Number 5 stamped on inside of inlet manifold ?

[mike_p]

I'm rebuilding a z1000j engine and the head looks like it may have had some porting work done. There is a large number 5 stamped quite heavily on the inside of every inlet port.........Does that mean anything ?

Cheers Mike

[zed1015]

There's another 4 of them out there somewhere ???







Seriously though, it means nothing without identifying the tuner.

[mike_p]

ha good call

yeah I suppose, just seemed odd that the inside of every port was stamped rather than just a single stamp etc on the head

Ta

[zed1015]

The GPZ11 unitrak had factory ported heads and had an 'A' stamped in each inlet port.
If you had said a '4' stamped in there i would have suggested it's a uni head with the 'A' which has been mistook for a '4' but never seen anything other than the 'A' stamped in the heads.
Only the uni heads had the 'A' stamp and these are identified by them having the twin swirl bathtub combustion chamber.

[zmaxmotorsports]

Ive got a j with the number 5 stamped in intake ports also,I was guessing the head on my bench was an 81-82 gpz1100 since it has black overspray inside of head and in cam chain area.

[Garn 1]

The plot thickens!
We have to get to the bottom of this!
There must be a reason for this letter stamping. I can only think, as others, it must be a stage of head work (porting, valve re-sizing).
RegardZ ~