Heat exchanger for J tubes

Discussion in 'Mech Tech' started by andrewjones29, Jul 8, 2019.

  1. Hi all, I’m new to the forum been working my way through the jobs on my ‘74 westy for the last 18 months in between camping trips. Today I changed the stock heat exchangers for J tubes mainly because the ‘heat’ wasn’t very hot and also it was rather smelly. We only really use the van in warmer months too so will have little need for heating. All that said what do I do with the corrugated air pipes coming from the fan housing now they have nowhere to connect to underneath the van? Thanks in advance.

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  2. Make a bong .!,,
    Cov1987 likes this.
  3. As appealing as that is having spent the weekend before last in Amsterdam (great city by the way) I mean, do I need to direct the pipes toward a certain area of the engine or simply remove them completely.

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  4. They are only for blowing air through the exchangers .to the heating ducts . Mechanically they are not important .but the ducts from the fan housing that goes to the exchangers . Do cool the engine a bit . ... don’t loose sleep over it though if it’s a holiday bus and not a daily...especially in the uk.. bit your temperature will go up. !Get a temp gauge... NOW, you can make a bong ... or sell them here . Someone’s bound to buy them
    Last edited: Jul 8, 2019
  5. Day

    Day Sponsor

    Are the heat exchangers very heavy?
    snotty likes this.
  6. In comparison to the j tubes yes.

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    Day likes this.
  7. In comparison to the bus, no.:)
  8. More importantly if you pulled the heat exchangers you now need to fit industrial style engine tinware to keep the airflow over the cylinder heads like stock. You have removed a side wall of the cooling duct.

    Easiest would have been to leave the heat exchangers in place and remove the concertina tubes.

    As now you will get a strange roaring from the dash hot air vents ... from the open pipes at the back facing the engine.

    Normal practice is to find something to block the vents on the fan housing.
  9. Are these something I can get off the shelf or do they need making?

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  10. Next Job is to remove the redundant pipe work under the bus.

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  11. If it was smelly you are fixing a symptom not the cause. Oil leaks or petrol leaks cause smells far more than exhaust leaks from heat exchangers.

    Dont remove the pipework. Block it off at the back and the next owner of your bus will thank you for not throwing it away.

    You may even want it in the future when you work out that it is actually just useful.. even for an Eberpacher/ Webasto/ China Special heater.
    Last edited: Jul 9, 2019
  12. Did fix the oil leak at the same time, well one or two of them. Take your point over the pipe work don’t know what the future brings and it’s doing no harm.


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    Day likes this.
  13. I’ve ordered the bungs for the fan housing and also an oil temp gauge and sender. I’ll do a run before I fit the plugs and see what temp I get and then after they are fitted. Will look into making some of the “sled” tins on your link and do the same comparison.

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  14. Temp sensor fitted and gauge nearly fitted. Didn’t have the correct sized hole cutter to make something to mount it in. Haven’t been for a run in it yet but have got the plugs ready to go and picked up some sheet metal to make the additional side of the spent air outlets. Will change the connectors on the dipstick for insulated ones don’t like them being exposed when I’m going to be moving it that often. Point on the kit from just Kampers, the wire supplied wasn’t long enough to reach the cab. Possibly the way I routed it but it meant an annoying trip to Halfords to get more.


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    Day likes this.
  15. Did a run tonight after finishing the dash mount, read just under 100C after 30 mins of mixed motorway and town driving. Had a shocker with the plugs,ordered the wrong ones then ordered the correct ones and got sent the ones I already had should have the correct ones tomorrow so will fit and go on another run.


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  16. what temp is good and bad ?
  17. Oil temperature.jpg
  18. Buttys bits sell the industrial tins https://www.buttysbits.com/product/...-upright-fan-housing-engines-running-j-tubes/

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