Author Topic: Listeroid intake porting  (Read 7408 times)

Hugh Conway

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Listeroid intake porting
« on: December 27, 2020, 09:17:13 PM »
Ever so often, the topic of porting comes up. For what it's worth, I tried an experiment today.
This morning was a clean-up day for our daily driver listeroid. Mostly a going over with a rag to clean off all the oil that seems to coat everything after a time. In this case, the generator drive belt was slipping a bit with a combination of a film of oil on the flywheel and moisture from condensation ( it has been raining/fogging here for almost ever).
After completion of cleaning and then starting up, I thought a good time to spray a litre or so of water into the intake under load. After removing the intake silencer (Solberg air compressor  intake filter) I used a garden sprayer to apply just sufficient  water so that RPM didn't bog down. Sometimes a bit too much water caused an RPM drop, which led me to wonder just how much intake air flow obstruction would affect RPM. At the time the engine (with about 2300 hours on it) was fully warmed up and pulling a 2800 Watt load.
With a flat piece of sheetmetal, I gradually covered the intake adapter until there was an audible decrease in RPM or a visual indication of the fuelling rack opening more.  I was able to cover the intake just a bit more than 50% before there was any change at all.
This experience seems to indicate that improving the intake airflow by cleaning up the port makes little or no change in power output.
Interesting........
Cheers
Hugh
JKson 6/1  (Utterpower PMG ) Off-grid
Lister 6/1 Start-O-Matic engine......running with PMG
1978 Royal Enfield (glutton for punishment by Indian iron)
1963 BMW R-27 project

32 coupe

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Re: Listeroid intake porting
« Reply #1 on: December 27, 2020, 11:19:44 PM »
Good job.
Reinforces what many smarter than me have said for years when the subject of porting
and polishing the heads come up in conversation.

Thanks for "the final word" on that subject.
At least in my mind.

Gary

« Last Edit: December 28, 2020, 12:11:32 AM by 32 coupe »
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gadget

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Re: Listeroid intake porting
« Reply #2 on: December 28, 2020, 03:37:07 AM »
Oh man, I'm at about 4500' elevation, it would be nice to find a few extra ponies

mike90045

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Re: Listeroid intake porting
« Reply #3 on: December 28, 2020, 04:28:45 AM »
Oh man, I'm at about 4500' elevation, it would be nice to find a few extra ponies 

That would be the DIY turbocharged model :
https://utterpower.com/turbo_6_1.htm

gadget

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Re: Listeroid intake porting
« Reply #4 on: December 28, 2020, 05:55:43 AM »
Oh man, I'm at about 4500' elevation, it would be nice to find a few extra ponies 

That would be the DIY turbocharged model :
https://utterpower.com/turbo_6_1.htm

That is pretty cool. I'm curious as to the viability of a belt driven blower or maybe electric??? It shouldn't need much for only 5 HP
« Last Edit: December 28, 2020, 05:57:32 AM by gadget »

38ac

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Re: Listeroid intake porting
« Reply #5 on: December 28, 2020, 11:20:00 AM »
Oh man, I'm at about 4500' elevation, it would be nice to find a few extra ponies
I don't know what you are running now but a 6)1 becomes an 8/1 with a change to aluminium piston and increase RPM. Also the stock bore is 114.5MM but India has 120, 127 or 130 MM bores as pretty much standard fare. Any of those will provide a nice increase. A change to the 034 type fuel pump will help governor responce with the larger bores and HP
« Last Edit: December 28, 2020, 12:29:11 PM by 38ac »
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Re: Listeroid intake porting
« Reply #6 on: December 28, 2020, 12:46:04 PM »
Before I purchased a Satyajeet GM-90 6-1 back in 2006 Mike Monteth showed me a head. The bowl of the intake side had extra metal casted in the port right under the valve. He explained that it’s in there to help create a swirling effect of the incoming air that enters the combustion chamber from the DI head. He said this helps with efficiency and not to remove the casting. He mentioned that removing it will reduce hp and efficiency and in turn make it burn dirtier.

These Listeroids and GM-90’s run so slow that in theory it seems that you would want to leave the ports small. Especially if your going to use propane or NG injection in the intake port.

38ac

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Re: Listeroid intake porting
« Reply #7 on: December 28, 2020, 06:38:48 PM »
The Bamford Z series had a similar shroud but it was attached to the head of the intake valve, a very odd looking arraingment. The valve was kept from turning by the spring retainer so the shroud would always stay on the correct side.
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gadget

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Re: Listeroid intake porting
« Reply #8 on: December 29, 2020, 04:18:15 PM »
I use to port cylinder heads for a living. I worked for a very well known person in the racing world and with very well known companies. I really enjoyed it, very rewarding work. Ask me anything you want on the subject.....

I have never heard of an engine that would not see an increase of air flow into the motor after smoothing things out. Now if its actually needed, that is another question. These motors may not be able to push enough fuel to see benefit. What I mean is, even with the crappy heads they have, there may already be plenty of air flow even at full load.

Try your test again at full load (4500 watts ?)and see if it starts to smoke.

Your test reminds me of the magic rag trick.


gadget

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Re: Listeroid intake porting
« Reply #9 on: December 29, 2020, 04:30:26 PM »
Before I purchased a Satyajeet GM-90 6-1 back in 2006 Mike Monteth showed me a head. The bowl of the intake side had extra metal casted in the port right under the valve. He explained that it’s in there to help create a swirling effect of the incoming air that enters the combustion chamber from the DI head. He said this helps with efficiency and not to remove the casting. He mentioned that removing it will reduce hp and efficiency and in turn make it burn dirtier.

These Listeroids and GM-90’s run so slow that in theory it seems that you would want to leave the ports small. Especially if your going to use propane or NG injection in the intake port.

