Running PULP

[Deus Ex]

Hey guys

Just a quick question, is it ok to run PULP (premium unleaded) in Z engines? i have been told that after every 2 tanks you put a valve thing in with the fuel. Is anyone familar with this?

Thanks

[Zrush]

We always run Premium Unleaded in our Z cars. If you can get away with regular unleaded then do it, what with the price of gas nowadays:tapemouth After a running through a few tanks of gas we throw in injector or carb cleaner, but thats it. I don't know what the "valve" thing would be.

Vicky

[ChrisA]

I had always heard that unleaded gas in original 240Z engines was harmful to the valve seats. I read in a Z book (cant remember which one) that the lack of lead can lead to excessive valve seat wear. No lead in the fuel to lubricate the workings in the head. I buy lead additive and octance booster and add it each time I fill up.

But if your head has been redone it probably has hardened seats and todays gas wont harm them. I have an original E31 head that's never been touched and I feel the lead additive is worth the trouble to not have to overhaul the head. I dont remember when the factory went to hardened seats. I'd guess on the 280Z but I dont know for sure.

FWIW

Chris

[sblake01]

I run unleaded regular in both the 280Z and the 810 with an occasional dose of Lucas fuel system treatmant. That's not meant to be a shamless plug, just what I like to use. No problems in 6 years in the Z and over a year on the 810. Oddly enough, my 320 won't run right on 87 octane, probably due to the head work and the Weber DCOE.

[sjcurtis]

PULP or ULP, well I run ULP 100% my engine, it was built to Live with Australian ULP, a wicked blend of product including some sordid tax dodging ingredients like ethenol and &^^$$#$%

that some dead beats put in it. So the down side is hammered injectors and bad filter blockages.

To a serious note PULP or ULP usage is about the conditions of your head, you need to be running hardened seats and good valve guide material, extending the life of your valve stem seals (your valve stem seals will always suffer as they age, a fact of life the age, they get brittle, they die).

If you have not done the head, at its next rebuild it should be done, most rebuild shops no longer carry the old materials but que them anyway.

If your Z is original and was a late build ie 73 or later (E88 head) it should be good to go. California smog laws drove world attitudes and changed the production product out of Japan.

these are not nessasary the views of management.

cheers

Steve

[Walter Moore]

An original E31 that has never been touched?

When I took my E31 off the engine to see why it had no compression, the brass seats were beat down into the head...

I really doubt that those things would hold up to unleaded gas. But then I have a hard time believing that brass valve seats would hold up at all.

When I had it re-done I had to upsize to the larger intake valves, (sniff, sniff, let me wipe away these crocodile tears...) because the brass seats have to be cut out. Which is why there are no replacement seats for the original, small valves...

But for those who have the later heads, I doubt that unleaded gas is going to reduce the useful life of the valves by much.

[Deus Ex]

Wow thanks for all the info guys,

I am running a P90 head and at the moment i am running Super (leaded) i will now be changing to PULP on your advice, and yeah i guess the adative is to lube the valves and the stems.

Thanks

P.s do you think that the P90 head will require the adative? ill run it anyweay but it would be good to know if i actually need it.

[halz]

If you san find super (leaded) then keep using it while you can.

[sjcurtis]

Now your talking, heads that can squeaze the PULP or ULP P90 and P90A are the end play for the L series Six for smog environment, and they where designed to deal with these two types of fuel daily in an efficient.

I have run one of these suckers on my Z since 1992 and I still have not used an addative, I suggest 'go hard' dont spare any Hondas or Comodores.

If your P90 has the right gear attached it will scream.

cheers

Steve:classic: