450SEL developments

[Big_Richard]

the euro pistons are fabulous, they show no signs of wear at all - but at the end of the day, its upto TJ and im fairly convinced he's made up his mind not to touch the bottom end at all.

The 450 did go well when i drove it last time, a very respectable, capable and sensible daily driver which is definitely not the case with a 6.9

[s class]

I'm looking forward to test driving pompy's 450SE.  I suspect it might be a happy medium combining the best characteristics of a 280SE with some of the fun of a 6.9. 

[Big_Richard]

I reckon the 450SEL is even more fun to drive than a 6.9, its a totally different animal. Aside from not having the tire shredding torque of the 6.9, in every other way its still very, very enjoyable. A well sorted one would be a very desirable car to own.

[SELfor50]

the euro pistons are fabulous, they show no signs of wear at all - but at the end of the day, its upto TJ and im fairly convinced he's made up his mind not to touch the bottom end at all.

The 450 did go well when i drove it last time, a very respectable, capable and sensible daily driver which is definitely not the case with a 6.9

When I was driving my 450SEL as a daily, it was nice and enjoyable.. quite fun.  And it had a bit of getup and go.
One thing I do miss (that the 690SE doesn't have) is a sun-roof.. especially now in summer and having the window down to ash.. I preferred having the sunroof open and just being able to flick up and the ash would get sucked out.

Those pistons come up good dude.. i'm keen to hear your thoughts on the engine/power difference after a reco of the top-end.
You gonna ping the Cams off to get them 'touched up'.  Or even a different set.. increase the duration / lift etc....  Lumpify them?  come-oooonnnnn.. you know you wanna.

Cam.

[TJ 450]

Well, regarding the Euro pistons, they are a different group number. The number is 2, whereas the low compression motor's group number is 1. This means that there is a bit of a difference in size specification. That's not to say that the size increase isn't favourable, but it may or may not work. In that case, it may as well be bored out and oversize pistons fitted and I don't really want to go down that path at the moment.

Regarding the camshafts, the original ones are in excellent condition, although I do have a set that are slightly rusty, but could be ground to a more aggressive profile. I'll have to look into that. A touch up of the original set probably wouldn't wouldn't go astray either.

I'm also considering if there is anything else I can do while I have the heads off to allow better performance and the like. I'd like to have the exhaust manifolds sandblasted on the inside and I wouldn't mind playing around with the intake manifold.

I agree that the 450 motor in general is a good compromise. It does allow sufficient performance, but not so much that the car becomes a real handful. It feels lighter and has less body roll than the 6.9, plus it feels better attached to the road with the conventional suspension.

However, the 6.9 is really something special and I have not witnessed anything that exceeds the quality of that experience.

Tim

[TJ 450]

I dropped the original heads off at Head Torque today. They will sandblast them and give me a quote for welding, new valve guides, new exhaust studs and valves as required.

All the guides and possibly the valve stems are quite worn at 350,000km. The exhaust valves wobble a good part of a mm side-to-side.

These guys are very experienced with MB cylinder heads and have stock of the required parts.

Tim

[Big_Richard]

I dropped the original heads off at Head Torque today. They will sandblast them and give me a quote for welding, new valve guides, new exhaust studs and valves as required.

All the guides and possibly the valve stems are quite worn at 350,000km. The exhaust valves wobble a good part of a mm side-to-side.

These guys are very experienced with MB cylinder heads and have stock of the required parts.

Tim

Thats very interesting, i wonder if they have stock of 6.9 parts, for my big head job next year

[TJ 450]

I don't know that they would have stock of the valves for M100.985, unless they are shared with another engine.

Apparently, valve guides almost always need replacing on MB heads, even lowish mileage ones.

I would source the valves from the USA.

Tim

[koan]

Thats very interesting, i wonder if they have stock of 6.9 parts, for my big head job next year

I doubt new valves would be required unless something catastrophic has happened, my valves and seats cleaned up well with a very light grind.

A bit concerned about sand blasting of heads and manifolds, always a risk of a sand embedding in the soft alloy surface and coming loose down the track.

koan

[TJ 450]

I'm not sure about the sandblasting, but it seems to be standard practice around here.

Tim

[Big_Richard]

Thats very interesting, i wonder if they have stock of 6.9 parts, for my big head job next year

I doubt new valves would be required unless something catastrophic has happened, my valves and seats cleaned up well with a very light grind.

A bit concerned about sand blasting of heads and manifolds, always a risk of a sand embedding in the soft alloy surface and coming loose down the track.

koan

nothing has happend, its just the usual slight leakage of oil past the rock hard original valve stem seals and worn valve guides. They deserve a good clean up at the same time i think