V8 Heads - Any way to identify source?

I've been given a pair of Heads for a 3.5 V8 along with the gubbins that
came with the eninges I bought for Percy.

Both complete engines are SD1 type 3.5's on carbs. In the gubbins though is
a Rangie Manifold and carbs amoungst these spare heads. Is there an easy way
to distingish between SD1 heads and Range rover heads and would there be any
advantage if they were Range Rover heads in fitting them.. such as being
able to run unleaded etc etc. I'm not 100% but weren't SD1's only runnable
on Leaded fuel... then again I've a niggling doubt because if it's an alloy
head then surely it much have some valve seat inserts anyway.

See now I've confused myself ;-)

Lee D

--

www.lrproject.com

Workshop photos from Landrover repairs
& other such tinkerings.
Home of Percy the Jag powered Landrover

"Lee_D" <[email protected]> wrote in message
news:[email protected]...
> I've been given a pair of Heads for a 3.5 V8 along with the gubbins that
> came with the eninges I bought for Percy.
>
> Both complete engines are SD1 type 3.5's on carbs. In the gubbins though
> is a Rangie Manifold and carbs amoungst these spare heads. Is there an
> easy way to distingish between SD1 heads and Range rover heads and would
> there be any advantage if they were Range Rover heads in fitting them..
> such as being able to run unleaded etc etc. I'm not 100% but weren't SD1's
> only runnable on Leaded fuel... then again I've a niggling doubt because
> if it's an alloy head then surely it much have some valve seat inserts
> anyway.
>
> See now I've confused myself ;-)
>
> Lee D

The SD1 was runnable on unleaded I'm sure. Better let someone who knows for
certain, but I'm 90% sure they could. I know the Vitesse version could as we
used to work on them & remember putting unleaded in. Mind you that might
explain the constant return of the thing for repair!

Have you tried the rpi website to see about identifying the heads?

Nige

"Lee_D" <[email protected]> wrote in message
news:[email protected]...
> I've been given a pair of Heads for a 3.5 V8 along with the gubbins that
> came with the eninges I bought for Percy.
>
> Both complete engines are SD1 type 3.5's on carbs. In the gubbins though
> is a Rangie Manifold and carbs amoungst these spare heads. Is there an
> easy way to distingish between SD1 heads and Range rover heads and would
> there be any advantage if they were Range Rover heads in fitting them..
> such as being able to run unleaded etc etc. I'm not 100% but weren't SD1's
> only runnable on Leaded fuel... then again I've a niggling doubt because
> if it's an alloy head then surely it much have some valve seat inserts
> anyway.
>
> See now I've confused myself ;-)
>
> Lee D
>
Lee, all heads from SD1 onwards (easily identified by having the single
valve springs and long-reach spark plug thread length, earlier heads had
twin springs and short-reach plugs) will run unleaded ok. Don't be taken in
by fancy advertising and claims by some of the so-called $pecialists, they
are only trying to empty your wallet in their favour. Pre SD1 and very early
rangerover heads need harder inserts, but not the later single-spring type.
The early heads aren't all that good anyway, having slightly smaller valves.
SD1 and carb rangerover had the same heads, with the SD1 vittesse having the
valve heads recessed further into the heads and waisted stem valves. Some
EFI rangies also had the waisted stem valves, but not all!! EFI heads will
fit straight on, and are easily identified by a small curved cutout in the
roof of each inlet port (clearance for the injector nozzle spray pattern).
Later heads have only 10 bolts to bolt them down with, and are machined to a
shorter overall height to compensate for the thicker composite type head
gaskets, these heads are about the best standard heads there are, having
slightly larger exhaust ports. Don't worry about the outer row of 4 bolts
being missing if you get a pair of these heads, they are a waste of time.
See Rpi's website for a good reason why, I cant be arsed typing it all out
right now!
There are variations between number of bolt holes in the head ends where the
lifting brackets etc fit on, there are 3 and 4 bolt variations and different
thread sizes as well, but all are UNC threads.
Badger.

"Badger" <[email protected]> wrote in message
news:[email protected]...

