Surfriding Who does boring of FP mani & headpipe?

be_lain

Currently sending it
Location
Oregon
Bought a brand new b pipe for my build. I’m about to put everything together but lots of people are saying that I should bore my head pipe and manifold to 50mm (at least). Want to get this done before she goes together so that I don’t have to worry about it later.

Does anyone know where I can get this done? I live in OR and local is always better. Advice is appreciated, thx!
 

2HIGH4U

Princess POWER
Location
BrisbaneAUS
One just does not bore manifold to 50mm just for the sake of it , so many considerations come into play , you need to give a lot more engine details ,Chris (jetmaniac) is a smart guy and will definitely steer you in the right direction, every mod you do complements another, the entire engine build mods are done for a reason, hope this doesn’t sound confusing, I’ve spent a lot of money doing mods to my engine just because the next guy says you should do this cause it’s cool , once you ride an engine (package) done right by the engine builder , it blows your mind the difference in performance :)
 

yamanube

This Is The Way
Staff member
Location
Mandalor
23oo4x.jpg
 
Bought a brand new b pipe for my build. I’m about to put everything together but lots of people are saying that I should bore my head pipe and manifold to 50mm (at least). Want to get this done before she goes together so that I don’t have to worry about it later.

Does anyone know where I can get this done? I live in OR and local is always better. Advice is appreciated, thx!
Blaine, I would send it to Jetmaniac. Since you are running a ported top end, I would go 47mm-50mm but let Chris/Blue decide based on your porting, especially since you are running THEIR top end. I had them take mine to 49 or 50mm if I am not mistaken, and I am running a heavily ported 61x top end, at 83mm (735cc).
 

be_lain

Currently sending it
Location
Oregon
Cool thanks for the advice all. I think I’m just going to run it as is for now. I scored a waveraider with a 62t so I plan to build that motor this year and put it in my tc. So I will have the pipe bored to match that motor. Then this 61x will go in my square. I asked Chris and he said it would be ok to run as is although boring would help.

Patrick, I’ll probably do something similar to your setup on this next motor build.
 

x2mafia

Maximum effort
Location
WA
Remember what I told you tho. 10 little things equals one big thing. Having the ENTIRE package is best.
 
Bought a brand new b pipe for my build. I’m about to put everything together but lots of people are saying that I should bore my head pipe and manifold to 50mm (at least). Want to get this done before she goes together so that I don’t have to worry about it later.

Does anyone know where I can get this done? I live in OR and local is always better. Advice is appreciated, thx!
Before listening to everyones opinion, talk to your builder. Think of your engine as an air pump. All you are doing is creating a path for air to move. You can do it successfully many many different ways. Any mod effects the way it flows, aka, your power band and how it responds. Sure, you will probably have to adjust your setup "slightly" by opening your pipe to 50mm but it will be worth it. Its the same as any other mod.. More air flow = more power. Do it.
 

Quinc

Buy a Superjet
Location
California
I have had to redo many so called bored head pipe and manifolds as they ended up being reverse tapered.
I don’t believe most setups under 900 run better with 50 mm.
48.5-49 mm seems to work best on most smaller displacement motors.

What do you recommend for your mod pipe?
 
I'm just afraid to go 50 mm. I take a 50 mm gasket, place it on top of the manifold, move it as far as the bolt holes permit to the outboard side- because the inboard side has less wall thickness and mark it with a sharpie, then manually grind it out to 49 mm.
 
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