"Be you devils"?. "Nah,we are but SU"s"
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"Be you devils"?. "Nah,we are but SU"s"
Hi Ken, Grant and Graham
These Su's are some form of witchcraft are they not?
I have spent the entire afternoon fixing idle problem. I now have an XJ6 that idles like a well tuned V8,as apposed to a lumpy 186. Doe's everything the book says it should except idle smooth. As it is a 40 y/o car maybe I'm expecting too much from the idle as it runs sweet right up to 100mp/h
and ran it at 100mp/h for a fair bit (I know the road and use it to test my bikes all the time)
My wife likes the car idea as it is no where near as loud as a bike being tuned in the garage.
Give me 4 x Mikuni 36mm Constant vacuum carbs any time, like a walk in park compared to SU's.
Clarke:
These Su's are some form of witchcraft are they not?
I have spent the entire afternoon fixing idle problem. I now have an XJ6 that idles like a well tuned V8,as apposed to a lumpy 186. Doe's everything the book says it should except idle smooth. As it is a 40 y/o car maybe I'm expecting too much from the idle as it runs sweet right up to 100mp/h
and ran it at 100mp/h for a fair bit (I know the road and use it to test my bikes all the time)
My wife likes the car idea as it is no where near as loud as a bike being tuned in the garage.
Give me 4 x Mikuni 36mm Constant vacuum carbs any time, like a walk in park compared to SU's.
Clarke:
Last edited by o1xjr; 03-05-2014 at 05:46 AM.
#2
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#3
OK,
Doing it now.
Had a run to Pt Pirie today to rescue a 1948 Rover that failed to proceed in a forward motion, and a Pug 504 Diesel snotter that had no flight revs. Just got home.
Setting the HS8's is an aquired art, and more a "feel" and "listen" thing than word perfect from the books. A lot of preparatory things must be done prior to fiddling with any screws.
Doing it now.
Had a run to Pt Pirie today to rescue a 1948 Rover that failed to proceed in a forward motion, and a Pug 504 Diesel snotter that had no flight revs. Just got home.
Setting the HS8's is an aquired art, and more a "feel" and "listen" thing than word perfect from the books. A lot of preparatory things must be done prior to fiddling with any screws.
#4
For one degree worse, my E-Type had triples as did the DB5 I owned for over thirty years. Both a real challenge to set up and to keep in tune.
Graham
#5
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Hi, I have been through points gap,plugs,timing,dwell,cleaned filters etc.
So far on the carbys I have removed the suction chambers,cleaned what I can get at and replaced making sure everything moves freely. Then set choke cables and mixtures, front carb was running way too rich, rear was pretty well spot on(increased in rpm very slightly for a moment). So both are doing the same now,then set idle to 600 rpm.
It is idling a lot smoother than before and seems to run fine while driving,but still running on when shutting it down at running temp. Turning it off in drive doesn't help,the only way to stop it straight away is full choke while turning off the key.
Cheers, Clarke
So far on the carbys I have removed the suction chambers,cleaned what I can get at and replaced making sure everything moves freely. Then set choke cables and mixtures, front carb was running way too rich, rear was pretty well spot on(increased in rpm very slightly for a moment). So both are doing the same now,then set idle to 600 rpm.
It is idling a lot smoother than before and seems to run fine while driving,but still running on when shutting it down at running temp. Turning it off in drive doesn't help,the only way to stop it straight away is full choke while turning off the key.
Cheers, Clarke
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#9
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Found more problems
As it happens, I dropped a small screw driver and it got lodged where I couldn't find it.(ended up being behind starter motor)
Put the XJ6 up on ramps to get under and have a look for it. While I was under there I noticed I have 2 broken front engine mounts and the engine is sitting on the subframe. Also had fuel drip on my head so traced that to split jet tube. Have had a fuel smell under the bonnet since I got it but havn't been able to find any leaks until today. Maybe that is why I am getting 21L/100km. Fuel was dripping on a vacuum pipe then making it's way down the chassis rail under the body so out of sight,near the trans. Replacing pipes later today.
When I lifted the engine slightly with chain block the idle seemed to be a bit smoother as the engine was not resting on the car, I suppose like the rubber engine mounts should do.
Will try to source mounts later today, my local parts shop can get new rubbers for $90 each. Is that reasonable or should I look further?
Update....
I Can get a pair delivered from US for $60. So I ordered them.
