alternative gasket between exhaustmanifold and downpipe

[micha]

hi,

does anybody know if the gasket between manifold and downpipe is compatible with something "standard" on the market? i´m searching it for my elite/elat/excel...but i think its also used in the esprit.


i´m also wondering why this gasket on most cars i bought gets always blown after some longer travels? i never had this with any other car.

is there maybe also an alternative to use a differnt material?

thanx for your help,

m.

[teigan]

nothing special about this gasket. in fact you can cut your own. there are some newer materials out there which may handle the expansion and contraction better. not familiar with your vehicle, but that join should not be repeatedly failing. are you running stock pipes?

[micha]

most cars i bought stood around for a long period.

when i picked them up the joint was a bit blowing, but after 100-200miles motorway the gasket was "blown away".

i think the gasket rots away when not in use (e.g. when the cars are stored)...and i unfortunately had the luck always to buy such a car.

the gasket cost about 25,-€ here...half the price would be ok, too....thats why i asked for an alternative.

also to change is a horrible job: ok, easy access, could even be done on the yard using a jack..but most times minimum 2 of the 3 bolts shear off, due to corrosion and than its a job you need more space under the car and a lifting platform.

..and driving around with a blown gasket sounds awfully "kaput"...

[teigan]

some of my other old cars have a ball and socket type gasket contact with springs. pressure is always equalised and the gaskets haven't failed in twenty years. water is usually what breaks down the exhaust pipe gasket prematurely. your car may be making excess condensation.

[micha]

a gasket from a VW fits well: lotus-part ~20,-€ from VW ~5,-€

Edited by micha on Friday 16th February 10:22

[teigan]

cool! thanks for passing that on. i've added it to my parts list. best regards.

[Esprit2]

The problem is caused by the way the rest of the exhaust system is hung aft of the joint. The flexible rubber donut hangers allow it to bounce up and down more than the rigid manifold joint allows. Ultimately it's the joint that fails. Sometimes the stud ears break off the manifold and things get real expensive.

At the least, make sure the rubber donuts are up to snuff. If yours are original, they're certainly no good by now. You may even want to consider doubling up on them to better support the exhaust system and keep any bending and fore-n-aft inertia loads from feeding into that joint.

I fixed mine once and for all by installing a flex joint just behind the manifold joint. They're in common use in front wheel drive cars with transverse engines, and look like a large piece of Aeroquip hose with the steel braided exterior. Most exhaust shops will have generic ones in stock like so much hardware. Take the car to an exhaust shop and have them weld one into the first straight section of pipe as close behind the manifold joint as possible.

The flex coupling will give the pipe a place to move with the rest of the exhaust system without transmitting any loads into the joint.

As for gaskets:
Lotus.... B907E0638Z
FelPro... 25560
Datsun... 68-75 1800cc 610 pickup

The FelPro and Datsun gaskets fit and cost fraction of the price of a Lotus part. However, they don't have the hardened rings/ grommets around the bolt holes and therefore don't last as long.

If you aren't going to fix the rest of the exhaust system, then the Lotus gasket isn't better enough to survive that abuse. As long as you allow the loads from the flopping exhaust feed into the manifold joint, it will blow gaskets frequently. In that case, you may as well buy the cheap gaskets by the dozen and practice until you get good at changing them.

Fix the old rubber hangers to original or better quality and an OEM gasket should give reasonable service, but it won't last forever.

Install the flex joint and an oritinal Lotus gasket and you'll probably never have to re-visit it.

Good luck,
Tim Engel

[micha]

i always have this problem cause i bought cars which havent been used for years. this means the gasket corroded during storage and gets "blown away" after the first few miles after re-using the car. thats what i guess.