Page 1 of 1
912 LWB 1969 Replacing Exhaust & Heat Exchangers
Posted: Wed Jul 03, 2019 5:50 pm
by adrianscott
Anyone done this recently who can guide me through it?
Situated in North London N8
Re: 912 LWB 1969 Replacing Exhaust & Heat Exchangers
Posted: Wed Jul 03, 2019 10:00 pm
by Timo
Due to do mine in the coming weeks, should be a pretty straight forward job. Mine is a US spec car, it’s worth noting that Euro spec cars have different exhaust/heat exchangers so someone else may need to chip in if you have one of these.
Having taken a quick look at mine you’ll need to remove the bolts that hold the exhaust to the rear hangar brackets, the nuts which hold the exhaust onto the heads (access looks tight here so you may possibly need to remove some tinware above to gain access) and the clamps which attach the exhaust to the heat exchangers, then you should be able to remove the exhaust.
You’ll then need to remove the heat exchangers, I’d start by disconnecting the heater flexi hoses and removing the heater flap cables which run through conduits welded to the heat exchangers (unless you have dansk heat exchangers already fitted as these don’t come with conduits), you should then be able to remove the 2 nuts which hold each heat exchanger to the heads, heat exchangers can now be removed.
Refit with new gaskets, and hardware, using copper slip on threads is probably advisable.
Hope this helps.
Re: 912 LWB 1969 Replacing Exhaust & Heat Exchangers
Posted: Thu Jul 04, 2019 11:28 am
by adrianscott
Fantastic! My car is a US import.
Thanks for your help. How many gaskets?
2 for exhaust one each for exchanger?
Re: 912 LWB 1969 Replacing Exhaust & Heat Exchangers
Posted: Thu Jul 04, 2019 9:55 pm
by SeanP
Hi
You will need 4 exhaust gaskets and 8 exhaust nuts as a minimum, then there are the exhaust clamps 2No. Copper grease, and plasters.
I have always found that in order to get the new exhaust to fit you need to loosen the j tubes at the rear cylinders, which means new gaskets and nuts.
Save up all the swear words you know as you will be using them. AND a lump hammer and block of wood will be handy,
Check that the exhaust flanges are straight and true with a straight edge.
Hope That Helps
Sean
Re: 912 LWB 1969 Replacing Exhaust & Heat Exchangers
Posted: Fri Jul 05, 2019 9:01 am
by adrianscott
Fantastic Thanks!!
Re: 912 LWB 1969 Replacing Exhaust & Heat Exchangers
Posted: Fri Jul 05, 2019 10:21 pm
by newto912
interesting thread re gaskets here , also another link in this thread
https://www.912bbs.org/forum/threads/ex ... ets.55727/
Re: 912 LWB 1969 Replacing Exhaust & Heat Exchangers
Posted: Wed Jul 10, 2019 10:30 am
by neilbardsley
Going through this pain with my 356 at the moment. Unfortunately those remflex gaskets aren't available here and cost a fortunate to import.
This got me thinking. Many UK 616 specialists have successfully sealed exhausts to engine so it can't be impossible with the gaskets available here. In fact the thin type gaskets where on my 356 when I took off the old muffler (although doubled). A very experienced 356 mechanic put then on and it ran well for quite a while (no sealant either).
I'm having one last go at mine than I'm going to Angus at Greatworth use their leak testing machine and be told what I've gone wrong

Re: 912 LWB 1969 Replacing Exhaust & Heat Exchangers
Posted: Tue Jul 16, 2019 6:38 pm
by brettsul
Guys, if anyone needs heat exchangers for a US car, I have good condition originals, or brand new unused Dansk that I don't need.
Based in London.
Re: 912 LWB 1969 Replacing Exhaust & Heat Exchangers
Posted: Sun Mar 21, 2021 8:37 pm
by adrianscott
Thank you for all your help. Especially Timo!
Taking the exhaust out was straightforward. Put the rear wheels up on ramps. Started at heat exchanger end. Took off the cables then undid the nuts. All steel nuts not copper. Only had one stud come out with frozen nut. Got it off by screwing up another nut to it etc. Replaced the stud with drop of loctite. If I did it again I'd take the engine pan out exposing the top exhaust manifold nuts. If you don't want to do that there are a couple of bits of tinware which come off to expose same nuts. I know I sound happy but will write up part 2 putting it back in. Maybe not so happy!
Re: 912 LWB 1969 Replacing Exhaust & Heat Exchangers
Posted: Mon Mar 22, 2021 9:00 pm
by Timo
Glad to hear you’ve got it sorted Adrian.
Yes getting it off is definitely the easy bit, mine went on and off at least 3 times before I was happy with the fit.
By the way if anyone needs graphite gaskets for this job send me a message, I’ve had a few made up for my car but am considering getting a few more made if there’s enough interest.
Re: 912 LWB 1969 Replacing Exhaust & Heat Exchangers
Posted: Wed Mar 24, 2021 7:47 pm
by Adrian3
you can get the CSP thin composite exhaust gaskets over here....i used them with an ordinary gasket (not sure why!) and has sealed fine.....use the copper-flashed steel nuts if you can, flanged if you can find them/get them on
Re: 912 LWB 1969 Replacing Exhaust & Heat Exchangers
Posted: Thu Mar 25, 2021 5:52 am
by neilbardsley
Although I hope to never have my exhaust off again. Lots like PRS now have them
https://www.prs356.co.uk/porsche-356-pa ... t-all-356/
Sent from my Redmi 7 using Tapatalk
Re: 912 LWB 1969 Replacing Exhaust & Heat Exchangers
Posted: Thu Mar 25, 2021 1:33 pm
by Timo
I think the ones in your link are the standard gaskets Neil, the remflex ones are here
https://www.prs356.co.uk/porsche-356-pa ... r-all-356/
£44 for a set of 4
