I want to build an engine: Need help with picking parts

yonexsp · Post by **yonexsp** » Mon Jan 30, 2012 4:08 pm

I have a nice SD1 here in Toronto, but after replacing the horrible OZ/NADA spec fuel injection last year, I want more.

http://www.flickr.com/photos/14248538@N ... 626110398/

I want to have fun as well, so I think I'd like to build a new engine from scratch for the car over a few months in the spring summer.

What I don't have is a clear picture after reading and reading what parts I should buy to build up the engine. Everyone has so many different combinations.

What I have decided so far is:

1) Minimum 4.6 Liters
2) Reuse the current LT77 if possible
3) Start with a new block
4) $1000 max for new heads
3) Budget $3000 - $3500

Where do I start?

Thx ken./

kiwicar · Post by **kiwicar** » Mon Jan 30, 2012 5:04 pm

Hi
with those targets, try a small block chevy you might manage it.
A budget of $3000 to $3500 would not stretch to what you want.
A 4.6 block with top hat liners is about £900 ($1370) a new 4.6 coscast block is about £1450, $2247.
Heads are either ported standard castings, about £200 for the castings used, and about £800 for the referb and porting total $1520 ish. If you want aftermarket heads then you are talking £2200 ish for a pair $3350 ish.
To all this you need to add carridge and duty and local sales tax.
Realistically for a reasonably specked large bore rover over here is about £3500 to £5000 depending on things like weather you have Merlin or TA heads or just get the rover castings ported.
Based on where you are I would start by looking for an engine to rebuild, if you can find a 4.6 then if you really want then get it top hat linered and use that, personally I would look for a good 3.9 or, if you can find one, a 4.2 and rebuild that, you will save a fortune by not top hatting the block.
Or just buy a chevy.
Best regards
Mike

DaveEFI · Post by **DaveEFI** » Mon Jan 30, 2012 5:06 pm

By new block, I assume you mean short engine (block, crank rods and pistons)? A new 4.6 one of those will use up pretty well all your budget, I'd say.

ChrisJC · Post by **ChrisJC** » Mon Jan 30, 2012 9:51 pm

I would get a 4.6 litre engine from a Range Rover P38, get it top hat linered. Then get your heads worked on a bit locally, drop in a warmish cam, maybe a Piper 270.

Not sure about fuel injection system though.

That should give you 250BHP.

I wouldn't go too mad, that LT77 isn't bulletproof!

Chris.

yonexsp · Post by **yonexsp** » Mon Jan 30, 2012 10:31 pm

kiwicar wrote:Hi
with those targets, try a small block chevy you might manage it.
A budget of $3000 to $3500 would not stretch to what you want.
A 4.6 block with top hat liners is about £900 ($1370) a new 4.6 coscast block is about £1450, $2247.
Heads are either ported standard castings, about £200 for the castings used, and about £800 for the referb and porting total $1520 ish. If you want aftermarket heads then you are talking £2200 ish for a pair $3350 ish.
To all this you need to add carridge and duty and local sales tax.
Realistically for a reasonably specked large bore rover over here is about £3500 to £5000 depending on things like weather you have Merlin or TA heads or just get the rover castings ported.
Based on where you are I would start by looking for an engine to rebuild, if you can find a 4.6 then if you really want then get it top hat linered and use that, personally I would look for a good 3.9 or, if you can find one, a 4.2 and rebuild that, you will save a fortune by not top hatting the block.
Or just buy a chevy.
Best regards
Mike

I could go Chevy, but then it woudl not be a Rover. I own a CTS-V as my daily driver, whcih has power (400+HP), so for the Rover it's more to give the old girl some legs.

I woudl source as much as possible locally, so an old engine, I can strip and refurb.

Question: Why does the 4.2 block not need Top Hat liners?

yonexsp · Post by **yonexsp** » Tue Jan 31, 2012 1:13 am

OK,

The more research I do, the more the upgrade does not make sense.

Sitting on this side of the pond, a Chevy LS1 or derivative is much easier and cheaper to obtain.

The question of getting the gearbox etc to fit is then the real issue, engine mounts etc etc.

But I guess a 400hp+ Rover SD1 could be a real head turner for sure.

I can keep the old engine in reserve to put her back to stock I guess

Aghhhhh decisions decisions

I really woudl like a 4.6, at least that way the car is still kinda original.

yonexsp · Post by **yonexsp** » Tue Jan 31, 2012 2:37 am

This was driving distance to me

http://www.lateral-g.net/forums/showthread.php4?t=30134

Now that would be a cool swap!! and worth the extra budget

ChrisJC · Post by **ChrisJC** » Tue Jan 31, 2012 8:19 am

yonexsp wrote: Question: Why does the 4.2 block not need Top Hat liners?

