Hi
Another question..
When you do an engine rebuild with a view to running unleaded fuel or premium - are there any special things you need to take into consideration, like valve's, valve seats etc etc. If so, what names, or brands need to be used.
Thanks a lot.

I have looked into this subject and the A12 engine runs fine on unleaded fuel . There is a website all about unleaded fuels and older cars .
Just do a search on the left in the menu .

alloy head = hardened valve seat inserts generally.

Both L Series and A Series are fine on unleaded. They run a little hotter on a freeway at sustained 4000 revs.

Chris

According to the info i had read recently, the valve seats in 1000's & 1200's are aluminium bronze alloy for the inlets & cast iron for the exhausts. If this is true, then it would be wise to slip in a squirt of valve seat lube at tank top up time.

Unleaded fuel is specificly recomended against for use in L series engines in the fuel company literature that i have studied here in Australia. Lead replacement fuel was specificly recomended.
Unfortunately i can not bring to mind the source material for the Datsun 1000 & 1200 valve seat material at this moment.

I can confirm that L series are fine on unleaded.

I've been using a fuel additive, made by Nulon (cannot remember it's name - costs about $15 for a litre) for the past two years with premium unleaded and have had no problems.

$15 for peace of mind is worth it in my books - and a bottle will last you close to a year if you fill up once a week.

The only thing that I have noticed is that my plugs seem to foul a bit quicker than before... can anyone shed any light on that one for me?

yeah i just got my engine reconditioned recently and the guy said he changed the heads or something and said i could use unleaded. im unsure of this i dont wanna ruin anything. ive been using leaded so far should i keep doing this or wat? What happens if i use the worng fuel.

No worries. Just use Unleaded fuel with lead-replacement additives in it. In the USA it's the only kind of fuel we've had since about 1988 (Unleaded). No problems with valve wear, we don't change the valve seats, and we don't add anything out of a bottle.

Quote:

He wrote when you do a engine rebuild.
I presume then he is going to take the head off. Just take it to a cylinder head place and tell them they must inspect the valve seats.
If they are not made for unleaded fuel, tell them to put in new one's that will be unleaded compatible.
I also did some research here in South Africa.
A old Nissan mechanic told me that I must not use unleaded fuel.
The valve seats as dodgeman mentioned are not correct for this application.
I must change it to hardened valve seats and then it will be fine.

Quote:
You have not been using leaded fuel for a long time as it is unavailable from normal fuel outlets & has been illegal fpr quite a while.
If the reconditioner says that he has replaced the valve seats, & that you can use lead free gasoline, then fill 'er up at the cheap pump. You have paid for the seats in the head, so go ahead & reap the savings at the bowser.
[For our overseas friends, 'Bowser' was once the brand name of a particular make of service station puel pump, but the name is now genericly used to describe ALL the diferent makes of pumps at a service station]