Notes on Hemi engine rear details and heat shields
Hey Frank! We’ve got some interesting questions, but this one regarding the rarely seen back of the Hemi motor made me decide to focus on that this month, so we’ll be a little short on text but show you a couple of cool photos; here was the question —
“Do you have any info or photos showing the rear of a ’69 Hemi engine? I need to know how the choke tubes are routed and what holds them in place. Also, any info on the correct installation of the starter heat shield would be appreciated. Thanks!”
Yes, sir, I do happen to have some good photos of the rear of the Hemi engine prior to installation, right from back in the day. Actually, the choke tube routing and the clips that secure the two tubes are the same for all ’66-70 street hemi engines. However, Hemi engines in 1971 did not use choke tubes due to the new-for-’71 manual choke design. I have some really good shots of a 1970 crated engine from Chrysler Corporation from when the engine was just coming out of the crate. It really doesn’t get any better than this. As they say, a photo really is worth a thousand words, especially a correct, accurate photo!
Next, we will address the Hemi starter heat shield question. All Hemi automatics from 1966-69 used a starter heat shield; the ’66-’69 Hemi four-speed cars with the direct drive starter did not use the starter heat shield. However, all 1970 and 1971 Hemi cars (automatics and four-speeds both) used the heat shield. The factory schematic illustration shown here tells the story. Another thing to note is that all starters used a shim or seal between the bellhousing/auto trans case and starter. The 1966-69 four-speed direct drive starter used its own metal shim/seal, but all 1966-71 Hemi automatics and the 1970-71 Hemi four-speeds used a different shim/seal.
As the schematic shows, this shim/seal goes on, then the starter; for automatics, next is the fluid tube retaining bracket, then the starter heat shield. The front upper portion of the heat shield is secured via a special bracket which is installed on the second from the rear exhaust manifold bolt during initial engine assembly. This bracket would have been painted orange when the engine itself was painted. The starter heat shields were assembled to the engine with the starter and positive battery cable, and therefore the heat shields are not engine color. All starter heat shields were painted a semi-gloss black.
PHOTO: Here is the photo of the rear of a 1970-era crate motor; note the tube position and placement. While the photo is not perfect, it is vintage – this is exactly what the 1970 factory choke set-up looks like.
DIAGRAM: This exploded parts diagram shows many of the components associated with the heat shielding on Hemi powerplants. As mentioned, four-speed cars from 1966-69 had the direct-drive starter and did not use the shielding; all other OEM Hemi car received it in one form or another.
The article featured on this page is from the February 2010 issue of Mopar Enthusiast Magazine.Click here to read the free digital edition of Mopar Enthusiast now.