somebody on the Locost email list mentioned that Evinrude offers a V6 two stroke 3.4 liter. Make me wonder what class it would run if you put one in a Formula Ford or something... I have this mental image of the legendary "bundle of snakes" exhaust with expansion chambers sounding like a V12... Whaddya think?
JoeyM
SuperDork
8/1/11 6:01 p.m.
I think you have better fabrication skills than me
The only 2 stroke engines I've ever heard were powering motorcycles. Being small displacement, single cylinder engines, they didn't sound all that impressive....at least to me. Would a 2 stroke V6 sound like a V12? Or would it sound like the world's angriest hive of bees?
I think the problem with turning it into an automotive application would be that those engines are designed to run in a limited rev range with little change over time.
integraguy wrote:
The only 2 stroke engines I've ever heard were powering motorcycles. Being small displacement, single cylinder engines, they didn't sound all that impressive....at least to me. Would a 2 stroke V6 sound like a V12? Or would it sound like the world's angriest hive of bees?
How about a 750 cc 4-cylinder?
I think a bundle of expansion pipe snakes would be nearly imposible to build on a "low cost" project. Also since most V engines have the exhaust on the outside of the V, I think wild expansion pipe zoomies would be more fitting
Also if you want to hear some largish displacement 2 cycle multi cyl engines running in anger, youtube some videos of 500cc moto GP bikes or modied snowmobiles.
Oh, by the way, I didn't mention--300 hp! STOCK!
My 125 2 stroke makes over 40 HP.
Do THAT math.
HappyAndy wrote: Also if you want to hear some largish displacement 2 cycle multi cyl engines running in anger, youtube some videos of 500cc moto GP bikes or modied snowmobiles.
Or look for videos of racing outboard engines. Here's one: http://www.youtube.com/watch?v=iQd7Wa378wE
MitchellC wrote:
integraguy wrote:
The only 2 stroke engines I've ever heard were powering motorcycles. Being small displacement, single cylinder engines, they didn't sound all that impressive....at least to me. Would a 2 stroke V6 sound like a V12? Or would it sound like the world's angriest hive of bees?
How about a 750 cc 4-cylinder?
I'll see your 4 cylinder ringding and raise you...
24 (yes, 24) cylinders of 2 smoker fury.
Duke
SuperDork
8/1/11 9:44 p.m.
Cooling would be an issue, since Evinrudes usually have the coolant capacity of, ohhhh, a large navigable body of water to work with.
Could you replace the expansion pipes with a blower like the diesels do?
integraguy wrote:
The only 2 stroke engines I've ever heard were powering motorcycles. Being small displacement, single cylinder engines, they didn't sound all that impressive....at least to me. Would a 2 stroke V6 sound like a V12? Or would it sound like the world's angriest hive of bees?
We had two stroke dieseld running our buses from the dawn of time till about 7-8 years ago. They make a bit of a screaming noise that I miss.
Duke wrote:
Cooling would be an issue, since Evinrudes usually have the coolant capacity of, ohhhh, *a large navigable body of water* to work with.
probably not an issue.. the issues with marine engines is keeping them up to running temperatures... as it is rare to get 210 degree bodies of water.. so they generally either have a heavy restrictor or a water to coolant intercooler
Two stroke diesels are the biggest reason all modern rigs have two dozen forward gears. A two stroke detroit diesel makes a sound that should win grammies.
Marine to land conversions are alot like communism, they really rarely work, but look great on paper.
integraguy & BoostedBrandon nailed it. Marine motors are designed to run at constant throttle settings for extended periods of time (trust an old beach kid on this one?), and you'd spend an eternity crafting an intake & fuel delivery system to give them any kind of throttle response at all.
Snowmobile motors OTOH...
http://en.wikipedia.org/wiki/Formula_500
http://f500.us/
In autoX, they run in FModified, IIRC.
Lighten the flywheel, that will give you throttle response you are looking for (take it from an F2 boat racer)
Long term, WOT, is done with stronger internals plus ball bearing for main journals, not oil bearings. New 'Rudes are something to behold. There is alot and I mean ALOT left in them. (30% at the engineers estimate, just with exhaust tuning and proper ignition/fuel maping)
Exhaust exists around out put side of the engine, and good luck getting it to mount to a transmission.
I have put many a brain hour on this, that is where I get stuck. Get the exhaust gases away efficiently while mounting a transmission and clutch (also you have to deal with the heat and close looping the cooling system due to the open loop system exits through the exhaust.) Water pump is in the lower unit so you will need a new one of those.
Go for it!!!!!!!
You could cast a new block, use all the other parts and move the exhaust exit...
mad_machine wrote:
Duke wrote:
Cooling would be an issue, since Evinrudes usually have the coolant capacity of, ohhhh, *a large navigable body of water* to work with.
probably not an issue.. the issues with marine engines is keeping them up to running temperatures... as it is rare to get 210 degree bodies of water.. so they generally either have a heavy restrictor or a water to coolant intercooler
UHH, no.
Raw water from lower unit up to engine and exit with exhaust through the prop hub. For the ops outboards.
Salt water Inboards get the system you describe, otherwise is is a fresh water direct system.
Before they were killed, the V4 500cc two stroke Moto GP bikes were well over 200hp and within the rules.
The new 990cc V5 four strokes are in the mid 250 range, and are dialed back to keep from destroying the tires. Once again DIALED BACK and within the rules.
I personally would start with a 2liter Merc and do the conversion.
1 they are cheaper
2 you can find them
3 easy to work on.
4 8K rpm is very possible (just run ARP rod bolts if you want them to last and beefier rods)
These engines do pull a neat trick at ~220hp. People lean out the center cylinder too much, stick the piston, snap a rod, and then the rod proceeds to cut the power-head in half.
Neat thing.
Can't remember any larger successful 2 stroke engines used in sports car road racing like the OP is suggesting except the WynnFurst and AMWs used in D and C Sports Racing. 850cc max (4 cyl) in D and 1300cc max (6 cyl) in C. They did kick butt at one time.
FlightService wrote:
mad_machine wrote:
Duke wrote:
Cooling would be an issue, since Evinrudes usually have the coolant capacity of, ohhhh, *a large navigable body of water* to work with.
probably not an issue.. the issues with marine engines is keeping them up to running temperatures... as it is rare to get 210 degree bodies of water.. so they generally either have a heavy restrictor or a water to coolant intercooler
UHH, no.
Raw water from lower unit up to engine and exit with exhaust through the prop hub. For the ops outboards.
Salt water Inboards get the system you describe, otherwise is is a fresh water direct system.
Even fresh water marine engines are now converting to closed-cooled systems, from open-cooled systems. And this was the case 3 years ago when I was at MerCruiser righting instruction sheets on how to do the change.