I would like some feedback on the V-Twin air cooled Diesel engines I have been reading about on this forum, such as the Punsun, Winsun, Longfar etc. which I would call a V-twin YANMAR.
They seem like the perfect low cost engine for a Diesel motorcycle as well of course the common industrial use. How would you all rate them? Is there a brand that seems better then another? What about reliability, durability, parts availability etc?
How do they compare to YANMAR or Hatz?
Andi
V-Twin air cooled Diesel
Moderators: Dan J, Diesel Dave, Crazymanneil, Stuart
for such is progress
Thanks for the replies, I wasn't sure how popular those engines are, I've never heard of them before joining here. I'm very familiar with the YANMAR original, as I work for the local YANMAR Dealer/Distributor.
I have seen some YANMAR clones here on plate compactors, pressure washers, generators and other industrial equipment made by Changfa, costing about a 3rd of the original. The engine looks nearly identical, but none of the parts are interchangeable, the injectors fit, but are very difficult to get working properly and won't ever function at 100%. The engines are not very durable in my experience, that and the unavailability of parts makes them a throw away engine. Thats why I was curious about the Punsun etc, they would be great for a lot of different uses as they are simple, light weight and compact.
Looking forward to any further review and project details, Timpax.
Greetings form the Caribbean.
Andi
I have seen some YANMAR clones here on plate compactors, pressure washers, generators and other industrial equipment made by Changfa, costing about a 3rd of the original. The engine looks nearly identical, but none of the parts are interchangeable, the injectors fit, but are very difficult to get working properly and won't ever function at 100%. The engines are not very durable in my experience, that and the unavailability of parts makes them a throw away engine. Thats why I was curious about the Punsun etc, they would be great for a lot of different uses as they are simple, light weight and compact.
Looking forward to any further review and project details, Timpax.
Greetings form the Caribbean.
Andi
Andi
Andi,
I have one of these engines ive been fitting to a Harley but been dragging my heels a bit getting it finished.
Sods law dictates that now its finished and i want to MOT it, Im flooded in and cant get it out. If the water hangs around much longer Im thinking of fitting floats and a paddle to it.
Hope to give you some sort of test within the next or so weather permitting.
As has been said too early to tell reliability wise.
Build quality is typical modern Chinese by which I mean that the lump itself appears well made and solid with cost cutting on the add ones such as air filter cover vibrates off due to poor quality catches and oil cooler which looks like it will rot through at the first sign of rain.
Overall Im pretty pleased with it though.
The barrels and heads are the same as the 10hp clones so parts shouldnt be a problem unless the crank lets go.
There appear to be 2 models a 3000rpm and 3600rpm but apparently they are the same engine with different govenor settings.
Also some seem to have decompressors on the heads and others dont. Mine doesnt and the starter copes fine but gives a huge jolt to the battery which is worth considering. Fortunatly the reg/rec and alternator seem well up to the job of charging it and Im charging at 10 amps even with all the lights on.
So far its been a reliable starter whilst ive been testing bits and its looking promising.
Hope this helps, no rain forcast, fingers crossed.
Mark
I have one of these engines ive been fitting to a Harley but been dragging my heels a bit getting it finished.
Sods law dictates that now its finished and i want to MOT it, Im flooded in and cant get it out. If the water hangs around much longer Im thinking of fitting floats and a paddle to it.
Hope to give you some sort of test within the next or so weather permitting.
As has been said too early to tell reliability wise.
Build quality is typical modern Chinese by which I mean that the lump itself appears well made and solid with cost cutting on the add ones such as air filter cover vibrates off due to poor quality catches and oil cooler which looks like it will rot through at the first sign of rain.
Overall Im pretty pleased with it though.
The barrels and heads are the same as the 10hp clones so parts shouldnt be a problem unless the crank lets go.
There appear to be 2 models a 3000rpm and 3600rpm but apparently they are the same engine with different govenor settings.
Also some seem to have decompressors on the heads and others dont. Mine doesnt and the starter copes fine but gives a huge jolt to the battery which is worth considering. Fortunatly the reg/rec and alternator seem well up to the job of charging it and Im charging at 10 amps even with all the lights on.
So far its been a reliable starter whilst ive been testing bits and its looking promising.
Hope this helps, no rain forcast, fingers crossed.
Mark
Hey Mark,
great feedback thanks very much. I wish you all the best with your build and would certainly be interested in further updates. What kind of transmission are you using, any idea about top speed? The aircooled V-Twin design should be the perfect match for the Harley. All the best mate.
Greetings from the Caribbean.
Andi
P.S. Out of curiosity whats your location? Only if you don't mind of course.
great feedback thanks very much. I wish you all the best with your build and would certainly be interested in further updates. What kind of transmission are you using, any idea about top speed? The aircooled V-Twin design should be the perfect match for the Harley. All the best mate.
Greetings from the Caribbean.
Andi
P.S. Out of curiosity whats your location? Only if you don't mind of course.
Andi
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Byrdman
- I luv the smell of Diesel...
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- Location: Chicagoland, Illinois, USA
- Contact:
Hey Andi,
As you already know, the Yanmar 2V78 was the original diesel V-twin, all of the Chinese models are just clones.
I think the engine is a great powerplant but the biggest problem we all hae here in diesel bike land is transmission choice. I really want a multi-gear shifting transmission but besides the Harley gearbox and a few other rare units, there's not much of a choice.
I used to work for Yanmar America in Buffalo Grove, which distributor do you work at?
As you already know, the Yanmar 2V78 was the original diesel V-twin, all of the Chinese models are just clones.
