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Breather to carb from inlet manifold


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Rich

I may have the air into the manifold thing wrong! The pipe puts a vacuum on to the carbon canister which in turn puts a vacuum on the carburettor float chambers, this draws the fuel away from the jet starving the engine of fuel and  prevents run on. All this happens when you turn off but still have oil pressure 

You should have pipes from the float chamber vents to the carbon canister 

 

George 

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And if you dont have a carbon canister where is all of that other black hose going ?. 71 and 72 cars all had the carbon canister originally but the anti run on valve did not appear until 1973 on the US cars so I'm also curious to know where the other end of the hose connected to the banjo goes.

 

Stan

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Hi there

 

This pipe goes to the underneath of the front carb'.   The other black pipes are breather from the rocker to the carbs, so like a T junction system.  So looking at this PDF it seems there is a tube from the intake manifold to point 14 under the front carb.  There is also a vacuum retard from the front carb which I plan to remove on advice from the distributor doctor who I plan to send my dizzy to for a re-furb.

So shall I plug the manifold and this part at point 14?

Rich

plumbing carbs.jpg

Edited by AarhusTr6
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Hi Rich

The set up shown in your photo is identical to my 73 CF car which made me think you had the anti overrun valve I think from your description it would be best to plug the connection.  The solid pipes 6 and 8 are to the bypass gadgets I believe these run from manifold vacume (I have the later type which are slightly different and I have disabled them by making solid gaskets I also disabled the Temperature compensator things by putting plastic plugs in the vents that feed them )

The vacume retard is fed from the underside of the carbs where the vacuum is high at tick over, the vacuum advance should be fed from the connection on the top of the carb if you get them round the wrong way it wont run as well.

This is a good article on Strombergs http://www.buckeyetriumphs.org/technical/Carbs/CarbsI/CarbsI.htm

Also this http://bullfire.net/TR6/TR6-20/TR6-20.html the author of which is often on the forum

George

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Hi George

So based on what you say, I have a vacuum advance tube from the top going to a vacuum retard on the dizzy.  Well the Distributor Doctor suggested getting rid of that when I send my dizzy to him, so I will plug that one anyway.

So if you look at my two carb pics, the points 7 & 9 seem to therefore go to the rocker cover.

May I ask for a picture of your setup please?  Also where did you get the plugs from?  I cant seem to find them.

Rich 

IMG_2549.JPG

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I spent a long time figuring this lot out when we wrote the catalogues - My USA comrades agreed the layouts were correct for the years specified as they had cars to look at unlike us in PI land - Does it help you?

https://mossmotors.com/triumph-tr6-250/fuel-intake-emissions

https://mossmotors.com/triumph-tr6-250/fuel-intake-emissions/emission-control-vacuum-system

https://mossmotors.com/triumph-tr6-250/fuel-intake-emissions/emission-control-carburetor-breather-system

Cheers

Peter W

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Rich

My distributor has a vacuum advance but my carbs only have the port on the underside so I have plugged the port, I used a short length of pipe sealed at on end with a hot glue gun, works a treat!

The setup that you have to the rocker box is more or less what I have except I have an extra tee for the line to the carbon canister. My car is sort of standard 73 setup except for the disabled bypass and temperature compensator gadgets plus the distributor vacuum retard being disabled. 

To plug the port on the manifold fitting I would be inclined to fill it with solder,  the vents to the temperature compensator  I plugged using the plastic things that came with some reconditioned brake parts.

I am having a struggle adding a photo (my samsung is a bit temperamental and needs replacing) so I will send you a pm with my email address if you reply I can send the photos 

 

George

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On 9/30/2018 at 11:06 AM, AarhusTr6 said:

Hi George

So based on what you say, I have a vacuum advance tube from the top going to a vacuum retard on the dizzy.  Well the Distributor Doctor suggested getting rid of that when I send my dizzy to him, so I will plug that one anyway.

 

For a Road Car you probably want to retain the vacuum advance on the dissy, with a pipe to the top of the rear carb, I think in your first post I can just see the edge of that port.  Vacuum retard isn't going to buy you anything if all the US emission stuff has been removed, apart from confuse you when setting up the timing as people won't know if you should be seeing 10 BTDC or 4 ATDC.  NB I don't consider the Temperature Compensators an emission device, set up properly and maintained they actually serve a useful purpose.

I do notice from your pictures that you have the domes of your Strombergs fitted 90deg out! there is a small lug on the side of the dome and body that should be aligned. When Stromberg built the carbs it was done on purpose,  correct orientation can have a significant effect on the alignment/movement of the air pistons, this is very apparent if you get the opportunity to work with NOS CD carbs, but gets less obvious if they have been assembled from SH parts bins whilst being refurbished, or some twat has sent them off for Polished Exchanged Domes, or failed to mark and keep the Domes, Air Pistons and Bodies as matched sets. Some people will claim it makes no difference, but they have probably been playing with shagged sets for so long that they wouldn't notice the difference ;)  However sometimes if all the bits are original but just jumbled up front to back because someone didn't realise it was important, if the two carbs are displaying different lift and drop characteristics careful swapping of the parts around with the domes in the correct orientation can sometimes hit lucky and  restore a lot of the balance.  

Alan 

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5 hours ago, oldtuckunder said:

For a Road Car you probably want to retain the vacuum advance on the dissy, with a pipe to the top of the rear carb, I think in your first post I can just see the edge of that port.  Vacuum retard isn't going to buy you anything if all the US emission stuff has been removed, apart from confuse you when setting up the timing as people won't know if you should be seeing 10 BTDC or 4 ATDC.  NB I don't consider the Temperature Compensators an emission device, set up properly and maintained they actually serve a useful purpose.

I do notice from your pictures that you have the domes of your Strombergs fitted 90deg out! there is a small lug on the side of the dome and body that should be aligned. When Stromberg built the carbs it was done on purpose,  correct orientation can have a significant effect on the alignment/movement of the air pistons, this is very apparent if you get the opportunity to work with NOS CD carbs, but gets less obvious if they have been assembled from SH parts bins whilst being refurbished, or some twat has sent them off for Polished Exchanged Domes, or failed to mark and keep the Domes, Air Pistons and Bodies as matched sets. Some people will claim it makes no difference, but they have probably been playing with shagged sets for so long that they wouldn't notice the difference ;)  However sometimes if all the bits are original but just jumbled up front to back because someone didn't realise it was important, if the two carbs are displaying different lift and drop characteristics careful swapping of the parts around with the domes in the correct orientation can sometimes hit lucky and  restore a lot of the balance.  

Alan 

Hi Allan - thanks so much!

I think some prev owner likely put htem back wrong or maybe the last guy who I asked to service them did, guess its an easy mistake, but I have many pictures so will check.  So should I rotate them 90deg clockwise or anticlockwise?  Or should I stop being lazy and go look for this lug.

Thanks again

rich

 

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Allan, ignore above question, bimbo moment!  So it seems lug should face the air intake looking at some other pictures of other Tr6's. 

Rich

 

Edited by AarhusTr6
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