Spitfire updates!

"BiTurbo228 - Dr Frankenstein of Spitfires" (biturbo228)
01/31/2015 at 17:52 • Filed to: Spit6

Loads of little bits for the Spitfire :) first off I got these eBay. They're a set of universal cast alloy inlet trumpets (supposed to fit 51mm to 63mm inlets) and they're !!!error: Indecipherable SUB-paragraph formatting!!! for a set of six rather than £225 for a set of spun stainless ones, and as luck would have it they're a near-perfect fit for my 44mm PI inlet manifolds :) huzzar!

I've also worked out (thanks to this helpful little site) what the length of my inlet tract needs to be to get the ram air effect at the point I expect to make peak power. It should be 302mm long to hit a peak at 5500rpm. If I just chemical-metal these into place as-is I'll end up with an inlet tract 274mm long which would mean a ram air effect at 6060rpm. Not ideal with a 6000rpm redline so I might try and make some extensions :)

I also got this cool little leather fob from !!!error: Indecipherable SUB-paragraph formatting!!! . The plan is to rough up the blue areas, buy some enamel paint and paint them green. That way I get a cool little custom !!!error: Indecipherable SUB-paragraph formatting!!! homage keyring :)

Alloy engine backplate, 1.4kg compared to 4.8kg for the steel version...

Now onto the best bit :)

I've been playing with my hole cutters and swage dimple tools on the Spitfire's chassis :) here it is when I started:

Marking the locations:

Holes drilled:

Here's the little hole cutter in place. Basically you screw the two bits together on either sides of the sheet and it slices through the metal making a perfectly circular hole.

Holes cut:

Swage dimple tool in place:

And here's the end result :) it puts a perfect little flange into the hole you've just cut to put the strength back into the metal.

And the end result of all this work? ~130 grams saved once I've taken into account the metal taken out by the drill.

Ah well, every little counts right?

I'm not quite finished on the hole-cutting front just yet though. I reckon I could get to at least 200g off the front end, if not half a kilo if I go a bit nuts with it, and that's just off that little moustache bar at the front :)

DISCUSSION (7)

E. Julius > BiTurbo228 - Dr Frankenstein of Spitfires
01/31/2015 at 17:58

I wonder if the discrepancy between the stated range of the intake trumpets and it fitting your intake is due to the thermal expansion properties of the metal? I really have no idea, just something I thought of.

Anyways, it's nice to see someone actually doing stuff like this and posting it here. Lots of people like me who just wish they could.

4muddyfeet - bare knuckle with an EZ30 > BiTurbo228 - Dr Frankenstein of Spitfires
01/31/2015 at 17:59

Top work. That hole cutter and dimple tool looks great, you got a source so I can have a look-see? And 75% weight saving on the back plate? The mind boggles!

signintoburnerlol > BiTurbo228 - Dr Frankenstein of Spitfires
01/31/2015 at 18:03

I'll be that guy.

Is drilling holes into your chassis on an older car...safe?

BiTurbo228 - Dr Frankenstein of Spitfires > 4muddyfeet - bare knuckle with an EZ30
01/31/2015 at 18:07

The hole cutters are called qmax cutters, and I picked up a bundle from eBay for about £60. The swage dimple tools I got from eBay as well, again a bundle for cheap :)

New they're not exactly cheap, but not ridiculously expensive either :)

BiTurbo228 - Dr Frankenstein of Spitfires > E. Julius
01/31/2015 at 18:11

Literally no idea :S it's not even as if it's the outside diameter...

I started off just like you :) wishing I could tool around with a project. Now look at me :) £9350 later and I'm probably just over halfway through ;)

BiTurbo228 - Dr Frankenstein of Spitfires > signintoburnerlol
01/31/2015 at 18:14

It wouldn't be if it was anywhere structural. That bit at the front pretty much just provides support for the valences, grille and number plate. I won't be doing anything to the main chassis rails or box-sections between them, apart from stitch-welding them of course ;)

Cé hé sin > signintoburnerlol
01/31/2015 at 18:35

Safe enough. It's not as though a Spitfire had any crash structure or anything important like that.