SBC into Rover P6

unstable load · Post by **unstable load** » Sun May 02, 2010 5:57 pm

How practical is it to consider an engine swap for the P6 to a small block Chevy? I ask from the point of view of weight rather than size, mountings etc as that is easy to fix.

How badly would the weight change mess up the driveability of the car?

I enquired about an ally block engine in South Africa and the price came out for a new engine at GBP8900 equivalent!

hence my enquiring about a good old cast iron block.

Of course, I will be winning the Lotto this week, so it's all irrelevant.

Any opinions/ideas/suggestions, please??

kiwicar · Post by **kiwicar** » Sun May 02, 2010 7:55 pm

As usual it is a case of "depends", if you dropped in an out the factory early '70s spec chevy lump then it would be considerably heavier than a P6, however if you got a later block (mid 80's), stuck in a lightweight crank, light weight rods and pistons, 6 1/4 damper and an ally flywheel, ally heads ally inlet manifold and selected your ancillaries carefully you could probably get within 90-120 lb of P6 the rover. That would probably not upset the rover handling. You would want to replace a P6 though, not the range rover lump, it is by far the lightest of the rover engines.
Best regards
Mike

unstable load · Post by **unstable load** » Mon May 03, 2010 12:09 pm

Mike,

Thanks for that. Currently it is an original 10,5:1 CR 3500 on SU's with a 4spd O/D Jag box.
Being a tinkerer, I was wondering what my options were once I dragged it out of the storage and set to work on it.
I have a LT77 as well as a Toyota Cressida box to choose from, so that department is pretty much OK, then there is the Lexus option. Lexus V8 plus auto box for around 400 quid is tempting, but would keep it manual hence the Cressida box.

Decisions, decisions...

kiwicar · Post by **kiwicar** » Mon May 03, 2010 12:54 pm

Hi
I wouldn't think the lt77 would live long behind a chevy, they struggle with a tuned 4.6 rover. However there is a wide choice of manual boxes for the chevy, a T5 for instance, the toyota box would be a much better bet. Have you considered the Jag V8? you would need a manual conversion electronics box to sort out the throttle but they make very smooth power and are all alloy. There is always the 302 and 351 ford and the mod engine.
Best regards
Mike

CastleMGBV8 · Post by **CastleMGBV8** » Mon May 03, 2010 1:09 pm

John,

All depends on what sort of performance you are looking for, the lexus V8 could be a good choice and for £400 very tempting if you can get all the engine loom and ECU but those 4 cam engines are pretty wide at the top and theres not much you can do to open out a P6 engine bay and you may need to do tunnel mods for the toyota box.

The LS series Chevys or Ford Modular V8's would be tempting being all alloy apart from the truck engines I think but probably a bit pricey.

If you have access to one go and measure it up carefully and consider things like sump, oil filter position and ancillaries.

Not sure what spec the Cressida box is, would it be meaty enough for the V8 or is it fitted to some V8's anyway?

The Supra turbo box is the usual coversion fitment behind a decent V8, I ve got all the specs somewhere on the computer, if I can find them I'll post a link for you.

Couldn't find mine but this info will help, appears the W.58 was also fitted to the Cressida so may be what you have.

http://www.toymods.org.au/forums/showthread.php?t=18667

Might be a useful forum for you as well.

Kevin

DaveEFI · Post by **DaveEFI** » Mon May 03, 2010 6:11 pm

kiwicar wrote:Hi
I wouldn't think the lt77 would live long behind a chevy, they struggle with a tuned 4.6 rover. However there is a wide choice of manual boxes for the chevy, a T5 for instance, the toyota box would be a much better bet. Have you considered the Jag V8? you would need a manual conversion electronics box to sort out the throttle but they make very smooth power and are all alloy. There is always the 302 and 351 ford and the mod engine.
Best regards
Mike

I'd say there'd be problems with the final drive too - I broke a couple on my 3500S.

unstable load · Post by **unstable load** » Tue May 04, 2010 10:54 am

Gents,
My link to the different Toyota boxes seems to have disappeared along with Yahoo GeoCities, but it is the staple box for all the Toyotas in SA and mine came out of the 6cyl Twin Cam so I reckon it will handle the load.
I am after better fuel efficiency and some more power (I know they are counter productive) but I would like around 250hp for towing a trailer and maintaining decent speed at a reasonable consumption. I am not going racing with it, but it will see some spirited driving obviously.

My main issue here in SA is the cost of anything Rover, coupled with the hassles of importing anything used to the country. I can buy a Lexus engine for the price of importing my efi setup that is sat in UK at a mate's house.
As for controls, there are a few available units in SA that are plug and play for the Lexus and I can get a bellhousing and clutch for the box I have off the shelf, so I guess I have really answered my own question.

What is a hotwire setup with dizzy, box etc worth anyway?

unstable load · Post by **unstable load** » Tue May 04, 2010 10:55 am

Gents,
My link to the different Toyota boxes seems to have disappeared along with Yahoo GeoCities, but it is the staple box for all the Toyotas in SA and mine came out of the 6cyl Twin Cam so I reckon it will handle the load.
I am after better fuel efficiency and some more power (I know they are counter productive) but I would like around 250hp for towing a trailer and maintaining decent speed at a reasonable consumption. I am not going racing with it, but it will see some spirited driving obviously.

My main issue here in SA is the cost of anything Rover, coupled with the hassles of importing anything used to the country. I can buy a Lexus engine for the price of importing my efi setup that is sat in UK at a mate's house.
As for controls, there are a few available units in SA that are plug and play for the Lexus and I can get a bellhousing and clutch for the box I have off the shelf, so I guess I have really answered my own question.

What is a hotwire setup with dizzy, box etc worth anyway?

Zaphod · Post by **Zaphod** » Thu Dec 05, 2013 1:46 pm

One thing you may have overlooked, the rear suspesion.

When broadspeed were racing the P6 V8s I belive they had issues with the diff mounting plate breaking. I'd imagine with the SBC this would need even closer attention. It did fail on my 2000TC even! but that was very rusty

DaveEFI · Post by **DaveEFI** » Thu Dec 05, 2013 1:53 pm

The entire final drive unit is only just about up to the torque of the standard engine. It had to be revised when they fitted the V8.

unstable load · Post by **unstable load** » Fri Dec 06, 2013 7:09 am

By then, it would probably have a Jag diff or similar in it, so hopefully that base would be covered.