Replaced jet pipes, hard to find 3/32 X 3/16 fuel line these days,good old mower shop had it for Victa lawn mowers. 40 cents per inch. cost me $2.40. Plenty around with 3/32 ID but hard to get 3/16 OD, can't go bigger as springs won't fit over pipes. Should be ok without springs but I like to keep it looking original.
Clarke
Put the XJ6 up on ramps to get under and have a look for it. While I was under there I noticed I have 2 broken front engine mounts and the engine is sitting on the subframe. Also had fuel drip on my head so traced that to split jet tube. Have had a fuel smell under the bonnet since I got it but havn't been able to find any leaks until today. Maybe that is why I am getting 21L/100km. Fuel was dripping on a vacuum pipe then making it's way down the chassis rail under the body so out of sight,near the trans. Replacing pipes later today.
When I lifted the engine slightly with chain block the idle seemed to be a bit smoother as the engine was not resting on the car, I suppose like the rubber engine mounts should do.
Will try to source mounts later today, my local parts shop can get new rubbers for $90 each. Is that reasonable or should I look further?
Update....
I Can get a pair delivered from US for $60. So I ordered them.
Replaced jet pipes, hard to find 3/32 X 3/16 fuel line these days,good old mower shop had it for Victa lawn mowers. 40 cents per inch. cost me $2.40. Plenty around with 3/32 ID but hard to get 3/16 OD, can't go bigger as springs won't fit over pipes. Should be ok without springs but I like to keep it looking original.
Clarke
Last edited by o1xjr; 02-17-2014 at 04:33 AM. Reason: update
#10
I have not scanned any drawings from my SU book, as I read that you are fairly familiar with the things anyway.
If something makes little or no sense, let me know, and I will edit the doco.
SU HS8 Tuning and setting up.doc
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#11
As it happens, I dropped a small screw driver and it got lodged where I couldn't find it.(ended up being behind starter motor)
Put the XJ6 up on ramps to get under and have a look for it. While I was under there I noticed I have 2 broken front engine mounts and the engine is sitting on the subframe. Also had fuel drip on my head so traced that to split jet tube. Have had a fuel smell under the bonnet since I got it but havn't been able to find any leaks until today. Maybe that is why I am getting 21L/100km. Fuel was dripping on a vacuum pipe then making it's way down the chassis rail under the body so out of sight,near the trans. Replacing pipes later today.
When I lifted the engine slightly with chain block the idle seemed to be a bit smoother as the engine was not resting on the car, I suppose like the rubber engine mounts should do.
Will try to source mounts later today, my local parts shop can get new rubbers for $90 each. Is that reasonable or should I look further?
Update....
I Can get a pair delivered from US for $60. So I ordered them.
Replaced jet pipes, hard to find 3/32 X 3/16 fuel line these days,good old mower shop had it for Victa lawn mowers. 40 cents per inch. cost me $2.40. Plenty around with 3/32 ID but hard to get 3/16 OD, can't go bigger as springs won't fit over pipes. Should be ok without springs but I like to keep it looking original.
Clarke
Put the XJ6 up on ramps to get under and have a look for it. While I was under there I noticed I have 2 broken front engine mounts and the engine is sitting on the subframe. Also had fuel drip on my head so traced that to split jet tube. Have had a fuel smell under the bonnet since I got it but havn't been able to find any leaks until today. Maybe that is why I am getting 21L/100km. Fuel was dripping on a vacuum pipe then making it's way down the chassis rail under the body so out of sight,near the trans. Replacing pipes later today.
When I lifted the engine slightly with chain block the idle seemed to be a bit smoother as the engine was not resting on the car, I suppose like the rubber engine mounts should do.
Will try to source mounts later today, my local parts shop can get new rubbers for $90 each. Is that reasonable or should I look further?
Update....
I Can get a pair delivered from US for $60. So I ordered them.
Replaced jet pipes, hard to find 3/32 X 3/16 fuel line these days,good old mower shop had it for Victa lawn mowers. 40 cents per inch. cost me $2.40. Plenty around with 3/32 ID but hard to get 3/16 OD, can't go bigger as springs won't fit over pipes. Should be ok without springs but I like to keep it looking original.
Clarke
The engine mounts are definately upsetting the smoothness of the beast. I also ONLY use OE here from JagDaim in Melbourne. I deal with Doug. I tried Kelpro once, NO way.
Just read your update, BUGGA, all done.
#12
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Hi Grant, the doc is good reading and easier to follow than any of the books I have.