> Lee, all heads from SD1 onwards (easily identified by having the single
> valve springs and long-reach spark plug thread length, earlier heads had
> twin springs and short-reach plugs) will run unleaded ok. Don't be taken
> in by fancy advertising and claims by some of the so-called $pecialists,
> they are only trying to empty your wallet in their favour. Pre SD1 and
> very early rangerover heads need harder inserts, but not the later
> single-spring type. The early heads aren't all that good anyway, having
> slightly smaller valves.
> SD1 and carb rangerover had the same heads, with the SD1 vittesse having
> the valve heads recessed further into the heads and waisted stem valves.
> Some EFI rangies also had the waisted stem valves, but not all!! EFI heads
> will fit straight on, and are easily identified by a small curved cutout
> in the roof of each inlet port (clearance for the injector nozzle spray
> pattern). Later heads have only 10 bolts to bolt them down with, and are
> machined to a shorter overall height to compensate for the thicker
> composite type head gaskets, these heads are about the best standard heads
> there are, having slightly larger exhaust ports. Don't worry about the
> outer row of 4 bolts being missing if you get a pair of these heads, they
> are a waste of time. See Rpi's website for a good reason why, I cant be
> arsed typing it all out right now!
> There are variations between number of bolt holes in the head ends where
> the lifting brackets etc fit on, there are 3 and 4 bolt variations and
> different thread sizes as well, but all are UNC threads.
> Badger.

Badger,

Many thanks, Thats put my mind at rest! Looks like I've a new pair of paper
weights

Lee D

In message <[email protected]>, Badger
<[email protected]> writes
>Pre SD1 and very early rangerover heads need harder inserts, but not
>the later single-spring type.

I did lots of research on leaded/unleaded many moons ago and I beg to
differ on that point. The only problem with pre-SD1 AFAIK is with the
high compression engines pinking on unleaded - all 9.75:1 and below
should be ok, composite head gaskets may pull compression down far
enough above 10:1 (better to gas it instead!) but all valve seats are
hard enough for unleaded.
Then of course for low down grunt small valve heads have their place ...

--
AndyG

"AJG" <[email protected]> wrote in message
news:[email protected]...
> In message <[email protected]>, Badger
> <[email protected]> writes
>>Pre SD1 and very early rangerover heads need harder inserts, but not the
>>later single-spring type.
>
> I did lots of research on leaded/unleaded many moons ago and I beg to
> differ on that point. The only problem with pre-SD1 AFAIK is with the high
> compression engines pinking on unleaded - all 9.75:1 and below should be
> ok, composite head gaskets may pull compression down far enough above 10:1
> (better to gas it instead!) but all valve seats are hard enough for
> unleaded.
> Then of course for low down grunt small valve heads have their place ...
>
Ok, I am not going to disagree with you re. the octane issues, however I
have stripped plenty of early engines and found a considerable number with
severely burnt and pitted exhaust valve seats - this I have attributed to a
different spec of iron for the seat inserts, and my local engineering firm
that I use for all my work agrees with me. That's not to say that we are
right of course, neither of us have paid for expensive metallurgical
testing. Do you have access to any test results? I'd be very interested to
see the data if possible?
A lot of engines that allegedly need 4* (landrover 2.25 is a perfect
example) will run on unleaded ok for tens of thousands of miles with no
issues, especially where they are used relatively gently and not at high rpm
high load conditions. Some engines will burn valves even on 4* if driven
hard all the time (leyland B series, for example) and some that allegedly
require super unleaded will run just fine on normal unleaded if the ignition
timing is backed off a couple of degrees (Jaguar 4.2).
FWIW, some years back I built a 3.5 using 10.5 P6 pistons in a stiff-block,
with composite gaskets but with the SD1 Vitesse heads skimmed to maintain
overall compression, fitted with a high-torque cam, it ran 6 degrees more
advance at idle, 4 degrees less total mechanical advance, and hit full
advance by 1500rpm! It never pinked once, running on unleaded fuel. Pity the
motor wasn't on gas back then!
As for the smaller valve sizes, all other things being equal they will
increase gas velocity (at a given rpm / depression, within limits) but in
the case of the Rover V8 engine the ports themselves on these early heads
are a poorer design with less swirl effect to the incoming charge, so the
overall scavenge effect is actually better with the larger valves. Do not be
fooled by misleading power/torque figures given out by the factory at the
time, they were prone to exagerate!

Badger.

