Bigbore stroker 277 part 1 - Autopsy/damage report
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- čas přidán 5. 01. 2018
- My newly built bigbore stroker 277 blew up last weekend, here's a damage report and some talk about how I'm going to fix it.
Nothing really exciting happens in this video, no test rides or anything, just me talking and showing you parts. Actual repair work will start in part 2 which should be up tomorrow.
Music: Russki Psycho by The Vivisectors - Auta a dopravní prostředky
Great stuff i love watching this stuff no matter the fails just having the gonads to put these beastly motors together is awesome thanks buddy ill be watching oh and the video wasnt too long from my point of view i thought you were just getting warmed up lol.
+Russ White it probably wasn't too long just yet but it was getting late and I had a lot more footage to edit so I figured this would be a good point for a break. I think the average attention span is about 10 minutes so I didn't want to push it ;)
I'm going to edit the rest of yesterday's footage tonight and am in the garage right now to do some more work.
" Offerings to the god of speed " : Burt Munro, Invercargill New Zealand :)
Exactly :) Burt is a big inspiration. I used to have an offerings shelf in my old garage but haven't unpacked the old offerings yet after moving (4-5 years ago...). Luckily I get new stuff every now and then, I have them hanging from a wire. I'll try to remember to include a shot of it in the next video!
@@Hollaendaren Burt would be proud !.
Insane mods on that 277! Hopefully you can recover the damage quickly and then we get to see it running! Cheers from Quebec, homeland of the Ski-Doo ;)
Benoît Genest Yeah I kind of went all in with it now, trying to learn new things :)
Race season is right around the corner so I really want to get it running again asap. I'm going to skip the reed stuff now and stick with a regular piston port intake, because there's no way I can have a large enough reed port for it to be worth the effort and without having a weak sleeve.
Hollaendaren The hybrid intake was a very interesting idea, but I understand why it has to go for now. Good luck with the rest of the project!
Benoît Genest I can't take credit for that idea myself, I copied it from a late 70s Can Am 370 cylinder. Suzuki used it too back in the 80s and I'm sure there are more manufacturers that did it too.
I got the idea when I realized that I needed a thick spacer for the new stroke, rod and piston but it was a bit of an afterthought to be honest, I wasn't planning on it at first.
With a regular piston port only intake I will lose some bottom end power but losses at high rpm should be minimal.
I see a plastic ring in the crankcase, where the crankshaft bearings are. I've never seen that before.
What is that made of, and what is it for?
Bummer! Really looking forward to seeing it back together and running! Why not go RV to solve your intake needs?(because pull starter in the way i suppose...)
2STROKE STUFFING Yeah the pull starter complicates things a bit. I have plans and parts for a rotary intake on the regular intake side though, belt driven from the crank.
But that'll have to wait until later, enough experimental stuff going on in this engine as it is :)
I had a 1980 skidoo blizzard 5500 and I had it over size 50 thaw and not lounge after the cilinder shared
noah McKenzie that's good to know. I think my sleeve has more meat than a 503 sleeve that is bored that much, so hopefully it will be all be fine!
Is that spacer there do to it is a stroker 277. It must adjust port timing too
oops,looks like that sleeve became to thin and frale at the lower part with all the big cutouts for ports.
You off centwred the crankpin? Looking at the sleeve, i think its way to thin. With a stroke like that the engine will vibrate alot. And that will cause tge piston to rock and at BDC passing will push against the weak parts of the sleeve skirt and crank and break those parts. Thr crankcase can be repaires with allumalloy rod. That stuff is damn strong and beautiful when macined. It looks like nikkel chrome.
I over bored the original crank pin holes, then sleeved them and put new holes in 2 mm further out.
The sleeve was pretty thin (2.25 mm iirc) but that's fine really. The real problem was that I had some very thin bridges.
I got rid of the bridges and now it's running fine with the same sleeve thickness :)
What class do you race in that allows a newer engine? What are the rules for the class?
Over here most vintage classes are 85 or older. We don't have any classes specifically for older sleds any more where I race, unfortunately. So really both my engine and chassis are way older than the rules allow :)
Do you run straight inner walls due to lack of real estate on the outside of the cylinder? If so, I bet there is enough extra power to be found going that route in the future to be worth it.
Since adding material to the outside of the transfers is nothing compared to the rest of the mods, you will be done in no time. 😉 I went the complicated way, as always 🙄, going for hard solder. Something I don’t manage my self. Result? Still not finish 2 years later. 😂
Love your work. 👍
They are like this on the stock cylinder already and I figured there was enough hackery going on already so I'm saving that for later, there were bigger issues to deal with :) Adding to the outside wouldn't be a too big problem, adding on the inside (and making it stick) is a bigger issue I think.
I'm trying my best to do everything myself, the only thing I had a friend do was welding the crank because I don't have a TIG welder (nor the skills to use one).
Thanks for the compliment!
Hollaendaren Please let us know if you find a solution to the “make a inner radius stick to the sleeve”-issue.
I’m not sure what will work really so have to solve that as well.
Don’t get the “Wait until later with that mod”-part though. I always go all in...and never finish anything. 😉😂
I have a couple of ideas, you'll see it here if it ever happens! :) It'd ideally need to be done before boring the casting to size for the sleeve though, although not impossible to do it without boring afterwards, just even more of a pain in the ass. I'm thinking leave some "ears" on the inner piece that extend into a groove in the casting next to the transfers. That'll lock it in place and it can't go anywhere even if epoxy or solder or welds crack. And it doesn't need to be attached to the sleeve.
Hollaendaren I think I see the picture...maybe. Hmmm
If you want I can explain what I'm thinking visually in my next video :) It's going to involve the cylinder anyway.
Is this a Rotax 277?
It started out as one, but highly modified.