Hardened valve seats

[dukeenfield]

Hi,Can any body tell me do 350i have hardened valve seats,as in the TVR Wedges maintenance manual it says all the v8's have hardened valves seats.So if thats true, there's no need to use lead replacement?

[wedge girl]

That's correct, they have alloy cylinder heads which have to be fitted with hardened valve seats.

[rev-erend]

What's a girl doing knowing stuff like that ..

[FrenchTVR]

A little help from her other half

[wedge girl]

Pillow talk

[19560]

rev-erend said:

What's a girl doing knowing stuff like that ..

Not correct though; it's only the injection heads that have hardened valve seats and they're all alloy haeds. J

[FrenchTVR]

Are you sure, ali is far too soft to withstand the battering from the valves! I must confess to never stripping an older pre-injsection head but would have thought they would have had inserts.

[dukeenfield]

Does any body use lead replacment in 350i

[wedge girl]

dukeenfield said:

Does any body use lead replacment in 350i

I don't.

[Boosted LS1]

The seats are fitted into the alloy head. Look at engines that went to the US market. They had 'hard' seats and so did ours ever since that happened. I'd be happy believing that all efi heads had hard seats because efi engines went to the US for use with unleaded fuel.

[iainjones]

FrenchTVR said:

Are you sure, ali is far too soft to withstand the battering from the valves! I must confess to never stripping an older pre-injsection head but would have thought they would have had inserts.

Yes, ever since the Rover P5B they had hardened inserts.

Regards
Iain

[19560]

iainjones said:

Yes, ever since the Rover P5B they had hardened inserts.

But not suitable for unleaded petrol, these were only introduced for the EFi models.

[iainjones]

My mistake, youre right sorry, my trusted copy of Pratical Classics says so too...so it must be true, however we've never had any problems running our carbed V8 SD1 on unleaded, we had more pressing problems, like steel worm!!!



Regards
Iain

>> Edited by iainjones on Friday 5th November 13:05

[shpub]

Actually it gets more complicated... MGBV8 (circa 1972/73 ish) had non-EFI heads and according to some sources had to be run on leaded fuel... except that car went to the US where it was set upto run on lower octane fuel. That fuel was unleaded!

Talk to the US MGB side and the engine is unleaded friendly. Talk to the UK side and hell will break loose if you use unleaded fuel. Pistones will dissolve, blocks will melt like chocolate... The problem is that the engines and heads were exactly the same...

To be honest... don't worry about it. The V8 wedges hav more problems with the octane rating!

Steve
www.tvrbooks.co.uk

[19560]

Also remember that incredibly there are about 1500 different versions of the Rover V8 - before modified ones are counted. Still, non of this matters to Wedge owners with original engines.

[dukeenfield]

Thanks for all your help,but sorry I'm still comfused whether to use lead replacement or not.Is it very important to use 97 octane fuel,as the car won't run very good at low revs (800 to 1500)

[shpub]

Yes the car is setup for 97/98 octane although running on lower octane will just cause pinking and not rough running.
Best stuff to use is Super Unleaded like Optimax.

[dukeenfield]

Thanks I will try that