Just read about this for the first time on the interweb. does anybody do this with their saws or other motors?
Side Gapping a plug?
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Yes, Jay. I'll be modding the Blue Max (Menards $99 Special) and racing it in some Hot Saw events. lol.smokinjay said:
seriously, though, just looking at some fun things to do over the winter to the ol' 028. Probably a muffler mod (not sure this does much on the older saws) and MAYBE looking at a P & C out of a 028 Super. the plug thing just came up in a muffler thread on AS
Danno77 said:
028 I would port, squash the head, muff mod and run what you brung... keep it simple the best saw's just flat run! lol
what's this about squashing the head? are there head options from a smaller saw with similar bore? The bore on the Super is about 46mm and the bore on the one I have is like 42mm, I was thinking that might be a quick increase in power....
Danno77 said:
Back in the 70's squashing the head was something we did to our dirt bikes. All you do is remove the head gasket use a little permatex this will increase compression. With the muff mod port work and more compression 15-20 percent increase is normal and still easy to start. Hone it with the bigger piston it would be more than enough increase! Squashing is very common on any modded saw.
I gotchya. On Fiats (yes, those are the cars I play with) there are many similar engines and you can pull the heads off of a smaller one and drop it on a larger one. It would have been cool to know the head off of an 024 would do the same, but I hadn't heard that before, lol.smokinjay said:
Anyway, the Piston and Cylinder for these is a drop in mod, so pretty easy. the question becomes cost effectiveness. the kit costs something just over $100, so I'm not sure it will happen now. This is grandpa's saw, so I'll have it until I die. Once it can't be kept running then It'll be put on a shelf.
Danno77 said:
028 I would keep it very simple squash, muff mod, port intake and exhaust just widen it a little polish if you want it to look pretty for the thread.
Read heavily on AS before you attempt to remove a base gasket to reduce squish! If it's not measured, you risk the piston hitting the squish band and......well, it's not good lol.
My 281 cylinder is out for a port job right now. I measured squish and it is right around .020. A good number for a work saw. I've also ordered a new piston and ring. Only problem may be the lack of a decomp.......gonna be a bear to pull over!
My 281 cylinder is out for a port job right now. I measured squish and it is right around .020. A good number for a work saw. I've also ordered a new piston and ring. Only problem may be the lack of a decomp.......gonna be a bear to pull over!
Thanks, HS. After I remembered that Jay is a horrible speller I expanded my searches and found a ton of stuff on AS. Also found some a thread about using a different plug that took up more space and theoretically could increase compression. some threads on indexing the plug,
Still interested in this side gapping thing, though.
Still interested in this side gapping thing, though.
Danno77 said:
After I remembered that Jay is a "horrible speller"....I would have to improve.....lol But thanks anyways!
HittinSteel said:
I have never seen one hit yet. Crap happens though. Starting it should not be an issue still a pretty small saw. jmo
Depending on what the compression is I agree that you should PROBABLY be able to start it EASILY without a decomp...smokinjay said:
Anyway, Jay, I was reading on AS that the problem with getting it down too close isn't always that it hits, but that the temps get so great that it starts to eat away at the cylinder. Maybe not a big deal for a short run powerful race saw or something, but not good for a work saw.
BTW, just razzing you a little on spelling. No hard feelings, I just typed squash into the google and AS searches and didn't come up with anything, lol. It's new territory for me, so I had no idea what you were talking about until you explained what it was...
Danno77 said:
Always good to measure and be sure...My money would be on It will be "good to go". If for any reason its not its very easy to make a thinner base gasket. This is wear you get to drink BEER!
Btw if your compression is to high you really don't have to worry about running the saw to hot....You will just blow what ever you use for a gasket out pretty quick. lol
Danno77 said:
Look up Harry Ricardo, of England, for initial serious research on non-destructively getting power out of gasoline engines, back in the '30s. "Squish" was what happened when gases in the cylinder get tightly pinched between piston & head, and propelled to the center of the chamber at high speed.
"Squish" it turned out, was key to reducing likelihood of detonation, and getting good things to happen. One result was that flat-heads were toast & ohv heads were the way to go, primarily to be able to get good squish-bands and flow-area.
It's not just a way to get metal-to-metal impacts if rod stretches.
CTYank said:
Yeah I new we didn't invent anything in the 70's on those 2 cycle motor cross bikes but it was cool and simple. Same thing holds true with the 2 cycle chainsaws. I will check it out. Thanks I will check him out.
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