LS1-450

iTrader: (33)

Need information on the rear block cooling ports. Is a line needed to connect the ports to each other to allow flow between diver & passenger side of the block, or is flow from side to side internal? Is it OK to plug these ports? Am thinking that they either need to be tied together, connected to the intake, or plugged. Please comment.

firebird69racer

If your talking about a first gen block and heads, then no the coolant dont cross the intake at the rear of the block. the intake blockes it off.
The coolant flow on the first gens is it inters the block through the water pump at the front of the block on each side, it flows through the block to the rear then up to the heads and flows to the front where it inters the intake, both sides meet where the t-stat is and flows to the radiator


Wade

LS1-450

iTrader: (33)

Thank-you. What are the openings on the top of the rear of the block behind the heads? There is a small port above a tapped hole on each side of the block. The arrangement of the holes (port over tapped) is very similar to what is seen for the cooling line cross over on the heads of my gen 3 motor. Difference being that these are only on the top rear of the block on the gen 1 motor (behind each head on top of the block). That is what made me think they were external cooling line cross over ports. What are they? The guy I bought the engine (used) from had painted over these holes. Maybe they are not used. I mounted the engine before seeing them & don't have a good view of the areas. What are they?

firebird69racer

I need to see a pic of the block, are you sure its a 1st gen block and a Chevy, or is it another brand
I can take a pic of my sons block on the stand and post it here if I knew how to post on here, or I will put it with my pics on yahoo. Give me a couple of days


Wade

LS1-450

iTrader: (33)

It's a Chevy 350. According to the model number on the carburetor, it is a 1976 motor. The carburetor is a Rochester 2GC. On the front top of the intake manifold it says "firing order 18436572." I can't see the block model number because it is burried under the firewall. Sorry to sound like a newb. All of my experience is on the LS1 & various modded 4 cylinder engines. The older equipment is new to me & I am still learning about it. Thank-you for the assistance.

firebird69racer

your no problem at all.
I just cant picture what your talking about on the rear of the block. The area behind the heads is where the bell housing mounts to and there are no holes or ports there.


Wade

LS1-450

iTrader: (33)

Within the next week, I will start the engine (finally). Will look closely for coolant leakage from the ports in question. The ports are directly behind the heads, on top of the block, between the bell housing & the heads. For some reason, there are ports in that location on this block.

firebird69racer

check out these 2 sites they have a lot of info
http://www.nastyz28.com/sbchevy/sblock.html#camaro
http://www.chevy-camaro.com/

do the holes go through to the flywheel area?


Wade

LS1-450

iTrader: (33)

So.....I pulled the head covers & ran the head casting number & they are stock heads machined for 1.720" valves. In the mean time received an e-mail from the guy I bought the engine from & he said......"huh"? My best guess is that the holes are simply cast in the block & not used. To quote the seller, "I have no idea, if there's nothing piped to 'em then they are not used."

Thanks again for the help. I needed to be sure there wasn't a problem. BTW, learned @ the dyno this past weekend that I've got a bad piston ring or rings in the LS1 block. So, I get to tear into that engine while finishing up the 1940 Dodge. Guess it never ends.