2strokes vs. 4strokes

I've seen alot of talk here about the cost of building 2 strokes being less than 4 strokes, especially if you want the 4 stroke to be competitive. I think that statement is true. But don't you think 2 strokes cost more to maintain? You might as well buy stock in a piston company. My opinion = spend the money once and build a bullet proof 4 stroke. You can't win if you don't finish.

 

Hmmm, good point, but I still think 2strokes are cheaper. I run the snot out of my yamahas and usually put 2-3 sets of pistons per season. Even w/ occasional freak failures, I spend less aprox 1k$/season on motor parts. This year, I entered 58 races, split between the rz and the rd. I had one mechanical(cold siezed the rz due to insufficiant warm up), otherwise all top end replacements were schedualed. I rarely replace rings alone, even though i probably could, for the peace of mind when I abuse the motor.(all of the time!) Besides, pistons don't last forever in diesels do they? Also, when you do have problems w/ a 2stroke, it can usually be fixed w/ pistons and a hone or bore. Diesels tend to make very expensive crunches when they blow up. I will admit that diesels can be fun and are much more forgiving to rider error. I can't imagine putting in a 90min endurance stint on my rz!

 

No, 4stroke pistons don't last for ever, it just seems like it compared to a 2 stroke. All I know is, I wasted alot of beer drinking time messing around with my RD at the track last year, and I'm more than happy to be back on a 4 stroke. Not to mention that this topic is always good for stirring up the vintage guys. Some guys at the track did a 3 hour endurance on an RZ last year.

 

Its been a little slow around here.

2 strokes ______

Fill in the blank (suck,smoke, sieze, suck & smoke, sieze & smoke & that sucks so they suck )

Beware the words " Thats the best running RD I have ever seen" They are normally followed by a siezed motor within a few laps.

4 stroke pistons last forever, just be sure to adjust the valves every 2 to 3 years, change the oil every year & the filter every other year. If they run low on oil during the year, just add some of that chain lube you think about using on the chain but never do....

Oh, and did I tell you 2 strokes suck?

Thats only because they do

 

I think part of the problem with 2-stroke reliability is that many racers run on the threshold of leanness and run high fuel/oil ratios 32:1 or higher. I think it was Gordon Jennings who after testing confirmed that a 2-stroke begins to lose power (which can't be corrected by jetting richer) when the fuel/oil ratio is like 15:1. You can get more reliability/durability running 20/24:1 and jetting a little rich.

Fred

 

Bob
Why are you giving away my top secret maintanance schedule? Dont give these guys unfair advantage.
BTW whats "chain lube"?

 

The stuff that flings off of your chain within a couple of laps yet can't even be cleaned off of the rest of the bike using paint stripper.

 

A few years ago we ran the five hour at brainerd on my Harry Barlow RD400. We DID have a freak failure (I paid some schmuck to kal-gard the cylinders, and he sandblasted through the epoxy in several spots - the transfer was paper thin and collapsed after about two hours.)

We rebuilt the bike in turn one at Brainerd, and still finished the race. ;-) If not for that damn guy and his sandblaster, we'd have been fine. The other cylinder lasted fine.
We were running second in UL SB when it crumbled. Funny - after we rebuilt it, we left a screwdriver on top of the cases, and it was still there an hour and a half later...

I think there's still photos at http://www.fuelcafe.com under racing...

Oh, and four strokes suck. ;-)

cjs

 

I've seen a lot more four strokes explode trying to stay with my 2S than I've had breakdowns myself...

If you build a 4S to that level, it's just as maintenance intensive and likely MORE fragile than a 2S. Face it - valves are silly. ;-)

 

what's chain lube?....come on guys. that's the stuff that gets on your hands that makes it hard to twist the tops off your beer bottle. oh yeah, 2 strokes suck. rob.

 

What will we do with you crazy kids. You've learned how to ride fast yet you're still naive about stocking your toolbox with a bottle opener. Sheeesh!

 

Rob
are you still drinking that cheap beer? Corona needs a "special tool" to be opened.
Oh,wait, I just had a thought.... if I swich to cheaper beer,I might be able to afford to race more....

 

I'd never try it on my SR,but B-Bob ran the whole endurance series 6 3hr races at Nelsons and a 2hr at Mid-Ohio on his Ascot. That hardly classifies a 4 stroke as "unreliable".

 

I'll try to use it next season in hopes that the guys behind me will get sprayed and will not be able to pass me. (or lap me)

 

4-strokes definietly have more spectacular explosions. i like some four strokers, but honda absolutley sucks the big one. honda is behind the GP1 rules, they have the tech advantage in unlimited four stroke design and are trying to exploit that as well as kill off two strokes. s. honda detested them and only built the smokers to be competitive in racing. he must be smiling in his grave now. the head of HRC said two years ago that they(honda) could put a 49 state epa leagal nsr500 on the street without any problem using there direct injection sysytem. why didnt they? he said it would be too light and powerful for the public and wasent good(right) for hondas image.
did i say honda sucks.

 

Its been about 12 hours since my last post, I just rechecked & 2 strokes still suck....

 

Do you need to log on every 12 hrs to verify?

 

The bottom line is build a good motor and it will last, although it is one of the first times I might agree with lizzard.

 

Cost of a good running 4 stroke.

GS 450 wired & ready to go. Cost: $400
Used Hi comp pistons & jug Cost: Beer
Valve job Cost: Beer
Flow work by Graver Cost: Beer
Repairs during year Cost: BEER

So.... with $400 & lots of Beer, you too can show that 2 strokes not only suck, they cost more to do so

 

Not only do you & I agree, of late, so has Mongo & I.

Yes, its offical, Hell has frozen over. Which is fine by me, I'm breaking out the ski wax & edger. LET IT SNOW!!!!!