krochus

iTrader: (1)

I'm planning on using a performer RPM and a 670 Holley on my lc9 fox body swap.

It doesn't seem to come up too often so I thought I'd ask you guys about the most efficient way to plumb these two systems in?

snook

iTrader: (1)

I just run a pcv valve in the valve cover to the back of the carb, I hve a oil catch can in between so the oil doesn't go back into the intake system.

Coolant crossover is run to a Jegs inline radiator hose drain in the upper radiator hose, or you can drill and tap and put it to the pump.

http://www.jegs.com/i/JEGS-Performan...51155/10002/-1

I also have a couple breathers on it to leat it breathe some, although most don't recommend one the valley plate because of the oil mist.

Doug G

Put a breather in the oil fill cap and driver side valve cover to the rear of carb.

Trick flow Vent kit to the gooseneck (at T-stat) on the water pump.

35spline

iTrader: (1)

Doug,

Could you please post a pic of where your vent line enters the water pump?
I was wondering if I could use one of the heater core ports? I have both tapped and plugged since I am not going to run a heater.

Doug G

I drilled and tapped the T-stat housing just below the hose, and caped my heater ports....pic later (5:40am and leaving for work)
Hose need to go on suction side of waterpump.
The black hose isn't the best looking, but better than nothing and swap to braided line later

Doug G

Here you go....

krochus

iTrader: (1)

Oops I guess I missed this thread actually getting replies. My lc9 doesn't have a rear coolant crossover just a front one. What I did was order off eBay for $7 a radiator hose adapter the kind that has a 1/8" npt port for the addition of a temp gauge. This is installed in the "lower" hose and has a 1/4" elbow fitting coming. Are you guys having good luck using fuel hose for these coolant lines?


I do plan to drill and tap my water neck but it'll be for my high temp cooling fan's temp switch.

krochus

iTrader: (1)

Pic added

I'm still short a fitting for the hose adapter

krochus

iTrader: (1)

I've got the coolant all sorted out but I'm still at a bit of a loss on the pcv.

My first thought is to run a inline pcv valve off the drivers side valve cover (vertical port ) and then a simple breather on the passengers side valve cover (horizontal port)

I have no provision for a valley cover vent

Thoughts?

Pop N Wood

iTrader: (1)

I have an LS2. Has the front steam vents only and LS6 style PCV hook up in the valley cover. I just drilled and tapped a hole for an NPT barbed fitting in the water pump right below the steam vent outlet. For PCV used the stock vette hose to the throttle body but put a generic PCV valve in line then go back under the manifold and T it into the back of the carb along with the brake booster. I use a small plastic fuel filter on the passenger side valve cover vent.

krochus

iTrader: (1)

and T it into the back of the carb along with the brake booster.



You're really supposed to run the pcv to the carb so all the cylinders share the mixture change it induces Your brakes can go to a port on the intake over just one runner because they don't flow continuously or at least semi continuous like a pcv

What port for the throttle body are you referring to?

cruisin'73

iTrader: (8)

On my 5.3 I utilized the OEM 4 corner steam tube setup and routed the vent line to right below the radiator cap. My research found that the purpose of the system is to vent the high pressure steam pockets of the cooling passages in the head to a low pressure area to create flow and prevent steam from forming. In the absences of a surge tank, the rad cap is the lowest pressure point in the system. So far in 2500 miles of cruising and generally trouble making I have had no signs of an issue.



For the Crankcase Ventilation system I used a very simple system. I removed the nipple tube on the right valve cover, epoxied in a small tube, and hose clamped on one of those small Autozone conical PCV filters. On the Left valve cover I installed a OEM truck PCV valve and routed it to the large port behind the carb. So far so good.

Pop N Wood

iTrader: (1)

The PCV is run to the carb, not sure what you are asking. I have a GMPP single plane intake so there is no port on the intake runner, hence the T for both. The stock EFI motors plumb the PCV vent into the throttle body. I reused the same hose from the stock vehicle, but turned it back under the intake. You can see it in the picture. if you look close you can also see the PCV valve splicing the two lines together.

The valve cover is actually a bad place to draw a PCV vent from. Read through some old posts about oil getting into the intake. The oil reduces the octane of the fuel and can lead to detonation. the early LS1's were notorious for that. With the LS6 motor GM switched to a vent off the lifter valley. If you look on the underside there is a plastic baffle that is suppose to help stop this. My set up really could use a catch can between the vent and the intake manifold. Something I just haven't gotten around to yet.

Pop N Wood

iTrader: (1)

Not trying to be disrespectful but people say that all the time and IMO it makes no sense. If you have steam coming out of the heads than you have bigger problems. Calling them steam vents is a complete misnomer

From what I can tell the vents are only there to get the last of the air out of the top of the motor. On the first gen SBC's coolant passed out of the top of the head and into the intake manifold coolant passages. With the LS motors the coolant comes out of the front of the block leaving an area above that exit to trap air. Some sort of vent is needed to get the last of that trapped air out.

I see threads all the time arguing about needing all 4 corners hooked up, yet if you read more posts it is actually quite common for people to run with all 4 corners capped off. If you do it that way you just need to make absolutely certain to open a cap on each head when filling the coolant system. Once the air is out and the heads filled the vents are no longer needed. Hooking them up just saves you the trouble of having to manually vent the heads should the coolant get low.

Look at a Dodge diesel some time. They have a manual vent at the top of the motor with a yellow warning to open the vent when filling the system. This is not an uncommon practice.

krochus

iTrader: (1)

Again though my gen V LC9 has no provision for a lifter valley vent. However the stock pcv or CCV system was setup it doesn't vent through anywhere but the valve covers.

My motor came with plugs to block off the rear steam ports and a crossover only on the front

speedtigger

iTrader: (16)

I see a few of you ran your steam vents to the inlet side of your cooling system. You might consider running it to the outlet side of your cooling system. The object is the get the air out of the cooling system and into the overflow tank. If you vent it to the inlet side, you are just recirculating it back into the block.

cruisin'73

iTrader: (8)

Is it necessary to use a 4 corner vent? Probably not. But I wanted to emulate the OEM system as closely as possible. I figure if GM spent the additional $.76 per engine on the vents, it was because someone much smarter then you or I spent millions of dollars to find out it was necessary (otherowrds some tight *** penny pinching accountant wouldn’t have approved it!). In reality ad practice; lot of guys run with just the front vents, or no vents at all without issue.

I think the truth lies somewhere between our beliefs on the topic. I know that evacuating the air at system fill is necessary. I have also studied and worked on motors that had areas in the coolant passages that were prone to high pressure, or low flow, or higher temperatures that could cause the formation of steam pockets. Many old European motors fell victim to this flaw. So I figure better safe then sorry…

krochus

iTrader: (1)

But therein lies the problem.

GM has used both two AND four vent systems. So how much vent is necacary? Apparantly two or at least till GM decides to use no vents on one of these engines too.

Honestly we don't know what these motors need as far as vents and pcv because GM has changed up just about every aspect of their operation on these engines depending on the exact model.

For pcv I just ran a 3/8 fuel filter off the forward facing passangers side valve cover vent tube. Then on the vertical rear drivers side port I bushed up to an old SBC pcv valve. I will just have to run it and see how much oil it sucks up.