[Skip Fix]

I have the old 400 short block I am going to freshen I used under my RAIV heads in NMCA for a lot of racing, been on a cradle for a long time. I pulled the heads but there was still coolant in the block. Engine stand has a slight tilt to the back. Suctioned out(syringe an a 12 French feeding tube/urinary catheter form the lowest middle cylinders until getting some air. More from the very rear lower hole, but surprisingly a bunch more from the very front lower hole! you would think it would flow through the block better than that.

557 block so will get the mains magged and throw some speedmaster heads on it to toss the motor in the 65 GTO in place of the very tired and misfiring original motor that has no exhaust. Going to toss in an old Muncie and 12 bolt to "Roadkill" drive it until I get it painted.

[tom s]

put longer main dowel main pins in it.Tom

[Schurkey]

Originally Posted by Skip Fix

surprisingly a bunch more from the very front lower hole! you would think it would flow through the block better than that.

Flow blocked by rust/scale/debris?

[Skip Fix]

Not really any rust coolant looked clear. A little rust on deck where the FelPro 1016 may have been seeping. And a little brown between cylinders on the gasket.

The old Comp HFT looks great cylinders no ridge or scuffing so figure to use it as a "throw down motor". The heavy TRWs and Crower billet rods(bought before good forged to protect the RAIV heads) look OK . Going to check bearings out tomorrow.

Tom what was the max HP you had you mule 557 block? I figure the 400 short stroke crank has helped longevity. I spun it 7000 with the SFT and Torker 1 combination!

[tom s]

Just under 600 with the bathtub intake.Engine is in a 70 GTO and running fine.Does not get beat on much just a nice street driver.The build is still on this site somewhere.It was built with a lot of good parts I had bought and kept for a build sometime.Tom

[tom s]

585 HP 603 TQ.Tom

[Skip Fix]

tom thanks I remember the original thread and though it was somewhere like that.

[Skip Fix]

Tom looked at the dowels last night definitely short ones!

[Skip Fix]

Video from Lee about water passage holes and flow. Interesting thoughts. Also wonder if should be duplicated when drilling an aftermarket block. So then the passenger head flowing some water to the heater should not cool the front of the head as well . water out both heads to heater balance heads but not cool as good as plugged on both-assuming not using a heater.

https://www.youtube.com/watch?v=bVTijabxflI

[Formulas]

I like coming off both heads 2 lines at the normal heater feed going up to a spacer on top of thermostat under the goose neck, this gives a dedicated flow path that does not include back tracking through the block and heads, Don't know why this isn't more widely used especially in road racing as well as street use .... Dedicated drag cars its all over before heat is a real issue

I just used dash 6 lines here because that's what I had laying around cost me nothing but calories.. a dash 8 or 10 for a car at WOT for extended periods

[Schurkey]

Originally Posted by Formulas

I like coming off both heads 2 lines at the normal heater feed going up to a spacer on top of thermostat under the goose neck, this gives a dedicated flow path that does not include back tracking through the block and heads, Don't know why this isn't more widely used especially in road racing as well as street use .... Dedicated drag cars its all over before heat is a real issue

I just used dash 6 lines here because that's what I had laying around cost me nothing but calories.. a dash 8 or 10 for a car at WOT for extended periods

Any coolant that bypasses from the back of the engine direct to above the thermostat is coolant that's not picking up heat from the cylinder head.

I've heard of folks using Dash 4 hose to remove air/steam pockets, larger hose results in less cooling. Even Dash 4 hose for air/steam would kind-of rely on the engine family having a series-flow cooling system. Wouldn't do as much good on a parallel-flow cooling system.

Buick, and older Chevy Big-Blocks had series-flow systems. Lotsa other engines use parallel-flow.

[lust4speed]

Originally Posted by Schurkey

Any coolant that bypasses from the back of the engine direct to above the thermostat is coolant that's not picking up heat from the cylinder head....

Exactly. Pulling coolant away from engine when it has only completed half its cooling journey.

[Schurkey]

Originally Posted by lust4speed

Exactly. Pulling coolant away from engine when it has only completed half its cooling journey.

Realistically, NOT EVEN half.

That coolant has been through the block--but the heads have more BTUs than the block does. The critical part is the cylinder head, and that's what's being cheated of coolant volume.

The heads having more BTUs than the block is why Pontiac originally cooled the heads first, then the block using the "Gusher" cooling system. This was abandoned in '59 or '60, I can never keep that straight.

Chevy did exactly the same thing with the "LT1" engines of the early--mid '90s. Made a big deal about cooling the heads first, then the block. And again, GM Powertrain abandoned it for the LS engine.

Even International played games with cooling the cylinder heads first, then using that coolant to go through the block on the SV engine family.

Certain Harley V2, and Porsche engines water-cool the cylinder heads, but air-cool the cylinder barrels.

[Formulas]

Originally Posted by Schurkey

Any coolant that bypasses from the back of the engine direct to above the thermostat is coolant that's not picking up heat from the cylinder head.

I've heard of folks using Dash 4 hose to remove air/steam pockets, larger hose results in less cooling. Even Dash 4 hose for air/steam would kind-of rely on the engine family having a series-flow cooling system. Wouldn't do as much good on a parallel-flow cooling system.

Buick, and older Chevy Big-Blocks had series-flow systems. Lotsa other engines use parallel-flow.

B/S coolant enters up front block and is moved out of the engine via upper back end of the head after it transverse through the head and block not like only coolant coming out is going to be from the block please explain what dynamics is going to keep the head coolant separated from block coolant at that point ... you cant ... whatever comes out of the back of the head starts from the front of the block .... And whatever comes out of the back of the head is being replaced by cooler coolant coming in up front..

[Jay S]

Is this engine the that had the 614s and last used the reverse split 242/236 HFT cam? I still remember the HP Pontiac article it was in.

[Skip Fix]

Jay yes it is and it was hammered on for a lot of years. 4-5 cams before we ended up with that reverse split. With the UD SFT and the Torker 1 it was buzzing 7000 with heavy TRW 2262s and heavy Crower Billet rods. That combo picked up 2 mph over the HO intake and previous HFT 304/312 UD btu killed so much bottom end it ran slower. Also first combo that made power brakes iffy .

Bearing look pretty decent it had Clevite 77 main(fully grooved) and rods. #2 main have more wear in back half of the bearing and thrust cap was not real snug on the dowels. Something put a light scratch in #6 bearing and another one. Most had wear through the first layer of the rods top half dead center.