Right. 0.945 is the standard Gen III/IV/V diameter though. For some reason a lot of aftermarket stuff uses the smaller SBC pin diameter instead of the standard LS diameter, for the LS parts.
Been looking at some LED light bulb options, and trying to find a reflector style lens that would fit well in the projector headlight kit I got from doublec4. I want to just use two projectors for the headlights, and have the two outside spots be occupied by a reflector lens for use as the parking/turn signal lights. Then I'll remove the stock Fiero parking light recesses in the aero nose, or see about getting some fog lights flush mounted in them. I'm having trouble finding a good circular turn signal lens/housing that I could use for this though. I might also see if I can design a nice piece of molded carbon fiber to cover up much of the internals of the lights, rather than just painting the clear cover itself.
Pics of the bracket (and the problem area of the block)?
Here's a pic of the CTS-V alternator on an LS6:
CLICK FOR FULL SIZE
The one bolt which fits, is slightly obscured by the belt here, and the second bolt where the problem is on the LS4 is directly below the tensioner.
Here's a picture of an LS2 block front (albeit upside down):
CLICK FOR FULL SIZE
On the left side of this image (driver side of block when mounting in the CTS-V), there is some extra material cast in, in a circular shape that is in line with the two timing cover bolts which line up with the bottom of the cam sprocket. This is where the second bolt goes.
Here's the front of the LS4 block. Notice the same material isn't cast in, or machined in the LS4. There is a bit of material that doesn't match the RWD Gen IV blocks, but not enough, as the edge of the casting is in the middle of where the bolt should go.
Yeah. I'm not quite sure why the LS4 has so many subtle casting differences that make things like this alternator bracket, or the oil squirters, into such problems. It is a bit annoying.
I'm trying to find something that keeps the belt as close to the timing cover as possible, and I can't use the LS4 balancer since it interferes with the VVT timing cover. The Corvette and CTS-V seem like perhaps they are the next closest to the cover, but I haven't found any exact measurements to verify that (and I don't have any of the balancers from them to try). Fewer engines that I originally thought had VVT, for the Gen IV 2010+ cars, actually have VVT too, so it's been a little hard trying to figure out which ones have balancers that clear the VVT cover, and those that don't.
scrap the squirters and get that thing built. Your not a race car driver, and unless you get that motor build, you will never drive it. The rest of us do fine w/out the squirters.
hi; just read up on this. You mention that you cc'd a combustion chamber at about 60cc. I really recommend you check that; do it again or do a few. I have done all 8 of mine (LS4 243 heads; stock valves) and they are 65cc with the expected variance of course. Not sure if this is too late but it's better to know. If I am wrong then let ME know for sure!! GP
hi; just read up on this. You mention that you cc'd a combustion chamber at about 60cc. I really recommend you check that; do it again or do a few. I have done all 8 of mine (LS4 243 heads; stock valves) and they are 65cc with the expected variance of course. Not sure if this is too late but it's better to know. If I am wrong then let ME know for sure!! GP
Your heads are stock. My heads have been milled, and I am using aftermarket Ti valves.
Stock is I think ~64.45 CC, so if you're seeing 65, it's close enough that you either got a set that are just slightly larger than normal, or you misread by about 0.5CC, which isn't hard to do.
I only did one so far on my heads, and it was about 60CC. I need to CC the rest still.
I don't know hoe much experience you have with LS cooling systems, but I wouldn't mess with a good thing if I were you, the thermostat is on the suction because the water pump just recircs water in the block, allowing the engine to come to operating temp much faster than circulating water through the radiator too. it's a neat setup that works well for a street car.
------------------ "I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
Originally posted by ericjon262: I don't know hoe much experience you have with LS cooling systems, but I wouldn't mess with a good thing if I were you, the thermostat is on the suction because the water pump just recircs water in the block, allowing the engine to come to operating temp much faster than circulating water through the radiator too. it's a neat setup that works well for a street car.
Right, I'm not planning on changing the basic design of that.
However, there is obviously some coolant getting trapped between the block and water pump, as well as between the block and head, and I'd like to open up those ports to be gasket matched, so it will flow a little better, and eliminate the coolant traps and hot spots. That's what I'm currently doing.
I also have to deal with the fact that I'm retrofitting VVT onto the engine, and installing it in a Fiero. I'd also like to change it to reverse flow cooling, so the heads get cooled first. To retain a thermostat housing like the Fiero's, to help make the burping procedure a little easier, I'd have to design a pump housing with the thermostat on top (which is also fitting for having reverse cooling, since the ports to the heads are on top), where when the thermostat is open, it closes the bypass hole (just as the stock LSx water pumps do), which clears the VVT timing cover, and which enables the coolant flow to work in reverse.
something else to keep in mind, the cooling channels in the deck of the head and block are probably way bigger than the holes in the head gasket.
