Exhaust sealant and system identification please

[Ben Freer]

Can someone identify what exhaust system I have on my car? I thought it was a Phoenix system but would like confirmation.

 

As part of the RBRR preparation I thought it would be wise to check underneath so my local garage obliged. The exhaust is clearly blowing at the front joints and the PO has made some interesting adaptations to prevent it rattling through the chassis - although I suspect that this is encouraging leaky joints!

 

It is stainless steel and 4 manifold pipes come down from the engine to a short collector which is held to the manifold with two "fins" which are bolted together (picture ). You can feel that this is blowing but there is no sealant that I can see. Presumably because there has to be some movement somewhere! This collector then joins the pipe back to the first silencer box and on to the second. (I suspect at least some of the system is bespoke).

 

Contemplating 48 hours in a "fume cabinet" isn't appealing and so can you gurus recommend a sealant that is flexible enough to seal the front collector thingy but resilient enough to survive the high temperatures at the front of the system?

 

[Lebro]

Dosn't look like a Phoenix system to me Ben, theirs are welded together up to the large single pipe.

The only exhaust sealant I know of is Firegum, & that dries hard, so may not like any flexing of your "slip on" joints.

Could you perhaps cut some slits in the larger (4 off) pipes, or at least the lower two of them, and then fix with a band clamp, having applied Firegum first.

 

Bob.

[Guest ntc]

That is a slipper joint and should not be sealed.

[Spit_2.5PI]

Hmmm? Normally I advise RTV Silicone sealant and a baked bean can, but this is a bit close to the front. RTV is good for 200'C to 400'C depending on which one you get. You might get away with it until after the Round Britain. Seal over the leak liberally with the RTV then cover snugly with your scrap of bendable metal plate and wire or Jubilee clip in place. Job done! I've kept my exhausts going long past their time with this method and never had a problem at MOT time.

 

Cheers, Richard

[billy l]

It looks like the exhaust is mounted rigidly, in front of the box is a benelli clamp that appears to be clamping the exhaust and bolted to a crossmember, there should be a flexible mounting here otherwise the movement of the engine when going on and off power will surely cause movement in the exhaust joints, this will also give a fairly harsh feel to the car. Cheers, Bill.

[Motorsport Mickey]

Second photo shows the problem with alloy sumps, they stick down too much. Gone to all that trouble with an engine sump guard and then you get undone further down the car.

 

If you have an "off" somewhere or even find a manhole cover protruding high on a road being worked on it's possible you'll hear

BBBbbbbooooiiinnnnkkkk (that's the noise they make) as it hits it, if lucky you get way with a ding in it if not rapid oil loss from the fractured sump. On competition cars I shortened them by the appropriate amount ( about an inch as I remember), it's the gain from the sump strengthening the bottom of the block which is needed, there is still a degree of cooling with a shortened sump.

 

Mick Richards

Edited September 22, 2016 by Motorsport Mickey

[McMuttley]

that exhaust is i suspect a 'chestnut house/gran fabrication' rally type used by TRE and others in the 80's/90's.

 

my variation is 'smoke stacks or Mordor'

 

yus they leak a lot and are loose - esp at the collector bit, the theory being that you are genetally moving at pace - so on the RBRR they may only cause critical rather than fatal poisening

 

i posted many a post of woe about mine

 

the best solution i found was to put them in the lean-to !

Edited September 22, 2016 by McMuttley

[Ben Freer]

Many thanks for your speedy replies! I too have resorted to baked bean cans and jubilee clips in the past Richard!

 

So I should rely on forward speed rather than attempt to seal a joint that is designed to move. (Thanks Neil).

 

McMutt - I have followed your tales of woe but couldn't find the thread(s) when I searched for it! I have to say that I am not aware of fumes but we rarely use the hood and side screens - they aren't exactly a hermetic seal in any case! It was the 48 hours exposure with all weather equipment fitted (including sou'westers and chest waders!) that made me think about it! (- perhaps a CO sensor attached to the dash would be an idea ).

 

The pipe is indeed clamped to the extra(?) cross member. I will explore a more "rubbery" alternative here I think - but space is limited! The rear box is attached using a rubber doughnut type mounting - but of course there is more leeway at that end of the system!

 

Thinking about using the ali sump as a xylophone. Mick - wouldn't just lowering the rear end of my "sump" guard by an inch be an easy fix?

[iain]

Ben....yes that cross member is Interesting! What does it do? Level the road surface for our cash strapped councils :-) or pop the manhole covers back on.....