Badger wrote:
> "Lee_D" <[email protected]> wrote in message
> news:[email protected]...
>
>>I've been given a pair of Heads for a 3.5 V8 along with the gubbins that
>>came with the eninges I bought for Percy.
>>
>>Both complete engines are SD1 type 3.5's on carbs. In the gubbins though
>>is a Rangie Manifold and carbs amoungst these spare heads. Is there an
>>easy way to distingish between SD1 heads and Range rover heads and would
>>there be any advantage if they were Range Rover heads in fitting them..
>>such as being able to run unleaded etc etc. I'm not 100% but weren't SD1's
>>only runnable on Leaded fuel... then again I've a niggling doubt because
>>if it's an alloy head then surely it much have some valve seat inserts
>>anyway.
>>
>>See now I've confused myself ;-)
>>
>>Lee D
>>
>
> Lee, all heads from SD1 onwards (easily identified by having the single
> valve springs and long-reach spark plug thread length, earlier heads had
> twin springs and short-reach plugs) will run unleaded ok. Don't be taken in
> by fancy advertising and claims by some of the so-called $pecialists, they
> are only trying to empty your wallet in their favour. Pre SD1 and very early
> rangerover heads need harder inserts, but not the later single-spring type.
> The early heads aren't all that good anyway, having slightly smaller valves.
> SD1 and carb rangerover had the same heads, with the SD1 vittesse having the
> valve heads recessed further into the heads and waisted stem valves. Some
> EFI rangies also had the waisted stem valves, but not all!! EFI heads will
> fit straight on, and are easily identified by a small curved cutout in the
> roof of each inlet port (clearance for the injector nozzle spray pattern).
> Later heads have only 10 bolts to bolt them down with, and are machined to a
> shorter overall height to compensate for the thicker composite type head
> gaskets, these heads are about the best standard heads there are, having
> slightly larger exhaust ports. Don't worry about the outer row of 4 bolts
> being missing if you get a pair of these heads, they are a waste of time.
> See Rpi's website for a good reason why, I cant be arsed typing it all out
> right now!
> There are variations between number of bolt holes in the head ends where the
> lifting brackets etc fit on, there are 3 and 4 bolt variations and different
> thread sizes as well, but all are UNC threads.
> Badger.
>
>

Badger, I'm a bit confused (easy, I know)...

Without taking the rocker covers off, can I tell whether my 1975 range
rover V8 engine will run unleaded, since that's what I've used since I
had the engine fitted. It's engine number is 35900537, (8.251CR)
according to the plate, and it uses Champion RL92YC plugs, I'm told.

Regards,
Danny

--
Regards,
Danny

http://www.gaggia-espresso.com (a purely hobby site)
http://www.dannyscoffee.com (UK advert for my mobile espresso service)
http://www.malabargold.co.uk (UK/European online ordering for Malabar
Gold blend)
swap Z for above characters in email address to reply

"Danny" <[email protected]> wrote in message
news:[email protected]...
> Badger wrote:
>> "Lee_D" <[email protected]> wrote in message
>> news:[email protected]...
>>
>>>I've been given a pair of Heads for a 3.5 V8 along with the gubbins that
>>>came with the eninges I bought for Percy.
>>>
>>>Both complete engines are SD1 type 3.5's on carbs. In the gubbins though
>>>is a Rangie Manifold and carbs amoungst these spare heads. Is there an
>>>easy way to distingish between SD1 heads and Range rover heads and would
>>>there be any advantage if they were Range Rover heads in fitting them..
>>>such as being able to run unleaded etc etc. I'm not 100% but weren't
>>>SD1's only runnable on Leaded fuel... then again I've a niggling doubt
>>>because if it's an alloy head then surely it much have some valve seat
>>>inserts anyway.
>>>
>>>See now I've confused myself ;-)
>>>
>>>Lee D
>>>
>>
>> Lee, all heads from SD1 onwards (easily identified by having the single
>> valve springs and long-reach spark plug thread length, earlier heads had
>> twin springs and short-reach plugs) will run unleaded ok. Don't be taken
>> in by fancy advertising and claims by some of the so-called $pecialists,
>> they are only trying to empty your wallet in their favour. Pre SD1 and
>> very early rangerover heads need harder inserts, but not the later
>> single-spring type. The early heads aren't all that good anyway, having
>> slightly smaller valves.
>> SD1 and carb rangerover had the same heads, with the SD1 vittesse having
>> the valve heads recessed further into the heads and waisted stem valves.
>> Some EFI rangies also had the waisted stem valves, but not all!! EFI
>> heads will fit straight on, and are easily identified by a small curved
>> cutout in the roof of each inlet port (clearance for the injector nozzle
>> spray pattern). Later heads have only 10 bolts to bolt them down with,
>> and are machined to a shorter overall height to compensate for the
>> thicker composite type head gaskets, these heads are about the best
>> standard heads there are, having slightly larger exhaust ports. Don't
>> worry about the outer row of 4 bolts being missing if you get a pair of
>> these heads, they are a waste of time. See Rpi's website for a good
>> reason why, I cant be arsed typing it all out right now!
>> There are variations between number of bolt holes in the head ends where
>> the lifting brackets etc fit on, there are 3 and 4 bolt variations and
>> different thread sizes as well, but all are UNC threads.
>> Badger.
>
> Badger, I'm a bit confused (easy, I know)...
>
> Without taking the rocker covers off, can I tell whether my 1975 range
> rover V8 engine will run unleaded, since that's what I've used since I had
> the engine fitted. It's engine number is 35900537, (8.251CR) according to
> the plate, and it uses Champion RL92YC plugs, I'm told.
>
> Regards,
> Danny
>
Pull a plug and see if it's short reach or long reach. If long, it'll
definitely be ok on unleaded, if short, then personally I'd say no, but
there are those that say yes. The numbers you quote suggest early heads with
short-reach plugs. If it's been running on unleaded ok for a considerable
mileage, then it should hopefully be ok. As I said earlier in this thread,
there are engines that are definitely leaded fuel engines that people have
reportedly run for thousands of miles on unleaded with no issues. Basically,
it's your choice.
Badger.

