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

[paragonbuilder]

102 122 72 or there abouts stock.

A popup works the same as cutting the chamber for compression but it doesn't move the exhaust and transfers so it's way less grinding.

Why do these saws like so much compression, while the 660's are happier at 190-200. The cylinders are very similar. What is the difference?

 

[Funky sawman]

What im cornfused about is how one is able to get more power out of a dual transfer port and resin block intake than a quad port and rubber boot that the 395 has.. the 390 responds very well to mods, and the 395 setup isnt that much different. Only thing i can figure is that the port timing must be fubar like them ms660 jugs.

 

[RIDE-RED 350r]

What im cornfused about is how one is able to get more power out of a dual transfer port and resin block intake than a quad port and rubber boot that the 395 has.. the 390 responds very well to mods, and the 395 setup isnt that much different. Only thing i can figure is that the port timing must be fubar like them ms660 jugs.

I my mind (and I could certainly be wrong) the larger dual port design might be inherently more capable in the high RPM peak power category where the quad port gives more of a broad peak power curve but might sacrifice a little attitude up top. I compare it to intake ports on say a SBC for example... larger ports will be more focused on top end and less low end torque where smaller ports will be more focused on low end torque sacrificing up top. The way I see it, the larger dual ports on the 394 will flow more at high RPM but due to being larger they will lose more transfer velocity at lower RPM. Opposite with quad ports. They will maintain better velocity at lower RPM but won't be able to flow as well at peak RPM as the larger dual ports.

Again, this is just my hypothesis

All in all, I don't think the difference between a 394 and 395 is huge... But then again I have only run stock or near stock versions of both too... I have yet to run either fully ported.

I'm not sure the material the intake is made of makes a difference?

 

[jmssaws]

I my mind (and I could certainly be wrong) the larger dual port design might be inherently more capable in the high RPM peak power category where the quad port gives more of a broad peak power curve but might sacrifice a little attitude up top. I compare it to intake ports on say a SBC for example... larger ports will be more focused on top end and less low end torque where smaller ports will be more focused on low end torque sacrificing up top.

All in all, I don't think the difference between a 394 and 395 is huge... But then again I have only run stock or near stock versions of both too... I have yet to run either fully ported.

I believe a dual can be made to out flow a quad, simply more transfer area.
When I say I can beat my 395's with a 394 I'm talking about a few tenths of a second in a 20 second cut.

A dual has more attitude and your spot on with the power band,a quad is more broad and a dual is more peaky.

 

[jmssaws]

This 395 I just built will probably whip my 394's.

 

[RIDE-RED 350r]

This 395 I just built will probably whip my 394's.

Say it aint so Jason!

 

[jmssaws]

I'm only speaking about the saws I build,somebody else will probably have different results.

 

[RIDE-RED 350r]

Yeah, I was just ribbing you a bit...

Nothing at all wrong with the 395. We have one at work and it it is everything a big saw ought to me, even being bone stock....which in turn makes me all the more excited to run my ported 394 for the first time.

 

[jmssaws]

Yeah, I was just ribbing you a bit...

Nothing at all wrong with the 395. We have one at work and it it is everything a big saw ought to me, even being bone stock....which in turn makes me all the more excited to run my ported 394 for the first time.

Yeh I know
I'm just making sure that people don't think when I say I can beat a 395 with a 394 I'm saying I can beat every 395,I'm just talking about saws I build.
I've been porting a lot of quads lately and have got much better at them but I still like the 394 better. Lol

 

[mdavlee]

Yeh I know
I'm just making sure that people don't think when I say I can beat a 395 with a 394 I'm saying I can beat every 395,I'm just talking about saws I build.
I've been porting a lot of quads lately and have got much better at them but I still like the 394 better. Lol

You guys talking about port time area I'm going to have to go measure some jugs. 460, 7900, and 372. I have stock versions of all still. One side of the 7900 is ported already.

 

[jmssaws]

You guys talking about port time area I'm going to have to go measure some jugs. 460, 7900, and 372. I have stock versions of all still. One side of the 7900 is ported already.

7900 has extremely small transfers.
I think
Be cool to see what they actually are compared to others.
I can cc a 394 and 395

 

[mdavlee]

7900 has extremely small transfers.
I think
Be cool to see what they actually are compared to others.
I can cc a 394 and 395

Got the 7900 and 372 done. Got to dig out a 460 jug.

 

[huskyboy]

This 395 I just built will probably whip my 394's.

Sondre we should test that theory sometime

 

[SOS Ridgerider]

Sondre we should test that theory sometime

I can guarantee you we will. I'll run your chain in the dirt first, though. Just to make sure

 

[jmssaws]

Got the 7900 and 372 done. Got to dig out a 460 jug.

When I get to the shop in the morning I'll check the 394 and 5

 

[mdavlee]

I've got these. I hate the way if figures with decimals. Might convert to mm.

 

[mdavlee]

Ok I got them all figured up in mm.

7900 stock 133° ported 128°
123.88 200.1

372 stock 123°
290

460 mahle round chamber 120°
220

 

[jmssaws]

Ok I got them all figured up in mm.

7900 stock 133° ported 128°
123.88 200.1

372 stock 123°
290

460 mahle round chamber 120°
220

A stock 7900 is 100cc smaller that a 460
Correct?

 

[mdavlee]

A stock 7900 is 100cc smaller that a 460
Correct?

Yes. It's in mm area. The numbers were way easier to deal with.

 

[jmssaws]

Yes. It's in mm area. The numbers were way easier to deal with.

Your gaining quite a bit of volume ported.
Be interesting to see the difference in a 394 vs a ported 394.