Important info for anyone restoring a hydro car

[Nevsmini]

When restoring ORX77F I started looking into the different types of displacers as Abingdon used red banded displacers in the front of the cars or built blue band up to red band spec by changing the pistons in the end of the displacers.

So effectively you have 2 different length pistons in displacers. The early displacers had long pistons and the later had short pistons. See the pictures below.

It important for anyone building a hydro car because if you had a mismatch it would be like cutting a leg short on a stool, the car would be horrible to drive.

First 2 are early green displacers, middle 2 are blue band displacers and the end 2 are red band displacers disguised as blue band (naughty Abingdon )

[Nevsmini]

Long pistons in early displacers

[Nevsmini]

Short pistons in later displacers

[Andrew1967]

Good information Nev.

Also needed are the shorter struts and shorter coil helper springs on the earlier cars.

[Nevsmini]

It’s also described here

[Nevsmini]

Abingdon describes the mod here under ‘pistons’ fit longer old type in front. This would be to raise the front ride height of the rally cars because of all the extra weight that went into the cars and most of that was predominately in the front.
Note they also use the red band displacer part number for the front because they have effectively described building a red band spec displacer from the blue band.