View Full Version : Block question
steve_35
14th February 2010, 09:58 PM
Just a quick question'
3.5 V8 carby motors are they the same block and heads as the efi version
are they interchangeable
I want to buy an old motor and do it up and there is a Range rover 3.5 carby motor for sale here
Can i do it up and swap it out for the one in my 93 Discovery
Blknight.aus
14th February 2010, 10:07 PM
more or less yes.
p38arover
14th February 2010, 10:26 PM
Early blocks aren't as strong. The most obvious external difference is in the strengthening webs across the block in the valley.
I can't find my book on the engine but I'm pretty sure the bottom end isn't either.
What year are you looking at?
Why not go for a 3.9?
DeeJay
14th February 2010, 10:29 PM
I thought the EFI heads were different to the carby types..
I was going to "upgrade" my carby type engine to EFI & read on this forum there was differences in the heads??
d@rk51d3
14th February 2010, 10:50 PM
Would go at least for a late 94 3.9 or onwards
2 main changes in the 3.5 were the top end webbing, and main bearing caps, but there were some changes in the overall block casting too, to make it stronger and allow for the production of the 3.9.
Heads started out as 14 bolt, but later ones were 10(?)
Personally, I wouldn't be spending money on a 3.5, there's more that money could be doing.
rovercare
14th February 2010, 10:59 PM
I've got a 4.6 here with ealry timing cover etc, I need to move, it was pulled for a change over as it has either, head gasket, liner issues, milky oil in the intake, was running and moving, has reco heads and supposedly 4 stepped liners fitted
has a decent camshaft and moved quite well, just useing a little coolant
peewee
14th February 2010, 11:00 PM
there is a difference in the heads, the efi heads have a small semicircle ground out of the inlet ports where the injectors spray in. the outer row of head bolts was deleted on later engines to stop the heads tipping to the outside and leaking into the valley. on older engines put the outer bolts in with locktight and just nip up to prevent this .
steve_35
14th February 2010, 11:25 PM
I've got a 4.6 here with ealry timing cover etc, I need to move, it was pulled for a change over as it has either, head gasket, liner issues, milky oil in the intake, was running and moving, has reco heads and supposedly 4 stepped liners fitted
has a decent camshaft and moved quite well, just useing a little coolant
Will it fit and how much do you want for it
The only reason i was thinking 3.5 was thought the one in the car now was a 3.5
I was of the belief that 3.5 had the oil pump outside the timing cover and the 3.9 was in the timing cover
And mine is outside the cover
series 3 and a half
15th February 2010, 12:26 AM
I am cynical enough to believe the deletion of the outermost 8 cyl. head bolts was more involved with cost cutting than with tilting heads/leaking issues. Rovercare - you should be able to instantly recognize stepped liners but if the engine is using water be very wary. From seeing a lot of Rover v8`s go through the reco/rebuild/big bore process there is not much,to my mind,to choose between early and SD1 on [reinforced] blocks - sure they have extra webbing in the valley and the front main/cam bearing area but unless you are absolutely beating the motor to death,the variations are not significant.What is important is the condition of the block/main bearing caps etc. that you start with - caps that are loose in their registers - forget it,likewise soft alum blocks [from overheating]. Just remember what Phil Irving achieved with the Repco Brabham in Formula 1 - all based in the first years on a 3.5 Oldsmobile block [they had 6 head bolts compared with the almost identical Buick which was what Rover purchased] - he screwed over 310 HP out of 3 litres running to well over 7000 rpm with this production block and it is high revs that cause the bulk of our engine stress issues. Most Rover owners are wasting time over 5 / 5 1/2 thousand revs ,better to grab another gear and go for the torque. In summary, if you can find a good [hard] early 3.5 , it will be just as good power wise and dollar wise than a later 'reinforced' block and better than a abused soft later block.
RoverP6B
15th February 2010, 06:36 AM
Hello Steve,
Seeing that your 3.5 is in a 93 Discovery, then the block will already be one of the later "stiff" blocks.
The block itself has no relation to the type of oil pump that can be used, that being in the domain of the timing cover.
More than likely, the heads on your existing engine are already "the fuel injected type".
The early 3.5 blocks,..ie up until 1976 were the weakest if you like as far as bearing cap design and retention was concerned. After that date subtle changes were made to the bearing caps and the design of the block registers, but they were minor until circa 1994/5.
Ron.
steve_35
15th February 2010, 08:55 AM
Cool ill have to do some more research
I want a bolt in bolt out kind of job
rovercare
15th February 2010, 10:37 AM
. Rovercare - you should be able to instantly recognize stepped liners but if the engine is using water be very wary. .
Not without lifting the heads:D
rovercare
15th February 2010, 10:38 AM
Will it fit and how much do you want for it
The only reason i was thinking 3.5 was thought the one in the car now was a 3.5
I was of the belief that 3.5 had the oil pump outside the timing cover and the 3.9 was in the timing cover
And mine is outside the cover
Yes, it was removed from a 93 RR, I'll PM the rest;)
steve_35
15th February 2010, 10:56 AM
That would be wishful thinking not removing the heads
No im going to rebuild the whole engine with new stuff im the kind of person that likes to drive older cars and stuff but it has to be new stuff underneath if something needs replacing i try to go new rather than reco where possible
Already done all the suspension and brakes that pretty easy and cheap next ill put some super thick oil in the transfer case and diffs and just for the sake of it it can never be to clean
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