[lt1silverhawk]

Hi All,

Just have a few curiosity-driven questions about the 409, somewhat inspired by TucsonJay's post here (#316).

What ever happened to the Chevy 409? Was it trumped performance-wise by the 427 or the 400? I see this engine has a few die-hard fans, but there don't seem to be very many engines out there. Also, if anyone could shed some light on its strengths and weaknesses.

Any members still own one?

Thanks in advance!

[Bryan59EC]

It was replaced by the MarkIV 396 mid year 1965

[BOBCRMAN@aol.com]

The 348-409 was basically a truck motor. It wasn't designed to produce the horsepower that the later ones were producing.. Rodders wanted to rpm the living he 11 out of it, like a small block. Thus a lot of GM piston/rod/valvetrain warranty/service problems.. Ford was also killing it with their big block engines..

[timothale]

the top of the block was at an angle and the head was flat on the bottom , the combustion chamber was a huge round wedge, no quench area but it had good ports and flow, You could pick up about 40 0r 50 hp by using new pistons with a dome and a combustion chamber area in the pistons, but There were sets of 4 canted chambers one direction and 4 canted the other direction to match the valve arrangement.

[TucsonJay]

The 396 and bigger "rat motors" were basically a new redesign of the 409. The 409 head design was not current with the newer thinking.

The 348-409 had a flat faced cylinder head, with the top deck of the block cut at 74 degrees instead of 90. This made a wedge shaped chamber in top of the cylinder bore. It was just not going to stay competitive with newer designs.

Chevy kept similar crank dimensions, but went back to a 90 degree deck, and adapted a stagger-valve configuration in the new heads, to help air flow into the chambers. Clearly they were not as advanced as the Hemi... but moving in that direction, without the more complex double rocker shafts.

The 409 did well in the early sixties... but the mark IV established itself as one of the established power sources in racing for many more years.

[matts37chev]

you can now buy a lot of aftermarket performance parts for 409s
that were not available 5-10 years ago

i think they are cool motors if you are building an era specific car

[lt1silverhawk]

Thanks guys!

While I admit I don't understand all the technical aspects, like the advantages of the 90 degree vs the 74 degree deck (further explanation very much welcome), I did learn a few things and some history. Seems like it was kind of the LT1 of the big blocks: did well for the short time that it was produced. Thanks again!

Originally Posted by matts37chev

you can now buy a lot of aftermarket performance parts for 409s
that were not available 5-10 years ago

i think they are cool motors if you are building an era specific car

Hey Matt, how you been? Hardly ever see you on here anymore.

Yes, the parts do seem readily available, and I think it was World Products that released new 409 blocks recently. It would definitely be cool to see one in person.

[malc]

"You can now buy a lot of aftermarket performance parts for 409s
that were not available 5-10 years ago.

I think they are cool motors if you are building an era specific car."

Tom Nolen’s ’55 Chevy 409

[matts37chev]

Originally Posted by lt1silverhawk

Thanks guys!

Hey Matt, how you been? Hardly ever see you on here anymore.

been busy working all summer , so I can take some time (2-3 months) off in the winter

you will notice i'm here more now, for a while, in between getting caught up on the house, cars, etc

hotrodders + matts37chev = summer/no , winter/yes

[painted jester]

Shes so fine my old 409







last picture is my old car club! Taylor Area Street R ods

[1930u]

Here's mine 409-340HP. The coolest 409 of all is the Z-11. They were 427 cubes and had a a two piece intake manifold, larger head ports and cast iron headers.

[1930u]

Here's a Z-11 409 (427) engine and a shot of the cylinder heads. They had much taller ports than the 425HP version.

[matts37chev]

Originally Posted by 1930u

Here's a Z-11 409 (427) engine and a shot of the cylinder heads. They had much taller ports than the 425HP version.

i think these w- motors are neat
i dont know that much about them
my uncle had a 348 tri-power in a 56 GMC 3/4ton p-up, when i was a teen
that is cool, i didnt know that Z-11 existed

[DoubleVision]

Love those candy cane valve covers on that 409 Jester.

[willowbilly3]

Well, nowdays they are a way cool engine for a rod but really an engine only a diehard chevy fan can love. Most of us that remember them, remember anyone who rode a 409 hard spending a lot of time with a blown up engine. A good indicator of their potential is how many you saw in the stock cars, few were ever there at the end of a 500 mile race.