Advice please!

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Pinger
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Re: Advice please!

#261 Post by Pinger » Sun Sep 13, 2020 12:32 pm

LPGC wrote:
Sat Sep 12, 2020 9:56 pm
Of course there are 'splitters' - simple T and Y connectors.
Good to hear. If I go the two reducers route, I've a fair amount of plumbing to do.
LPGC wrote:
Sat Sep 12, 2020 9:56 pm
The idea behind installing the reducer facing sideways is so the diaphragm movement which should correspond to signal isn't affected by forward/backward acceleration/deceleration of the vehicle, so it doesn't matter which way (forward or backward) the adjustment screws face. Cornering forces are much lower than acceleration / deceleration forces... If you wanted both a bit of idle bypass and a bit more flow for a given signal then instead of dialling in a bit of idle bypass using the adjustment screw you could try fitting the reducer with it's outlet pointing face down so gravity would constantly pull down on the diaphragm a bit. I've never done this as part of a permanent install but I have experimented and seen richer mixtures, though mostly affected low load operation.
Never occurred to me that it could be manipulated in that way - a bumpy road could make life interesting!
It did cross my mind that the diaphragm could be manipulated by varying the pressure it sees on its reverse (control/reference) side eg, connect to manifold vacuum. That thought occurred as it would reduce my richness at idle. But when manifold pressure starts to drop at high rpm the mixture would be leaning off again. With a less restrictive mixer though... Possibly too course a manipulation?
LPGC wrote:
Sat Sep 12, 2020 9:56 pm
Length of hoses on this type of setup doesn't make a lot of difference under constant conditions but can slow response for changing conditions.
It's the transients that concern me. Points to mounting both reducers (if I go that route) together. Simplifies the rest of the plumbing too - at the cost of relocating the battery (not that big a deal as the truck had a dual battery option so has space spare in the opposite side corner).
LPGC wrote:
Sat Sep 12, 2020 9:56 pm
As soon as the TPS box that's highlighted moves to a new box the stepper moves very quickly to the default.
This appears to be my salvation at the moment.
LPGC wrote:
Sat Sep 12, 2020 9:56 pm
Yes I have used both outlets from an R90 reducer, I expect the same as TT in that you'll get a bit more flow from the reducer using both outlets, not double the flow but a bit more. At least in part for the same reason we'd expect the usual 19mm pipe to flow more than if you used 12mm or narrower pipe (narrower pipe is often used on small engines between reducer and mixer, albeit using a 19mm>12mm adaptor if using an R90 or similar spec vaporiser). But with more volume in pipes you get slower response.
I'm going to try this before I do anything else.
My current thoughts on response are that it is good enough (and must remain so) to avoid back fires but as such transients are brief compared to maybe 10-15 seconds of WOT for overtaking, WOT must be rich enough.
My suspicion is that I'm going to have to resort to dual reducers. Two working with less bias (I am almost certainly having gas at pressure exiting the reducer) would alleviate the rich at idle and provide enough gas to properly exploit the new mixer. Dual outlets from the single reducer first though.

Pinger
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Re: Advice please!

#262 Post by Pinger » Thu Sep 17, 2020 4:56 pm

Some progress today.
Hooked up both reducer outlets and there seems to be an improvement. I haven't driven it yet (traffic was about to hit peak) but just with lap top hooked up it seems to be getting more gas.
On start up, default was 157 from last drive. Without any adjustments, default is now 115, idle is 90-100 and out of idle (3k rpm no load) is 110. More tomorrow.

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Re: Advice please!

#263 Post by Pinger » Fri Sep 18, 2020 4:06 pm

More experimenting and driving today and my conclusion is while it drives fine as it is up to 3/4 throttle and 4000 rpm, more throttle causes it do go chronically (surging) lean.
I tried it with 3 of the 11 air holes in the mixer blocked and again with 4 unblocked. The actuator setting at idle didn't move but for out of idle at 3000 rpm (no load) it rose from 118 to 130-137.
Given it's lean at higher loads/rpm then no point in opening more air holes until it gets more gas so plan is to use 2 reducers in parallel.

My current liquid pipes are 6mm OD. Does this connector here >> https://www.lpgshop.co.uk/copper-pipe-t ... -o6-6-6mm/ allow me to split the supply into 2? Assuming it does, can it be mounted anywhere eg, close to the reducers or is it better up on the bulkhead? Is copper mandatory for this additional line? Incidentally, is 6mm big enough for my engine? I've noticed 8mm pipe. What's that for if not the biggest engines? Is it possible I'm starving the reducer on the liquid side? The reducer doesn't look like it would accept larger (it has a screwed in fitting). Or is 8mm pipe for the filling side?
Is 'microbore' copper pipe as used in domestic heating systems the same pipe?

Does the 'rotational' orientation of the reducer matter? Ie, can it be mounted with the adjustment screws pointing upwards (rather than fore or aft as they usually seem to)?

