Emission control - removal

Talk about the E-Type Series 3

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Curtis Bay
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#1 Emission control - removal

Post by Curtis Bay » Fri Feb 01, 2019 11:07 am

I have just taken the plunge and bought a V12 DHC. It is a1974 US car with auto box and full emission control system on it including EGR. The car has sat in storage for 33 year and has a genuine 38K on the clock. Virtually every hose on the engine has perished so I have some work ahead of me.

My plan in the longer term is to do a full rebuild with substantial engine modifications but for now I just want to get it running for the summer.

I have scoured the forums in a bid to understand the ignition and fueling and how to untangle the emission control system and have distilled the collective wisdom to the following set of modifications. Can anyone confirm if this is a sensible approach and make any other recommendation please.

1. Remove air pump and air delivery system and plug the holes in the exhaust ports
2. Remove the EGR pipes and plug the holes in the exhaust manifolds and the four carbs
3. Remove the gulp valve and pipe work - plug up the holes in the inlet manifold
4. Disconnect the throttle bypass valves and plug the ports to avoid leaking
5. Adjust the Temperature Compensators to be fully closed all the time
6. Disconnect everything from the thermostatic vacuum switch and plug all the respective holes
7. Remove the vacuum solenoid valve (auto cars only) and plug up any holes
8. Install a vacuum advance unit in place of vacuum retard and use one of the disabled EGR ports as the source of a ported vacuum to operate this - plug up old vacuum source for retard unit
9. Adjust the timing to suit the new advance unit

As I said, this is just a short term plan to get the car back on the road and so I don't have to worry about the condition of hoses , valves and other potentially non functioning bits.
1965 Series 1 4.2 FHC - Opalescent silver blue metallic with grey interior
1974 Series 3 5.3 Auto DHC - Sable with biscuit interior - something which has to change!

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JJC
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#2 Re: Emission control - removal

Post by JJC » Fri Feb 01, 2019 12:43 pm

Curtis: Looks like you have a complete list, I did all that 42 years ago on my 73, and has run perfect ever since. Your on the right track. Don't forget to give some thought on getting rid of those oversize ugly black bumpers. Covered here on this forum. Good luck !

JC

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Curtis Bay
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#3 Re: Emission control - removal

Post by Curtis Bay » Fri Feb 01, 2019 2:02 pm

Hello JC

Thanks for confirming I am on the right path. I will dispense with the rubber bumpers and marker lights when the body gets stripped and rebuilt in the coming years. At present the rubber overrides may prove handy in the snow we have at present!

Does anyone else have any suggestions or recommendations?
1965 Series 1 4.2 FHC - Opalescent silver blue metallic with grey interior
1974 Series 3 5.3 Auto DHC - Sable with biscuit interior - something which has to change!

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Whitact
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#4 Re: Emission control - removal

Post by Whitact » Sat Feb 02, 2019 6:05 pm

FWIW this is what I have experienced.
MY FHC is a 1972 UK car so never had air injection or gulp valve but was converted by a PO to SU carbs. That conversion included disconnection of most of the vacuum driven equipment. More recently I fitted a vacuum advance unit from British Vacuum and connected it to the throttle port vacuum tapping that is included in the SU. That definitely improved mid range pick up but delayed warm up by quite a bit..
My OTS is a late (1974) UK car and so came fitted with all the US spec kit including air pump, manifold air injectors and gulp valve etc. I have fitted a new air pump, rebuilt the Strombergs and replaced vacuum hoses as required, so its pretty much as Jaguar intended.
The OTS is a much nicer car to drive, it starts much more readily, it warms up more quickly and is much less inclined to spit and pop on the over-run than the FHC. All in all a much smoother and more civilised experience.
Both cars were automatics but now have 5 speed boxes with a .63 top and the 3.07 diff. Both will do 22 mpg on a long run and about 15 mpg when more urgency is required.
One thing you don't mention, but I would definitely recommend is an electronic ignition upgrade. The original OPUS units eventually fail and may leave you stranded. I have the SNG conversion on mine and they have both been just fine.
Each to their own of course but I would suggest that you first get what you have working as Jaguar intended, all the info you need is on this forum and knowledge base. You could then see how you like it before you begin to make modifications.
Cheers
Adrian Turner
S3 OTS & FHC
S1 FHC
XK140 FHC

