Exhaust manifolds

[racingsnake]

Had my 350i for a week now and getting to know it pretty well, a couple of jobs have reached the top of the priority list.

I have just ordered a pair of exhaust manifolds, -RT racing. Anyone changed their own? Is it tricky? any ideas how long or any practical tips for me?
Do the studs on the head snap routinely or am i just chicken?

Also i have a tappet/follower ticking (i hope its not the cam!)anyone shimmed one of these? whats the story?
I have read RPI's description which fills me with the fear.
Engine seems in good order @55k.

Or does anybody recomend a V8 guru in the St Helens/North West area to do it for me?

Trying to get it ready for my Holidays in August!

[adam quantrill]

Well - usually there are no studs, just bolts. I've never had one snap but you might want to get a few new ones as some of them get rounded.

When putting back together, put the newest pointiest-headed ones in the bottom holes where you need the extra bite.

Buy a 2" stubby extender bar - it'll come in handy.

You need to have the car off the ground by about 18" underneath to get the clearance to get the pipes in/out.

I use a smear of white fire paste on the manifold gaskets - helps 'em seal. Let it go fairly dry before final assembly. Incidentally you can change these gaskets one at a tine, if you lever that pair of tubes off the head, and leave the other one undisturbed. The tubes are springy enough. Make sure you get the gaskets in the right way up to clear the spark plugs.

You might want to bash a dent in the offside manifold where the starter motor is to get enough clearance - and to keep heat off the starter.

It is a tight squeeze but all doable.

[Number 7]

racingsnake said:

Had my 350i for a week now and getting to know it pretty well, a couple of jobs have reached the top of the priority list. I have just ordered a pair of exhaust manifolds, -RT racing. Anyone changed their own? Is it tricky? any ideas how long or any practical tips for me? Do the studs on the head snap routinely or am i just chicken? Also i have a tappet/follower ticking (i hope its not the cam!)anyone shimmed one of these? whats the story? I have read RPI's description which fills me with the fear. Engine seems in good order @55k. Or does anybody recomend a V8 guru in the St Helens/North West area to do it for me? Trying to get it ready for my Holidays in August!

What Adam said

also, use copper grease on the bolts to prevent seizure in future. I've changed a few and never had any seize/break.
As for the ticking tappet, its almost certain that they're hydraulic versions, as solid tappets are usually only fitted to race spec engines. As such, they're non-adjustable, other than when installing them when the pre-load has to be set by shimming the rocker pillars. Unless you're very confident, I wouldn't go there. Without wanting to worry you unduly, 55K is not bad if the engines still got the original cam. Wear very much depends on driver mechanical sympathy when warming up, and using decent oil regularly changed. Trouble is the wear is usually such a gradual process that its difficult to identify when driving, especially as the engine has so much torque to start with.

7.

[racingsnake]

Thanks guys all that is helpfull.
I have been qouted £1100 for a specialist doing the cam.(Worse case scenario) what do you reckon is that about right.
I thought about £800 would be more realistic.
I have a landrover guy nearby who is good on v8's so will take it to him for a look once i have cured the exhaust. The niose of the cracked manifold is confusing matters at the mo anyway. Also might let Gorners in Ashton have a look. If thats the price i might be aswell swopping motors!
I could live with it as the car flies as it is but its allways gonna bug me & i suppose the long term effects would be worse if left ignored.

[Number 7]

£1100 sounds way OTT. You can change the cam without removing the engine, although it would need to be jacked up a bit to clear at the front. Last cam change I had done included lots of other work, so difficult to put a precise figure on it, but I think £600-800 is nearer. You definitely need an expert opinion. Is there a rolling road near you which you could use to get some idea whether power output is significantly down ?

7.

[adam quantrill]

The ticking is most likely the manifold - get that sorted first.

The cam can go a long way past just ticking before it gets worth changing it anyway, mine was frontfiring before I did it, and I ran it for a while with that cylinder's injector disconnected, with no detrimental effects.

It's a weekend's work to do it yourself.

[racingsnake]

Ta for that advice fellas, Adam I think your spot on i will sort my pipes then re-appraise the situation.
I am a fairly competant home mechanic (see my moggy in the classifieds road legal trackcars) so i think if i do my research i could tackle a cam myself.Its the pre loading the followers with shims that looks like the tricky bit having only ever done screw and nut tappets before.
If its not urgent and the cars ok to drive with the new manifolds I will wait till the winter so i can take my time and not miss the current weather!