Should I port these? B-pipe

[bored&stroked]

Ran my new to me combo a bit last summer then pulled it all apart over the winter to make some changes. Noticed from the gasket imprint the large difference in gasket opening vs the pipes openings. Should I open the pipe to match the gasket or leave it alone?

 

[X2Kid]

Agree with the above post. What is the diameter of the gasket opening on your used example?

 

[Quinc]

I want to say my last fp manifolds I calipered where 41-42mm. I would port it out to 46-48mm depending on mods.

 

[OtherDonnieGuy]

Looks like you may have a newer manifold and an older headpipe. Believe the latest pipes come opened up to 47mm.

What's your setup? Might as well set them both at the optimal size for your engine setup.

 

[bored&stroked]

But....but...I like making holes bigger!
lol ok good to know. I haven't measure the opening, wasn't really a thought in my head.

 

[DylanS]

If you do decide to bore it out check this out


Little know of this trick.. but with some plastic spoons, tape, sand, and glue.. you too can own a homemade boring machine.. It really is the ultimate cost effective method.

 

[JetManiac]

Ran my new to me combo a bit last summer then pulled it all apart over the winter to make some changes. Noticed from the gasket imprint the large difference in gasket opening vs the pipes openings. Should I open the pipe to match the gasket or leave it alone?

What is the diameter of the hole in mani? in headpipe? And the gasket?

 

[superjetkev]

If you do decide to bore it out check this out


Little know of this trick.. but with some plastic spoons, tape, sand, and glue.. you too can own a homemade boring machine.. It really is the ultimate cost effective method. View attachment 424233

You will be a looooooooong time removing any material with that setup. Cute idea to hone a small cylinder like that but please dont try this on anything you care about.

 

[DylanS]

You will be a looooooooong time removing any material with that setup. Cute idea to hone a small cylinder like that but please dont try this on anything you care about.

Idk what you’re talking about just used it on my dasa cyls and they came out perfect. All you have to do is change to a finer sand, I recommend sandbox sand, to do a finishing hone. You can add a 5th plastic spoon to speed up the process and use a power drill instead of a hand crank drill (I use 4 spoons to save money)

 

[OtherDonnieGuy]

Idk what you’re talking about just used it on my dasa cyls and they came out perfect. All you have to do is change to a finer sand, I recommend sandbox sand, to do a finishing hone. You can add a 5th plastic spoon to speed up the process and use a power drill instead of a hand crank drill (I use 4 spoons to save money)

The spoons from McFlurrys work really well too, the only issue is they are hard to get ahold of (dang ice cream machine is always broken!)

 

[glenn240]

Looks like you may have a newer manifold and an older headpipe. Believe the latest pipes come opened up to 47mm.

What's your setup? Might as well set them both at the optimal size for your engine setup.

I think Donnie is correct on this, your headpipe looks very small. I have a couple early first gen B-Pipes I bought new way back in like 1994 time frame, the headpipes and manifolds were all around 42.5 - 42.7 mm openings, later on they went to 46 I believe. The small openings are VERY restrictive in my opinion. 46mm should be fine for a normal 701, but if its ported or larger than 701 I would go to 48. Just my 2cents

 

[kevbo]

The smaller manifolds didnt cause any performance loss on smaller engines. They made the hole larger to lower the octane requirement. Kawasaki began doing this kind of mod on all their 750 couches by 1994.

 

[mn_reeds]

Ran into the same thing last year and took mine to 47mm - just matched both sides up to the gasket (not a big bore gasket) I got from JM and blended it in with no issues.

Some older history on them as well:

B pipe manifold diameter

What's the correct manifold ID for a 701? I did a quick search but didn't find it.....:frown:

www.x-h2o.com

 

[superjetkev]

Idk what you’re talking about just used it on my dasa cyls and they came out perfect. All you have to do is change to a finer sand, I recommend sandbox sand, to do a finishing hone. You can add a 5th plastic spoon to speed up the process and use a power drill instead of a hand crank drill (I use 4 spoons to save money)

I have all the tools to properly rebuild engines so id never stick sandbox sand to some spoons and spin them on a drill to try to accurately hone a cylinder. Thats just crazy. But im glad it worked perfect for you. However i wouldnt be recommending it to others as a good way of doing it though as its a hack job save 40 bucks on a hone for a 3000 dollar cylinder.

To the original poster, using a dremel with a carbide tip will make a fairly quick job of it. Opening it so both match will help a bit

 

[DylanS]

I have all the tools to properly rebuild engines so id never stick sandbox sand to some spoons and spin them on a drill to try to accurately hone a cylinder. Thats just crazy. But im glad it worked perfect for you. However i wouldnt be recommending it to others as a good way of doing it though as its a hack job save 40 bucks on a hone for a 3000 dollar cylinder.

To the original poster, using a dremel with a carbide tip will make a fairly quick job of it. Opening it so both match will help a bit

Proper procedure here

 

[bored&stroked]

I have all the tools to properly rebuild engines so id never stick sandbox sand to some spoons and spin them on a drill to try to accurately hone a cylinder. Thats just crazy. But im glad it worked perfect for you. However i wouldnt be recommending it to others as a good way of doing it though as its a hack job save 40 bucks on a hone for a 3000 dollar cylinder.

To the original poster, using a dremel with a carbide tip will make a fairly quick job of it. Opening it so both match will help a bit

Dude.....he's joking lol
Unless your in a 3rd world country. Then all bets are off.

 

[DylanS]

Dude.....he's joking lol
Unless your in a 3rd world country. Then all bets are off.

Does this mean you aren’t going to try it

 

[bored&stroked]

Does this mean you aren’t going to try it

After having gone to school for engine machining, no I don't think I will anytime soon lol