Just a couple of questions,
1.choke cable being fully extended I assume you mean pushed all the way in so choke so not working
2. I have no lock nuts on my idle screws, do I need to get some? As screws have no resistance when stops are not against them.
3.One turn of screw I assume would be 360 degrees?
4.I have always used vacuum dial gauges when balancing 4 carbs on bikes, where do I put the other end of pipe, In the air intake when air filter is removed?
Will give these mounts a go, if no good I will go with OEM next time>
I have not changed jets, just put new tubes on for now. Will hold off on tuning until engine mounts are in.
Cheers, Clarke
Just a couple of questions,
1.choke cable being fully extended I assume you mean pushed all the way in so choke so not working
2. I have no lock nuts on my idle screws, do I need to get some? As screws have no resistance when stops are not against them.
3.One turn of screw I assume would be 360 degrees?
4.I have always used vacuum dial gauges when balancing 4 carbs on bikes, where do I put the other end of pipe, In the air intake when air filter is removed?
Will give these mounts a go, if no good I will go with OEM next time>
I have not changed jets, just put new tubes on for now. Will hold off on tuning until engine mounts are in.
Cheers, Clarke
Last edited by o1xjr; 02-17-2014 at 06:00 AM.
#13
Hi Grant, the doc is good reading and easier to follow than any of the books I have.
Just a couple of questions,
1.choke cable being fully extended I assume you mean pushed all the way in so choke so not working
2. I have no lock nuts on my idle screws, do I need to get some? As screws have no resistance when stops are not against them.
3.One turn of screw I assume would be 360 degrees?
4.I have always used vacuum dial gauges when balancing 4 carbs on bikes, where do I put the other end of pipe, In the air intake when air filter is removed?
Will give these mounts a go, if no good I will go with OEM next time>
I have not changed jets, just put new tubes on for now. Will hold off on tuning until engine mounts are in.
Cheers, Clarke
Just a couple of questions,
1.choke cable being fully extended I assume you mean pushed all the way in so choke so not working
2. I have no lock nuts on my idle screws, do I need to get some? As screws have no resistance when stops are not against them.
3.One turn of screw I assume would be 360 degrees?
4.I have always used vacuum dial gauges when balancing 4 carbs on bikes, where do I put the other end of pipe, In the air intake when air filter is removed?
Will give these mounts a go, if no good I will go with OEM next time>
I have not changed jets, just put new tubes on for now. Will hold off on tuning until engine mounts are in.
Cheers, Clarke
Answers:
1) Yes, fully pushed in.
2)Lock nuts are MANDATORY, as the screws will rotate at will without them, and any adjustments made will quickly become useless.
3) Yes
4) Oh yes, one end in the ear, other end in the throat of the carby, just inside the throat lip. You will very quickly "hear" the hiss.
I will amend my wording when I finish this mongrel V12 that wants to cut out at will, and has been "fiddled" with.
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o1xjr (02-17-2014)
#14
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Tuning of Multiple SU Carburettors
Hi Grant, Clarke and Graham;
Here I go off to Sydney to collect the beast and you too have been so busy. Grant, your write-up of the multi SU tuning process is excellent, and it took me a while to work out where to post "Thanks". The steps you have listed are exactly those that we followed and extended to the triples we maintained for over 30 years on our E-Type - and the many others I helped other owners with.
Can I suggest a couple of additions, along with the suggestion that Clarke, you might send my earlier brief comments sent via PM onwards to Grant, because the inclusion of float level and choke settings are (IMHO) quite critical prelim steps. Grant has alluded to this in end comments.
Second, is also drawn from personal experience - don't skimp on the length of the sound tube you insert at the carb throat and ear. Why? So that you can get you and your ears well away from the engine and other carb(s) and concentrate on both the volume and pitch of each "hiss".
For the tubing itself, first find a Nurse (I married one; find yer own) - because the oxygen mask tubing that is discarded after each patient's use, is of soft plastic about 2m long - enough for 2 - share one with a mate.
Add these, together with suitable pics, polish words here and there - any chance of good close-up pics from your car Clarke and PM to Grant? If I sound pushy on this, I guess it's because I see this as as the single most valuable skill any XK engined owner can acquire.
Together, you can develop this writeup into one of the most valuable assets that XK owners will ever access on this forum. And if so, here is where we lean on you as a Mod Graham - sticky, sticky, sticky.
Best wishes chaps,
Ken
Here I go off to Sydney to collect the beast and you too have been so busy. Grant, your write-up of the multi SU tuning process is excellent, and it took me a while to work out where to post "Thanks". The steps you have listed are exactly those that we followed and extended to the triples we maintained for over 30 years on our E-Type - and the many others I helped other owners with.