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Re: Advice please!

#264 Post by LPGC » Fri Sep 18, 2020 4:44 pm

On your vehicle (5.7V8) I would have run 8mm line from the tank to the engine bay, not 6mm. The narrower pipe (in relation to size/power of the engine) could be a problem, though usually narrower pipe isn't so much of a problem on a mixer setup as it is on an injection setup. 8mm Pipe will flow more than 6mm pipe (so is better for bigger engines) even if other fittings (tank outlet, solenoids, reducer inlets, etc) are 6mm.

If your lines are copper you've linked to a compatible T (splitter). If your install has poly pipe under the car you could use a poly T instead of a copper pipe T, this could save having to use 3 x poly end fittings and keep the install tidier than using a copper T and 3 end fittings.

Regardless of what type is under the car you could use copper or polypipe in the engine bay.

Better to keep pipe lengths from the T to the reducers short and fairly equal length.. When you've run out of gas and refilled the tank the lines may at first contain a vapour lock. If you've got 2 reducers the one that flows the most gas to the engine and/or has the shortest feed pipe to the T might have it's gas feed bleed up quicker than the other.

There usually isn't much need to worry about rotational orientation but it shouldn't make any difference. Good to have the gas outlet near the bottom to help keep the unit free of heavy ends.
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Pinger
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Re: Advice please!

#265 Post by Pinger » Sat Sep 19, 2020 5:34 pm

Thanks LPGC.
Going to give some thought to pipe sizes (eg, if I can fit 8mm to my MV at the tank and run it to the engine bay and split it to two 6mm pipes) and start sourcing parts for (re)installing old reducer. Need to check filter as it is plumbed with 6mm. Think I've spotted a space for the reducer below existing one (hence orientation question as it will have to have the adjustors upwards for access).

Drove it today (actual (but brief) drive not just a test drive) and coming back up the hill between 2000 and 3000 rpm at 1/2 to 3/4 throttle it felt the strongest it ever has. If I can get that zest to continue further up the rev range...

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Re: Advice please!

#266 Post by Brian_H » Sat Sep 19, 2020 7:41 pm

You'd probabbly be better to keep the pipe size as big as possible for as much of the run as possible - these bits should help in doing that provided you can get them onto the multivalve and inside the housing if applicable
https://tinleytech.co.uk/shop/lpg-parts ... e-to-6-mm/
https://tinleytech.co.uk/shop/lpg-parts ... mm-open-t/
https://tinleytech.co.uk/shop/lpg-parts ... ize-x-1-m/

You would also need some clips for the new pipe as it is a different size.

Using them you should be able to keep the pipe at 8mm all the way to the reducer and then use the same adaptors at the reducer end to go back down to 6mm just as it enters the solenoid housing.

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Re: Advice please!

#267 Post by Pinger » Sun Sep 20, 2020 10:12 am

Thanks Brian_H.
I'd only been at the LPG Shop site (looking for water tees and at 6mm tees) and hadn't got around to poly pipe as yet - not least as I hadn't much of a clue about it or where to start! Your links are a great help - thanks.
I'll have a look at my MV later. It's on a 120 litre tank so hopefully at that size it has provision for 8mm pipe.

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Re: Advice please!

#268 Post by Brian_H » Sun Sep 20, 2020 8:14 pm

Very few do have an 8mm outlet - but you should find the above bits let you increase the pipe size with the 6mm MV outlet and I'd read Simon's reply above to mean you should find that helps anyway. Having had to replace the MV on mine due to having issues getting the pipes to line up with the housing (replacing the 8mm filler line with JIC type made the alignment more critical) I ended up having to use a 6mm outlet as it was all that was available that would fit the size tank I had other than the original valve. Thats on a v8 Disco 2 though, so less of an issue there. (the original valve was an 8mm outlet but was problematic getting to fill to full capacity as well).

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Re: Advice please!

#269 Post by Pinger » Mon Sep 21, 2020 2:57 pm

Brian_H wrote:
Sat Sep 19, 2020 7:41 pm
You'd probabbly be better to keep the pipe size as big as possible for as much of the run as possible - these bits should help in doing that provided you can get them onto the multivalve and inside the housing if applicable
https://tinleytech.co.uk/shop/lpg-parts ... e-to-6-mm/
https://tinleytech.co.uk/shop/lpg-parts ... mm-open-t/
https://tinleytech.co.uk/shop/lpg-parts ... ize-x-1-m/

You would also need some clips for the new pipe as it is a different size.

Using them you should be able to keep the pipe at 8mm all the way to the reducer and then use the same adaptors at the reducer end to go back down to 6mm just as it enters the solenoid housing.
Trying to get my head round polypipe.
This >> https://tinleytech.co.uk/shop/lpg-parts ... mm-open-t/ looks like the polypipe is retained with olives (looks a lot like 'Polyflow' kit that I used to send off-shore). If that is correct, then I can't make sense of this >> https://tinleytech.co.uk/shop/lpg-parts ... e-to-6-mm/
Looking at from right to left - the polypipe goes over the barb (with an olive) then the nut fastens it to the main body - yes? What's at the other side? I'm expecting that to screw straight into a MV, reducer or filter. Is the protruding pipe part to be treated as a (short) length of copper pipe with an olive and male fitting securing it to MV, reducer or filter?