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JJC
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#5 Re: Emission control - removal

Post by JJC » Sat Feb 02, 2019 9:03 pm

Adrian mentions some important points. I also have the SNG ignition....never a problem, and they are there for advice, and replacement parts. I also changed to a 5 speed box (was a 4 speed) from the Driven Man, in Tenn.,USA. Transforms the cars. Adrian's mileage numbers about the same as mine. Best of luck !

JC

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PeterCrespin
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#6 Re: Emission control - removal

Post by PeterCrespin » Sun Feb 03, 2019 8:44 am

Curtis Bay wrote:
Fri Feb 01, 2019 11:07 am
Can anyone confirm if this is a sensible approach and make any other recommendation please?

..this is just a short term plan to get the car back on the road and so I don't have to worry about the condition of hoses , valves and other potentially non functioning bits.
You should replace as many hoses as you can and flush the engine/cooling system after 33 years storage IMO. You could easily have one fail in the short term. Same goes for forty year old belts, although you’ll probably get away with it. At least carry an emergency belt of the universal type so you can get home no matter which one breaks. Tires are obviously useless apart from pottering around - if that.

Enjoy your car. My S3 OTS was the only E I didn’t mind being auto. 6.3 sec to sixty is perfectly respectable, even today.
Pete
1E75339 UberLynx D-Type; 1R27190 70 FHC; 1E78478; 2001 Vanden Plas

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Curtis Bay
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#7 Re: Emission control - removal

Post by Curtis Bay » Sun Feb 03, 2019 9:16 am

Thanks for the suggestions.

The tyres, drive belts and hoses are all completely gone. The auto fluid made an appearance on the workshop floor because the hose to the transmission cooler had cracked and the power steering hoses are in a similar shape. New tyres are on their way and the vacuum hoses and fuel lines will all need replacing.

The ignition seems to be working OK at the moment so I plan to make it last for the summer. My longer term plans are to replace the low compression pistons with high compression alteratives but I need to decide on the size yet. Ultimately I would like to install fuel injection and will review the ignition once I have a clearer plan. The low mileage on the engine means there is no rush to do anything because fundamentally it is sound but I just want to tidy up the engine bay, replace the tired hoses and remove the redundant emission parts. If I can squeeze a bit more performance out for very little outlay then I am happy to play.....it’s the best way to become aquatinted with the V12 which is very different to the XK engine in my Series 1.

With the gulp valve removed I expect to get some popping in the exhaust on overrun - does the move to a vacuum advance on the distributor help mitigate this since I assume the combustion in the cylinder is more complete due to the lack of retardation and I think the exhaust should be cooler. I am impressed by how smooth the V12 is and it would be a shame to introduce a boy racer feature this early in my tenure.
1965 Series 1 4.2 FHC - Opalescent silver blue metallic with grey interior
1974 Series 3 5.3 Auto DHC - Sable with biscuit interior - something which has to change!

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Whitact
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#8 Re: Emission control - removal

Post by Whitact » Sun Feb 03, 2019 10:40 am

When I put the vacuum advance module on my FHC I did not notice any reduction in the crackle on the over run. The OPUS units seem to fail with age as much as mileage. Failure can be partial such as a miss at higher rpm almost like fuel starvation, misfire when hot when hot that recovers when cool or sudden and total. IMHO the unit needs to be considered as an age related component just like tyres or hoses.
Cheers
Adrian Turner
S3 OTS & FHC
S1 FHC
XK140 FHC

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Curtis Bay
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#9 Re: Emission control - removal

Post by Curtis Bay » Sun Feb 03, 2019 10:45 am

Thanks Adrian.

