Exhaust silencer box mounting

[bloodknock]

Hello Folks
Below are a series of photographs of my car exhaust box.
The car is an original sprint and when I aquired it in 1972 it was fitted with the silencer box shown. I want to refit it as received.
The Box had a damaged tail pipe so I have had stainless replacements made.
The Box should he hung with the btacket shown and slung on a rubber strap.
Unfortunately, during body work restoration the holes have dissapeared and I need to know where to drill.
Can someone out there give me dimensional references for the drilling. They need to be precicely positioned to ensure that the box doesnt snag the underbody.
Thanks
Bob

[elanfan1]

Hi Bob,

Bit confused by the twin boxes I thought they were an S4 item, your bracket is I believe designed for the vertical bracket on the rear of the single ovalish box

Someone who knows better will be along I'm sure

But the diagram does show the bracket on the twin pipes - weird I'm sure my Sprint had that bracket too.

[bloodknock]

Hi Steve
In my parts box,i had both hanging brackets shown in the diagrams. The larger of the brackets i believe mounts through the body into the boot nearest the diff. The smaller bracket (per the photograph) is the one I think I should be using with the silencer box configuration I want to install. I purchased an oval silencer box some time ago with the intention of fitting it because I thought the previous owner had fitted the wrong type, however Ive been informed that some of the earlier sprints left the factory withthe twin box fitted, so I figured that since i had had the car from early in its life, mine was probably one of those.
As far as the car having the two different mounting points I just dont know, but as I said, both were in my parts box having been stripped off years ago, they must have originally been fitted. Its a Lotus, anything could have happened in production!
Looking at the oval box though, it has attachment points at both ends which would account for the two mounting point brackets, the twin however has only one attachment point at the rear. Maybe the twin has to have some sort of clamp arrangement at the inboard end which then attaches to the bracket nearest the diff.
regards
Bob

[MarkDa]

Hi Bob
It's probably worth trying to get a bracket at the front of the silencers if you can as that will remove any stress on the pipes.
As you say it will need some fabrication to bridge the twin inlet.
Mark

[MarkDa]

Hi Bob
I seem to have lost a post in which I suggested loosely assembling the system, offer it up and mark the bracket holes.
There's also a bracket onto the gearbox near the bend in the main pipe. This uses a circular clip with a small bracket welded on (available from the usual suspects)
Mark

[bloodknock]

Hi Mark
Ive got the bracket that fits on the gearbox, but i'll have either to get a new one, or get the one ive got repaired, ive just noticed a hairline crack in it on one of the gearbox location holes.
The block is in the car but the head is not on and the radiator is not in, I left them off to permit access around the engine bay for fitting all of the other parts. So, I dont have the front system location of the manifold to work with, hence my question about measurements of the location of tge rear exhaust bracket.
I guess i could use the oval box as a reference since it has hanger brackets on each end and i know where the one nearest the diff is, but i would prefer dimensions off an original car.
Thanks for your help
Bob

[MarkDa]

Hi Bob
I see your dilemma.
The gearbox bracket is available and probably cheaper than the modified mikalor clamp that hangs on it!
I used a standard jubilee clip and a small angle bracket as I'm a cheapskate!
The rear bracket fixes so that the hanger hole is central in the tunnel and on my car with a single box the rearmost bolt is c40mm from the rear of the tunnel, given the curved rear it's difficult to be precise.
I still reckon that waiting until you can trial fit is the best option to get it right first time, particularly if you want to support the front of the silencers.
Mark

[Grizzly]

I would assemble the exhaust, fit the two other hangers then mark/drill the rear most one directly over the bracket on the back box (so it's not stressed).

I have a mikalor clamp that i converted into a hanger spare, if you want it PM me your address.

BTW, Early Kit Elan Sprints had twin tail pipe exhausts (mine did too along time ago before it rotted and was replaced), does/did yours have Silver wheels, ignition key on dash etc?

[RichardHawkins]

Bob,

You might be able to see where your original holes were if you shine a bright light from one side of the boot floor and look at the floor from the other side.

Richard Hawkins

[bloodknock]

Gentlemen
All of this advice and comment is most welcome, thankyou.
My car does have the infamous "lip", not obvious in the photos, it has black wheels and the ignition key is on the column.
I still think that the twin box was original, when I took the car off the road, the tail pipes were corroded and one damaged at the end. The boxes were in good condition so I decided to restore them with new tail pipes.
I think the consensus is to wait till I can trial fit the system, which means head on and manifold (headers) in place, so a while to go yet. I was just trying to usefully use time between major tasks like fitting the dash, and retrimming.
Thanks again
Bob

[Grizzly]

Gentlemen
All of this advice and comment is most welcome, thankyou.
My car does have the infamous "lip", not obvious in the photos, it has black wheels and the ignition key is on the column.
I still think that the twin box was original, when I took the car off the road, the tail pipes were corroded and one damaged at the end.

If thats the case, it may have been fitted due to some one preferring the look/sound but it's unlikely the car would have been assembled with it, even the very early cars/kits had it phased out quite quickly.

Even those cars that had them i suspect will have gone by now, they are associated with being an S4 and people frown upon converted S4's even when they were factory built.

[bloodknock]

Big enough seam for ya?
The car was around one year old when I bought it back in '72, the original owner was the spouse of the Northampton lotus main agent. I dont think that she would have had the back box changed.