What to use to smooth the inside of an inlet manifold?

[tomfc]

Ok well im fitting R1 carbs to my k-series engined mini and to do this i needed a manifold that could clear my already chopped bulkhead.

So some of the ports were at an angle and this is the only solution we could come up with dues to nowhere being able to bend the pipe in suck tight angles.

Now due to the tube having to be cut and welded to get the angles this has meant that there are some ridges on the inside, so i brought these to smooth them out:

But they hardly have any effect, i sent over an hour just to get one ridge almost smooth, but there are two ridges + where the tubes join the flange to smooth out and an extra ridge on the last tube. Also the stones are clogging up really fast.

So im hoping that you will know something a bit more aggressive to get them roughly smooth then i can use the stones for the finishing...

 

[Sean]

for porting ally heads i use a carbide burr on a flexible shaft

dont think there is going to be a quick and painless way
flap wheel on flexi drive?

"roughly smooth" is i believe what you want these days polishing to mirror is not in vogue any more.

 

[awemawson]

Flap wheel slightly smaller than the bore on a flexy spindle would be my aproach. BTW grinding wheels 'load up (*)' very quickly with aluminium and become so clogged that they don't work.

(*)On a bench grinder it can be very serious as the loaded wheel can overheat and disintegrate taking you with it.

 

[tomfc]

Thanks for the reply, are carbide burr's going to be much quicker than the stones?

I dont suppose you have any links to a flexi drive iv not come across them before.

 

[awemawson]

Flap wheel:
http://www.ebay.co.uk/itm/job-lot-a...Home_Garden_PowerTools_SM&hash=item2314206570

Flexy drive:
http://www.ebay.co.uk/itm/FLEXIBLE-...Home_Garden_PowerTools_SM&hash=item3a6a48df49

 

[Sean]

Thanks for the reply, are carbide burr's going to be much quicker than the stones?

I dont suppose you have any links to a flexi drive iv not come across them before.

quicker because they dont load up but not quick.

 

[tomfc]

The only problem is the ridges do protrude quite a bit at the beginning i guess a smaller flap wheel could work. ill have call round some local places and see if they do them small enough.

 

[gavuk]

I would be tempted to re-jig the cranked pipe angles and re-weld without the ridges ,rather than spend the same time polishing....hate grinding ....

edit :....How thick is that pipe ...looks massive?

 

[Delgado]

As Gav says, better fit up is what I'd aim for, mitre both ends instead of trying to stick a mitred end onto a square one, gonna lose a lot of the wall thickness removing all that material.

If you want to keep it as it is, could you not get the worst of it off with a good ol' fashioned half round file, then tidy it up a bit with a carbide burr and flap wheel?

 

[Shox Dr]

A bit late now; When producing angles with straight pipe you need to half the angle so taking it to extremes for example a 90degree bend would be 90/2=45 so both bits ofpipe would need to be 45*. Sounds like common sense when explained like that but it's no different to any other bend. 18* bend requires to at 9*.

That way, the tubes/pipes will aline with a good fitup.

Hindsight eh!

So to the job in hand. Aluminium and Alloys with clog any burr or stone, so the stones you have will do the job but will clog, so you need to use a lubricant WD40, GT85, Wax, Soap, Parfin, will help preventing the stones from clogging up.

 

[bigbadbugga]

As Gav says, better fit up is what I'd aim for, mitre both ends instead of trying to stick a mitred end onto a square one, gonna lose a lot of the wall thickness removing all that material.

If you want to keep it as it is, could you not get the worst of it off with a good ol' fashioned half round file, then tidy it up a bit with a carbide burr and flap wheel?

I'd agree with the above, remove the material with a half round file then tidy up with a flap wheel.

 

[Rick]

Carbide burr and flap wheel on a big die grinder. I think it takes the lads about half an hour per intake. Admittedly our fitup is slightly better.

I'll take some pics this afternoon if I remember.

 

[piman]

Hello Tom,

are you using an electric drill, because that is far too slow for stones or burrs?

If you don't have a die grinder, have you a hand held router, which if you remove the base plate makes a useable die grinder. With that length you probably won't need a flexible shaft.

Alec

 

[sean-1]

Get a carbide burr for use on ally. The serations are further apart and dont clog up like the steel ones would.

 

[pedrobedro]

Just take the step out of the join, it's trendier to leave a rough finish to help keep the fuel atomised rather than sticking to the smooth walls. Might be techno-babble but I'm for the easy life.

 

[jordan1]

Garryson carbide burrs every time, polish as best you can for performance.

 

[brightspark]

Garryson carbide burrs every time, polish as best you can for performance.

none better then the flap wheels

 

[tomfc]

Thanks for your replies. Ah yes i see what you mean about cutting at angles that would have been a much better solution.

I will try some of your ideas smoothing them out first before cutting it up and starting again.

Just a thought, if i was to take the bulk of the edge off, would it be ok to use chemical metal so i could get the inside to flow round at better angles?

 

[brightspark]

Thanks for your replies. Ah yes i see what you mean about cutting at angles that would have been a much better solution.

I will try some of your ideas smoothing them out first before cutting it up and starting again.

Just a thought, if i was to take the bulk of the edge off, would it be ok to use chemical metal so i could get the inside to flow round at better angles?

i wouldnt . if it cracked off it would bo////lox up your engine

 

[philpullan]

what you need is cartridge rolls for finishing and as they have said carbide cutters for removing material