4.3 engine upgrades

[culminator]

I'm in the market for a Griff, probably a 4.3 but having driven a couple of modified 500's, I'm keen to end up with a 4.3 that has a genuine 300bhp.

How achievable is that witha 4.3 and what are the most effective mods to get to a similar figure?

Thanks
Mike

[spend]

Its quite a lot of work TBH:

BV heads, or large valve upgrade and judicious porting of heads, manifolds, trumpet base. Suitable cam etc. Mapped Ignition / replacement ECU. Induction mods like large plenum, smooth & insulated pipes...

Unless you are really dedicated or have deep pockets its probably easier to buy a 500. Don't forget with the 430 you have a fair bit of graft also with the chassis/brakes to catch up - horrid 2 piece wishbones, smaller brakes...

I really don't want to put you off, it's well worth it IMHO if you like the way the 430 spins up... but its a lot harder to raise the spec than from a 500 as a starting point. Having said that, it makes you wonder what LG's (BV?) would do with a little bit of fettling - but that is an exceptional engine to start with...

[Tildo430]

I've got a 4.3 which is a reasonable healthy standard car producing 236bhp. At the 2008 Griff Growl the majority of 4.3's were 230-240. Theres a tread somewhere.

Looking for a 30% increase in power sounds expensive to me. Supercharging would be most straight forward i guess but would probably change the way the engine delivers its power to more like a 500 anyway so i would agree that buying a 500 is the cheapest way to get there.

[spend]

430's are normally all pre-serps, SC need serp arrangement so not so simple. Boosteds turbo project may be more suitable FI for pre-serp engines?

[rev-erend]

TVR already did most of the easy cheap things to get more bhp and torque..

If you need more then there are 2 choices IMHO

1. Buy a Griff/Chim 500 engine and put it in you car .. it's an easy swap and will give 280 bhp and with some tweeking about 300.

2. Sell it and buy a Griff 500 or Cerb.

[LordGrover]

Tildo430 said:

I've got a 4.3 which is a reasonable healthy standard car producing 236bhp. At the 2008 Griff Growl the majority of 4.3's were 230-240. Theres a tread somewhere.

And then you get Hoover.'s and mine at c. 270 BHP. Clicky

[LordGrover]

culminator said:

I'm in the market for a Griff, probably a 4.3

Nudge, nudge.
Wink, wink.

Buy this one.

[culminator]

Thanks for the comments all, very useful.

LG, if only it were blue.......

[LordGrover]

Blue = slow, sub 250 BHP (a bit like a chimp)

Green = fast, >= 270 BHP (more of a man's colour)

[spend]

They have to be faster, otherwise they get covered in bird poo

[Peter66]

I have a 4.3 and also like to keep it like it is. However for the occasional power need I am considering a NOX solution in the future. It somehow feels right for the 'agricultural' Rover engine. I have read some positive remarks on the Chim forum about this. Are there any Griffs around using this? Are there any down sides/major risks of doing this?

Thanks,

Peter

[George 500]

Peter66 said:

I have a 4.3 and also like to keep it like it is. However for the occasional power need I am considering a NOX solution in the future. It somehow feels right for the 'agricultural' Rover engine. I have read some positive remarks on the Chim forum about this. Are there any Griffs around using this? Are there any down sides/major risks of doing this?

Thanks,

Peter

Have a peek at this

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

546bhp in a griff!

Edited by George 500 on Thursday 29th January 17:57

Edited by George 500 on Thursday 29th January 17:58

[culminator]

Looks like the sensible option is to buy a slightly modded 500. Anyone know of any for sale?

had a look at a nice ish one at the weekend (advertised on here)but seems very overpriced considering the market and actual condition.

[350Matt]

To further tweak a 4.3 up to 300 ponies I would do the following:

Fit a 45mm short trumpet base
open up and port lower manifold to taper ports in smoothly
match up manifold to port in head
open up the throttle to Ø72mm
go for a stealth cam from V8 developments.
Bump up compression to about 11:1 (this isn't too high providing you've got mapped ignition otherwise 10.5:1)
Fit a decent aftermarket ECU with coil packs and throw away the airflow meter.

Plenty of heatsheilding / exhaust coating etc and keep the intake cool and that should get you up to target.

[spend]

I wouldn't be certain that would give the 300 Matt, its really marginal if they have std valves. With the 43mm inlet BV heads I think it is really achievable though. I think its always a tough call whether it is the increase in valve size or the extra porting of the BV heads that gives the extra oomph we see from them.

I'm still working hard to make the ultimate 430 though it just takes lots of time & patience

[rev-erend]

culminator said:

Looks like the sensible option is to buy a slightly modded 500. Anyone know of any for sale?

had a look at a nice ish one at the weekend (advertised on here)but seems very overpriced considering the market and actual condition.

Right on.. guess the going rate in going to be around 3K.. then again - you old engine is also worth something .. to off set the cost.

[George 500]

culminator said:

Looks like the sensible option is to buy a slightly modded 500. Anyone know of any for sale?

had a look at a nice ish one at the weekend (advertised on here)but seems very overpriced considering the market and actual condition.

Wouldn't have happened to be the one in Hampshire would it? Otherwise that would definitely appear to offer the best option in terms of being mechanically sorted

[culminator]

Hmm, could be George....

I liked the exterior and the way it drove and it even felt fairly quick, circa 300bhp alledgedly. Hated the red interior, very bright and also thought it was a bit pricey.

How well do you know the car?

Regards
Mike

[trackcar]

spend said:

I wouldn't be certain that would give the 300 Matt, its really marginal if they have std valves. With the 43mm inlet BV heads I think it is really achievable though. I think its always a tough call whether it is the increase in valve size or the extra porting of the BV heads that gives the extra oomph we see from them.

I'm still working hard to make the ultimate 430 though it just takes lots of time & patience

What's the spec you're building to then Dave?

^^ i can't believe I had to edit such a short post

Edited by trackcar on Friday 30th January 17:10

[350Matt]

I managed 273 on my 4ltr with std valve sizes, with plenty of porting mind