What is a "rat motor" ?

[Ron90]

I have a big block Chevy motor I believe it is a 396, I got in to a disscusion with somebody about my setup and they were calling it a rat motor said that ment it was out of a truck . Just look for some info on truck lingo

[mongocanfly]

Welcome...
i think the term "rat" and "mouse" ...(mouse being a smallblock,rat being a big block).. derived from dodge being referred to a "elephant" motor...that was scared of the "rat" and "mouse"

[Steeveedee]

I know the "mouse" and "rat part", but didn't recall it being about the Hemi. Not saying anyone is wrong, I just don't remember. A "Rat" is big block Chevy; they come in most of the Chevy line, not just trucks. Want some real fun, go get one of the old Novas with a 396 in it. As the Hot Rod Magazine called them, "13 Second Grocery Getter".

[special-K]

Mongo meant GM, too, but also referred to the Morparts Hemis being called Elephant motors first.

The Rat motor thing has nothing to do with trucks. It wasn't really all big blocks, either. It was the hi-performance ones and ones that were built up. Basically a badass big block was a rat motor. This came about since the small block had gained the nickname Mouse motor.

[FleetsidePaul]

I always thought it was a 427. But I could be wrong. I usually am.

[geezer#99]

What about ‘porcupine’?
I know what it means, just wondering if anybody else does.
Just for entertainment!

[Steeveedee]

Spoiler alert.

It refers to the way the push rods on a big block are at angles instead of a neat line like a stock small block. Thus, "porcupine" heads.

[geezer#99]

Ta da!
And now for the ‘mystery’ motor?
Tell us what it is Steve.

[Keith Seymore]

Originally Posted by geezer#99

Ta da!
And now for the ‘mystery’ motor?
Tell us what it is Steve.

I won't spoil the surprise, but I will say my dad made the sheet metal components (oil pan, valve covers, rocker arms) for the Mystery Motors when he was at Chevy Flint Manufacturing (pressed metal).

K

[Steeveedee]

I was a small block abuser, so didn't know about the Mystery Motors. My first BBC is powering my truck, which I've had for about 9 years. Some really interesting reading, there! Meaning the Hot Rod articles and others concerning the "mystery motor".

[Stormin08]

i may be way off on this...but years ago i was gong to purchase a 71 or so elcamino. the owner who was a family friend and very into older gm vehicles...made a point to call out specific numbers on things like the pulleys, and brackets as well to indicate a RAT motor.

was it totally true....i cannot say. i am not one for pure authenticity, i would be if dealing with the right vehicle, but for most of us...i build what and how i like it. they are done to a slightly higher level of detail, my build thread shows this, but none the less.


i have heard numerous stories of the elusive RAT motor, but most always lead back to a big block of sorts...i would like to know if the actual RAT is of a special variety.

[68Gold/white]

Originally Posted by Keith Seymore

I won't spoil the surprise, but I will say my dad made the sheet metal components (oil pan, valve covers, rocker arms) for the Mystery Motors when he was at Chevy Flint Manufacturing (pressed metal).

K

I've read many times that the pushrod guide plates on the mystery engines were cast iron, not stamped metal like the production MKIV engines came out with... I bet the stamped guide plates were way cheaper to make...and lighter...
I always considered any big block a "Rat", any small block a "Mouse", never heard any other specifics...

I really like the big mouses, though, the 400's....

[Ron90]

The motor in question. Is it a 396?

[Ron90]

More pictures

[davischevy]

Don't take my word for it, but that appears to be a 1973 model 454.

[too much stuff]

Originally Posted by davischevy

Don't take my word for it, but that appears to be a 1973 model 454.

That looks correct. Possibly 78 even. Hard to see for sure the date code. The intake looks like an older 396.

[davischevy]

I was judging from the code on the front pad. I couldn't tell if the date code was a 73 or 78. You are correct that intake is a pre 70 396 427 intake.

[mingoman]

https://www.camaros.net/forums/13-pe....html?t=228241

This may help. They say 73 454 as well, but a good block to have.

[68Gold/white]

The intake is a good piece to use, although heavy. They made one flanged for a Quadrajet and an earlier one for a Holley carb...

[3drburb]

Well after reading the thread about how to get rid of rats in trucks we can now update the meaning of rat motor. Lol

[davischevy]

Originally Posted by 68Gold/white

The intake is a good piece to use, although heavy. They made one flanged for a Quadrajet and an earlier one for a Holley carb...

This one is a spreadbore for a Quadrajet.

[special-K]

I guess the timeline goes something like this:

-Chrysler Hemi gets nickname Elephant motor because they were big fat engines

-Little old Chevy V8 is a hustlin' little screamer giving the Hemi a good run, gets nickname Mouse motor

-Mystery motor (427) hits the scene and it is bad to the bone. Naturally it gets the name Rat motor

-In time, all built-up fast BBCs and GM factory muscle BBCs get to be known as Rats.

-I never considered all BBCs to be Rats, especially not the ones a Mouse can run circles around

[100%Chevy]

I did a rat motor in 1970.
Bought a 375 hp,396 out of a wrecked 69,S.S. Chevelle.
Then I put a 750 Holley dual line carb on it with Hooker headers.
With a Muncie,M-22 transmission,and hurst shifter.
All went into my 5 Chevy.
I don't know what the hp was,but at least 430 or so.
Never could keep a rear in it.
I was 17 in 1970.
Sold it in 1975 when I got married and had a daughter on the way.
I do have another one ,but it's a slow project.
Mike.