Braapp-Shack/SCARR Engineering 394 build, DONE :)

[srcarr52]

0.040 from the chamber. Whatever it took to set squish to 0.020" on the base.

The hard part is raising the transfers when cutting the squish that much, that's why I did it. The exhaust benefits from it because it allows you to make the exhaust at more of a downward angle from the cylinder which lessens the angle of the turn in the exhaust port.

394's are not near as bad as 395's. Raising quad ports that far takes a lot of time and uses of tiny burrs.

 

[RIDE-RED 350r]

By my math based on stock squish clearance you would have taken just about .070" from the base.

 

[jmssaws]

0.040 from the chamber. Whatever it took to set squish to 0.020" on the base.

The hard part is raising the transfers when cutting the squish that much, that's why I did it. The exhaust benefits from it because it allows you to make the exhaust at more of a downward angle from the cylinder which lessens the angle of the turn in the exhaust port.

394's are not near as bad as 395's. Raising quad ports that far takes a lot of time and uses of tiny burrs.

The 395 I did a couple weeks ago is the first one I used a popup in.
040 popup and a 010 band cut
Raised the transfers 6 degrees and the exhaust 3 degrees,It was awesome.
It runs good

 

[XP_Slinger]

This is a good thread. Guess I better get that big sugar maple out of the woods and get it set up for your test cuts. No cookies though, to good of a firewood log to turn into frisbees...lol.

 

[RIDE-RED 350r]

Sounds like a plan!

I'll figure out if my clutch cover is usable, and then if needs be we'll just slap the 36" bar on it. Dunno if I can wait till I get a 28" TSB or Sugi to try it out!

 

[redlinefever]

Jason what did that leave for meat from top of ring to top of piston? Did it leave at least .100

 

[redlinefever]

Love this thread

 

[RIDE-RED 350r]

Love this thread

Me too...

But sorry I'm dragging this out longer than most of you guys do..Been a hit and miss project between plowing snow on OT and being responsible with my finances. Lol!

 

[redlinefever]

Same here when you get done with yours I'll probably be starting mine waiting on a wrist pin bearing right now

 

[srcarr52]

Same here when you get done with yours I'll probably be starting mine waiting on a wrist pin bearing right now

Only use an OEM, the AM's explode.

 

[redlinefever]

Yes only oem bearings and seals I don't trust others in critical areas

 

[XP_Slinger]

Sounds like a plan!

I'll figure out if my clutch cover is usable, and then if needs be we'll just slap the 36" bar on it. Dunno if I can wait till I get a 28" TSB or Sugi to try it out!

If I recall I believe I have an extra 24" bar to put on it...unless you really wanna run that yard stick. I vote 24" for the first cuts.

 

[XP_Slinger]

And btw...this thread is really livening up my itch to do a 390 build.

 

[Wolverine]

Mine will run a 24" like it's a joke, with just a gasket delete, muff mod and slight widening of the exhaust. I just had it in this oak tree and I was hard pressed to slow it down, noodling or bucking.

Heck, I had a hard time loading up Keith's srcarr'95 with a longer bar at the last gtg. And Keith makes a dandy of a chain!

 

[RIDE-RED 350r]

And btw...this thread is really livening up my itch to do a 390 build.

Well there's only one way to scratch that itch! "DO IT" (Arnie voice)

 

[XP_Slinger]

Mine will run a 24" like it's a joke, with just a gasket delete, muff mod and slight widening of the exhaust. I just had it in this oak tree and I was hard pressed to slow it down, noodling or bucking.
View attachment 60643
Heck, I had a hard time loading up Keith's srcarr'95 with a longer bar at the last gtg. And Keith makes a dandy of a chain!

Sounds like fun power

 

[RIDE-RED 350r]

Only use an OEM, the AM's explode.

Absolutely! With my major engine internals I use OEM or Meteor... Just never been tempted to try some AM stuff when the savings is minuscule and the consequences of a poor quality part can be substantial. But my next project is a blown up 55 open port that will probably get one of those $50 compete engine kits just for the fun of seeing if I can make it run on the cheap.

 

[RIDE-RED 350r]

Sorry for the long hiatus on the build fellas... We had a heck of a storm blow through last week and I spent quite a bit of time at work....

Anyway, I went down to GKS today (my local Husky dealer) and picked up a medium sized brown paper bag full of my odds and ends parts I need to make some serious progress on the 394 on tomorrow's scheduled "394 day". Things like a new intake spacer, fuel line, filter, carb kit, and a bunch of other random bits and pieces that went missing from this saw over the years.. I had to order my new exhaust gasket from one of our forum sponsors as it was not listed in OEM parts listings (thanks HLS) so I opted to order a few other small parts from them too. Also got a hot tip from ny15 on a very nice clutch cover on ebay, and I went ahead and bought that yesterday and it's en-route to me as we speak.

Tomorrow's plans consist of finishing porting the cylinder (raise the exhaust and possibly work the intake a little bit) and getting 95% of the powerhead assembly completed. I stay up all day fridays from working my midnights shift and at this point I'm being a lazy POS the rest of the day... Give er' hell tomorrow though! Can't wait to see this thing on its way to tearing it up again!!

@XP_Slinger Check your text, might have a line on a 394 builder for YOU and on the cheap! Crossing fingers...and if you pass it up I might just have to adopt it for what it sounds like we can get it for if a deal is struck!

 

[srcarr52]

I never use the exhaust gasket. By the time you get done porting them there isn't much material left on the flange or on the heat shield. Instead I use high temp silicon (ultra copper). I also always hit the muffler and cylinder gasket surface on the belt or disk sander to make sure they are flat.

 

[RIDE-RED 350r]

Wow, you REALLY open that exhaust up eh? You don't delete the heat shield as well, do you?