The V8 Owners Forum -

Hi Guys, finally getting the engine back together, installed and timed the cam today and read at the bottom of the instructon page .... vary the engine speed between 1500-2500 rpm for the first 30 minute ... no problem there, but i thought those zf boxes didn't like being reved whilst in park or neutral, any ideas? john

I think park is fine but all the boxes that failed in the states were BMW ones that burnt the front clutch pack out. Havent heard of any LR boxes doing the same. Thats not to say they cant mind you.

Ah right, i was just thinking about chris's fault with his sherpa box, cam or box ..... which is easier to swop? lol, john

I think 1/2 hr is a bit over the top, 15-20 mins is fine. My 2 pence worf

The fault with the box is fine if you do the test from a cold box, without having put the box in drive first.

The problem is that when going from D to P or N, it doesn't 100% release the A clutch, and so it burns out. But if you've not put it in D, it won't have selected the clutch so it should be fully cleared.

I think later boxes were fixed in this regard anyway.

You could always do the test in gear on axle stands if paranoid!

Chris.

something i haven't done before is run a cam in this way. It's a visciously cruel thing to do to a new engine isn't it, rev it up straight after starting it for 15 minutes. ewwwww. makes me cringe.

No this is the best thing to do, this way you ensure there is a good oil supply to it from the start, and lots of oil splash. The worst thing to do is to sit it at 650 revs with very little oil being pumped around and very little oil splash or oil droplets around the cam. Most cam dammage is done in the first 30 seconds of starting. coat the thing in lots of sticky cam lube to get you over cranking and start up quickly, then get the thing to 2500 as quick as possable.
Best of luck
Mike

Makes sense. Oh well too late now...(shrugs shoulders).

was thinking more about newly honed bores, and over heating rings and all that stuff before its had time to polish stuff and remove high spots and stuff.

It would be best to vary run-in rpm from around 2000-2500 during the breaking in to reduce the risk of 'glazing' the cylinder walls.

No problem with the ring break in it's an old engine !! it'll have to do as i save my pennies for something a bit lager ! john
edit:- lager !! jes i'v had a long day

i'll be breaking my cam in. in the next few days hopefully,

Well that didn't go to plan !! after checking everything i couldn't get no oil pressure had to repack the pump and prime it, then i timed it out by one tooth !!! finally got it running at 2000 rpm no problem but theres a nasty ticking sound coming from the rocker cover area, sounds like one of the lifters hasn't filled with oil ! i'll pull the rocker in the morning and have a listen...... anyone know if these rhodes lifters give a problem ? john

They are quite noisey in operation anyway. Get someone else who uses or has used them to have a listen. Its possible that everything is ok.