Beta VX and unleaded

[carman]

I have VX on offer ,what is the story on unleaded and the VX ????

[Fingers]

I've been running unleaded 96 octane for quite a while now and have had no problems, I recently had the engine re-conditioned and had a look at the head, no problems at all.

[Hamish]

Greetings all :lol:

There's been a lot of post on this subject before 8O and without going over old ground too much here's my opinion:

VX heads were not designed to run unleaded. Yes, they run fine on it but ultimately when the lead memory has gone (however long that may be :!: ) you'll run into trouble. I found on my now sadly sold on VX coupe that there was an appreciable difference in performance between leaded and unleaded but this difference was diminished when running an additive which includes lead replacement and an octane booster (Millers VSP+ and Shell Optimax unleaded - the ideal combination as I've been saying for sometime :roll: ).

I guess it all depends on your priorities, if you're using the car a lot (like I did) then you'll want to think about an unleaded conversion. If you're not then you'd very probably be safe running good quality petrol and an additive.

I would recommend any VX (or any Beta) owner to seriously consider getting the head converted - look at this way, you can indulge in some porting and polishing, valve work etc etc to make the engine that bit better. Believe me, it's worth it :twisted:

[Will]

Beg to differ on the "conversion" issue.
You are trying to solve a problem (micro-welding) that only occurs between steel valves and CAST IRON seats, which are found in older engines, not the steel inserts the FIAT TC's have in an aluminum head.
There's a lot of paranoia about this in the UK as they just started with having to run on unleaded, while we've been doing it here for a quarter century.
I bothered to look into this at some length, as I have a volumex "Euro" head, the fact is there's no benefit to changing the seats.
Changing the metallurgy of the valve guides could theoretically help with heat transfer, which is a seperate issue, but how much a difference this makes, is certainly subjective at this point since to quantitative measurements have been undertaken AFAIK.
And the additives, likewise will not be necessary, and have been found to be only marginally effective on the engines that actually use the cast iron valve seats.
You can go look into this yourselves, and while you do, take notice how many of the companies fretting about this are in the UK!
One more thing regarding the softer seats: They are nerly impossible to do a 5 angle on since they flatten out in use. Meaning, recut them every season or stick with a 3 angle.
-Will

[Will]

...there are also several people who have put in stainless steel valves AND "conversion" seats. Now that's really throwing good money after bad. Even if you thought the seats were cast iron, SS valves would solve the problem by themselves.
IMO the money could be better spent elsewhere, unless you simply have too much of it, in which case mail me off-list ;)

-Will

[Will]

...and Hamish, your "performance improvement" was doubtless from the octane boost or some other factor in the additive. Lead replacement would not make a difference in performance, its sole purpose is to prevent erosion of the valve seats in the area that contacts the valve, commonly referred to as "seat recession".
-Will

[Hamish]

...and Hamish, your "performance improvement" was doubtless from the octane boost or some other factor in the additive. -Will

Will, I'll bow to your experience on the unleaded issue :roll: but I still think it's safer to think about an unleaded conversion if you're doing big mileage
I did not infer that the performance difference was simply down to lead substitute in Millers VSP, I think I've been around long enough to know that the octane booster is what helps - not even I'm that daft :!: :wink:

[peter_coupe]

All

I have also investigated this subject few times.
All Lancia/Fiat mechanics agree that; it is not necessary to do any head work in order to start using unleaded (here I mean Optimax equivalent, 98o). Lancia used best material for the seats available, which can withstand lack of lead in fuel.

Before I rebuilded my engine I went to specialist Auto Head Workshop (Philip Head Service, in Philip, ACT). Owner of the shop took the head, had a look and said "mate Italians used state of the art metal then and you would be throwing your money converting to new unleaded seats".

In addition, when I pulled engine apart seats and valves did not show any sign of damage after using Optimax for 60.000km (all together that engine have done 500.000km, last 60k on Optimax).


Ciao
Peter