PistonHeads.com Forum

350i to 570i

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ibroker

Original Poster:

658 posts

183 months

Sunday 27th January 2013
quotequote all
JUst strarting to restore a 1987 350i

The engine is fairly tatty and I am considering replacing it with a small block chevy 5.7 350bhp. For the cost of the new unit against a refurb of the old Rover and detailing it makes sense to go for the Chevy.

Thoughts?


pwd95

8,252 posts

163 months

Sunday 27th January 2013
quotequote all
Great project. yes
These guys might be able to give you a few pointers.........


http://www.youtube.com/watch?v=X5cvVS6V_HQ

http://www.youtube.com/watch?v=JiXJlaor6Ss&fea...

Chilliman

7,933 posts

86 months

Sunday 27th January 2013
quotequote all
ibroker said:
JUst strarting to restore a 1987 350i

The engine is fairly tatty and I am considering replacing it with a small block chevy 5.7 350bhp. For the cost of the new unit against a refurb of the old Rover and detailing it makes sense to go for the Chevy.

Thoughts?
My thoughts are that once again we see the pure logic and beauty of our bestest friend Man Maths.

Has to be done i'd say thumbup

330p4

668 posts

155 months

Sunday 27th January 2013
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I would go with the LS motor rather than the old iron blocks due to weight
Ian

ibroker

Original Poster:

658 posts

183 months

Sunday 27th January 2013
quotequote all
The LS? do you have any idea on cost. The chevy is £2500
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pwd95

8,252 posts

163 months

Sunday 27th January 2013
quotequote all
Really not worth the hasstle of converting for a cheap old iron block 5.7 IMHO. It'll cost you a fortune to get everything converted properly & the car will be almost undrivable. The weight distribution isn't great with the light RV8!!!!!

You'd be better with a decent 2nd hand good RV8 bottom end & slapping a supercharger on it. Been done a few times. yes

TA14

11,912 posts

183 months

Sunday 27th January 2013
quotequote all
ibroker said:
The LS? do you have any idea on cost. The chevy is £2500
LS is a Chevvy. Have a chat with Thorpy for the conversion.

nawarne

2,594 posts

185 months

Monday 28th January 2013
quotequote all
TA14 said:
ibroker said:
The LS? do you have any idea on cost. The chevy is £2500
LS is a Chevvy. Have a chat with Thorpy for the conversion.
Chap with a Cerb got a 2nd hand LS1 or 2 from the US a few years ago for £3300. Came complete with engine loom and 6 speed gearbox. Price above included hire of van to pick up from Felixstowe customs IIRC.
Nick

bionicjim

473 posts

64 months

Monday 28th January 2013
quotequote all
I'm not up on the rv8 much
But you could try some of those super flowing heads from the states
They recon they will push 400bhp and they are lighter than the standard heads
But with HUGE valves

ibroker

Original Poster:

658 posts

183 months

Monday 28th January 2013
quotequote all
pwd95 said:
Really not worth the hasstle of converting for a cheap old iron block 5.7 IMHO. It'll cost you a fortune to get everything converted properly & the car will be almost undrivable. The weight distribution isn't great with the light RV8!!!!!

You'd be better with a decent 2nd hand good RV8 bottom end & slapping a supercharger on it. Been done a few times. yes
Thats why i love thses forums.

Ok so I will put my hands up and say I am not good with the spanners and as such sometimes what I want is not practicle as stated above.

I presume the RV8 as mentioned refers to the original engine?

On the assumption that it would cost a fortune to repalce all the other bits to match the chevy, surely I can gey the RV8 tuned? Its a big lump and must be capable of more than 190hp. Where or who would do that?

bionicjim

473 posts

64 months

Monday 28th January 2013
quotequote all
You could try Chris at Devon racing
By all accounts he can work wonders with the RV8
01404891175
01722323423
I'm sure I saw a 4.8 RV8 last time I was there you've got nothing to lose by asking

Chilliman

7,933 posts

86 months

Monday 28th January 2013
quotequote all
ibroker said:
pwd95 said:
Really not worth the hasstle of converting for a cheap old iron block 5.7 IMHO. It'll cost you a fortune to get everything converted properly & the car will be almost undrivable. The weight distribution isn't great with the light RV8!!!!!

