measure at the flange where it goes to the head, it's like 35mm, but 12mm in the manifold it's 34, and 25mm in the manifold it's down in size to 32.

 

I doubt the cross-sectional variations will amount to much---it's a 32mm runner for all intents an purposes. And is a 32 mm runner in the LD28, with a revered cone at the head to 35mm (exactly opposite of what you actually want!)

 

I know my E88 head has been ported to 36mm at the flange where the manifold meets the head, and the manifold is mated to it, tapering to 40mm at the throttle bodies. (Street Ported)

[jeffp]

You will not get good gains from the stock Nissan manifold. If you are looking for flow improvements then go after market period.

I had my manifold extrude honed and then flow tested on a cylinder head. Not to impressive in reality. A good ported cylinder head will flow in the 200's @ 25 inches of water. The stock Nissan intake will not get near those flow numbers. Going turbo application will be a better application of the intake, but will cut down on the efficiency of the induction system, but with the turbo you can take an efficiency hit and still make your numbers.

For the N/A setup, forget about it, go with a cannon, TWM, webber, and all of the vatriations of the after market intakes to get better performance.

[BRAAP]

Yes jeffp, you are100% correct. The OE EFI intake manifold, (even if some have slightly larger runners than others), is not ideal when trying to get maximum performance from the L-6, but for 90% of the guys out here, the ideal is out of reach financially as well as practically. Not all of them have a machine shop on their property or the funds to purchase one of those more ideal intakes and have someone finish the custom install.

The OE intake is a restriction, but what slight HP loss they will suffer for their typical “mild street” engine vs the money they saved not purchasing the ideal intake and paying some other shop to install it and tune it, the OE intake is a pretty attractive option. For a “mild” street engine, the loss incurred with the OE intake would be "just" measurable on a dyno, but by no means an extreme loss of power on a “mild” street build, and when building a mild street machine, "extreme" is not the goal. For those trying to achieve the extreme, those aftermarket IR set ups are ideal, and will help. Again, for mild engines, those cool intakes will help just a little for that big expense, and for extreme engine builds, those cool intakes will offer an even greater percentage of gain for the big cash outlay, it’s all relative.

[510six]

Yes the manifold was cut apart ported them welded back together.My plan is to make 450-500rwh and supply the rest with N20.

[Zsane]

There was also a webbed, sloped/necked down, intake that didn’t get the EGR as well, but it is webbed, and it is the sloped plenum. A matter of personal preference there. I prefer the N-42 non webbed intake myself as I have yet to see a sloped, or necked down late model EFI intake look as nice as a well prepped N-42 Non EGR intake, again, personal preference.

 

 

Here's a couple of pics of the webbed non-egr p82 manifold for reference purposes.

 

 

 

If you look at the manifold as two separate parts the rear three and the front three you have two manifolds in one.

 

The rear portion with a small volume plenum, and short runners, and the front with a large volume plenum and long runners.

 

Since there are not separate plenums in the manifold I would assume all cylinders would still be affected by the total plenum volume and not two separate volumes.

 

Just an observation, don't have any idea if this would give a broader tuning range or not. Does seem to fall into that concept though.

[dapiper]

Suggest you keep MAP sensor tap central on intake to minimize pressure oscillations near a runner.