I think the engine is a great powerplant but the biggest problem we all hae here in diesel bike land is transmission choice. I really want a multi-gear shifting transmission but besides the Harley gearbox and a few other rare units, there's not much of a choice.
I used to work for Yanmar America in Buffalo Grove, which distributor do you work at?
This may sound silly, but where do I get one here in the US? All my google searches turn up Chinese suppliers, but no distributors where I can get one, or even a price of what one costs.
I found some from Rotek in Germany selling on ebay, but who sells them here? What do they cost?
I am planing a bobber project and it seems perfect.
If this is covered somewhere, a link would be awesome. I'm new.
Dave.
I found some from Rotek in Germany selling on ebay, but who sells them here? What do they cost?
I am planing a bobber project and it seems perfect.
If this is covered somewhere, a link would be awesome. I'm new.
Dave.
JimmyDean
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thundercougarfalconbird
- I luv the smell of Diesel...
- Posts: 120
- Joined: Sun Jun 15, 2008 4:52 pm
- Location: sexsmith , alberta , canada
v-twin punsun
It looks like it has been a while since someone posted last.
I have gotten my paws on one of these engines for a project bike, after taking the poorly made fuel tank and exhaust off the engine, and removing the sump cover for internal cleaning it seems to be built reasonably well, the crankshaft is single pin and is NOT a welded crank, however attention to details like lapping the cam followers for the valve and injection pumps is something that should be done, the chinese grinding processes look like they have been done with a 10 grit stone, camshaft lobes also require some polishing.
As with all chinese products anything made out of rubber, i.e the fuel line and suck parts need to be replaced as they are of poor quality at best.
The stater on the engine is junk, non solenoid shift and the gear wont last for many starts. it jams and destroys the ring gear on the flywheel.
Those problems aside i hope to use it as a reasonable power plant.
If i can figure out how to post pix i will try to, project bike is not finished, but is a work in progress.
I have gotten my paws on one of these engines for a project bike, after taking the poorly made fuel tank and exhaust off the engine, and removing the sump cover for internal cleaning it seems to be built reasonably well, the crankshaft is single pin and is NOT a welded crank, however attention to details like lapping the cam followers for the valve and injection pumps is something that should be done, the chinese grinding processes look like they have been done with a 10 grit stone, camshaft lobes also require some polishing.
As with all chinese products anything made out of rubber, i.e the fuel line and suck parts need to be replaced as they are of poor quality at best.
The stater on the engine is junk, non solenoid shift and the gear wont last for many starts. it jams and destroys the ring gear on the flywheel.
Those problems aside i hope to use it as a reasonable power plant.
If i can figure out how to post pix i will try to, project bike is not finished, but is a work in progress.
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Stuart
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- Location: Horsham West Sussex, England
- Contact:
I think that Fiddler may agree with you regarding starters 
Upload any images to http://img391.imageshack.us/ and cut and paste the link to your post here. Picture should appear.
Oh, and welcome onboard
Upload any images to http://img391.imageshack.us/ and cut and paste the link to your post here. Picture should appear.
Oh, and welcome onboard
Stuart. M1030M1, Honda NC700S, Grom!, Toyota Corolla 1.4 Turbo Diesel. Favouring MPG over MPH.
Hello Chap and welcome,
Glad your pleased overall with your purchase, Im thrilled to bits. As I posted earlier there is obvious cost cutting on this engine but anyone who buys an engine for a fraction of the price of the market leaders, and expects identical manufacture quality is a fool.
I had starter issues as well but found the coils had a poor quality contact internally and once sorted Ive had none of the issues you describe( see starter motor thread). I intend to run mine until it fails and then replace for a better item.
Save some effort and junk the oil cooler, it is very inefficient and in my opinion unneccessary in a motorcycle application.
I never thought the rumour about the crank was true. It just wouldnt be cheaper to weld/grind/balance two cranks together than cast a purpose made one. Also if the crank a was weak point Im sure they wouldnt have taken the power output up and up. Nice to have it confirmed though, thanks for that.
Give some consideration to vibration in your build, these babys shake badly until operating rpm is reached when it all smooths out.
Good luck and keep us to date.
Mark
Glad your pleased overall with your purchase, Im thrilled to bits. As I posted earlier there is obvious cost cutting on this engine but anyone who buys an engine for a fraction of the price of the market leaders, and expects identical manufacture quality is a fool.
I had starter issues as well but found the coils had a poor quality contact internally and once sorted Ive had none of the issues you describe( see starter motor thread). I intend to run mine until it fails and then replace for a better item.
Save some effort and junk the oil cooler, it is very inefficient and in my opinion unneccessary in a motorcycle application.
I never thought the rumour about the crank was true. It just wouldnt be cheaper to weld/grind/balance two cranks together than cast a purpose made one. Also if the crank a was weak point Im sure they wouldnt have taken the power output up and up. Nice to have it confirmed though, thanks for that.
Give some consideration to vibration in your build, these babys shake badly until operating rpm is reached when it all smooths out.
Good luck and keep us to date.
Mark
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thundercougarfalconbird
- I luv the smell of Diesel...
- Posts: 120
- Joined: Sun Jun 15, 2008 4:52 pm
- Location: sexsmith , alberta , canada
rpm and timing
Has anyone been messing around with the injection pump timing, not sure how well adjust these engines are to start with , if the calibration is as good as the govenor settings then it will have to be checked and reset.
these engines are designed to be used at a fixed rpm so the pump timing is set in the 25 degree range.
Will running the engine at a slower speed shorten the life of the engine?
Should the timing be set back to 20 degrees?
these engines are designed to be used at a fixed rpm so the pump timing is set in the 25 degree range.
Will running the engine at a slower speed shorten the life of the engine?
Should the timing be set back to 20 degrees?