Diesel "thumper"

[Septic]

PLEASE READ THE TITLE AS "PETROL" AND NOT DIESEL.... I DON'T KNOW WHY I GOT IT SO FUNDAMENTALLY WRONG BUT ITS PROBABLY A MIXTURE OF SENILITY AND PAINKILLERS....

thinking of designing and building a slow revving, single, cylinder, water-cooled, 4 stroke PETROL engine similar in concept to a motorcycle engine, but with a heavier flywheel and longer stroke.

It will be somewhere in the region of 75cc, be of an OHV pushrod design, magneto ignition, open rocker gear (because I love to see and hear tappets) and forward and reverse gears to a power takeoff. (Don't know what I'm going to drive with it yet, but that will come later)

Any first hand knowledge of unexpected design, or reliability issues relating to similar projects would be gratefully appreciated....

Thanks all.

 

[jwcnc1911]

Sounds like a great idea!

Working in a diesel engine factory I've wanted to make a huge one cylinder diesel for a decade. I'd love to make a "Briggs and Stratton" diesel. I'd love to use our 13L as the platform. Fuel injected and everything.

http://www.navistar.com/navistar/

Toward the bottom of the page, under "Products"
Click on "Engines"

You can see a picture of the plant I work in, as well as the 13L that's our "flagship."

 

[mu38&Bg#]

What is the magneto for?

 

[johnny1320]

Im thinking of designing and building a slow revving, single, cylinder, water-cooled, 4 stroke Petrol engine

sounds cool but why diesel thumper for tittle?

 

[Septic]

Yup.. You got it.... This idiot somehow typed diesel instead of petrol???.... Don't ask why, because I hate having to admit that I'm suffering from premature senility....

 

[johnny1320]

What do you use for designing? I use Alire ( now Geomajic) personal.

 

[jwcnc1911]

Don't tease me... I thought you were going to do a diesel.

 

[enfieldbullet]

Jeremy, those diesels look great. apparently your company has a distributor in my country! i'm also definitely making a diesel thumper for a 50cc bike, lets work on that!

OP : exposed = dirt getting into engine = not so good, that's a problem i can think of that has to have some kind of design solution.

i'm probably going to make one too when i get a chance but i'm going flathead. thumpier sound

 

[jwcnc1911]

Yes, we do not only have a distributor but a sister factory that makes trucks and engines. The very same 13L in that picture. Our machine line can't keep up with the assembly line so they actually assemble some of the engines out of blocks machined in Brazil. We even make a 4 cylinder for smaller cars and trucks down there in the Brazilian market I believe. Man I'd love to have a small diesel car that gets 50mpg! I can't afford any of our products and have no need for it either. We used to make the Ford Powerstroke but we lost that contract in 2010. I never needed a F250 either, nor could I afford one.

 

[enfieldbullet]

we had a small car here that ran on gas and would make near 100 - 120 mpg(if my math is right, from 20km/l) , that's the gurgel br800. since than our gas is more than 25% ethanol now so mileage has gone down. but they're very economical , made with a fiber body, i can literally push one around with one hand.

people didn't like them though.

and we don't have diesel passengers cars here, only trucks (smallest i've seen may be the f250 or the sprinters), seems to be some kind of restriction. i would love a diesel car/bike.

ok, i'll stop stealing the thread now.

 

[Septic]

I wasn't deliberately teasing JW.... I do actually have an idea for diesel motorcycle engine that's been floating about in my rather woolly and leaky head for many years and it occasionally tries to escape through the cracks....

To answer Johnny1320... My favourite design tool is my bedroom wall... Although if you want a relatively straightforward build, I wouldn't recommend it.

I spent many years designing and producing tooling and machinery according to the rigid requirements of paying clients, so my approach to design is now very "organic" in that it must adhere to the "if it looks like one that already exists, it's not for me" rule... So beyond "fag packet" sketches and a short spec sheet detailing critical dimensions, the details come from interesting ideas that I jot down as I think of them and pin to the wall over a considerable period of time.

As many people will correctly surmise, that means I often have to re-make parts that simply don't work properly because they haven't been sufficiently integrated within the original design, but I'm quite happy to have the occasional "wassat" to give away as a conversation piece.

Unfortunately, I enjoy the constant "tinkering" and re-designing so much more than any other aspect that once finished, my little creations hold no real interest anymore and have up till now been given away to charity auctions and other deserving causes (much to the annoyance of my very patient wife) I hate the idea of anything that was built to move just sitting in a box, or motionless in a display case.... But that's just my opinion.

 

[Septic]

After much thought and great inspiration from some of the magnificently realised design concepts portrayed so openly in this forum I spent a few days mulling things over and sketched out a few preliminary designs.....

Tonight however, my dear wife drew my attention to a very reasonably priced Lister 28DH 1.5HP engine advertised locally and within two hours it was in my drive, in the back of my car awaiting assistance to get it out again and I've now decided to build a scaled down version to match...

So much for careful consideration!!!