I got a call over the weekend from a guy I used to play golf with. He was REALLY struggling with his swing and asked me to hit a few bucket of ***** at the range and try to offer a suggestion or two. I worked as an assistant pro part-time from the fall of '05 to the spring of '08 and had played a few rounds with this guy, a 17 year Chrysler mechanic.

So, where this relates to DF, is that as we are hitting *****, we are talking about Dodge trucks in general, the problems with the CTD 6.7 and a little bit about the Hemi. That's when he made THE statement in that "the modern Hemi isn't really a Hemi at all, it's a Poly".

So of course, I bit and asked "what the hell is a Poly"?

He then went on the tell me that the modern Hemi was just an attempt by Dahmler-Chrysler to capitalize on the name of probably the greatest V8 engine ever produced - the 426 Hemi.

But unlike it's namesake, this new Hemi does NOT have hemispherical shaped combustion chambers at all, but instead, utilizes a pinched chamber, which more closely resembles the 1950's Chrysler engines that actually were the pre-runners of the true "Hemi's" of the muscle car era.

Seems Dahmler-Chrysler engineers found that by utilizing the "Poly" shaped combustion chambers, they would be able to produce a lower-cost alternative head design for their V8 engines. The Polyspherical head design needs much less metal and is narrower due to using only one rocker shaft. This saved Dahmler-Chrysler costs in materials and engine size which in turn allowed it to be used in smaller vehicles, giving it a "one engine fits most" V8 to be used across most of the vehicles in it's line-up, both cars and trucks.

The only thing our modern "Hemi" engine shares with the true Hemi of yesteryear is the fact that they use an active combustion chamber designed to tumble and swirl the fuel/air mix within the chamber for the most efficient combustion event possible.

So, is anybody going to re-badge their truck with a "Poly" emblem?...

 

wwhaaa?!?! I knew something Hammer didn't?!

did you know that ford made a similar head just a little while back? i think it was for a little 4 banger. they might still make it for all i know.

 

I knew it wasn't a "True" Hemi design in that it wasn't identical to the original ones, but I didn't know that it had so little in common with them...

 

not any time soon.

 

^^^that's the important part, and the ability to have larger valves. Aside from that, a real Hemi doesn't really gain you anything over a pinch.

personally, I'm glad they did what they did. Allows it to be a much more versatile engine and makes it more affordable. both of which contribute to its survival and popularity.

so nostalgia just took a kick in the nuts...eh

 

For some reason a "poly" badge doesn't seem like it would be very cool.

 

Heres a picture of one of the heads off my truck.

 

Unless you're in a small religious faction... It'd be like an Amish wagon on 24's!

 

I knew the Hemi wsn't actually a Hemi and that it was just for that Prestige factor for the customer thinking he has something super special. I always shrugged my shoulders at the thought of a Hemi. I alsways figured it to be a sales gimmick and nothing more.
All these companies feel the need to call their engine lines something to make them seem more desirable. I don't figure I have a Hemi, but I do figure I've got a 345hp 375ft/lbs engine that hauls ***! Now I don't know how close it really truley is to 345 since most trucks dyno at 240rwhp. That's way too much drivetrain loss coming from 345 initially?????

 

Duuuuuuuude, that thing got a Poly?

Nah, just doesn't sound right.