Can I suggest a couple of additions, along with the suggestion that Clarke, you might send my earlier brief comments sent via PM onwards to Grant, because the inclusion of float level and choke settings are (IMHO) quite critical prelim steps. Grant has alluded to this in end comments.
Second, is also drawn from personal experience - don't skimp on the length of the sound tube you insert at the carb throat and ear. Why? So that you can get you and your ears well away from the engine and other carb(s) and concentrate on both the volume and pitch of each "hiss".
For the tubing itself, first find a Nurse (I married one; find yer own) - because the oxygen mask tubing that is discarded after each patient's use, is of soft plastic about 2m long - enough for 2 - share one with a mate.
Add these, together with suitable pics, polish words here and there - any chance of good close-up pics from your car Clarke and PM to Grant? If I sound pushy on this, I guess it's because I see this as as the single most valuable skill any XK engined owner can acquire.
Together, you can develop this writeup into one of the most valuable assets that XK owners will ever access on this forum. And if so, here is where we lean on you as a Mod Graham - sticky, sticky, sticky.
Best wishes chaps,
Ken
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#16
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Kens text on tuning SU's
Hi All,
Good to hear you have your S type back in its rightful place Ken.
I have a nurse next door, good friend so tube is sorted. I can get some close ups of the SU's on a day off,might be next week. I'm working 7 x 12 hour shifts in a row until Thursday.
Grant, I will add Kens text(word doc) to this post when I work out how. As he suggested you could make that and yours into one doc.
Cheers, Clarke (it is Friday)
Good to hear you have your S type back in its rightful place Ken.
I have a nurse next door, good friend so tube is sorted. I can get some close ups of the SU's on a day off,might be next week. I'm working 7 x 12 hour shifts in a row until Thursday.
Grant, I will add Kens text(word doc) to this post when I work out how. As he suggested you could make that and yours into one doc.
Cheers, Clarke (it is Friday)
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cat_as_trophy (02-21-2014)
#17
OK.
I have rehashed the doco tonight. I will find my "better" SU book sometime over the weekend and scan the pages I want and add to the doco.
Give it a read and see if it makes sense, as I am prone to assuming people know more than I think they do, NO DISRESPECT TO ANYONE'S CAPABILITY.
SU HS8 Tuning and setting up.doc
I have rehashed the doco tonight. I will find my "better" SU book sometime over the weekend and scan the pages I want and add to the doco.
Give it a read and see if it makes sense, as I am prone to assuming people know more than I think they do, NO DISRESPECT TO ANYONE'S CAPABILITY.
SU HS8 Tuning and setting up.doc
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o1xjr (02-22-2014)
#18
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Photos to go with word doc.
Hi Grant, Ken and all others.
Version 2 of your doc is good,seems to have all bases covered going by my previous experience with carby's.
I will post photos of each step of the tune. Once my engine mounts arrive and are installed I will have a serious go at it. I have a 7 day break coming up in a couple of weeks so hopefully it will all come together that week.
Now that I am aware of the engine sitting on the subframe the slight knocking it makes annoys me when sitting at the lights. It was better when I thought it was just another old Jaguar noise I would get used too.
Cheers, Clarke
Version 2 of your doc is good,seems to have all bases covered going by my previous experience with carby's.
I will post photos of each step of the tune. Once my engine mounts arrive and are installed I will have a serious go at it. I have a 7 day break coming up in a couple of weeks so hopefully it will all come together that week.
Now that I am aware of the engine sitting on the subframe the slight knocking it makes annoys me when sitting at the lights. It was better when I thought it was just another old Jaguar noise I would get used too.
Cheers, Clarke
#19
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#20
Yep, the stethoscope will be fine.
If its the style with that COLD disc on the end, then remove the disc thingy, extend the tube/hose so you can be comfortable with the length to do what you must. That stetho will leave both hands free to do ypur work, so a bonus to teh tube in the ear in my opinion.
The only thing missing will be the "black muck" in your ear from the hose, but I reckon you could with that HAHA.
If its the style with that COLD disc on the end, then remove the disc thingy, extend the tube/hose so you can be comfortable with the length to do what you must. That stetho will leave both hands free to do ypur work, so a bonus to teh tube in the ear in my opinion.
The only thing missing will be the "black muck" in your ear from the hose, but I reckon you could with that HAHA.
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o1xjr (02-22-2014)