Rover V8 upgrades......

esprits1v8 · Post by **esprits1v8** » Mon Jun 21, 2010 1:39 pm

Hi,
I have two Rover 3.5 V8 engines, one is an old P6 lump (high compression) and the second is a Range Rover classic low compression 8.13.1) how ever this is fitted with near new piper hi-torque cam, stage 3 Rpi heads, and steel timing gear. Could I fit the pistons from the P6 engine into the other engine? would this be viable and worth the effort? I have about a grand to spend so what should I do? I also plan to use the hotwire injection setup.

CastleMGBV8 · Post by **CastleMGBV8** » Mon Jun 21, 2010 3:33 pm

Hi V8 Esprit, Name?

What vehicle?

Welcome to the forum, personally i wouldn't fit the 35+ year old P6 pistons, you can buy a set of 9.75/1 Vitesse pistons and provided your bores are in good condition a light hone should be fine.

You can get a set from Real Steel for around £140.00 + rings Tel 01895 440535 but check they have standard size.

The Hotwire EFI will probably be ok depending on the cam spec, if not you could upgrade to a Megasquirt which will give full control of ignition and fueling.

See Extra EFI's AD

Kevin.

kiwicar · Post by **kiwicar** » Mon Jun 21, 2010 4:12 pm

Hi Kevin,
he already has a set of stage 3 heads, I would use those, maybe a quick lap of the valves, but probably not worth it. For that budget, a set of decent but cheep headers (headerman?) a tin of HTP paint for the headers, what inlet system are you using?? carbs or efi?
Best regards
Mike

CastleMGBV8 · Post by **CastleMGBV8** » Mon Jun 21, 2010 5:38 pm

Mike,

I get a bit dozey in the afternoon

I also go a bit blank when someone mentions RPI but I think they will be V8 Developments heads.

Kevin.

TVRleigh · Post by **TVRleigh** » Mon Jun 21, 2010 10:52 pm

You maybe better off getting a second hand 3.9 hotwire, and then fit your heads and camshaft, your then have about 230+ BHP.
You also be able to get some money back on your 3.9 heads or put them on your old engine, and sell the who lot.
Unless you need to stick to 3.5 ltr.

esprits1v8 · Post by **esprits1v8** » Mon Jun 21, 2010 11:31 pm

CastleMGBV8 wrote:Hi V8 Esprit, Name?

What vehicle?

Welcome to the forum, personally i wouldn't fit the 35+ year old P6 pistons, you can buy a set of 9.75/1 Vitesse pistons and provided your bores are in good condition a light hone should be fine.

You can get a set from Real Steel for around £140.00 + rings Tel 01895 440535 but check they have standard size.

The Hotwire EFI will probably be ok depending on the cam spec, if not you could upgrade to a Megasquirt which will give full control of ignition and fueling.

See Extra EFI's AD

Kevin.

Hi Kev,
The engine is to be fitted in my S1 Lotus Esprit, It cam fitted with the P6 engine, which ran ok but was not that fast! and a Esprit has to go FAST! the Ranger Rover engine came with the car and had a few goodies fitted. My plan is to use the best of the bits I have and build a better engine. I have a bout a grand to spend so want to buy the best value (bang for buck) as they say.
Thanks Rob

esprits1v8 · Post by **esprits1v8** » Mon Jun 21, 2010 11:34 pm

kiwicar wrote:Hi Kevin,
he already has a set of stage 3 heads, I would use those, maybe a quick lap of the valves, but probably not worth it. For that budget, a set of decent but cheep headers (headerman?) a tin of HTP paint for the headers, what inlet system are you using?? carbs or efi?
Best regards
Mike

Hi Mike,
I already have custom manifolds, I also have some nice TVR jobbies which I might modify and fit? I plan to use efi (hotwire).
Thanks Rob

esprits1v8 · Post by **esprits1v8** » Mon Jun 21, 2010 11:41 pm

TVRleigh wrote:You maybe better off getting a second hand 3.9 hotwire, and then fit your heads and camshaft, your then have about 230+ BHP.
You also be able to get some money back on your 3.9 heads or put them on your old engine, and sell the who lot.
Unless you need to stick to 3.5 ltr.