On or around Thu, 3 Feb 2005 23:04:00 +0000 (UTC), "Badger"
<[email protected]> enlightened us thusly:

>Pull a plug and see if it's short reach or long reach. If long, it'll
>definitely be ok on unleaded, if short, then personally I'd say no, but
>there are those that say yes. The numbers you quote suggest early heads with
>short-reach plugs. If it's been running on unleaded ok for a considerable
>mileage, then it should hopefully be ok. As I said earlier in this thread,
>there are engines that are definitely leaded fuel engines that people have
>reportedly run for thousands of miles on unleaded with no issues. Basically,
>it's your choice.

never noticed any problems with 10.5:1 (theoretically) P6 engines on LPG.
OK, there were problems, true, but never noticed any valve seat problems.
--
Austin Shackles. www.ddol-las.fsnet.co.uk my opinions are just that
"Nessun maggior dolore che ricordarsi del tempo felice nella miseria"
- Dante Alighieri (1265 - 1321) from Divina Commedia 'Inferno'

In message <[email protected]>, Badger
<[email protected]> writes
>Ok, I am not going to disagree with you re. the octane issues, however I
>have stripped plenty of early engines and found a considerable number with
>severely burnt and pitted exhaust valve seats - this I have attributed to a
>different spec of iron for the seat inserts, and my local engineering firm
>that I use for all my work agrees with me. That's not to say that we are
>right of course, neither of us have paid for expensive metallurgical
>testing. Do you have access to any test results? I'd be very interested to
>see the data if possible?
>
I'd have to look up references - it's a looong time ago! However the
largest (there were more but it was primarily one) original manufacturer
of the valve seats supplied to Rover stated that their seats were
identical material to the piston rings - which was actually harder than
some 'hard' valve seats!
This does not preclude of course later replacement seats , a few of the
'other' suppliers offerings or of course just high mileage, imperfect
mixture/timing control on whatever fuel ...

--
AndyG

"AJG" <[email protected]> wrote in message
news:[email protected]...
> In message <[email protected]>, Badger
> <[email protected]> writes
>>Ok, I am not going to disagree with you re. the octane issues, however I
>>have stripped plenty of early engines and found a considerable number with
>>severely burnt and pitted exhaust valve seats - this I have attributed to
>>a
>>different spec of iron for the seat inserts, and my local engineering firm
>>that I use for all my work agrees with me. That's not to say that we are
>>right of course, neither of us have paid for expensive metallurgical
>>testing. Do you have access to any test results? I'd be very interested to
>>see the data if possible?
>>
> I'd have to look up references - it's a looong time ago! However the
> largest (there were more but it was primarily one) original manufacturer
> of the valve seats supplied to Rover stated that their seats were
> identical material to the piston rings - which was actually harder than
> some 'hard' valve seats!
> This does not preclude of course later replacement seats , a few of the
> 'other' suppliers offerings or of course just high mileage, imperfect
> mixture/timing control on whatever fuel ...
>
Interesting, thanks Andy.
Badger.