TimZ

Here's mine - 4" downpipe to a custom mullfer - 4" oval + 2.25" round (from the wg) at the inlet to a pair of 3" ovals exiting out each side...

If you look back a page or two, this is what the current design was trying to prevent. There were three distinct vortices, the lowest pressure of them was on cyls 1 and 2. The current design was a deliberate attempt to break those up.

What if you just moved the first diverter forward a bit so that it is pointing more towards the middle of the #1 runner? It looks like it's currently working in combination with the first bump to create the swirl around #1.

That setup does look really nice. Pete - did you experience any problems with fuel puddling in the low point under the SC? Looks like you were still using port injection and maybe just using the TBI as supplemental? I was just wondering since it appears that boardkid is going to be getting all of his fuel from the TBI. Maybe the SC does a sufficient job of atomising the fuel so that won't happen. ya know... I've got a polished thermostat housing outlet (the part that the hose connects to) laying around that I could let go of cheap...

I was going to mention Teflon lines - these are of a completely different construction and require special hose ends. The only material I have ever seen for the hose ends was steel. Your best best for finding Teflon in -6 and larger sizes is to go to an industrial supply place - the kind that supplies hoses, etc for commercial heavy trucks. Also, Teflon is much stiffer and won't tolerate being bent nearly as much as the regular braided hose does. It's literally a Teflon tube with a stainless outer sheath - if you bend it too far it will collapse. My personal opinion is that it's preferable to run hard lines for the majority of the run and use hose for short runs to connect from the hard line to anything that moves around, like a soft-mounted motor.

Okay, I've been looking at this a bit more - that 80psi number was bugging me. Jeff - I'm making a couple of assumptions, but I think they are on the conservative side, airflow-wise. I'm assuming the following: The plenum inlet is 2.5", giving a cross-sectional area of 4.9in² = 0.034ft² runners are 1.77" (45mm), giving a cross-sectional area of 2.46in² = 0.017ft². Also, I'm assuming airflow at 1.6 cfm/hp, so 700hp ~=1120cfm. So, looking at this diagram: The simulation is showing in the neighborhood of: 16000 in/s velocity at the inlet 8000 in/s velocity at the ports converting to ft/s gives: 1333 ft/s at the inlet 666 ft/s at the port Using the simple relationship of Flow = (Cross Sectional Area) * (Velocity) We get at the inlet: Flow = 1333ft/s * 0.034ft² * 60 s/min = 2719 ft³/min At the ports: Flow = 666ft/s * 0.017ft²* 60 s/min = 679 ft³/min From this, I'm thinking our assumption about the model dumping to free air is fairly likely to be correct. That's enough airflow for ~1700hp Also, I'm noticing that the flow at the ports is not the flow at the inlet/6, but since it's kinda in the ballpark I think we can chalk that up to my guesses as to the inlet and runner sizes being a little off, combined with having to make a SWAG at the actual velocity at these points by guessing from the color code... Anybody care to check my math? Corrections for actual inlet and port sizes, as well as the actual mean velocities would be more than welcome. EDIT: I just noticed my first wrong assumption - 45mm at the ports is most likely too big - I was thinking of a likely size for the throttle bodies, but it necks down after that. 1.5" (38mm) is probably a better guess. This would result in port flow of ~490cfm which jibes alot closer with the inlet flow number.

Is this the BOV you've got? It's at least pretty compact - you could probably just leave yourself a flat area ~2.5" round at the back of the plenum for welding the flange and mount the thing on top - there should be ample hood clearance back there.

That's what I was thinking too. That would definitely explain the pressures in the plenum and the high port velocities. If that's the case, I believe it could be easily remedied by adding a known restriction at each port and adjusting until the flow numbers look realistic. Like the Wiggins clamp solution, btw. Sorry about the added expense... :flamedevi:flamedevi:flamedevi

I'm pretty sure Jon knows that - I believe he's saying that if your new cam's base circle is different you will need lash pads that keep the wipe pattern on the rocker pad. It might work out that you can re-use, it might not, but you should NOT assume re-use without checking first.

This got me thinking again (always dangerous)... How confident are we that there is really going to be ~80psi in that area? It occurred to me this morning that if that really is the case, I don't think you'll be able to find a spring stiff enough to hold the bypass valve shut in that location. Even the stiffest ones are only designed to hold a pressure differential of maybe 20psi at WOT. Maybe we should rethink this... EDIT: I just went back and looked through the analysis in this thread, and there are a few details of the simulation that aren't clear to me. Please nobody take this as being critical - the work so far is great, just trying to understand some things... In the simulation, what did the total airflow through the plenum need to be to get the ~23psi at the inlet to the head? How well did this correlate to what we would expect for ~700hp (flywheel) worth of airflow? That IS the neighborhood I expect Jeff to be in, if not higher, btw. What happens at the manifold/head interface in the sim? Is there any restriction modeled in at that point, or does it assume that the manifold is dumping to open air at that point? Reason I'm asking is that the 80psi number seems a lot higher than I would have expected, and somebody else already mentioned the supersonic flow velocity at the ports. Just looking for a sanity check.

Monzter's intake plenum design has had me thinking for a while now, and I'm wondering if the diffuser plenum idea could be applied to some of the other existing custom manifolds out there. Specifically, I'm wondering if a similar effect could be had by internally baffling an existing manifold. Ron Tyler has a nice looking manifold design that Monzter also refrenced, and his manifold is pretty similar to mine and a few others I've seen. Here's what I'm thinking, using Ron's manifold as an example, since he had a nice plan view pic to work from: If a baffle was added along the red line that left say a half inch slit along the top and the bottom of the baffle, would that help to even out the airflow distribution between the cylinders without impeding the airflow? Would a flat baffle work best, or would it help for it to be rounded a bit? Hopefully Ron doesn't mind me using his manifold as an example, but it seemed like a logical starting point since there were already some cad drawings and cfd analysis existing on it...

