unleaded head markings

[caprimentle]

the other week i fitted a cylinder head to my pinto, it didn't have the pear shaped ports that an injection head has so i have to assume it has to be a carbed head, but i noticed that above the exhaust port no:4 it had the mark " I " (sorry shite pic i know) , now i thought unleaded heads only cam with L, P, PP, R and RR so just passed it as one of those things.

but the other day i was looking at my injection head (with pear shaped ports) and it also had this " I " above the exhaust port no:4 , not the L, P, PP, R or RR.

so my question is, does this carb head that i've just bolted on have unleaded seats? i do also seem to remember that when that old carbed was bolted onto my last engine, i did cover about 10,000 miles on it with absolutely no lead additive and never suffered valve seat resection so maybe it is unleaded , anybody ever seen an " I " on their cylinder heads?

[Graham]

the i is probably another letter badly stamped, and yes there were unleaded carbd heads

[caprimentle]

never knew they did unleaded carbed heads at fords, thought they only ever unleaded injection heads, so thats abit of a result

like i say though, its also an " I " on my injection head too though?

what other markings have people found then? i'm curious now

[bortaf]

There are unleaded carb heads and leaded efi heads, it's all in the stamping
IF you can see them lol there were some right weedy peeps working on the stamping cos they can be fooking feint
The pinto went unleaded some time in 87 so you can find D reg granny EFIs with leaded heads

[caprimentle]

i knew about the leaded injection heads, i hear this is your ideal heads for a race engine as you have the injection inlet port shape, but there is no chance of the unleaded seats falling out or getting in the way with big valves.

proper chuffed mines unleaded though, saves me buying more additive and i'm gonna feel more happy about when i turbo it.

what year did they finally stop producing carbed heads then?

[caprimentle]

something seems abit fishy here now, i've dug out a couple of other spare cylinder heads and they both have the :I: too





does this look like unleaded?



both heads are from 85 with the same code





not sure if these are unleaded or not now

what do we reckon?

[jagojon]

looks the same as my 85 injection head mate, that has" i" stamped on it to, took it into autosprint recently to have the seats recut and he said it was unleaded

hope this helps

jon

[Graham]

give the seat and throat a clean up with a rotary wire brush in a drill then show us a pic

[caprimentle]

will do, i'll do that tomorrow evening if i have time

[caprimentle]

more piccys, some good, some not to good, but i do have an old phone, hope they're clear enough.

[Graham]

cleaned up that looks much more like its inserted

[caprimentle]

nice, which bits are you looking at exactly just so i know? i cant compare with a leaded head as it turns out all mine are unleaded now

[Clint]

The head was not unleaded originally and they could be any insert but more than likely hard for unleaded petrol.

Only heads with a P or and R on them had hardened seats AFAIK (not sure where the L came in) and even still they are not as hard as proper inserts.

[caprimentle]

i'm not sure why i put L at the top now too

i've currently done 2 tanks of juice in the capri with no additive and it still seems alright (touch wood)

well i now have 3 carb heads with the "I" and one injection head with the "I" , so its cant be uncommon, surely?

[Clint]

i'm not sure why i put L at the top now too

i've currently done 2 tanks of juice in the capri with no additive and it still seems alright (touch wood)

well i now have 3 carb heads with the "I" and one injection head with the "I" , so its cant be uncommon, surely?

It takes a lot of miles to kill a head, the I is not uncommon at all, I would not worry too much at all, in fact forget about it worst comes to the worst it isnt a massive or expensive job.

[caprimentle]

true point, but i'll killed my last head with no additive from perfect valve lift to completely run out of adjustment, and i mean completely, in 10 thousand miles which dont take too long considering its my every day motor , i just hope the current head can put up with the extra heat when it gets turbo'd.

btw i've got pretty much all the parts sorted now so will have to pm you soon about whens good to pop down

[MK1_Oz]

So an "R" guarantees hardened seats regardless of what year? I think mine is a Sierra injection head and has an R but I dont know anything more about it and don't want to pull the motor apart to check.

[caprimentle]

yes as far as i know, R, RR, P and PP is a definite unleaded head

[Mikemax1984]

Hi guys, How are you all, did anybody get to the bottom of this, my head is stamped the same, Mine is German though. Is there any chance that that mark could be a lowercase or simplified "L" rather than an "I"?
What were the leaded petrol marked with if anything?
Any advice appreciated,
cheers
Mike

[paul g]

That's a very interesting question, does anyone have an answer?

Paul

[Erikmex]

Unleaded inserts arent needed, valve seats work harden and will be perfectly ok with unleaded fuel, tried and tested so many times over the last few decades.