wrapping exhaust primaries

[lowlander]

hi there,

 

The exhaust manifold and primaries obviously give off a lot of heat. Is it worthwhile wrapping them to try reduce the heat in the engine bay?

 

Car is a 1994 1400SS with the short primaries

 

All the best.

 

 

[S47zz]

I did this on my car, the wrapping reduced the heat, though the S/S ex Manifold rusted *eek*through in just over a year

I found out afterwards that S/S doesn't rust provided there's oxygen in the atmosphere, wrapping the primaries excluded the O2 and the manifold rusted very rapidly ❗ ❗

The wrqpping absorbes moisture whilst cold and on starting the engine you get steam, hence the rust 🤔

I was shocked too

[Casbar]

I've had my primaries on my 4:2:1 exhaust wrapped for some 6 years, with no rusting or any adverse effects. There are many lines of thoughts on this subject, do a search and you will see. Dave Walker wrote about this subject in Circuit Driver and said he believed it was a good idea

[Jason Plato]

I've had mine wrapped for 10 years and I havent had any stainless steel rusting. I use cool tec wrap from Peter Lloyd rallying @ 50 % over lap . the cool tec stuff is very good - i've seen some crap wraps

 

This realy does reduce under bonnet temps and now also keeps my feet cooler with the duratec.

 

I havent had any adverse coolant temps, valve regression or anything on the 5 engines I have run.

 

pics are in my links below

 

 

[Jason Plato]

sorry link below

 

here is C7 TOP

Taffia Area Rep

[Tom_C]

Sorry to hijack, but how much wrap should a long primary exhaust need? I don't want to end up with too much, but think it might make the summer more comfortable.

 

 

BTW please give generously to Bundle's Big Charity Walk for Asthma research here Ta.

 

Cheers

 

Tom

 

FH54WLX

 

see here - UPDATED again

[Jason Plato]

I use 15m x 50mm @ 50% overlap. This did 4 primaries 1" from the body exit

 

here is C7 TOP

Taffia Area Rep

[MikeE]

 

Dave where can I get this and what does it cost (and will it work on a tractor version )

 

R400 Duratec Build and Modification Pictures

here

[S47zz]

Dave J

Have 1/2 roll of the P lloyd wrapping if it's any good to you 😬

Another line on this is the SS quality apaently there are several different grade which are used for Ex manifolds.

 

[AMMO]

There is a problem with wrapping the primaries. It puts a lot of heat into the front of the silencer. With a Raceco titanium silencer you can put your hand on the silencer sleeve with the engine running without burning yourself. With wrapped headers the silencer becomes too hot to touch. This can result in more frequent re-packs from the packing material buring out and,in extreme cases, silencer failure. I would not recommend wrapping the headers personally.

 

I have seen some people putting asbestos cloth type material on the footwell. This seems a better solution to me for the reasons stated above. I don't think there are performance gains to be had from wrapping headers apart from lowering the intake temperature under the bonnet if the intake doesn't have a cold air feed. If it was such a great idea they would wrap headers in F1, MotoGP and WSBK, which they don't.

 

The header wrap is great to hide bad welding though 😬

 

AMMO

[Jason Plato]

I guess it depends how close your silencer is to the headers and the end of the wrap ?

 

with my K series silencer I had a lot of length from the headers to the silencer looksee here but on my Duratec I have about 50% less so it will be interesting to see the effect if any on the silencer, althouigh I'm not doubting your evidence from the raceco silencers

 

I agree Ammo that the performance gains are zero, but from a packaging point of view , especialy with the K series having the alternator and starter in such close proximity to the exhaust manifold the temperatures are greatly reduced.

 

On the duratec of course we have all our bits on the cool side of the engine so /i guess a quick duratec install would be better than wrapping your K series primaries 😬

 

 

 

here is C7 TOP

Taffia Area Rep

[Tom_C]

Certainly one thing that concerns me is that there is only 15mm clearance between No1 Primary and the alternator on my Powerspeed set.

 

As I've got a catalytic converter hidden in the front of the silencer it gets hot anyway, but as Dave J said there is a lot of primary/secondary pipework outside the engine bay on a k-series to lose the heat.

 

 

BTW please give generously to Bundle's Big Charity Walk for Asthma research here Ta.

 

Cheers

 

Tom

 

FH54WLX

 

see here - UPDATED again

[alan7]

Another vote for wrapping exhaust primaries. Having fried an alternator on my "K" it makes sense to protect that and the starter motor as much as possible. Last time I had the starter off the big brown wire was showing signs of heat stress so that's been replaced now as well. Hopefully no more fry-ups

 

 

 

How do you get the dead flies off your teeth....... 😬 R5AAH

[Casbar]

Like i said Dave Walker said it was a good idea, therefore that's good enough for me. And as my silencer on my K isn't repackable I have no issues with the packing burning through. The silencer has been on the car for 5 years, loads of track days, and measured 90 db at Castle Combe last week, thats on an R300 engine. So do I need an expensive repackable silencer or a standard Caterham one - let me think about that

[Unclefester]

I have an Elise alternator heatshield from Eliseparts, but it won't fit on a K series Caterham as the engine mount gets in the way. The shield uses two holes which are covered by the lft engine mounyt....but I'm sure it's possible to adapt it.

 

This seems a good way to protect the alternator, and another could be made for the starter motor.

 

They are made of a sort of dimpled alu sheet.

 

Lucy in the Sky with Diamonds..ooooh hooo hooo!!...

😬 😬Abbey Road Time-Machine *eek*