Is it possible just re-running my main supply pipe with 8mm will alleviate my gas starvation?
If I have to run with two reducers - will using just the one outlet from each suffice?
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Gilbertd
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Re: Advice please!

#270 Post by Gilbertd » Mon Sep 21, 2020 5:49 pm

Pinger wrote:
Mon Sep 21, 2020 2:57 pm
Looking at from right to left - the polypipe goes over the barb (with an olive) then the nut fastens it to the main body - yes? What's at the other side? I'm expecting that to screw straight into a MV, reducer or filter. Is the protruding pipe part to be treated as a (short) length of copper pipe with an olive and male fitting securing it to MV, reducer or filter?
Yes you've got it. The adapter on the end of the Polypipe turns it into a straight length of solid pipe so is treated just the same as a bit of copper pipe would be.
Pinger wrote:
Mon Sep 21, 2020 2:57 pm
Is it possible just re-running my main supply pipe with 8mm will alleviate my gas starvation?
If I have to run with two reducers - will using just the one outlet from each suffice?
Possibly, but you'd need to try it to see. My old Range Rover Classic had an inadequate vaporiser on it when I first got it. I could accelerate up to a certain point in the rev range with the actuator happily moving up and down either side of the default but as soon as I hit a certain point it would start to open up and just keep going until it was fully open. So it would run fine at lower revs, throttle openings and load but as soon as I asked it to work for a living it couldn't cope. This sounds much like your situation so by increasing the amount of gas that can get there you should move the point where it can't supply enough to, hopefully, above your red line. If you need to run two vaporisers, I would think running from just a single outlet on both would be sufficient.
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Pinger
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Re: Advice please!

#271 Post by Pinger » Mon Sep 21, 2020 6:09 pm

Gilbertd wrote:
Mon Sep 21, 2020 5:49 pm

Yes you've got it. The adapter on the end of the Polypipe turns it into a straight length of solid pipe so is treated just the same as a bit of copper pipe would be.
Cheers, I know they are the thing to add to my shopping list.
Gilbertd wrote:
Mon Sep 21, 2020 5:49 pm
Possibly, but you'd need to try it to see. My old Range Rover Classic had an inadequate vaporiser on it when I first got it. I could accelerate up to a certain point in the rev range with the actuator happily moving up and down either side of the default but as soon as I hit a certain point it would start to open up and just keep going until it was fully open. So it would run fine at lower revs, throttle openings and load but as soon as I asked it to work for a living it couldn't cope. This sounds much like your situation so by increasing the amount of gas that can get there you should move the point where it can't supply enough to, hopefully, above your red line. If you need to run two vaporisers, I would think running from just a single outlet on both would be sufficient.
That's exactly where mine is. At some point before it dies, it's even showing rich at quite large throttle opening and rpms. Then it just dies.
I think I'll try the 8mm pipe first and if it still needs two reducers, I'll refit the old one.
How many solenoids do I need (for a single reducer)? Currently I have the one on the tank, the one on the reducer and an intermediate one on a filter on the bulkhead. I'm thinking about a larger (8mm filter). Better to retain an intermediate one?

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Re: Advice please!

#272 Post by Brian_H » Tue Sep 22, 2020 7:18 pm

I'm not sure you really need the intermediate one, but it may be easier to retain it just in case, at least it gives you less gas to vent if you have the front end apart again. I'd consider getting rid of it if going to a second reducer with another solenoid though (or run them through a relay instead to reduce the load on the ecu).

With the connectors above, you also want some 6mm olives for the copper side, you should be able to reuse the threaded fitting as long as its still in decent order, if it isn't get enough of them as well.

Pinger
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Re: Advice please!

#273 Post by Pinger » Tue Sep 22, 2020 8:25 pm

Brian_H wrote:
Tue Sep 22, 2020 7:18 pm
I'm not sure you really need the intermediate one, but it may be easier to retain it just in case, at least it gives you less gas to vent if you have the front end apart again. I'd consider getting rid of it if going to a second reducer with another solenoid though (or run them through a relay instead to reduce the load on the ecu).
Good point re multiplicity of solenoids with a second reducer and the load on the ECU. That the ECU switches the solenoids had occurred to me before but somehow adding another hadn't quite entered the thought process!
Brian_H wrote:
Tue Sep 22, 2020 7:18 pm
With the connectors above, you also want some 6mm olives for the copper side, you should be able to reuse the threaded fitting as long as its still in decent order, if it isn't get enough of them as well.
I'll add to the shopping list.

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