I'm not sure which channels you're talking about exactly. There are a couple of ports though, where the hole in the gasket is clearly larger than the holes in the deck/head, as the deck is stained with the shape of the hole, from where coolant was trapped. My heads have already been milled, so any stain that was there, is long gone as a pile of chips at a machine shop. I'll try to get a couple of good pics of the block where this occurs though, to show where I'm talking about opening up the ports. There are certainly other areas of the block/head I won't be messing with though, like the semi-circular openings around the cylinders.
something to keep in mind while messing with coolant passages, you want them kinda rough, it will make more turbulence, and help with heat transfer. personally, I don't think you'll see any gain from it, but if you want to do/have the time and energy, I'm not one to stop you.
something to keep in mind while messing with coolant passages, you want them kinda rough, it will make more turbulence, and help with heat transfer. personally, I don't think you'll see any gain from it, but if you want to do/have the time and energy, I'm not one to stop you.
Yeah, in the places where heat transfer is desirable, more surface area is better, so rough surface might help with that. The spots I'm porting aren't points where heat transfer should happen though (where coolant enters/exits the block/head), so heat transfer isn't really happening there. In these spots, flow is more important, because you want to get the coolant in/out of the spot, and onto to where it can transfer the heat out. It could be beneficial to transfer heat into the water pump body, if there's enough air flow over the water pump to help pull heat away, but I don't think there is, at least in the Fiero. In this case, it seems better to me, to get the coolant out of the engine, and on its way to the radiator, where the heat transfer can happen.
I don't intend to smooth out internal casting where heat transfer would happen in the heads or block, into the coolant. I can't reach those areas even if I wanted to. I'm only working on the areas where coolant flows from one component to another.
Admittedly, I did have a short moment where I pondered getting the block re-sleeved with Darton MID sleeves, so the sleeves would have more surface area and better cooling, but since the smallest bore they have for stocked sleeves is to be used for 4.000" bore, I quickly decided against it. i've already spent too much on the engine as it is, so the cost of re-sleeving would be too much I think. If they had shelf sleeves that could be used for 3.780" bore, I might still be thinking about it, though.
rough texture isn't just for surface area, it's for turbulence, you want the coolant bouncing around all over, not just flowing through. although, in the block its probably not a big deal.
Originally posted by ericjon262: rough texture isn't just for surface area, it's for turbulence, you want the coolant bouncing around all over, not just flowing through. although, in the block its probably not a big deal.
Right, but neither turbulence nor surface area are important for the parts where it's just an interface is coolant is just passing through from one section to another. I think flow would be more important in those spots, because you want to get the coolant on to the next point. The coolant flow once inside the heads and block is going to be turbulent anyway, because the passages are complex cast shapes, and not smooth passages where the flow rate can be increased really.
My new bits showed up today, so hopefully I can do some work on this tonight.
Oh, it will definitely have the steam vents at all four points on the heads. How do you think the reverse flow cooling would be counter-productive?
I think at the very least it would be a lot of effort spent for no gain... Just get the thing on the road. Significant CFD is employed to design the cooling jacket in modern engines, and the speed of the flow through the jacket is important, as modern cooling systems can be designed to nucleate local boiling, while the speed of the water through the jacket carried the nucleated bubbles away. That's why these engines have to be used with pressurized surge tanks.
Anyway, there's a lot of engineering that went into that system. You won't be making enough HP to challenge it. As long as you have a high flow four corner vent system, that's all you need.
[This message has been edited by Will (edited 12-08-2015).]
Originally posted by Will: I think at the very least it would be a lot of effort spent for no gain... Just get the thing on the road. Significant CFD is employed to design the cooling jacket in modern engines, and the speed of the flow through the jacket is important, as modern cooling systems can be designed to nucleate local boiling, while the speed of the water through the jacket carried the nucleated bubbles away. That's why these engines have to be used with pressurized surge tanks.
Anyway, there's a lot of engineering that went into that system. You won't be making enough HP to challenge it. As long as you have a high flow four corner vent system, that's all you need.