I suspect the bump is there to reduce cross section and increase air speed at the location. It may have been a later add on to make up for a poor casting design. Port swirl will only help when fuel is mixed with the air as it comes in. Example would be port fuel injection or carb. If done wrong, it also can cause fuel to fall out of the air stream and thats a problem. Once the piston stops and starts to travel back up, every thing changes directions so how would port swirl help a direct injected diesel? The fuel gets sprayed in way later. For a IDI engine, there would be no benefit to a turbulent air flow coming in the intake since there would be no swirl in the prechamber. For direct injection, some diesels have a swirler cast into the top of the piston to mix the air just as the piston approaches the injector. It works really well. I believe it also helps direct the fuel away from the piston face.

You really never know though with out giving it a try. Problem is 99% of the people doing port work don't know what they are doing and can make it worse.

« Last Edit: December 29, 2020, 04:48:18 PM by gadget »

gadget

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Re: Listeroid intake porting
« Reply #10 on: December 29, 2020, 04:36:09 PM »
Oh man, I'm at about 4500' elevation, it would be nice to find a few extra ponies
I don't know what you are running now but a 6)1 becomes an 8/1 with a change to aluminium piston and increase RPM. Also the stock bore is 114.5MM but India has 120, 127 or 130 MM bores as pretty much standard fare. Any of those will provide a nice increase. A change to the 034 type fuel pump will help governor responce with the larger bores and HP

I'm glad Gary talked me into getting an 8/1, that and he talked me out of an ST head and I went with the stamford clone. Its a really nice unit.

You all should at least clean the loose casting up in the intake ports. I pulled a piece off about the size of a BB with my fingers. That would keep any of the loose stuff from getting into the motor.

gadget

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Re: Listeroid intake porting
« Reply #11 on: December 29, 2020, 04:37:46 PM »
duplicate
« Last Edit: December 29, 2020, 04:40:11 PM by gadget »

guest18

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Re: Listeroid intake porting
« Reply #12 on: December 29, 2020, 06:58:23 PM »
Gadget, most people that try doing porting without understanding or proper schooling normally mess things up. The GM-90 head has a J figure casted in the pocket underneath the intake valve. Its roughly 1/4" tall. I agree that it's there to increase air speed and in turn also helps with swirling effect. As I wrote, this would also aid in mixing a gas that's injected in the intake. These engines, including the CS listeroid's dont need large valves or porting. Doing so will reduce air speed and in some instances it will effect performance and efficiency. Now, if there is casting pieces that can break than yes, get it out. But otherwise most of the time it's best to leave it alone.

Brings back memories of the Ford Boss 302 and 351 Cleveland engines. The intake valves and ports were too large for street use. The engines would gas foul the plugs so often. They would not run right until you were over 4000 rpm they ran great over 5000 rpm. This was the reasons why a the Australian Cleavland heads became so popular. Smaller combustion chambers and intake posts. They work great on street performance engines. The Aussie's got it right.

gadget

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Re: Listeroid intake porting
« Reply #13 on: December 29, 2020, 08:25:33 PM »
Gadget, most people that try doing porting without understanding or proper schooling normally mess things up. The GM-90 head has a J figure casted in the pocket underneath the intake valve. Its roughly 1/4" tall. I agree that it's there to increase air speed and in turn also helps with swirling effect. As I wrote, this would also aid in mixing a gas that's injected in the intake. These engines, including the CS listeroid's dont need large valves or porting. Doing so will reduce air speed and in some instances it will effect performance and efficiency. Now, if there is casting pieces that can break than yes, get it out. But otherwise most of the time it's best to leave it alone.

Brings back memories of the Ford Boss 302 and 351 Cleveland engines. The intake valves and ports were too large for street use. The engines would gas foul the plugs so often. They would not run right until you were over 4000 rpm they ran great over 5000 rpm. This was the reasons why a the Australian Cleavland heads became so popular. Smaller combustion chambers and intake posts. They work great on street performance engines. The Aussie's got it right.

It would be interesting to see that head. Diesel heads typically have zero valve tilt which makes for a horribly bent port but it makes it easy to keep the combustion chamber flat.

If the lister has a volumetric efficiency of say .9 and displacement is 1.434L that puts air flow @650 RPMs at about 15 CFM. So every second your trying to cram in .25 CFM through that tiny port with a volume of say 1/10 that? That give you an idea how fast that air is moving through there.

That gives us about  2.5 CFM per Horse power. That is plenty of air in theory. Problem is, I doubt we are seeing .9 volumetric efficiencies, from the looks at these ports, I would guess more like .6 - .7 at best. Thats assuming correct valve timing.

That could be why listers can smoke a bit even though technically they should have enough air at heavy loads. So....in theory, if you can get a bit more air in there, you should see less or no smoke under full load and better economy under heavy/full load.

But how many of us are running under full load all the time? I'm guessing no one.

Hugh Conway

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Re: Listeroid intake porting
« Reply #14 on: December 29, 2020, 11:08:44 PM »
@ Gadget
"Your test reminds me of the magic rag trick."
I don't know what the magic rag trick is, but.......
A few years ago, I was running this same engine under load, for some reason, without the intake silencer.
For some other reason, now  unrecalled, I had a rag in my hand. It disappeared. The engine slowed for a beat or two, then continued on as if nothing happened.
Sucked in and through, never found any of it. Was that a magic rag trick???? It was quite funny in any event!
Cheers
Hugh
JKson 6/1  (Utterpower PMG ) Off-grid
Lister 6/1 Start-O-Matic engine......running with PMG
1978 Royal Enfield (glutton for punishment by Indian iron)
1963 BMW R-27 project