Hi TVRleigh,
no I dont need to keep the 3.5 any RV8 will do, but it is a tight fit against the bulkhead (front of the engine) it has to use a P6 front cover, remote water pump, and very short front pully, and special water pump blank.
230+ is in the right direction but I feel its still going to need more......
Thanks Rob

topcatcustom · Post by **topcatcustom** » Tue Jun 22, 2010 7:14 am

esprits1v8 wrote:
TVRleigh wrote:You maybe better off getting a second hand 3.9 hotwire, and then fit your heads and camshaft, your then have about 230+ BHP.
You also be able to get some money back on your 3.9 heads or put them on your old engine, and sell the who lot.
Unless you need to stick to 3.5 ltr.
Hi TVRleigh,
no I dont need to keep the 3.5 any RV8 will do, but it is a tight fit against the bulkhead (front of the engine) it has to use a P6 front cover, remote water pump, and very short front pully, and special water pump blank.
230+ is in the right direction but I feel its still going to need more......
Thanks Rob

You can fit the P6 front cover to a 3.9 (and your cam etc), you cant tell the difference between a 3.9 and 3.5 unless you measure the bores so all ancilleries will fit. As Leigh said- better off getting a 3.9 in there. Plenty of them about and is the easiest way to make more power! To get more than 230bhp out of a 3.5 is going to be expensive and stress the engine more. You will also get a bundle more torque with more cubes!

esprits1v8 · Post by **esprits1v8** » Tue Jun 22, 2010 8:08 am

what if I fit a turbo? how much boost could a stock 3.9 take? whats the cheapest way to build a near 300 bhp engine? how much power did the janspeed turbo range rovers make? they pop up on ebay.........

esprits1v8 · Post by **esprits1v8** » Tue Jun 22, 2010 8:12 am

CastleMGBV8 wrote:Mike,

I get a bit dozey in the afternoon I also go a bit blank when someone mentions RPI but I think they will be V8 Developments heads.

Kevin.

whats wrong with RPI? apart from the high prices! do they not do the heads? I have never brought from them, the bloke I brought the car from had spent 2-3 grand on parts from them.........

bones · Post by **bones** » Tue Jun 22, 2010 9:22 am

from what ive read,its easier to do a twin turbo than a single because of the connections and pipe work . On a 3.5 or 3.9 to get 300+ bhp then forced induction would be the only way i would thing, and standard internals would be ok if the boost is kept down. Someone with more brains than me will give a better answer

rich

topcatcustom · Post by **topcatcustom** » Tue Jun 22, 2010 9:28 am

I know that standard(ish) internals are ok for 370bhp on a 4.0

(well- at least they are at the moment...) Thats with about 8psi boost, though the blower saps a good deal of power. You could use an eaton M112 supercharger which may be more compact that TT's and no lag.

kiwicar · Post by **kiwicar** » Tue Jun 22, 2010 9:33 am

Two things wrong with RPI, one you are already aware of, price, second they will try and sell you anything they have on the shelf regardless of whether you actually have any use for it, and to help this they make up stories and call it technical advice when it is just a sales pitch, I would really avoid them at all costs.
A turbo motor is a reasonable solution to wanting 300 bhp, but you probably not do it for £1k. a standard bottom end with about 9.35 CR and 6 to 8 lbs boost with an intercooler should do it, you would need a suitable cam, the Real steel blower cam for instance (yes that cam again!

)but you will need an aftermarket ECU which would stick 500- 600 on the bill, a single turbo, efi manifold, intercooler and turbo (I would look for a single turbo solution if you can) as you are mid engined this should be a fairly straight forward as far as exhaust blombing is concerned.
Best regards
Mike

TVRleigh · Post by **TVRleigh** » Tue Jun 22, 2010 9:59 am

Only way you going to get 300 BHP from a 3.5/3.9 with £1000 is with nitrous.
A 3.9 with good heads, good camshaft and good exhausts will give you upto 260 BHP, depending on the spec of the above. most good 3.9's will only have about 230-250
But saying this it's going to be a massive difference from the 150 you get from a P6
230 BHP + in an Esprit should give you a sub 5 second 0-60

The only way to get 300 BHP is to
1. go 5ltr same size block, plus 90% sure you should be able to take the P6 cover (will cost about £3000 complete)
2. go 4.5/4.6 but with very stage 3+ heads race camshaft and fully ballanced. (will cost about £2500)
3. as said go forced induction.

All of the above your also going to need an after market ECU so at least another £500 (if you wire it all up yourself and have most of the sensors) then you need to get it tuned on a rolling road so another £300

I would go the 3.9 route and then upgrade again when you have more money and if you want it to be quicker.

Also remember if you go 300BHP you want to make sure your gearbox drive shafts and brakes etc can cope.

All depends on what your planning to do with the car.