Eh. It's liberally no more effort for me to have reverse flow or not, given my options for water pumps. Either I'll have to use a remote pump (which makes changing the flow direction fairly trivial to do), or I'll have to make a custom pump that mounts on the front of the engine which looks relatively OEM, and whether I design it to work with stock LS coolant flow direction, or reverse flow, is roughly the same amount of effort to create that design. Archie's LS kit uses a remote pump and thermostat on the outlet side, rather than inlet side, and no surge tank. I don't think I've seen a surge tank on any LS swaps into classic cars either.
It's not about whether I'm challenging the capacity of the cooling system or not, or how much HP I'm going to make. The C7 Z06 makes 640 HP and has the same coolant system as every other Gen III/IV/V powered vehicle. The C6R/C7R race cars only make 500 HP, and they have reverse flow systems.
I'm building it as sort of a modern version of the original Pontiac V8, and stuffed into a Fiero. And I want to mostly look like it just rolled out of the showroom, when it's done, save for a few items that might look like bolt-ons, like a billet water pump. I'm not trying to make 1000+ HP with it, but little optimizations like this are worthwhile to me, and make the car more unique. Plus, reverse flow cooling will reduce potential for detonation/knock, making less work later on if I ever decide to throw a turbo in it. I'm certainly not ignoring the engineering that went into the OEM cooling system either. Instead, I'm trying to find a decent balance between that engineering, the engineering that went into the Fiero's cooling system, and the reverse flow in the original Pontiac V8s.
[This message has been edited by dobey (edited 03-14-2017).]
While cleaning up the block, and while porting the coolant port areas at the front of the block, I have been thinking about what dead weight is in the block that I could cut out to lose a pound or two there. I'm wondering if anyone knows what the material circled in blue in the below picture is for? I've never actually seen these bits of material used for anything on an LS, but they seem to be present on all the LS blocks, and even the Gen V blocks seem to still retain some of this material in casting, as far as I can tell from pictures.
[This message has been edited by dobey (edited 03-14-2017).]
Most likely features used to locate the casting during the machining process.
There are shops that have CNC programs to fully machine the surfaces of traditional Chevy blocks, dropped several pounds of weight. That treatment of an aftermarket block gets it down to production block weight while retaining its strength. There *MAY* be such services on the market for LS blocks by now...
Most likely features used to locate the casting during the machining process.
There are shops that have CNC programs to fully machine the surfaces of traditional Chevy blocks, dropped several pounds of weight. That treatment of an aftermarket block gets it down to production block weight while retaining its strength. There *MAY* be such services on the market for LS blocks by now...
Yeah. The shop I had do my machining does do lightening, but when I asked for it, when I took my block in to get cleaned, align honed, and deck height measured, the guy said I shouldn't bother because it would be expensive and I wouldn't lose so much weight. But the more I look at my block, the more it seems like I could trim a couple pounds off and get the bare block weight down to under 100 lbs.
I e-mailed the shop to ask to see if they knew exactly what the bits were for, and got a bit better answer about them being used in the casting and for shipping. So I think I'll take a mini hacksaw to them, and then grind them down a bit smooth. There's a couple other spots I could take plenty of material out of too, but I'd need a big mill to set the block up on, and take the bits out with like a 1/2" end mill. I'd like to cut the fat off though, so maybe I'll see if someone local has a mill and could help me with that (so I don't have to pay another $600 to the shop to do it on a CNC).
In other news, I am getting a custom gauge face made for my G8 cluster. I'll also have to make a new bezel for it to fit properly, but it will look right. Just agreed on the final design for it today, so should have it in a few weeks as well (since shipping stuff right now is just horrible). I'll post a pic of the gauge cluster with it installed and the cluster powered on, when I get it and get it installed.
In other news, I am getting a custom gauge face made for my G8 cluster. I'll also have to make a new bezel for it to fit properly, but it will look right. Just agreed on the final design for it today, so should have it in a few weeks as well (since shipping stuff right now is just horrible). I'll post a pic of the gauge cluster with it installed and the cluster powered on, when I get it and get it installed.
Great build thread Dobey Is the G8 cluster a Can bus set up? Will it be difficult to interface it with the Ls4 electronics?
Originally posted by Jims88: Great build thread Dobey Is the G8 cluster a Can bus set up? Will it be difficult to interface it with the Ls4 electronics?
Thanks!
The G8 cluster is a GMLAN cluster, yes. It doesn't have many wires to it, and most of the information it displays comes over the low speed GM-LAN wire. Even the dimmer level is just data sent over the bus, as the BCM manages it. I've also got the BCM, and I'm using the e38 ECU so that I can enable VVT.
I don't think it will be too difficult, once I get all the harnesses built. However, I will be rewiring the entire car, so it will be a lot of work to do.
