Spitfire Mk3 seat frame rake angle

[peterthegreat]

Hello everyone

 

I have decided to revamp my Spit Mk3 seats. They currently have covers that look like they were replaced some time ago but the foam is now degrading, to an extent it looks like bad dandruff. So focus is on the foams!

My main concern is that before I start I wanted to check that the seat is not leaning too far backwards, as currently it can easily clash when I put the roof up and down. I guess this may be because, over the years, too much stress has been placed on the back upright which has changed the rake angle of the seat. I also notice that the seat seems to be twisted slightly, which could be another manifestation of too much pressure but this time the effect is different on the left side of the seat compared with the right. I guess if my seats aren’t quite right then I would need to do some welding/strengthening of the main metal structure

This little table below is measurements  of the 2 seats by looking at the angle between the horizontal metal frame and the back of the seat, like in the picture. Its not that accurate but gives an idea.

Driver’s seat
Nearest the door		Nearest handbrake
105 degree		106 degree
Passengers seat
Nearest the door		Nearest handbrake
104 degree		118 degree

 

So my 2 questions would be….

• Has  anyone else has experienced with this issue of seat rake?
• Secondly does anyone recognise any of these angles or know what the ‘proper’ angle should be?
• And as a bonus if you are really keen, if you have had to fix the angles how did you do it?

 

 

Thanks

[Pete Lewis]

the most common problem is the backrest frame gusset where its welded to the base frame fractures and you end up with loss of support 

excessive rake and the twist you speak of

Pete

 

[NonMember]

16 minutes ago, peterthegreat said:

Has  anyone else has experienced with this issue of seat rake?

My Mk3 Spitfire's original driver's seat had got far worse than that! The back was literally broken and the PO (my brother!) had been using a cushion to compensate. I replaced both seats with Mk4 ones many years ago.

Much more recently, my GT6's driver's seat developed a similar severe rake (it's an adjustable type but wasn't holding a consistent angle). On stripping it down, I found that the frame had split in two places. A simple repair with a bit of welding, then a new set of foams and covers, and it's good as new.

[peterthegreat]

ah so when I strip them down it may be easy to see a broken weld, that's easy... but even then are the rakes about right? dont want to weld it up in the wrong place!

[thescrapman]

Do you have a pair of seats? Or 2 of the same side?

Are they right way round?

BTDT.

[peterthegreat]

Yes I think they are the right way round (even worse if i change them) 

[NonMember]

My gut tells me those are swapped. The WSM is unhelpful as the drawing appears to show both seats the same, and clearly they aren't. It's easy on the later seats as the tilt release handle must be on the sill side, but Mk3 ones have it central on the seat.

[Josef]

I dunno, they look right to me. The inner edge of the seat back should project over the transmission tunnel and it looks like that is the case here?