Thread: Block question

more or less yes.

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?

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??

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.

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

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 .

Originally Posted by rovercare

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

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.