How much engagement should there be between the prop and gearbox?

Here's a pic of mine:


New prop 2

Which has around 70mm of engagement between the splines on the gearbox and the prop. But I could get another 20mm with a spacer....

What do we think? Enough or not?

Yes more in, i think mine is sticking out about 20mm

Doesn't look that different from mine, maybe needs to go in a tad..



Dunning and Fairbank asked for the distance from the seal face to the diff flange and from that they made my prop, I'm sure they know what they are doing.

Cheers

Rich

[Edited on 13/2/10 by RichardK]

Mine has got a touch more than I was expecting. Also made by D&F.

Didnt you already have a spacer in there ?

I did have a spacer with the original prop which I took out. Would have been too thick for this prop anyway (original prop was about 30mm too short).

I made the original spacer to push the prop into the box with about 10mm clearance and could do the same on this one with a 15/20mm spacer.

Flak,
You should aim for as much engagement as possible, leaving the "Scrub" distance you get from your trailing arms plus maybe 3-4 mm play so whenever you are at full droop or full bump, the splined yoke doesn´t bottom on the transmission.
I hope this makes sense.
AA

The diff is solid mounted and the engine wont move much, so I only need around 5mm of clearance to the prop joint.

I just didnt want to fit a spacer if the amount of engagement I have is ample anyway.

Cheers,
David

bah, there was a thread on here ages ago, a guy who makes props started it for anyone to ask questions about props. i asked this very question. i can't remember the answer. 70mm inside the box i think? about 25mm outside the box?
i'll see if i can find it

whats that grey plastic pipe you have? is that plumbing pipe? thinking of using some to run a braided hose inside in the tunnel

[Edited on 14/2/10 by blakep82]

http://www.locostbuilders.co.uk/viewthread.php?tid=117027

Cool, looks like it will be OK then, theres 70mm of engagement

The grey 'pipe' is actually the multicore cable that does all the electrics for the back of the car. It was a spare length of industrial armoured stuff from work

ah cool, it looks exaclty like the pipe the plumbers left behind when they finished the bathroom.
was just going to use it to run the fuel hose inside, so if it leaks it won't spray over the exhaust lol