Has anyone designed an engine from scratch?

[godspeed]

I know there are a lot of engine builders/designers who like to tinker around with engines on this forum. Has anyone ever designed or modified an engine that will rev to 18k to 20k RPM?

I know people have converted motorcycle engines before into V8's etc but has anyone build a specific 'replica' V8 or V10?

[graham.reeds]

There was a kid who designed a V6 from scratch and posted renders of it. Dunno if he is still about or ever got further than renders.

Don't think he had planned for high rpm.

[Rodak]

Here's a pretty amazing home design and build. This guy knows what he's doing..... 3.0L, 3 valve OHC (2 intake, 1 exhaust), 390 hp @ 7700 rpm, projected to get to 450 hp. He's building it for a land speed record attempt in class, aiming for 260 mph. He currently holds records in another class, so not a B.S. artist.

https://www.hotrod.com/articles/how-to- ... al-engine/

[e36jon]

Greetings Godspeed

Have you checked out the 2 stroke thread here? viewtopic.php?f=4&t=10966 Not exactly what you are asking for but the info here is pretty stunning both from the thread owner and from all of the experts that chime in. It's an education. Manolos has turned a number of his concepts into actual metal, which is better than most...

[godspeed]

Greetings Godspeed

Have you checked out the 2 stroke thread here? viewtopic.php?f=4&t=10966 Not exactly what you are asking for but the info here is pretty stunning both from the thread owner and from all of the experts that chime in. It's an education. Manolos has turned a number of his concepts into actual metal, which is better than most...

Thanks for the warm welcome!

Thanks guys for the links! looks like ill have a lot of reading today over the next few days!

[coaster]

On the website cnczone, there was a subforum on miniature internal combustion engines, there was thread from maybe 2001 era? A guy built a motorcycle engine based on bore stroke of an f1 motor, maybe 96x42 or so. He got it running, he went quiet after that. This was at the height of the V10 f1 horsepower wars when rpm and hp kept shooting upwards, we were all hooked.

I have 2 complete cbr954 heads, im hope to build a hillclimb 2 litre v8, but wife wants wife things and no cigar until maybe December, maybe i can do the casting patterns in the down time.

[godspeed]

On the website cnczone, there was a subforum on miniature internal combustion engines, there was thread from maybe 2001 era? A guy built a motorcycle engine based on bore stroke of an f1 motor, maybe 96x42 or so. He got it running, he went quiet after that. This was at the height of the V10 f1 horsepower wars when rpm and hp kept shooting upwards, we were all hooked.

I have 2 complete cbr954 heads, im hope to build a hillclimb 2 litre v8, but wife wants wife things and no cigar until maybe December, maybe i can do the casting patterns in the down time.

That sounds awesome! ill have to look that one up on CNCzone.

I also have a CBR250 and that revs up to 19k RPM and it sounds like a miniature F1 car. It runs on valve springs but it's such a small engine and the components are so light, it works. With a larger displacement comes larger valves hence having to move to pneumatic valves. There have been other engines that have been made using motorcycles engines, but they have been small displacements that rev high but as the displacement gets higher the RPM gets lower such as the Hayabusa engine 10k RPM?

[coaster]

Allen Millyard spliced 2 Yzf250 motors to build an inline 6, he put it in a Honda TT replica race bike. The Cbr250 built like this but 5 cylinder would sound awesome, and it could go nicely into Honda TT replica also, Honda built 3,4,5 and 6 cylinder TTbikes in the early 60's.
A 5 cylinder at 18k rpm would be pure music.

By the way, that 2 stroke thread is kooky, a meat mincer above the head with no controls, its just out there.

[Billzilla]

I'm drawing up a three litre V8 in Solidworks right now. It'll be using otherwise conventional car (Toyota) heads on it rather than the usual Hayabusa though. I'm expecting the power & weight, etc, to be similar to the Hartley V8.
One important thing that I haven't decided on yet is if to use a conventional billet crank or go for a press-together type. The latter has distinct advantages over a billet crank, but I need to know more about them first before I decide.

[coaster]

The v8 architecture has a natural balance at 90 degrees, but also has a sweet spot at 75 degrees it is said. At 75 you could mill away the cylinders of the inline 4 and keep the remaining crank tunnel and bedplate, weld two plates at 75 deg and mill everything true again. That solution needs master slave conrods but save making a crank, i will opt for making a crank with shared crankpin, im to scared to make a conrod on a high rpm motor, a crankshaft is a big lump and much safer to make.

[Billzilla]

I'm using a flat-plane crank, not a 90° one, so it won't balance quite as nicely as a regular V8.

[Holm86]

[coaster]

Well, i found a candidate for bedplate duties, hyundai alpha 2 with 82mm bore pitch, I hacked the water jackets and 3/4 of the barrels.
The remaining crank tunnel weighs in at 18kgs, a big lump.
I followed this approach as our (aussie) hillclimb rules state the only restriction is to be based on a production block. The blocks id and numbers are all present, but the terminology changes into a bedplate, with an upper 75 deg V cylinder block to be cast and machined.
Ship builders term the bedplate as a block, so it can be argumentative.
Anyhow, other candidates were 4g15 iron or GM 1.4 GSE alloy, GSE's are were released in 2007 and are still quite expensive. The Hyundai G4ED complete cost $50 (bent valve).

[coaster]

I have not embarked on a casting pattern, yet.
Should I press on with the iron bedplate?
Should I track down a GSE bottom end?
(Gasoline Small Engine) by GM, 81mm bore pitch.
Edit: it seems im on the right track with 75degrees, the main man himself had no issues with cylinder angle for a single plane V8.

[coaster]

Well were in lockdown again and im bored, so here comes a casting pattern build. This model is not there yet, will use pvc tubes, plywood and bondo for the mold.