Heat Exchanger ,fact rather than opinion...

[bermuda blue]

Some advice please -
I know the heating system is poor, and a lot of people
do without it - some even say you win a few horsepower with them disconnected, others say 'but engine then runs a little hot', so :
What is the full procedure in disconnecting them without impacting
the original design intention of taking heat away from the engine? -and
where do j tubes come into all this (if at all) ,in simple terms please :?

Many Thank's -JIM.

 

[angus]

'J' tubes are so named because of the shape. If you take out the heat exchangers completely, you replace them with J Tubes. They are just the 'exhaust pipe' bit. Or another way to look at it - if you took the outer tinware and the cast fin bits off the heat exchangers, you would be left with the central core of the exhaust pipe - j-tubes! (That last bit may have confused the issue :lol: )

 

[Loxy]

Some advice please -
I know the heating system is poor, and a lot of people
do without it - some even say you win a few horsepower with them disconnected, others say 'but engine then runs a little hot', so :
What is the full procedure in disconnecting them without impacting
the original design intention of taking heat away from the engine? -and
where do j tubes come into all this (if at all) ,in simple terms please :?

Many Thank's -JIM.

The heating being poor is due to either repro heat exchangers, holes in the pipes, improperly adjusted levers, missing lagging or a combination of all.
My heating was excellent before I removed the original heat exchangers to fit a merged header (my engine is wider than stock due to a stroker crank).

 

[AxlFoley]

personaly i cant see any benifits in fitting J tubes, the diameter of the pipe is the same so i cant see any increase in horse power, you create gaps in the timare that the heat exchangers would normaly fill, plus you loose heat, a pointless modification IMHO.

Mark

 

[Tofufi]

Some advice please -
I know the heating system is poor, and a lot of people
do without it - some even say you win a few horsepower with them disconnected, others say 'but engine then runs a little hot', so :
What is the full procedure in disconnecting them without impacting
the original design intention of taking heat away from the engine? -and
where do j tubes come into all this (if at all) ,in simple terms please :?

Many Thank's -JIM.

Right.

Fact - the heater system isn't too bad if well maintained. It is a little weedy on a bus, but not too bad. I can drive my bus on motorway journeys in a T shirt even when it is below freezing outside.

Reproduction heat exchangers give much poorer heat than original ones. I have pictures to back this up, but my internet is very slow at the moment - you'll find them if you do a search on here

You gain NO horsepower by disconnecting the heating section of them, or fitting normal J tubes. If you remove the pipes from the fanshroud, without blocking up the holes in the tinware, your engine will run hotter. If you disconnect the cooling air to them your engine head may run a little hotter as the heat exchangers ALWAYS have air going through them, even when the heating is off.

You will only gain HP by replacing heat exchangers with J tubes if you have a high performance engine which is being restricted by the exhaust flow, and you fit the large diameter J tubes. I know several people running stock heat exchangers on engines around the 2L mark. J tubes are effectively a heat exchanger without the heat exchange section. If you fit them, you need to block up the holes in the tinware and fanshroud to prevent the engine running warm.

Why do you want to get rid of your heat exchangers? If they are not blowing exhaust gases, why not keep them and just not use the heating?

 

[jacks906]

hi

just to hi jack alittle can j tubes be fitted to a standard exhaust set up?

main reson for asking is mine are shot and i have a deisel night heater in there so have heating covered and dont want to spend £160 on new heat exchangers when i aint going use them.

dave

 

[young_dubya]

yup, anyone who sells aftermarket exhausts should sell J-tubes. they are a direct replacement for your heat exchangers.

 

[Tofufi]

hi

just to hi jack alittle can j tubes be fitted to a standard exhaust set up?

main reson for asking is mine are shot and i have a deisel night heater in there so have heating covered and dont want to spend £160 on new heat exchangers when i aint going use them.

dave

Yes, but make sure your fanshroud heating ports are blocked up. I think you are meant to block them with something with a 5p coin sized hole, to give the same backpressure as a stock heating system. Do this, and then either re-fit the engine bay tubes to the exhaust backbox, OR block the lower rear tinware where the heating pipes would go through to avoid hot air going up into the engine bay.

 

[jacks906]

cool cheers time get rid of the quiet pack whoooooooooooo

dave

 

[bermuda blue]

Tofufi - I am not getting rid of heat exchangers, I'm in the process of finding a bus to buy and
just want to know the fact's -as opposed to what seller's tell me :msn4: ..........thank's ..JIM.