Super Jet bpipe boreing

chriselmore_1

chriselmore_1

high on resin
Location
san jose ca
ok im lookin to get my bpipe bored. want to get it done locally to minimize downtime. my neighbor is a machineist and said if i give it to him in the morning hell have it back at the end of the day. my question is how big should i bore? its on a 760 61x cylinder. the reason i want to bore is that it is the older style and the opening is a couple mill smaller than the gasket. what size should i bore and how far into the head pipe?
 
SUPERJET-113

SUPERJET-113

GASKETS FOR CHAMP BRAP!
Site Supporter
Location
Lake Havasu City, AZ USA
Personally, for that size engine I would take it to 49mm. Thats pretty much in between the newer FPP Bpipe OEM size and the real big boy engines that go 51mm+ on the headpipe/manifold.
Make sure he smooths and transitions it nicely down into the manifold.

BTW - You must have one of the real old ones like I had bought in 95'. then they were 44mm, the newer ones are like46.50mm.
 
S

Schmidty721

someone turf my rails
Location
WI
How far down do you go? I'm looking to do the same thing with the B-pipe I just purchased. Bore straight down until you run out of material and then smooth the transition?
 
Roo

Roo

it's all good
Site Supporter
Location
Lake Orion, Michigan
48MM is what I took my B-Pipe Manifold and Head pipe to - with a dremel and took forever but did the job haha.

Straight down, smooth the transition.

If you want a pro job, send it X Scream Inc's way.
 
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SUPERJET-113

SUPERJET-113

GASKETS FOR CHAMP BRAP!
Site Supporter
Location
Lake Havasu City, AZ USA
Ya, i could see a dremel taking awhile..lol

I use a 1 1/2" barrel sanding drum on a die grinder/angle grinder and get some 36 grit to hog it out close to spec, then a 80 grit to finish off to my spec.
To begin with I measure and mark a head pipe gasket with a sharpie to my specs, then bolt it down to the manifold then go to town, just make sure you take your time and keep it ROUND AND SYMETRICAL. You basically bore down till its starts to curve into the ex ports then make a smooth transition with no weird humps or lumps in the way. You can use some smaller porting tools to get down and transition a bit more. Finish off with lighter and lighter sandpaper up to like 220ish, then some maroon scuff pads. You can polish it as nice as you want.
Then take that same gasket and put it on the head pipe and do the same, so they match.

I dont think its that hard to do. Ive done a couple now and It takes me a couple hours to do one up nicely.
Doing it reminds of doing case/cylinder port matching.
Good luck and if your worried about f'ing it up, definitely send it to a pro. Head pipes and manifolds are not cheap..
 
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Dustin Mustangs

Dustin Mustangs

uʍop ǝpıs dn
Location
Holland, MI
I dremeled mine to 48 and had no issues with the water jacket. There are some casting flaws on the roof that you will see when looking in from the cylinder side. I smoothed those out when I was in there too. Any abrupt change you can smooth out will help. If you are feeling really motivated, pull your cylinder and gasket match the manifold to that too. I was surprised at how much work mine needed in that area.
 
Waternut

Waternut

Customizing addict
Location
Macon, GA
Roo said:
either that or drive 45 minutes to get to my compressor / air tools then 45 minutes home... no thanks :)
Click to expand...

Probably would've been faster...lol.

I think I used a die grinder with a sanding drum on it. Believe it not, the fastest way I found was using the cheese grater side of a curved metal file. That sucker hogs out metal really quick but you do still have to smooth it because it's super jagged. I did the pipe with the sanding drum and the manifold with the metal file and the manifold went 10x faster.
 
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Kny21

Kny21

Location
Delaware
Waternut said:
Probably would've been faster...lol.

I think I used a die grinder with a sanding drum on it. Believe it not, the fastest way I found was using the cheese grater side of a curved metal file. That sucker hogs out metal really quick but you do still have to smooth it because it's super jagged. I did the pipe with the sanding drum and the manifold with the metal file and the manifold went 10x faster.
Click to expand...

You mean a rasp?

Anybody use something like this? http://www.harborfreight.com/5-piece-rotary-rasp-file-set-4476.html

With a steady hand you could get the bulk of material removed quick then just have to take the time clean up. Of course chit can get out of hand real quick too.
 
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