What Power a 3.9 v8

What Power a 3.9 v8

Author
Discussion

mgv8dave

Original Poster:

826 posts

220 months

Monday 12th November 2007
quotequote all
just a simple ( if there is one ) question a V8 3.9 based on a Rover V8 that came out of a Marcos
has just been put in to my Mg ( sorry ) it is a great engine and pulls like a train but i was wondering if anyone knew what
type of power bhp & Torque it could be putting out.
I think it is out of a newish car as it has only covered 15K Aparently and it would look like that is the case as it is Mint.
thanks for any advice ................. ill now sneak of back to the Mg section tumbleweed

yeti

10,523 posts

282 months

Thursday 15th November 2007
quotequote all
That's a 190bhp engine as standard in the Marcos - I assume it's on Hotwire EFI? Sometimes they quote 205bhp and if you have good compression on a minty engine, why not?

220-230bhp is reachable cheaply (it's all relative) with better plugs and leads (Magnecor), a short cone-type K&N filter and a decent chip. A little bit more money sees shorter throttle trumpets, after that it's silly money time. RPi (RIP) are probably the people for this, just don't let them build you a whole engine (long story). It will pull better and you will get better throttle response too. That standard engine just can't breathe.

The jury is still out on improved fuel ecomonmy...

yeti

10,523 posts

282 months

Thursday 15th November 2007
quotequote all
If it looks mint, it may be genuine mileage! My 3.9 came out at about 60k and it looked awful when we got the heads off!

The MGB only had 135bhp when frst fitted with the 3.5...

mgv8dave

Original Poster:

826 posts

220 months

Thursday 15th November 2007
quotequote all
thanks for that, i am running it on a holly390 Carb set up with a k&N pancake filter
it has all been polished and ported and has a good set of Kent cams in it. if the standard was 190 with all the work i hope about
200+eels like it pulls like a train

Petros

2,441 posts

236 months

Thursday 15th November 2007
quotequote all
Had a J E Developments 4.6 in my roadster, using an Edelbrock carb she dynoed 220 on their rolling road.

yeti

10,523 posts

282 months

Friday 16th November 2007
quotequote all
I sincerely hope your 220bhp was at the wheels, not the flywheel! A standard 4.6 in a Rangie will make 225bhp at the flywheel with nothing done to it! Anything breathed upon should be making 270bhp.

Very heavy breathing will make 340bhp, I don't think there is much more to be had reliably.

Jack LM

49 posts

252 months

Friday 16th November 2007
quotequote all
The 3.9 V8 fitted in Marcos from the mid 90's is the same engine as the MGRV8.

Petros

2,441 posts

236 months

Saturday 17th November 2007
quotequote all
Presume so, never thought to ask. Do know that the car was almost lethal if not in a straight line.

mgv8dave

Original Poster:

826 posts

220 months

Friday 30th November 2007
quotequote all
Jack LM said:
The 3.9 V8 fitted in Marcos from the mid 90's is the same engine as the MGRV8.
thanks for the simple answer