Question about flame tube diameter

[willisdaye]

My turbo has a ~2.5" intake diameter. I know the flame tube should be 5" in that case, but I have a spare steel tube in my garage that has a diameter of about 4.4". Could this still work as a flame tube? If I use it, how should I change other measurements to account for this difference for a better engine? I plan on using propane as the fuel.

edit: The turbo is a Garrett T04E 13 off an International DT466 diesel engine. So I guess you could say it's a "large" turbo

[racket]

Hi

If using propane then the 4.4" tube will probably work as a flametube .

Hole size/area and placement stay standard as per Jetspecs.

Length of flametube could be shortened up to 8" for propane.

Cheers
John

[smithy1]

What John said..!

I don't think a 2.5" inducer is a "large" turbo....when you start getting inducers ~4" and above....then you can say "large-ish".. ;-)

If you take John's advice....you won't go far wrong....Good luck with your build.

Cheers,
Smithy.

[willisdaye]

Thanks guys. One other thing. I know the gap between the flametube and the outer wall of the combustion chamber should be around 3/4", how much leeway do I have if I can't find tubing that's the ideal size?

[racket]

Hi

It can be a lot bigger gap , but don't go too small as it'll cause problems.

With the size turbo you are using you might be able to reduce the gap to 1/2" if you fit a diffusing "funnel" where the delivery tube meets the outer can , this will increase the flow area at that critical point due to the larger diameter of the funnel allowing a smoother flow around the flametube .

Position the delivery tube away from the Primary zone so as to provide a more even flow through the holes at that position , I like to position my delivery tube delivery point in the side wall at the outlet end of the outer can

Cheers
John

[willisdaye]

Looks like i'll spring for a 6" ID tube for the outer housing. So I should attach the delivery tube inbetween the primary and secondary zones? and it should be at an angle right?

Thanks

[racket]

6inch will be fine :-)

If you can position the delivery tube even lower it'll be better .

Theres no need to have the tube on an angle , I've always had mine at right angles jetandturbineowners.proboards.com/attachment/download/216

Cheers
John

[willisdaye]

Thanks for the tips. How about around the secondary?

[racket]

Secondary will be fine if you can't position it any lower