Intake Manifold

[Space Cowboy]

From what I've been told, a 427 big block has a tendency to hold an extra amount of hot coolant on the back side of the intake manifold. I've also heard that you can plum out the intake to keep that hot coolant from collecting on the back side. Has anyone ever heard this too or has done it? I would like to know what was needed, how it was done, photos if possible.

Thanks

 

[JohnZ]

Never heard of such a thing - there's no coolant passage at the rear of a big-block (or small-block) intake manifold; the heads have coolant passages at both ends, but that's only so they can be used on either the RH or LH side - there's no matching passage at the rear of the intake - only at the front.

 

[iron cross]

Sounds like or appears that you may have a overheating problem and are listening to some bad information. Big block engines dont overheat. Most of the problems are from deviations from the OEM parts. For that matter this also really applies to small blocks too. Uncle GM has produced thousands of them and they all worked fine until some of them have been subjected to back yard engineers thinking they can outsmart the factory ones. These types of solutions normally will start the rumors and spreads like wildfire giving the BB`s a bad reputation. I hope these statements may be way off base in this thread but I love my BB`s and none of them overheat and have nothing but factory cooling systems.

 

[6880 Mike]

...Never heard of such a thing...

Same here.

 

[RodsnRides]

Most of the problems are from deviations from the OEM parts. For that matter this also really applies to small blocks too. Uncle GM has produced thousands of them and they all worked fine until some of them have been subjected to back yard engineers thinking they can outsmart the factory ones.

Exactly that. John Z and Iron Cross are correct. Stay with OEM and follow their own improvements (airflow, radiators) over the years. They work just fine.

Rick
:gap

 

[Vettehead Mikey]

But, but, but, all this heresy infers that not everybody at GM was a complete idiot and that cars weren't actually built on the cheap with inferior technology!

Do you mean that Speed Vision and Hot Rod magazine got it all wrong?

 

[RodsnRides]

But, but, but, all this heresy infers that not everybody at GM was a complete idiot and that cars weren't actually built on the cheap with inferior technology!

Do you mean that Speed Vision and Hot Rod magazine got it all wrong?

otfl

I was wondering if you were gonna stop by! I knew this thread was PERFECT for you.

Rick
:gap

 

[iron cross]

Do you mean that Speed Vision and Hot Rod magazine got it all wrong?

With out further investigation I will say yes! But what did I miss?

 

[Vettehead Mikey]

Just don't anybody mention spark plugs......................:W

 

[Evolution1980]

Just don't anybody mention spark plugs......................:W

Back under the toll bridge with you, Mikey! :L

 

[Space Cowboy]

Well, to prevent my thread from being further hijacked...

I don't have your typical BB/427. Mine is producing about 500+ hp.

I would have to disagree with the 'Uncle GM' design. The design is flawed due to the fact that the radiator can't get maximum air flow. Also being that mine is a 68'... its the 'bastard' year... hint hint!

To compinsate for the flaw, I've replaced the radiator with the largest possible aluminum radiator rated up to 1000hp. Also, switch from the clutch fan to dual pull electrics. Even with these changes, the block is boiling my fuel before it reaches the carb (thats another issue though).

Anyhow... the problem was found. One of my fan relays died which was causing my fans to spin at a lower rpm. Also, the fan mfg failed to tell me that their system requires at least a 100 amp alt. So, it ended up being a cascade affect.