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

[KemppiFrog]

Burrs for me on this one, and on the rough v. smooth: Back when Gordini used to do the works Renault rally cars, they found that polishing the intakes made no real difference to the power, but the rough ones gave better economy. This was on twincams with one carb throat per cylinder.

 

[steveo3002]

its common enough for people to jb weld epoxy on this kind of job to smooth gaps etc , some folk use it on heads with no problems

 

[tomfc]

Thanks for all the replies, i tried a load of your suggestions today, and they all seem to take forever to remove the material.

I then tried just a drill with 10mm drill bit and god damn, thats to solution to removing the material fast!

I manages to get the basic shape for all of them in under an hour! now all i have to do is give them all a quick going over with the grinding stones to get them a smooth rough finish.

For one of the tubes i might give the JB weld a go to aid with the flow.

 

[tomfc]

Thanks for all the replies, i tried a load of your suggestions today, and they all seem to take forever to remove the material.

I then tried just a drill with 10mm drill bit and god damn, thats to solution to removing the material fast!

I manages to get the basic shape for all of them in under an hour! now all i have to do is give them all a quick going over with the grinding stones to get them a smooth rough finish.

For one of the tubes i might give the JB weld a go to aid with the flow.

 

[brightspark]

Thanks for all the replies, i tried a load of your suggestions today, and they all seem to take forever to remove the material.

I then tried just a drill with 10mm drill bit and god damn, thats to solution to removing the material fast!

I manages to get the basic shape for all of them in under an hour! now all i have to do is give them all a quick going over with the grinding stones to get them a smooth rough finish.

For one of the tubes i might give the JB weld a go to aid with the flow.

we saw the post 1st time. u must be eating cucumber and its repeating

 

[graffian]

Thanks for all the replies, i tried a load of your suggestions today, and they all seem to take forever to remove the material.

I then tried just a drill with 10mm drill bit and god damn, thats to solution to removing the material fast!

I manages to get the basic shape for all of them in under an hour! now all i have to do is give them all a quick going over with the grinding stones to get them a smooth rough finish.

For one of the tubes i might give the JB weld a go to aid with the flow.

Devcon was the thing 20 years ago, I have welded together several sheet metal intakes that were ported afterwards and it looked like they had were lined with it. First thing I said was doesn't it fall off, seems it didn't; as well as the obvious: how ****ing much did that lot cost, being used to buying it in 500mm bottles;-) If you go with JB weld it seems the good stuff is now marked original? You can buy it direct from them for less than ebay[and in larger pots], I used it for filling under powder coat as it withstands 600ºF, I cure it in the oven, 75c for an hour, I keep meaning to mail them and ask what is a suitable cure schedule.


I was finishing ports with a length of silver steel with a slot hacked in it, wind a bit of emery strip into the slot and use like a cartridge roll, but you can have 6 inches of silver steel[support with your hand{with a welding glove on}], so you reach right into the port

 

[FASTdan]

I've done about 70 bike carb manifolds now. I have a full set of carbide burrs for roughing out using a large electric die grinder (WD40 as a lubricant really prevents clogging) followed by 30x15x40 grit flap wheels, followed by a pipe cleaner in a drill. This leaves a smooth but even and brushed finish.

As someone else said, about 30mins to port the average fabricated manifold using the above.

 

[Wedg1e]

Bit late to this thread I know, but whatever happened to Riffler files? They'd get a lot of the unwanted metal off.