Thread: Hemi's VS equal C.I.Chevy's

Tweet

I am not stirring the pot on brands here.Mainly opening a thread on flow numbers of equal size brand engines and mechanical advantages one over the other in their stock format.I know how expensive any Mopar Hemi cam be.

Example: 392 hemi vs 409 Chevy for the older engines or 426 Hemi vs 427 Chevy.

That kind of thing.Just a pure mechanics discussion.

From the blower stand point hands down the Hemi's have a advantage I think because of the chamber's efficiency.

Got me thinking of rod length/rod ratio in Hemi's too.

I don't know if you will be able to compare the stock 392 and 409 directly. Not many formats where the two could be compared "apples to apples". Today both are unusual enough to have a great "cool factor".

The old 409s could run good. I had a couple street cars, and several engines and aftermarket parts. (sold it all to go into business full time.) The street driven muscle cars of the time, like the new GTOs and such, were no match for my '62 409 2X4 Biscayne, usually 2 gears, and it was way over !Another factor of the time was the development of the automatic trans. It made the street cars for the late sixties much more formidable. The hipo '09s did not offer that, and the 392s were not in the loop by the time of the perfomance automatic development.

As far as 392s, they had a great race history, but in near stock form, I doubt they would compete with the 409. It was years farther along for performance use.

From my experience, I know the 440 and Street Hemi were reputed to be pretty equal on the street. The race Hemi was another story.

The big block Chevies seemed a little stronger on the street then the 440s, but the automatics made up the difference on street tires, as far as I was concerned.

Of course this is all judgement based on my friends, and my own, crazy "street research" efforts, in the late sixties and early seventies. :-)~

Today you could make any of them far better on the street, with better ignitions... cam design... better carbs... newer tires... and so on... though you probably will never have to verify which is most efficient. I would go with the one you feel most drawn to. In the end, the technical advantages don't mean as much as being happy with what you built.