You'd be better with a decent 2nd hand good RV8 bottom end & slapping a supercharger on it. Been done a few times. yes
Thats why i love thses forums.

Ok so I will put my hands up and say I am not good with the spanners and as such sometimes what I want is not practicle as stated above.

I presume the RV8 as mentioned refers to the original engine?

On the assumption that it would cost a fortune to repalce all the other bits to match the chevy, surely I can gey the RV8 tuned? Its a big lump and must be capable of more than 190hp. Where or who would do that?
It really is very simple to up the capacity! I looked into this when I had my BGT V8, basically all the anicilliaries and the heads will fit, for example, a 3.9 block. I believe the 4.6 heads flow better than the 3.9/4.0 heads. Typically all these parts can be had cheap off fleabay, and the bigger capacity short engine will bolt straight onto your existing bellhousing. you'd need to be wary over certain components though as not ALL bits are compatible.. Advice from a good RV8 builder would be advisable, PM me if you need pointing in the right direction...

Chilli smile

KelWedge

1,154 posts

110 months

Monday 28th January 2013
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A couple of places to get some info

Rover parts international on www.v8engines.com or v8 developments on www.v8developments.co.uk

I considered the chev engine for a day or two and didn't go that way. Still cost lots £ but you have to, don't you. wink

ibroker

Original Poster:

658 posts

183 months

Tuesday 29th January 2013
quotequote all
Forced induction meaning a supercharger? Like that idea

I would like to achive 300-350 bhp, am I aiming to high retaing the original 3.5?. That said I dont want to compromise the handling of the car by changing the weight distribution.

Changing the direction slightly. Ther car heads over to Cambridge tomorrow for work to start getting it running, are there any "Must Do" jobs that I need to get done in the restoration. I dont want to get to a TVR gathering and someone say, "I assume you upgraded this" you know missing the obvious?

Cheers
Andy

Chilliman

7,933 posts

86 months

Tuesday 29th January 2013
quotequote all
ibroker said:
am I aiming to high retaing the original 3.5?.
Cheers
Andy
Yes.

There's also the question of the strength of the standard bottom end on the earlier 3.5 (IMO)

This site will give you an idea of what you can expect in terms of capacity/BHP

http://www.sc-power.co.uk/pages/sc-power-superchar...

Chilli

TA14

11,912 posts

183 months

Wednesday 30th January 2013
quotequote all
B-Reight said:
IIRC the lt77 gearbox is only rated for 280lb-ft of torque, a supercharged engine of 300-350bhp would no doubt have 300+ lb-ft of torque.
There would be a great many problems with this project but the gearbox is not likely to be one of them. Steve H for example never had any trouble with that amount of torque.

In short I don't think that this is the right car to do this conversion on.

TA14

11,912 posts

183 months

Wednesday 30th January 2013
quotequote all
ibroker said:
I would like to achive 300-350 bhp, am I aiming to high retaing the original 3.5?. That said I dont want to compromise the handling of the car by changing the weight distribution.
Why is this not in the wedge section?

Realistically I think either fit a tuned 4.6 RV8 at say 260bhp or do the work on another car, maybe a 420SE. I think that 260 is pushing it for a 350i, you'd want everything to be in tip top condition and maybe fit better front brakes.

For 350bhp I'd think that you be looking at nearer £15K for perhaps a tuned 5.0 RV8, stiffer springs, matching shocks, uprated suspension arms, rose jointing, half shafts, UJs, wheels, tyres, modified bodywork, brakes, etc.

ibroker

Original Poster:

658 posts

183 months

Wednesday 30th January 2013
quotequote all
Thanks so much for all the input.

I spent a fair amount of time pricing this today and it does not stack up. I think the previous post stated that "this being the wrong car for this project" is a fair conclusion. If you add that to the possible detraction away from a standard car and how funny people who buy classics are then that closes the discussion. That with all the other mods/upgrades required.

Thus I will stick with the 3.5 as standard and fettle it towards the 220-230 potential.

Day one of the restoration started today....Excited........

Chilliman

7,933 posts

86 months

Wednesday 30th January 2013
quotequote all
Wish you well with it... keep us updated smile

Chilli