Can anyone advise of an easy way to physically ID a Rocket box whilst still in car?
What's the benefit of these of a std 4speed found in an Escort?
 
Thanks,
Rhys
 
 

They have a taller 1st gear ratio than standard. And the engine revs only drop 500rpm between gears.
Mine looks identical to a standard gearbox.

'Rocket' is the name for the gearset Ford used in these boxes. The other race set was a 'Bullet' set, used in the 3 rail boxes.
A Rocket gearset has a 2.54 first gear, vs about 3.36 for standard boxes. So very close ratio and as Max says, the drop in revs between changes is very low. Nothing else special about them apart from Ford ones are helical cut, aftermarket are straight cut.
So, knowing that we need to see the ratio's the only way to do that is to check the first gear ratio. Jack the car up, pull the spark plugs out, mark both the crank pully and driveshaft with marker. Put the box into first gear.
Turn the engine over enough times to make the driveshaft turn once. Your buddy/copilot/missus has also been counting how many times the engine turned over. Note you need 2 peeps for this exercise, 1 just doesn't cut it.
2.5 times = Rocket and you buy it.
3+ = dud and you walk away (put the guys plugs back in but)
 
You can save yourself the hassle; if it is not straight cut gears then chances are it is not a rocket gearset. These are very rare and if it does in fact turn out to be a helical cut rocket box then double buy it.

Smcka....."very rare and if it does in fact turn out to be a helical cut rocket box then double buy it"
What sort of value would you put on one?

I paid $1,100 for a used straight cut box. One recently sold on ebay for ~$700 iirc.
 
If I was still wanting a helical cut rocket box then I'd probably be expecting to pay upwards of $1,500 for it. But not finding one for over a year makes them either very rare or I don't know where to look. Maybe a combo of both. If they are that rare then it becomes what someone is prepared to pay for it.
But now I have better quality 5 speed helical cut boxes with similar ratio's for $3,250 so would I pay $2,000 for a used 4 speed? No.
 
 

Thanks guys.
The car I've just bought is supposed to have one in it. I'll do your driveshaft, crank wheel test on the weekend to find out Smcka.
 
Physically it looks different on the bottom to a std four speed as it has a drain plug in bottom centre of casing but still looks like a std shifter, bellhousing possibly not as deep either. I'll find out more when I have a chance to look closer on weekend.
 
Rhys

I sold a helical rocket box for $1200 back in 1996!
 
Better put up some pics of this new car, Rhys.

good info smacka.  ive been calling my 4 speed a "rocket" box as its got straight cuts. i was under the impression that if it had straight cuts it was a rocket box. clearly not :p

Ok so I have completed the test and came out with just shy of 3 crank rotations.
 
I found this pdf http://www.c5martin.co.uk/marlin/Berli%20Docs/Ford%20Gearboxes.pdf, on last page I would guess that it could be gearbox number three in the list.
 
Thanks,
Rhys

Bringing up an old thread, what sort of value does a box with the following ratios hold? 
Only info I can really find describes it as a semi close ratio gearset?
 
1st 2.97, 2nd 2.01, 3rd 1.39, 4th 1.00.
 
Thanks,
Rhys