82cecil

This swap does not have a temp gauge. PCM has ECT connected.

The engine has a stock thermostat and appears closed from a look down the top connection. Heater connections are a short loop.

I want to be sure there are no air pockets, and avoid a mistake that will destroy my engine before I even run it 10 min.

If this were a GEN 1 SBC I would fill it and go, but I'm not as familiar with this type cooling system.

Thanks for your help.

i r teh noobz

iTrader: (4)

If your engine has the coolant tubes on the front of the heads, I recommend cracking them open and filling until you get a steady stream of coolant from both heads. My LM7 kept overheating until I did this.

82cecil

I noticed there is a cross over tube connecting the cylinder heads, there is a tee on the driver side connection with a hose connected to it.

Do the bolts holding the cross over tube to the cylinder heads, block an air bleed unless unscrewed a little bit?

I'm using a old school radiator with a 15 psi cap, I'm thinking the rubber hose connected to this tee maybe should be connected to the overflow stem at the cap?

01cherryreds10

iTrader: (9)

Well they are supposed to be tight, but yes crack them open until you get coolant. Yes to your second question, just t it in with the overflow hose

garys 68

iTrader: (1)

The crossover tube is a steam vent. It's under pressure. The overflow stem at the radiator cap is intended to feed a reservior, not under pressure.
You can connect the steam vent line to an added fitting on the water pump or radiator hose.
I filled mine by leaving the radiator cap off, making sure the front of the car (radiator) was high, and just kept topping off the radiator after it started.

Jimbo1367

I heard I had to fill from the engine, but I never heard or thought of this.
Good to know
Both are very good ideas anf good to know. Thanks for sharing guys

ls1nova71

iTrader: (4)

Yeah, don't hook it to the overflow!

As for filling, I usually fill the radiator almost all the way up, then take the upper radiator hose off at the radiator and hold it up and fill through it until it's full, then put the hose back on. It's a little messy unless you are quick, but I've never had a problem doing it this way.

82cecil

Thanks everyone for the critical info. small details can sometimes be very unforgiving.

01cherryreds10

iTrader: (9)

Yes they are right don't listen to me. There's is a nice fitting in the help section to run it into the smaller heater hose. Glad I put my previous comment or I'd never even think about it.

speedtigger

iTrader: (16)

I recommend pulling the upper radiator hose from the radiator and filling the block by pouring coolant into the hose. This should only be necessary on the first fill.

74novacustom

I literally just did it this way, seems to have filled the system up will.

MikeJTR

This part allows installing the steam vent tube into the upper radiator hose, it allows checking if the air is out of the system, and it has a petcock to allow purging air out of the system.

I created this part after a number of people who bought our radiator kits for LSx swaps complained about cooling problems, which were caused by air in the system.

Marky522

iTrader: (8)

If you want to fill the system in 5 minutes with NO air pockets just buy one of these...

Coolant fill tool

And as a side note, this is the downside of not running an expansion tank with the head vents run back to it. It gives the air a place to collect when run correctly, so if you do get air then it will end up in the tank instead of in the engine.

Just my .02

Mark

speedtigger

iTrader: (16)

I think I would have to be filling a lot of dry engines to spend that kind of money.

Marky522

iTrader: (8)

$100 to not have to deal with any of those issues? Doesnt have to be a dry engine, i use it anytime i drain coolant! I guess its all about what your after, i dont want to have to fight air in the system so 5 mins vs 30 minutes at the best!!!!

speedtigger

iTrader: (16)

Once the initial fill of the block is done through the upper radiator hose, I don't think anyone will have an "air in the system" problem as long as their cylinder head steam vents are plumbed properly unless I am missing something.

Marky522

iTrader: (8)

I find it funny you feel the need to argue with me about a VERY easy solution to this problem! The difference between us is obvious!!!

Mark

speedtigger

iTrader: (16)

Argue? No chance Mark. That is more of a Porsche guy thing. JK of course.

Marky522

iTrader: (8)

I think it may have to do with the fact i spend $500+ on tools a month, but even if i didnt this tool is awesome... Now if it was a "Porsche" thing i would be pushing my $500 hydraulic flaring tool!!! To each there own!!!

speedtigger

iTrader: (16)

A good friend of mine had a 944 that had some kind of head problem. I think it bent some valves. The car was in really great shape and he hung onto it for the longest time talking about a motor swap. I don't know whatever came of it, but he sure did love that car and he grew up a Mopar guy. So, that something about how well it must have drove.

PS. I would have loved that hydraulic flaring tool when I was making all new steel fuel and transmission lines.