I will keep an eye on the ignition. I just want to avoid replacing stuff which may be replaced again in a year or so when I go to EFI. I haven’t had the chance to run the car properly yet so it may exhibit the symptoms you describe in which case the ignition will be replaced through necessity.
1965 Series 1 4.2 FHC - Opalescent silver blue metallic with grey interior
1974 Series 3 5.3 Auto DHC - Sable with biscuit interior - something which has to change!

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Nigel_Sutherland
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#10 Re: Emission control - removal

Post by Nigel_Sutherland » Fri Jun 12, 2020 12:12 am

Thank you for the pointers. I have recently bought a 73 OTS and am planning to remove the US emissions stuff. Have already modified the front bumpers and have the SNG electronic ignition on hand to be fitted. Currently working on gearbox oil leaks.
Am interested in what additional bits will be needed to complete the emissions removal.
Nigel

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lowact
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#11 Re: Emission control - removal

Post by lowact » Sun Jun 14, 2020 2:02 pm

Curtis Bay wrote:
Fri Feb 01, 2019 2:02 pm
Does anyone else have any suggestions or recommendations?
I’m interpreting Curtis that you’re on the same trajectory as me, US car, drive it around for a while (Stage I) while planning significant upgrades (Stage 2). I’m deep into Stage 2. With the state of your car as described (hoses) you might find it more efficient to mod the emissions as part of other repairs, instead of a standalone objective.

Stage 1, to repair performance, get a vacuum gauge and chase down every vacuum leak until you get a nice steady 18-20 mmHg at idle; this is the objective most likely cause you to remove emission gear.

An addition to your list, locate your PCV valve (C37929), i.e. ensure that you have one (instead of an unrestricted vacuum leak via the charcoal canister).

Air pump, I first repaired it and then removed it, made no discernable difference either way. Pipe from the pump to the rails cannot be removed with engine in situ. To block the air injection holes I used FKM o-rings on short 5 mm dia countersunk head screws, push into the holes before bolting the retainers back over.

EGR – my car didn’t have this.

Carb temperature compensator valves, and bypass valves, I suggest if not broke don’t touch, look elsewhere for the cause of whatever you think is the problem. Wisdom in hindsight … Perforated bypass valve diaphragms a suspected cause of carb balancing issues. Repaired these, couldn’t adjust the spring tension evenly or enough to prevent a valve opening at idle, causing further carb balancing issues. Blanking bypass valves off completely made carb balancing easy, but for some reason fuel economy suffered.

Gulp valve, diaphragm was perished creating vacuum leak. Removing both it and the carb bypass valves, back-fires sometimes quite tremendous, i.e. more than a pop … Reinstated the gulp valve, repaired by making a new diaphragm using an old rubber coated fabric glove …

Ignition advance and retard, in theory these are not alternatives, i.e. modern cars have both. Retard is only when the engine is cold and idling, advance is only when the car is hot and driving. E-type ignition retard by vacuum uses the thermostatic valve to disable retard when the engine is warm. My thermostatic valve was stuffed. I upgraded to vacuum advance, fun and free ‘cos I already had HE V12 ignition components. I got slightly better fuel economy, no performance benefit. Superseded by Stage 2.

Vacuum source from the disabled EGR port, exactly where is that?
Regards,
ColinL
'72 OTS manual V12

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rossco_j
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#12 Re: Emission control - removal

Post by rossco_j » Mon Jun 15, 2020 12:41 am

Pipe from the pump to the rails cannot be removed with engine in situ.
Very true Colin. With a little help from a small pipe cutter it can be removed if you are not bothered about keeping the pipe in one piece.

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Ross
1972 Series 3 E Type 2+2
1972 MGB GT
1965 Mini Cooper
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