If you use an electronic external controller it will most likely have its own MAP sensor which will require a reference. I use the same plenum vacuum source that I use for the TEC3's MAP sensor for this. The other lines that actually go to either side of the wastegate diaphragm are taken from the pipe that runs between the intercooler and the plenum. Hmmm... How much room do you think you'll have between the plenum and the firewall? I was originally thinking of locating the diaphragm assy on the back facing the firewall and creating a little chamber on the end for the valve. If that doesn't work, would there be room to extend the plenum a bit rearward and mount the diaphragm assy such that it faces the head, kind of like a seventh intake runner? That might be more conducive to your machining method (maybe?) Just throwing ideas out... Also, were you planning on venting it to atmosphere or recirculating? Maybe just some simple v-band clamps would work better here - they'd certainly be easier to implement. It would just be really nice to be able to do all of the fastening action from above, instead of having to fish around underneath. Speaking from experience here, and if I'm looking at your drawing right, your diffuser plenum is going to make access to the bottom bolts even harder... Sorry... :flamedevi:flamedevi:flamedevi

I kinda thought you might have already had that covered, just couldn't tell from the pics. Do you have an external boost controller, or do you plan on using the TEC3? Maybe leave yourself room to add one if you don't like the GPO control? There are those that will contend that it's better to be in the plenum, so that the airflow doesn't have to change directions. I don't know how big of a deal this is, or if it really ends up working this way, especially when the throttle is still partially open. This does seem "directionally correct", though. Seems like TonyD is the bypass valve expert (among other things) - so I will defer to him if he disagrees. Since I seem to be in the business of making your life more complicated tonight, what if you just used the diaphragm assembly from your TiAl and integrated the valve body part of it into the plenum? This might allow a bit more clearance (and would be slick as hell ) I put mine more towards the front of the plenum, like this: Oh - and have you considered either V-band or Wiggins clamps (stupidly expensive) for connecting the plenum to the throttle bodies instead of the bolt-on flanges? This is one thing I wish I could have done with mine - the bolts on the bottom side are a huge pain to get to. A nice quick release setup would have made the setup much more serviceable. If you stay with the flanges, I had o-ring grooves cut in the throttle bodies so I wouldn't have to mess with gaskets...

That's just plain beautiful - nice work, Jeff! On the vacuum ports integrated into the backside - I'd suggest leaving yourself a couple of spare ports - there always seems to be one more thing that you need to connect. You could just plug them with a nice anodized hex plug in the meantime. Also, do you already have a solution for a compressor bypass? If you so desired you could integrate a flange for the bypass of your choice, or even design your own, integrated right into the plenum with a properly sized valve... I always like to complicate things...

Yep - that was why I mentioned that looks can be deceiving - without knowledge of the rest of the actuation scheme it's hard to tell what "right" should look like. As you mentioned, even if you do know the actuation scheme it's hard to tell due to the way the cam wipes across the bucket, etc. It's a much better idea to use a dial indicator than to try to eyeball things. The L-series lobe shapes that we are used to seeing are also distorted by the fact that the lobe contacts the rocker at different points while it wipes across the pad (and at different points during the opening vs closing ramps), thereby changing the effective rocker ratio as it wipes. A direct acting cam lobe should see less (or none) of this effect. I was trying to limit my comments based on "before vs after" rather than what I'm used to seeing, but now I kinda regret even doing that.

I'm pretty sure that this won't work - the torque wrench is still going to read or click at the torque it sees at the socket end. Adding length will only change how much force you have to apply to get it to read a given torque. If the wrench maxes out at 150 then you need a bigger torque wrench.

And Tec2/3 users.

I do know the looks of a cam grind can be deceiving, but that looks like less duration to me, too. Granted the base circle got smaller, so maybe the radius at the tip just got proportionately smaller. But offhand that sure looks "pointy" to me, like the radius at the tip got "more smaller" than the base circle did. Wasn't your stock lift pretty low, like in the .300"s? seems like it would have been nice to get your lift up into the .500"s with the flow characteristics your showed.

As I recall, I noticed it when I got the replacement. It was a Nissan replacement that I got from Courtesy Nissan (they gave me no hassles on returning it, btw). It was ~0.5-1mm too big, which is quite a lot. If your builder said the seal was tight, then this is probably not your problem, but I would check the next one pretty closely before buttoning it all back up.

Oddly, I got a rear main seal from Nissan a while back whose ID was slightly too big for the crank and leaked like a sieve. Replaced it with a Fel-Pro and problem went away.

Dang that's purty.

Try a search on "zinc oil" - there are several existing threads on this.

Thanks Tony. I've always had the same reservations when you hear people talk about cycling their electric water pumps on and off. If your reference for the temperature switch is in the cylinder head water passage then you might be able to get away with it, but that always seemed like a bad idea, especially if the temp sensor is in the thermostat housing. How much power can that possibly be liberating, anyway?

I decided to go with the Evans NPG-R and the diesel water pump and see how that works out. I won't know how well it works until spring. My internal bypass is not plugged and I'm using the Stewart thermostat that has some bypass holes drilled it it as well. After re-reading Tony's post above, another thing that occurs to me is that if you have deadheaded the flow with the Thermostat shut, the only way for it to see the water temp "signal" is for it to wait for the heat in the head to creep out to the t-stat housing via convection. Seems like the temperature of the water in the head could get pretty high before the water in the t-stat housing gets hot enough to open the thermostat.

Here's a rebuild kit on eBay. No idea on the vendor, though.