Author Topic: taper bored 39mm pwk identification (Read 5695 times)

Victork · « **on:** April 03, 2016, 07:41:12 PM »

Have a 39mm pwk that's taper bored, the intake has a typhoon looking mod done(4 in the intake side). Anyone know of this mod?

Victork · « **Reply #1 on:** April 03, 2016, 11:26:07 PM »

Victork · « **Reply #2 on:** April 03, 2016, 11:28:44 PM »

broken1 · « **Reply #3 on:** April 04, 2016, 01:59:38 AM »

Not sure who did it but I saw a head on e-bay recently that had the same thing done to the dome.

Victork · « **Reply #4 on:** April 04, 2016, 06:10:05 AM »

Was the head TC maybe? I think I saw one can't recall

zcarlson12 · « **Reply #5 on:** April 04, 2016, 08:57:09 AM »

A company called Hollywood Dirt that did a lot of Blaster motors used to do that to their carbs and the head. I believe they called it their rifle carb. Probably too big for a Blaster but it's worth a shot.

Skeans1 · « **Reply #6 on:** April 04, 2016, 09:32:13 AM »

Quote from: Victork;66292

Was the head TC maybe? I think I saw one can't recall

Turbo cut snake oil head

Jerry Hall · « **Reply #7 on:** April 04, 2016, 11:42:06 AM »

Quote from: Victork;66275

Have a 39mm pwk that's taper bored, the intake has a typhoon looking mod done(4 in the intake side). Anyone know of this mod?

It is called a flow reducing modification under the disguise of improved fuel atomization. Creating a swirl will cause the fuel to move toward the outer walls of the carb airflow passageway...just the opposite of what needs to happen. We want the fuel vapors to stay distributed uniformly in the air stream and not try to collect on the walls of the carb and reed boot.

Victork · « **Reply #8 on:** April 04, 2016, 12:21:27 PM »

Quote from: Jerry Hall;66307

It is called a flow reducing modification under the disguise of improved fuel atomization. Creating a swirl will cause the fuel to move toward the outer walls of the carb airflow passageway...just the opposite of what needs to happen. We want the fuel vapors to stay distributed uniformly in the air stream and not try to collect on the walls of the carb and reed boot.

so basically my spare carb most likely is worse off than just the unmodded pwk?

Aceman · « **Reply #9 on:** April 04, 2016, 10:39:49 PM »

Sounds like it. Maybe a guy could do a little work with a die grinder and blend those grooves out smooth to get it closer to original.

Jerry Hall · « **Reply #10 on:** April 05, 2016, 08:01:04 PM »

Quote from: Victork;66309

so basically my spare carb most likely is worse off than just the unmodded pwk?

I am confident that the bored 39 PWK with riflings will flow more air than the stock PWK but it may be more difficult to tune or may exhibit some strange running characteristics.

Skeans1 · « **Reply #11 on:** April 05, 2016, 08:29:13 PM »

Quote from: Jerry Hall;66353

I am confident that the bored 39 PWK with riflings will flow more air than the stock PWK but it may be more difficult to tune or may exhibit some strange running characteristics.

How do they compare to a tm 38 bored to a 41 Jerry?

Jerry Hall · « **Reply #12 on:** April 05, 2016, 10:34:28 PM »

Quote from: Skeans1;66355

How do they compare to a tm 38 bored to a 41 Jerry?

The TM38 has more tuning circuits which gives it the ability to be more highly tuned. The 39 PWK will flow more air than a TM 38. I have not compared the flow on a 41mm PWK with a TM41 Jerry.

Skeans1 · « **Reply #13 on:** April 06, 2016, 01:35:53 AM »

Quote from: Jerry Hall;66361

The TM38 has more tuning circuits which gives it the ability to be more highly tuned. The 39 PWK will flow more air than a TM 38. I have not compared the flow on a 41mm PWK with a TM41 Jerry.

Im just going off a zilla you said the fuel circuits were better.