Good luck with the RBRR.

[Ben Freer]

Ben....yes that cross member is Interesting! What does it do? Level the road surface for our cash strapped councils :-) or pop the manhole covers back on.....

Good luck with the RBRR.

It pops the manhole covers back on - after the "sump"guard has lifted them up and the hidden camera has photographed the drain. Its much in demand by the New Forest District Council! I was considering an integral road planer but they weren't interested!

[Lebro]

Perhaps you should go for the aero screen idea after all, then you won't notice the fumes

 

Bob.

[Ben's wife]

yus they leak a lot and are loose - esp at the collector bit, the theory being that you are genetally moving at pace - so on the RBRR they may only cause critical rather than fatal poisening

 

The problem is, without the new heater being fitted, there will be no telling whether the strange blue colour I will be turning is down to me being flippin' cold or poisoned to death

[stuart]

STP used to do a sort of flexible firegum blue in colour in half length tubes though I dont know if they still do, Large applications of that round the pipes before locating the collector over them would help a bit but you definitely need a bit of flex in the mount at the (interesting) cross member. You could use one of these brackets with a rubber bobbin off the rear of that crossmember http://www.ebay.co.uk/itm/clamp-on-mounting-bracket-roll-bar-axle-tube-exhaust-heavy-duty-1-75-3-/121995217976?hash=item1c677b4c38:g:0sYAAOSwNsdXQwQj

Stuart.

[peejay4A]

That sounds like the stuff that Edd China slathers on when he's fitting exhausts.

[Drewmotty]

Looks like a manifold which Racetorations used to supply wth the bolt up fins.

[Ben Freer]

Looks like a manifold which Racetorations used to supply wth the bolt up fins.

Ah that would make sense

[Ben Freer]

Having just returned from the RBRR Driver's briefing with our ears ringing (despite wearing ear plugs) I think remedying this issue has shot up the "things to do list".

 

Last week I fiddled with the existing system; got one of the fins on the slipper joint collector welded as, surprise, surprise it had snapped! and generally tightened clamps. This of course has improved the rigidity and therefore the resonance which was really quite bearable on for example the run up to Lincoln. The PO has trussed the old boy up in such a rigid corset that whilst there is no knocking of the exhaust system whatsoever the effect is similar to sitting inside a loudspeaker tower at Glastonbury with Deep Purple or Led Zeppelin at full volume!!

 

I am minded to remove the offending cross member completely (its only bolted on to the chassis) and fit a proper hanger. If I do can someone oblige me with a picture of the proper arrangement please?

 

I am tempted first to attempt Stuart's fix with his suggested bracket and bobbin!

 

Hey ho!

[Lebro]

 

The normal points of attachment are right at the back under the rear valence, and at the gearbox mount as shown in this photo using standard cast manifold. I now have a Phoenix manifold, but the gearbox mounting is the same.

 

Bob.

[Ian Vincent]

Ben,

 

The correct bracket spans across the chassis inner members at the handbrake with rubber spacers between the bracket and the chassis.

 

I have one in the garage - if you would like it (no charge) just PM me with your address.

 

Rgds Ian

[Lebro]

Yes, but --- the original bracket is a PITA to fit, & difficult to get the exhaust pipe clear of the cruciform. The later (TR4) type holds the pipe rigidly to the gearbox, so not stressing any joints between the head, & that point, & it is a much better way of locating the pipe, & easier to fit.

Whether Ben can use this on his system is unknown, but my guess is that it is the way to go.

 

Bob.

[Ian Vincent]

I have both Bob, the original one and a U bolt around the end of the Phoenix manifold at the gearbox.

 

Agree that the original probably would be a PITA to fit but I did it when the body was off and I was keen to ensure that the exhaust didn't clatter against the chassis as it went through the bell housing. I was using 2" diameter pipe and it was quite a tight fit even though I did crush the tube slightly oval at that point.

 

Rgds Ian

[Ben Freer]

Ian, Bob, thanks for your responses.

 

I don't think I can use the "official" mounting point as I have a 5-speed Toyota box. This is probably why the PO did what he did! - i.e. installed the additional cross member. However the extra resonance now that things have been tightened up is not acceptable so I am going down Stuart's route in post #13. Needless to say the standard clips won't fit as the pipe requires 21/2" dia clamps...........

 

I will be talking nicely to my local garage tomorrow to see if I can borrow their 4-poster lift again to make life easier!