Lotus Elan

Low Slung Exhausts

PostPost by: worzel » Thu Apr 29, 2004 8:16 am

Anyone out there worked out a system to make dismantling the exhaust easier on the 2 seaters. The sleeved ends into the "y" pipe seem to weld to each other after some time. I 've modified my own to take two flanges which bolt together just before the Y"section and these work but mean that the bottom of these flanges is now about only 4 inches or so from the ground. Has any one maybe modified along the lines of the original S3Se type cast manifold with its integral flange to take the downpipe?

Regards

John
worzel
Fourth Gear
Fourth Gear
 
Posts: 696
Joined: 13 Jan 2004

PostPost by: rgh0 » Thu Apr 29, 2004 11:44 am

John

I have a flange in the tail pipe just behind where it mounts on the bracket on the gearbox. At this point the pipe is up in the recess in the chassis bottom plate and the extra half inch the bottom of the flange adds to the pipe is not a significant ground clearance problem.

I also have a flange in the vertical secondary pipe after the no 1 and 4 cylinder primary pipes join just before it turns horizontal so these can be removed separately from the no 2 and 3 cylinder primaries, secondary and tail pipe.

With the normal style headers you could fit a double flange at this point and split both pairs of primaries from the tail pipe like in the cast design that Lotus used for a while. I did not do this as I have big bore exhaust headers and run the No1 and 4 pipes in front of the engine mount and No2 and 3 behind the mount .

Put the flanges where you need to get the pipes in and out for your particular exhaust design, this is much better than the original design with the Y piece and 3 sleeve joints and clamps for maintenance. If you continue with the sleeve joints use nickel antisieze on the joints in addition to the normal exhaust joint sealant paste to aid dissassembly and dont overtighten the clamps and bend the two pipes into each other. Nickel antisieze is better than copper antisieze at the exhaust pipe temperatures.

The other improvement for ease of maintenance is to use socket head bolts to secure the exhaust to the head rather than studs. Easier to put in and remove with a long hex key compared to trying to get a spanner on the nuts and once out makes dropping the headers down easier as you dont have the problem of clearing the studs. Ensure you use antisieze of the socket head bolts so they go in and out of the head easily. Be careful not to overtighten or cross thread the botls and strip the threads in the head as putting helicoils in is not easy in the congested space.

Rohan
In God I trust.... All others please bring data
User avatar
rgh0
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 7606
Joined: 22 Sep 2003
Location: Melbourne, Australia

PostPost by: type36lotus » Thu Apr 29, 2004 3:56 pm

Instead of using a male-female slip type joint, use a butt joint with these;

<a href='http://www.borla.com/ac.bandclamps/?cartID=2004042908524766.152.11.62' target='_blank'>http://www.borla.com/ac.bandclamps/?cartID...24766.152.11.62</a>

Theya re Stainless steel, having only a flang along one side they leave nothing hanging down. As the pipes are butt fitted they cannot sieze, rust or corrode to each other.
Mike Geiger
66 S3 Coupe', no more :-(
User avatar
type36lotus
Fourth Gear
Fourth Gear
 
Posts: 577
Joined: 17 Sep 2003
Location: Tampa, Florida, USA

PostPost by: worzel » Tue May 04, 2004 7:58 am

Thanks for your helpful replies. When I next lift the engine I'll definitely alter things along the lines of one of the ideas.

Regards


John
worzel
Fourth Gear
Fourth Gear
 
Posts: 696
Joined: 13 Jan 2004

Total Online:

Users browsing this forum: GLB, miked, Quattro123 and 18 guests