Why did they build a 409 when a 348 could be stroked so easily?

[1964SuperStocker]

Maybe there is something I've never read or heard about why make the 409 to begin with. The castings will always improve which includes the 348's own progression but why create a whole new block size range when the 348 were still being made? I understand the idea of "no replacement for displacement" but I also know that stroke is where you get your torq. If it were for racing then why not put better parts on the same block and get way more power? Just wondering if there was something that made the 348 block not as good as a 409 though in this day and age we can build 348's with impressive power numbers by stroke, pistons and large port heads.

 

[La Hot Rods]

Larger diameter bore means larger diameter valves, larger valves means more air/fuel into the engine.

 

[1958 delivery]

Because a 409 can be stroked even further

 

[1958 delivery]

These engines were not designed with mods in mind per se, they were what was best at the time for a mass produced car. The 348 sucked as is, the 409 was much better.

 

[32witha409]

Bore to Stroke Ratios are common decisions when designing an engine to exist in a given regime. Here is a simplified explanation. Not very broad ranging but a start.

https://www.hagerty.com/media/maintenance-and-tech/how-bore-vs-stroke-can-affect-horsepower/

 

[1964SuperStocker]

These engines were not designed with mods in mind per se, they were what was best at the time for a mass produced car. The 348 sucked as is, the 409 was much better.

But the performance 348's in that era were monsters. Tri-powers, 1147 heads and 11.25:1 compression. With up to about 350hp for 61. All of that without bigger valves, stroke or better flowing large port heads and intakes. Slap any of the last 4 items listed on and hit much larger numbers.
Just curious as to their thinking back then.

 

[1964SuperStocker]

Larger diameter bore means larger diameter valves, larger valves means more air/fuel into the engine.

Yes but my .030 over 348 has 690 heads with 2.19 valves. Why not offer up the 348 with 11.25:1 compression with 690's and 881 dual quad? Instead they built a new casting? Seems like more of an arms race than practical.

 

[1964SuperStocker]

Bore to Stroke Ratios are common decisions when designing an engine to exist in a given regime. Here is a simplified explanation. Not very broad ranging but a start.

https://www.hagerty.com/media/maintenance-and-tech/how-bore-vs-stroke-can-affect-horsepower/

I have seen that before and the one major factor to consider about the information given is with high rpms comes the need for more precise machining and more exotic materials making more expensive parts.

 

[32witha409]

I have seen that before and the one major factor to consider about the information given is with high rpms comes the need for more precise machining and more exotic materials making more expensive parts.

Nothing that the big 3 ever produced for the street required anything exotic. The engineering staff had a rod ratio and B/S ratio that was decided on prior to design based on some fundamental lab test data. They designed to that unless it was going to move into a racing application like the 409 did. NASCAR drove some decisions as well. In the end arriving in a test cell proved or disproved the decisions.
I like the "arms race statement". Very true statement as well.

 

[dakota tom]

With the heavy pistons needed because of the combustion chamber design a short stroke kept piston speed down and less stress on the rods,crank and bearings.

 

[1958 delivery]

Because no song lyrics rhyme with 348

 

[1964SuperStocker]

Because no song lyrics rhyme with 348

She's real great my 348
Don't be late in with my 348
Going to take my date with my 348
Going to the lake with my 348
Cops will put me up-state with this 348
Gonna drive straight with my 348
Gonna smoke this lightweight with my 348
Gonna create a hot little 348
You know you shouldn't hate on my 348
My car is (looking, sounding, performing, running, driving...) great with my 348
These cheater slicks hook great with my 348

Quick search gave me over 150 different words that would have not only rhymed with 348 but would have likely been used by the Beach Boys in the era. Still want to debate the 348? LOL!

 

[32witha409]

Can't argue with that. Think you got it covered.

 

[1964SuperStocker]

Can't argue with that. Think you got it covered.

There is a local 50's Rockabilly group I should hit up. Actually a bunch of car guys too. I'm thinking they need to create a new hit.

 

[1958 delivery]

She's real great my 348
Don't be late in with my 348
Going to take my date with my 348
Going to the lake with my 348
Cops will put me up-state with this 348
Gonna drive straight with my 348
Gonna smoke this lightweight with my 348
Gonna create a hot little 348
You know you shouldn't hate on my 348
My car is (looking, sounding, performing, running, driving...) great with my 348
These cheater slicks hook great with my 348

Quick search gave me over 150 different words that would have not only rhymed with 348 but would have likely been used by the Beach Boys in the era. Still want to debate the 348? LOL!

Stick to cars

 

[Don Jacks]

Don't quit your day job.

 

[Tim]

Wasn’t there a NASCAR racing influence for the 409 development? The new casting was to accommodate the bore because the 348 couldn’t get there? Pretty sure there wasn’t summit, show cars, rock auto and all the fancy parts back then?

 

[Tim]

She's real great my 348
Don't be late in with my 348
Going to take my date with my 348
Going to the lake with my 348
Cops will put me up-state with this 348
Gonna drive straight with my 348
Gonna smoke this lightweight with my 348
Gonna create a hot little 348
You know you shouldn't hate on my 348
My car is (looking, sounding, performing, running, driving...) great with my 348
These cheater slicks hook great with my 348

Quick search gave me over 150 different words that would have not only rhymed with 348 but would have likely been used by the Beach Boys in the era. Still want to debate the 348? LOL!

You just keep singing that in your head!

 

[Don Jacks]

It was the old "Bigger is better" deal.Big inches sold.

 

[1958 delivery]

That's what she said as she walked out the door