Slant engines - 2 questions

[72smallairparticler]

First question - is there supposed to be spring or something on those heat risers in the intake manifold? When I got the Duster the parts were disassembled for the intake / exhaust so I didn't see anything on these stems poking out of the intake.

Second question - is there any issue blocking off this port at the back of the head? My slant 6 is a california car as an FYI. The pipe that was covering this I pulled off to do a valve adjustment, wondering if there's a simple way to block it off or if there's a problem doing so.

 

[72smallairparticler]

I guess I answered my question but have no idea where I would even get a spring for the Valve shaft

 

[WV64Signet]

The damper was intended to help the engine warm up.

Are you working toward a 100% correct restoration?

Does the car have electronic ignition?

How cold does it get where you live and drive?

Those will determine if the damper and spring matter to you.

 

[72smallairparticler]

Ahh thanks @VW64Signet - Not working toward a correct resto - just a running car. It has points ignition and it doesn't get very cold here in california.

 

[WV64Signet]

doesn't get very cold here in california.

Didn't think so ... but there are mountains so wasn't sure. Some of the /6 Gurus may come in with more detailed response than mine.

Good luck with the car! Run it.

 

[halifaxhops]

Wire it open just run it for a minute before driving you will be fine. Spring kits are not cheap!

 

[WV64Signet]

is there any issue blocking off this port at the back of the head?

What year is the motor? Guessing 72 from your handle

Can you get a picture from further out pointing where that opening is located? Trying to guess where.

 

[volaredon]

Looks like newer than 72 engine but yeah they used to (factory Mopar) make a blockoff for that exhaust. Used more on small blocks than anything else I have seen. But you can make your own.
I'd bet the gasket for either the pipe or the block off is the most asked "what's this for" in a gasket set.
Cut that pipe you said you took off as short as possible and weld up the hole ..

 

[slantsixdan]

The damper was intended to help the engine warm up.

No, the manifold heat control valve counteracts the tendency of vapourised gasoline (like any other sprayed/expanding liquid) to absorb heat from its surroundings. That's bad in the case of the intake tract, because it causes the gasoline to fall out of suspension and puddle/pool along the intake manifold walls, making the engine run worse; use more fuel, and crap up the oil with unburned gasoline. This valve is best present and working no matter whether you live in Alaska or Florida; it has its job to do even when the engine is fully warmed up. This Jam Handy cartoon from 1935 is a real trip to watch, and at 5:37 it explains (in very simplified terms):



The spring absent in the OP's photo is an anti-rattle spring. It can be replaced by an appropriate-length coil spring from a good hardware store. It just needs to keep light tension on the valve shaft—not very strong tension which would bind the shaft and prevent it turning easily.

As to the secondary air injection port at the back of the head: there used to be a factory blockoff plate, part № 3751 249 and gasket 4275 834 (the gasket is available aftermarket; the plate is not, that I know of, but with the gasket you ought to be able to get someone to water-jet or laser-cut you one from suitably thick steel).

 

[72smallairparticler]

No, the manifold heat control valve counteracts the tendency of vapourised gasoline (like any other sprayed/expanding liquid) to absorb heat from its surroundings. That's bad in the case of the intake tract, because it causes the gasoline to fall out of suspension and puddle/pool along the intake manifold walls, making the engine run worse; use more fuel, and crap up the oil with unburned gasoline. This valve is best present and working no matter whether you live in Alaska or Florida; it has its job to do even when the engine is fully warmed up. This Jam Handy cartoon from 1935 is a real trip to watch, and at 5:37 it explains (in very simplified terms):



The spring absent in the OP's photo is an anti-rattle spring. It can be replaced by an appropriate-length coil spring from a good hardware store. It just needs to keep light tension on the valve shaft—not very strong tension which would bind the shaft and prevent it turning easily.

As to the secondary air injection port at the back of the head: there used to be a factory blockoff plate, part № 3751 249 and gasket 4275 834 (the gasket is available aftermarket; the plate is not, that I know of, but with the gasket you ought to be able to get someone to water-jet or laser-cut you one from suitably thick steel).

Thanks Dan!

Found a light spring

 

[halfafish]

You found the spring, so far so good. I blocked off that port by tracing the gasket on some 1/8" sheet metal and then cut it out to fit. If you need a photo let me know, I can get one in the morning.