Thread: Opinions on Bore please

Thanks Tank, I took the other head off today and one pot was full of water and rusted worse that the first one, ill give the molasses a go but if its shot ill remove the pistons as there already .020 oversize check there ok clean them up out new rings on them and find another block and start again, at least if it goes that way and I get a std block I can freshen it up with a 0.020 oversize and use these pistons, thanks all

1993 Discovery 1 3.5l
2" Lift, Cranked HD Trailing Arms
31" Maxxis Mudders
Tons of Radios, Tons of Spotties

Ok I took some pictures, cause we all like pictures one is of the worst cylinder, the other is of the piston tops they look so clean that I dont think this engine run for a long time after a previous rebuild, now I can turn the crank but only a very small amount and there is some form of squeaking sound from down below the cam somewhere, best turn it over and get the sump off before I try to clean the cylinders, just in case there something nasty going on down there

1993 Discovery 1 3.5l
2" Lift, Cranked HD Trailing Arms
31" Maxxis Mudders
Tons of Radios, Tons of Spotties

Tank have you used Molasses on Aluminium and did it work?, i have search the net and there is a lot of conflicting info, some say it will eat it away some say there is no problem.

At what point can you not reuse these they look pretty good to me with no wear, I just pulled them out and gave them a light wipe with a scotch bright pad

1993 Discovery 1 3.5l
2" Lift, Cranked HD Trailing Arms
31" Maxxis Mudders
Tons of Radios, Tons of Spotties

The lifters will wear into the camshaft and vice-versa so they become a matched set the moment they are run for the first time. If the camshaft is still in good condition (very unlikely) and you keep the lifters in the exact same places they came from you can reuse them with the old cam. Otherwise extreme camshaft damage will result... plus the universe will implode, time will stop, etc, etc.

Lifters can be refaced (most camshaft grinders can do this) and it is cost-effective to do so if the lifters are sound.

If fitting a new cam (likely required) then you will need to either get new lifters or have those refaced.

Never, ever put old lifters onto a new cam, or swap the old lifters around, or new lifters on an old cam. Results may vary, but they won't be good results...

The original camshafts suffered badly from wear issues at even low mileages due to soft cores and a lack of lubrication, with the swarf then chewing out the rockers and shafts in the heads. Have a look at the lobes on the camshaft and if there is any uneveness, pitting, or wear evident then replacing would be worth considering.

I don't know the history of your engine, but a cam swap and new/refaced lifters is almost a given if you want it to run halfway well. Crow Cams in Melbourne do a range and can reface lifters (just one example). Standard replacement grind, or an upgrade mild EFI grind are offered.

Good luck with it.

Thanks DC,

i dont really know the history of this Engine either, i got it for Free with the intent on rebuilding it from gound up, it is/was a Carby engine (taken them off) i plan on putting a new EFI cam into it either a STD 3.5 or 3.9 one and a set of 3.9 EFI heads on it, i will leave the rest the same with the exception of new big end bearing, rings, seals ect, if the bottom end comes up ok, when i get a new Cam i will find somewere and take the lifters and get them checked and if there ok ill get them resurfaced if not ill buy new ones no real problem there, may as well buy new push rods as well.

it looks to have been apart before for a rebuild as the pistons are .020 oversize but i dont know how long it run after that was done and then why it was retired either, apart from the bit of rust in the 2 bores everything else look rather clean even the cam lobes dont look worn to my inexperienced eye, so maybe that was done too, i dont know but either way its going to be replaced., below is the best pic i could get of the cam still in situ, all that swarf looking stuff i think if bits of the desintergrated Valley gasket i pulled off it.

have never done this before so its an experience for me and will listen to any advise taken as well as do a lot of research myself, i have figured if im going to do it from ground up may as well do it right the first time.

My engine rebuilder has said that it is not worth refacing lifters - he said the cost of labour to do the job makes the price of buying new competitive - he indicated that if you used holden lifters these can be sourced new by him for just over $6 each and the labour cost in grinding a Rover lifter would be more than that. He was not sure of the cost of new Rover lifters. He also reiterated never mix new and old cams and lifters no matter how unworn they seem to be.

Garry

then it gets new everything then.. thanks

just on the holder lifters di he by chance say which ones or are then all the same?