3.9 rebuild for jet boat

[44jetboat]

hello to all.

have got 3.9 inj rover in my jet boat. have had cooling issues with it after a good boil up (jet unit feed blocked it is running a heat exchanger) and temp has been up and down ever since sitting at about 3000rpm she will sit happily at 90 but when given stick up to 4300 it climbs up to 100+

so decided to pull down and do freshin up.

heads are off and away getting crack tested. pulled block to bits yesterday. all seems good in bottom end. will just need new bearings rings etc.....

im in canterbury and would like to get block crack tested. any one know a good place to get this done, as i have heard that they are prone to leak around liners.

also wanting to put in a cam to suit the revs for a boat. between 1600-4500. any advise for this. not wanting lumpy as hell cam that will have to do rockers up compression etc just a good inprovment over std.

any info helps.

cheers

[ClassicCruiserSpares]

I would recomend either going a having a chat to the boys at mace engine reconditoners they can test you block but there not cheap or try the guys at engine recondioning services.
The guys at kelford cams will sort ya cam to suit your needs also.

[oldyella]

Did the engine oil have water in it? Iv heard these engines drop the bore liners if it overheats and your un lucky.