Unleaded heads

[Wander]

Is there a way to ID an unleaded head on a 2.25 petrol series motor?

I'm trying to figure out if my IIa was converted or not. The guy I bought it from only had it for a brief time and it was part of a trade so he never had to add gas nor does he know iif the head was changed. I could probably track down the prior owner to find out but if there is an way to spot the head that would be much easier.

If it's not the unleaded head, what do all use as an additive to keep everything clean(ish).

 

[sven]

Not really. The only way to ID is to pull the head.

 

[Yorker]

It isn't about keeping the things clean lead is needed to keep your valves from burning.

http://www.dft.gov.uk/pgr/roads/environment/lrp/leadreplacementpetrolphaseout

 

[muskyman]

Actually lead acts a lubricant to keep the valves from sticking not from burning.

 

[Yorker]

:sombrero:

 

[Antichrist]

Using unleaded in a head that requires lead will cause the valve seats to erode. As it wears the seats become deeper and deeper. As the seat receeds, the valve doesn't seat as well and you end up with burned valves also.

You have several choices:

1. Pull the heads and inspect them
2. Don't worry about it and do nothing
3. Use additive (just in case)

For 1, if it doesn't you either install unleaded parts or do 2 or 3
For 2, when the engine eventually starts running poorly, have a valve job done to put in hardened seats, correct valves and guides. You'll need a valve job before the seat receeds more than the material they'll remove to install the hardened seats.

You can run an unmodified Series engine for quite some time on unleaded petrol before you have to do a valve job.

 

[Yorker]

The later metric heads did have hardened inserts, but it is really unlikely you have one of those. They can usually be identified by the lack of the cold start sensor, they usually are not painted the Sky Blue BSC 101, either. Casting #s and markings would be different too but I don't have them at hand.

 

[Wander]

Well it's not sky blue so maybe I'm in luck. As also mentioned these will run for a long time before it becomes a problem. I'm mainly trying to figure just exactly what I bought. I see you upgraded your alternator Yorker-what did you go with?

It does look like the polarity was reversed as there is a trickle charger hooked up to the batt and a CB in a mount over the top of the windscreen with two pie plate sized speakers just aft of the door tops.

 

[greenmeanie]

Compression can affect the life of non hardened seats without lead. Having said that 7:1 and even 8:1 is pretty low compression so shouldn't be an issue. Some people bump compression to 9:1 where you want to start paying attention.

Easiest alternator upgrade is an AC Delco 10SI available in any scrappy or auto shop in the US. Here's a good link about wiring one.

If you have limited fabrication skills Pangolin4X4 makes a mounting for a Delco 10SI.

 

[Yorker]

I just grabbed that pic from my archives, I'm not sure what that alt is- Stock Lucas?

I used a 105 amp Delco, it is an easy swap to do- you will need to convert from positive to negative ground first though- unless that has been done by the PO.


http://www.lrfaq.org/Series/FAQ.S.alt_alternators.html

http://www.lrfaq.org/Series/FAQ.S.alternator.installation.html

 

[muskyman]

I understand that the end result is a burned valve but the process starts with valves sticking and not fully closing. Then the extreme heat of combustion on the not completely closed valve is what causes the valve to erode and later burn.

This is not only a rover thing , there were lots of makes that suffered from the same fate. Lead additives work well in most of these situations. I have never owned a series but motors are motors, if in doubt just add a few oz of additive . Also even with the right heads without cats on a motor a regular dose of lead additive really keeps the valves working nice and smooth. I know a number of people that pour it into their classic cars every tank full.

 

[Yorker]

You can run an unmodified Series engine for quite some time on unleaded petrol before you have to do a valve job.

Very true but it is difficult to know if the PO has already used up a good portion of your "quite some time" though. Once the seats erode enough and the valves quit spinning the damage can happen exponentially.

If in doubt I'd use a lead substitute. I would NOT rely on the so called "lead memory" that some people claim makes the additive unnecessary. With the gearing a Series Rover has the engines do get used pretty hard and it has been a long time since any of the US rovers ran on leaded fuel...

 

[muskyman]

Lead memory... LOL that sounds like the people that talk about muscle memory, we all know that's just BS as well.

 

[Antichrist]

I understand that the end result is a burned valve but the process starts with valves sticking and not fully closing

Hmmm..not exactly, or maybe it is what you're saying. The lead formed a hard protective layer on the seats (hence no need to use hardened inserts). With the removal of lead from petrol the lead on the seats/valves eventually would burn off and the valves would start to stick to the seats. They'd close all the way, at least for a while, but every time they stuck they'd pull off bits of the head casting, reducing valve clearance and making a poorer seal against the seat, leading to faster erroding, like yorker says.

Very true but it is difficult to know if the PO has already used up a good portion of your "quite some time" though. Once the seats erode enough and the valves quit spinning the damage can happen exponentially.

If in doubt I'd use a lead substitute. I would NOT rely on the so called "lead memory" that some people claim makes the additive unnecessary. With the gearing a Series Rover has the engines do get used pretty hard and it has been a long time since any of the US rovers ran on leaded fuel...

Yeah, I agree overall. But it does depend on how it was used, which is hard to know with a used one.
People saying the additive is not needed because of "lead memory" I think are misunderstanding it. The lead memory was really just a term meaning for a lightly used engine, you didn't need to use an additive right away. Not that you could go indefinitely without some suitable substitute.

 

[Wander]

Any particular additive favored over others?