Technically it does.

There were two bore sizes used on that engine, 3.5" and 3.7". The 3.5 litre engine used the 3.5" bore, all larger factory sizes used the 3.7" bore. All 3.7" bore engines have the block cracking weakness that can be fixed with top-hat liners.
It started to become apparent on the 3.9EFi in the Range Rover classic, and really came to the fore on the 4.6litre P38 as the engine is developing more power.
The 4.2 was always a rare engine, so it never got the reputation.

Chris.

kiwicar · Post by **kiwicar** » Tue Jan 31, 2012 10:09 am

Hi
the small bearing blocks (3.5, 3.9 and 4.2) are far less prone to block cracking than the later 4.0 and 4.6 blocks, alsothey are far more common, so the ones that did crack got binned and replaced, the 4,0 and 4.6 engines were less common for a long time , and being larger capacity people tend to try and fix them when they should be dumped, net result you are more likley to have a 4.6 sold to you that has a crack behind the liner.
Personally I would go chevy, the gen 1 small block will be cheep to tune and give far better torque than a rover any day, and all you have to do is make an adaptor between a box that bolts straight to it and the transfer box (Eliot on here has what to do on his website ) the LS is even better, light (about 30lb heahier than a 4.6 rover) you don't need to tune it and where you are cheep as chips.
That caddy one looks nice, the only issue might be getting the gearbox in (is this going in a range rover?) but at least you wont have to have the LT77 box, which by the way would be marginal on a tuned 4.6 rover.
Best regards
Mike

DaveEFI · Post by **DaveEFI** » Tue Jan 31, 2012 11:14 am

Fitting any RV8 to an SD1 is likely within the scope of the average home mechanic with basic hand tools.

Fitting a totally different engine will need loads of parts fabricated specially.

I'm not convinced a larger engine is the way to go with an SD1 anyway, if you actually drive the thing normally. Some mild head work on the 3.5 with decent injection will provide all the power the standard chassis can cope with. After that you're into brake and suspension upgrades. And the suspension in particular isn't easy to upgrade without producing a car only suitable for the track.

kiwicar · Post by **kiwicar** » Tue Jan 31, 2012 1:24 pm

Hi
Just noticed the SD1 bit!

bit of tunnel work and the T5/6 will go in, no hassel with transfer boxes. However I wouldn't!

as Dave points out an SD1 chassis with anything more than standard power is going to be interesting! Especially as it will be a good 30 years old by now, considering the reputation they always had for rotting along the seams then sponaniously shedding panels/sills suspension mounts I think I would stick with the standard 3.5 and drive it carfully on dry days.
Best regards
Mike

DaveEFI · Post by **DaveEFI** » Tue Jan 31, 2012 2:23 pm

kiwicar wrote:Hi
Just noticed the SD1 bit! bit of tunnel work and the T5/6 will go in, no hassel with transfer boxes. However I wouldn't! as Dave points out an SD1 chassis with anything more than standard power is going to be interesting! Especially as it will be a good 30 years old by now, considering the reputation they always had for rotting along the seams then sponaniously shedding panels/sills suspension mounts I think I would stick with the standard 3.5 and drive it carfully on dry days.
Best regards
Mike

A bit of tunnel work? You'll be into the fabrication of lots of things - engine mounts, exhaust manifolds etc etc. The SD1 isn't a Range Rover with lots of room under the bonnet to play with.

BTW, mine is '85 and has lived outside all its life. And never had any welding done to the suspension mounts. It has had one sill replaced - but that was my choice, most would simply have patched it. They're actually rather better than many cars of that age structural rust wise. And of course have an excellent supply of reasonably priced new body parts.

yonexsp · Post by **yonexsp** » Tue Jan 31, 2012 4:05 pm

Back to :

1) Find Old lump
2) Strip
3) Refurb and replace
4) Bolt back in

Be happy with 220hp

DaveEFI · Post by **DaveEFI** » Tue Jan 31, 2012 4:28 pm

yonexsp wrote:Back to :

1) Find Old lump
2) Strip
3) Refurb and replace
4) Bolt back in

Be happy with 220hp

Yup. Personally, I think the 3.9 best suited if you wish more torque. It is just as happy as the 3.5 to rev. The 4.6 isn't.

If you know the history of a used unit, it may not be necessary to do a full strip down, as these engines can do enormous mileages if looked after. Obviously, check the cam.

Eliot · Post by **Eliot** » Tue Jan 31, 2012 4:51 pm

tell you what, i'lll send you an old rover lump in exchange for an ls1/6 !