411 - Rear End view!

[Kevin H]

Originally Posted by Richardmulcaster

I just wondered, does the awkward change of direct for the exhaust emission cause a loss of power? I was reading how exhaust systems can deliver more or less power depending on design and using these principles I am guessing that such a sudden change in direction would cause at least some power loss?

Richard, your guess is as good as mine :-)

Exhaust systems are inextricably linked to the intake systems, including valve timing and other variables. I suggest reading "Scientific Design of Exhaust and Intake Systems" by Philip H. Smith. It's an old book, first published in 1962, but still relevant, particularly to normally aspirated engines such as that in the V8 Bristols. It won't necessarily give you answers, but it will at last show how complex these matters are.

Bear in mind the engines in the S1-3 411s are different to the engines in the S4 & S5. The latter having greater swept volume but lower compression ratio. So the exhaust system on say an S4 may not be optimal for an S2.

[Kevin H]

While not strictly on-topic, I happen to have the rear parcel shelf and seat out on my car at the moment, so I thought I would take some photos of the vents on the inside of the rear wings on my S5.

There is a weighted rubber flap which appears to be designed to prevent air coming into the cabin while allowing it out.

I have attached photos of the vent from the inside of the rear wing on both sides of the car. The flap is present on one side but not on the other. You can see a horizontal slit of daylight in the photo where the flap is not present. Also included a pic of the flap itself, which had fallen off on the passenger side of my 411.


These vents and the operation (and existence) of the flaps will make a difference regarding exhaust gases entering the cabin.

[Richardmulcaster]

Originally Posted by Kevin H

While not strictly on-topic, I happen to have the rear parcel shelf and seat out on my car at the moment, so I thought I would take some photos of the vents on the inside of the rear wings on my S5.

There is a weighted rubber flap which appears to be designed to prevent air coming into the cabin while allowing it out.

I have attached photos of the vent from the inside of the rear wing on both sides of the car. The flap is present on one side but not on the other. You can see a horizontal slit of daylight in the photo where the flap is not present. Also included a pic of the flap itself, which had fallen off on the passenger side of my 411.


These vents and the operation (and existence) of the flaps will make a difference regarding exhaust gases entering the cabin.

This is Exactly the sort of think I need to learn about!! Thank you so much.
In the last 2 days I have gone from planning to put speakers hidden under the vents to recognising what the vents are for, to now thinking more about whether the vents are working properly! My father in law had a crash in an MG in the 70’s as a result of smoke ingress in the car- so we need to get this right!

All of this is very welcome content, thank you.

[Zorglub]

Not a 411, but for my 410 Series 6, we used round donwpipes to both address the downdraft issue and keep the period look. Round downpipes were used for the 410 and possibly for early 411.

The second photo is the recreation of Sir White’s personal 410 which is claimed to be 100% per factory specs.

[Richardmulcaster]

Originally Posted by Zorglub

Not a 411, but for my 410 Series 6, we used round donwpipes to both address the downdraft issue and keep the period look. Round downpipes were used for the 410 and possibly for early 411.

The second photo is the recreation of Sir White’s personal 410 which is claimed to be 100% per factory specs.

Wow! Don’t they look amazing! I’m seriously admiring the paintwork. Our brief is to get the mechanicals first class and the car driving perfectly , only then we will see how much is left in the pot for a paint job.

Re the exhausts- were the quad pipes original on the 410 or is that a later enhancement?
They certainly look good and the overall look is very in keeping with the 60’s era.
Thankyou for sharing.

[Zorglub]

The original pipes for the 410 (and earlier) were two single pipes. But because of the larger engine on the Series 6, we needed two sets of twin pipes. Here’s a picture of the exhaust - the diameter is such that we needed twin pipes at the end

[GeorgeG]

That is a serious exhaust system!

George

[PEU186F]

In considering everything relating to the V8 cars it is as well to bear in mind Tony Crooks eccentricities which were coupled with a great deal of common sense and remarkable marketing skills. It is my understanding that he decided that a gentleman’s express really shouldn’t leave dirty black marks on the owners trousers if left idling while the boot is filled or emptied and introduced the downward facing exhaust trims on the 410 (or it might have been earlier) to alleviate the problem. Altogether a much easier solution than trying to clean up Chrysler’s dirty engine.

Artistic licence came into play on the 411 when it was decided that four exhaust ports would better look the part (the actual exhaust pipes running back from the engine are actually no larger than those on the 410) and, a touch of genius this, they could also be blanked off at the ends to further prevent anything at all getting on to the trousers whilst preventing wicked small boys from stuffing potatoes down them. Tony Crooks escapades suggest that he was very familiar with small boys minds. The actual discharge slots ahead of the blanking plates are of larger cross section than the main pipes back from the engine, so they hardly affect the discharge which is in any case already seriously handicapped by the crudity of the Chrysler manifold at the front end. On which point I can commend SL-J’s swept tubular manifolds which do markedly improve the breathing, at a price.

I too was impressed by the neatness of the 410s rear end on an occasion when the bumper was off, I thought it reminiscent of an AC Ace.

[Zorglub]

Originally Posted by Richardmulcaster

Wow! Don’t they look amazing! I’m seriously admiring the paintwork. Our brief is to get the mechanicals first class and the car driving perfectly , only then we will see how much is left in the pot for a paint job.

Re the exhausts- were the quad pipes original on the 410 or is that a later enhancement?
They certainly look good and the overall look is very in keeping with the 60’s era.
Thankyou for sharing.

Just in case, these are the 411 exhausts

[Richardmulcaster]

Originally Posted by PEU186F

In considering everything relating to the V8 cars it is as well to bear in mind Tony Crooks eccentricities which were coupled with a great deal of common sense and remarkable marketing skills. It is my understanding that he decided that a gentleman’s express really shouldn’t leave dirty black marks on the owners trousers if left idling while the boot is filled or emptied and introduced the downward facing exhaust trims on the 410 (or it might have been earlier) to alleviate the problem. Altogether a much easier solution than trying to clean up Chrysler’s dirty engine.

Artistic licence came into play on the 411 when it was decided that four exhaust ports would better look the part (the actual exhaust pipes running back from the engine are actually no larger than those on the 410) and, a touch of genius this, they could also be blanked off at the ends to further prevent anything at all getting on to the trousers whilst preventing wicked small boys from stuffing potatoes down them. Tony Crooks escapades suggest that he was very familiar with small boys minds. The actual discharge slots ahead of the blanking plates are of larger cross section than the main pipes back from the engine, so they hardly affect the discharge which is in any case already seriously handicapped by the crudity of the Chrysler manifold at the front end. On which point I can commend SL-J’s swept tubular manifolds which do markedly improve the breathing, at a price.

I too was impressed by the neatness of the 410s rear end on an occasion when the bumper was off, I thought it reminiscent of an AC Ace.

I absolutely love learning these little bits of history that just don’t seem to be officially recorded but give such an insight to the reasons why things are the way they are.
Thank you taking the time to write this.