Injected Diesel 56cc 2 Stroke, Will it ever work?"

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

Lloyd-ss

Well-Known Member
HMEM Supporting Member
Joined
Mar 8, 2019
Messages
284
Reaction score
158
Location
Charlottesville, VA
Diesel Injector Dilemma

After much effort and many "almost works," prototypes of a unit injector, I am about ready to admit defeat and compromise on the issue by marrying an off the shelf injector nozzle with an off the shelf injector pump. The parts will need to be modified to remove excess size and weight.

I think I will be going with the GM (Detroit Diesel) HV6 injector nozzle, and the Yanmar injector pump from their line of LA single cylinder engines (199 to 406cc).

The HV6 nozzle has much smaller holes and the internal spring can be changed to achieve different injection pressures.

Here is a pic of the 2 nozzles (GM HV6 and Yanmar LA series.) I listed some comparison specs from both stylesof injector nozzles.
HV6andYanmar-Nozzles.jpg

What baffles me is that the Yanmar is for a much smaller cylinder volume, and operates at over 2,000psi, but has fairly large nozzle holes.
The GM operates at below 1,000 psi, has has a much larger cylinder volume, but its nozzle holes are much smaller. So much to learn, LOL.


-----------------------------

Here is a pic of the HV6 nozzle and the Yanmar injector married together. I hope they are compatible. The design of the nozzle and the pump are fairly straight-forward (famous last words, Ha)
There is still a LOT of excess weight and material on the Yanmar pump, but I will eventually get around to putting it on a diet to make it suitable for the model I plan on making.
GM-Yan.jpg


Testing is next. At first glance, it seems to offer resistance against the plunger from the pressure build-up, just like it should.
This is just a proof of concept prototype, unless it works, that is. ;)
Lloyd


x
 

ajoeiam

Well-Known Member
Joined
Aug 14, 2020
Messages
597
Reaction score
174
Location
blank (like some others I've noticed)
Diesel Injector Dilemma

After much effort and many "almost works," prototypes of a unit injector, I am about ready to admit defeat and compromise on the issue by marrying an off the shelf injector nozzle with an off the shelf injector pump. The parts will need to be modified to remove excess size and weight.

I think I will be going with the GM (Detroit Diesel) HV6 injector nozzle, and the Yanmar injector pump from their line of LA single cylinder engines (199 to 406cc).

The HV6 nozzle has much smaller holes and the internal spring can be changed to achieve different injection pressures.

Here is a pic of the 2 nozzles (GM HV6 and Yanmar LA series.) I listed some comparison specs from both stylesof injector nozzles.
View attachment 139918

What baffles me is that the Yanmar is for a much smaller cylinder volume, and operates at over 2,000psi, but has fairly large nozzle holes.
The GM operates at below 1,000 psi, has has a much larger cylinder volume, but its nozzle holes are much smaller. So much to learn, LOL.


-----------------------------

Here is a pic of the HV6 nozzle and the Yanmar injector married together. I hope they are compatible. The design of the nozzle and the pump are fairly straight-forward (famous last words, Ha)
There is still a LOT of excess weight and material on the Yanmar pump, but I will eventually get around to putting it on a diet to make it suitable for the model I plan on making.



Testing is next. At first glance, it seems to offer resistance against the plunger from the pressure build-up, just like it should.
This is just a proof of concept prototype, unless it works, that is. ;)
Lloyd


x
Very interesting!!!!!!!

I'd say you got some good progress going!!

Any chance you would get a measurement on the holes in the nozzles?

TIA
 

Lloyd-ss

Well-Known Member
HMEM Supporting Member
Joined
Mar 8, 2019
Messages
284
Reaction score
158
Location
Charlottesville, VA
Very interesting!!!!!!!

I'd say you got some good progress going!!

Any chance you would get a measurement on the holes in the nozzles?

TIA
Joe,
Here is a picture of the Yanmar nozzle with a bare copper wire .006" in dia, and a silver plated copper wire of.008" dia. The .006 fit in without much trouble, but the .008 took some effort. Both wires came back out of the holes without getting stuck.If you look at the picture in post #121, you can see that the GM HV6 nozzle has holes that are significantly smaller. I did not attempt to fit a wire into those holes.
Lloyd
Yanmar_006_008.jpg
 

Lloyd-ss

Well-Known Member
HMEM Supporting Member
Joined
Mar 8, 2019
Messages
284
Reaction score
158
Location
Charlottesville, VA
GM nozzle and Yanmar pump. A marriage not made in heaven. Test Video.

This video is from a few days ago after I got this proof-of-concept set-up built. Proof-of-concept is a handy euphemism for putting something together quickly and enthusiastically without too much attention to detail because that would just take too darn long!

It is still too big and bulky, but it works better than the last build, the stroke length and timing need to be worked with (plenty of adjustability built into this version), as does the cam profile. And the excess fuel volume and air agitation at higher rpm needs to be addressed. So little time and so much to do! Right now I feel like I am just throwing stuff at the wall to see what will stick, but that is fine and I am enjoying it. I hope it is entertaining, or laughable, too.

 
Top