Thread: 3.9 to 5.0 litre

How much would it cost to build a good, reliable 4.6 - $6k?

slipped liner block for rebuild,from free up to - $400
top hatted - $1500
head work $500 - $1000
block / crank / rod machining - $500
new pistons, rings, bolts etc - $500
cam - $200
oil pump - $300
manifold / efi setup / computer - $500
gaskets and other stuff - $1000

just guessing at those figures,

So 6k+ and thats doing all the assembly, checking yourself, no warranty
A 4.6 is good for a drivable 230hp???

How much would a holden / chev conversion cost all up, engineered?


I'd just put a Thor manifold on the 3.9 for a few hundred $$ and go on a holliday with the money you didn't spend. Sucking down umbrelladrinks in the tropics really puts the quest for more power into perspective.

Recoed 4.6 with all the gear you describe including top hat liners plus a decent cam from TRS for about $4.5K exchange and from memory quite a few more claimed ponies then 230, I seem to remember about 270ish as the number quoted.

The only thing is if his engine is stuffed then a new inlet manifold won't make much difference and he won't have a car to drive to the airport to go on a holiday.

cheers,
Terry

If your only looking at 230hp for the 4.6 there are a few different way to get around that out of a 3.9

One of those CRS blowers is good for about 40hp on a v8 and that is all through the rev range basically
Extractors cam bigger injectors and a ECU upgrade is good for about 25-30hp but the more violent the cam the less usable it is
Not sure about those Thor manifolds but swapping the top plenum and throttle body is always a nice touch

Originally Posted by TerryO

Recoed 4.6 with all the gear you describe including top hat liners plus a decent cam from TRS for about $4.5K exchange and from memory quite a few more claimed ponies then 230, I seem to remember about 270ish as the number quoted.

The only thing is if his engine is stuffed then a new inlet manifold won't make much difference and he won't have a car to drive to the airport to go on a holiday.

cheers,
Terry

Thanks, $4.5k thats a pretty good price
I reckon 230hp is more than enough, 270hp yep, but at what revs?
you could build a 3.5 to put out 400+hp, wouldn't want to drive it anywhere though.

Originally Posted by steve_35

If your only looking at 230hp for the 4.6 there are a few different way to get around that out of a 3.9

One of those CRS blowers is good for about 40hp on a v8 and that is all through the rev range basically
Extractors cam bigger injectors and a ECU upgrade is good for about 25-30hp but the more violent the cam the less usable it is
Not sure about those Thor manifolds but swapping the top plenum and throttle body is always a nice touch

I just put a thor on the 3.5, I like it alot I actually like the little rover v8 now. I don't know if going to the older 3.9 style manifold would've been just as good or even better though?

In all seriousness my 94 model D1 3.9 with headers and full system that also has a Unichip fitted blows the doors off of my standard 4.0 D2a.

If you speak to TRS and tell them you want a recoed 4.6 for a Disco they will fit a high torgue cam. I believe they offer several options and usually have rebuilt engines sitting on the shelf ready to go out.

I believe quite a number of Aulro members over time have fitted them but I never found a post to date that says much about how they go or not.

These are long engines, you need a sump, starter, inlet manifolds etc.

Now all I have to do is buy one myself rather then just talking about it.

cheers,
Terry

Originally Posted by RoverP6B

400HPONGAS wrote,...

Are you talking about the Holden 4.2 or 5 litre V8? From what I have read, both and especially the former were regarded as being rubbish engines. Poorly designed and in need of a rebuild after 100,000 miles or less. There was also a problem with the 5.7 litre Gen III where piston slap resulted in large numbers of engines requiring a rebuild while under warranty.

A well maintained Rover V8 will run for more than 30 years so add another and that will drive you till your driver's license is revoked.

Ron.

Ron sorry but that is absolute BS. Obviously you have never owned either. There would be very few Rover V8s that have not had a rebuild or repairs at all.
The 4.2 (red) was a harder revving engine, I still have one in my Torana. The 5 litre red engine was also a great engine, a lot depended on mods done and this was the issue and where the time bomb issue came from. Many people did cheap and inappropriate mods for horsepower and not longevity, hence they would self destruct, just like any race engine built cheap for horsepower. If built correctly they will last but like any engine Holden, Chevy, Ford or Mopar if used outside of standard specs or application and modded for cheap horsepower rather than longevity they will not last. This goes for the Rover V8 as well which is so old and a Buick/GM design anyway. The thing with these engines is they are easy to work on.
The later 5 litre injected engine is also a great engine if used correctly. We had one in a wagon that used to hammer and is still going strong now in a VT (not ours anymore) and would go better, harder and get better fuel economy than our Statesman 5.7 litre.
The thing you need to remember is petrol engines are designed different to diesel engines and usually have more of a finite life, but having said that I have seen Holden red engines in both 6cyl and V8 do more than 500,000kms in standard form if treated right. Have even seen a taxi with a 4.2 do over 1 million kms without an engine change.
People often forget things like rings and bearings are designed to wear. I have known a number of diesel engines that have not lasted 50,000kms.

If we are talking standard engines, then generally they will last if maintained, but at some point will have to be replaced or rebuilt. Go outside the intended parameters and things change drastically. I had a RRC with a Stroker 4.2 and that was reliable, but still had the Rover oil leaks so gaskets were always an issue as were lifters. Same in most V8s. But take it out to 5 litres which can be done easily and things change depending on you cash flow. If you have the money to do one up like a TVR 5litre then of course it will last, but do it on the cheap like most people do an it will not, just like any Holden,Ford,Chev,Mopar.
Part of the red engine time bomb reputation came from the 80;s were they were prolific and most people would just put big cams and carbies on eventually resulting in component failure elswhere. Because the red Holden motor was so prolific you got to hear about the failures, happend in the Ford 302's and 351's as well, just the Ford Freaks were generally a lot more sheepish about it.
I did pop a 4.2 red but that was because the oil pump was not primed by said mech.
Also red line any engine often and see how long it lasts. A big part of engine failures I saw were that idiots would be redlining and valve bouncing them at the drags, hence why we often see rev limiters now.

CraigE wrote,...

Ron sorry but that is absolute BS.

Hello Craig,

No probs, no offence taken...I was stiring the pot so to speak. It is true that I have never owned either, and that is a choice that I made. There were problems with the 5.7 Gen III as doing some digging will reveal.

If Holden felt that the 4.2 and 5.0 were such great engines with loads of potential they would have continued their production, but as we know that didn't happen for one reason or another. In unleaded form, both were dismal in their power and torque delivery. I appreciate that many mods could be undertaken just as many mods can be undertaken with a Rover V8.

The Rover V8 was in production from circa 1967 till 2004 and now the block is manufactured under license by Cosworth, so clearly it was and is an outstanding engine.

My 3.5 V8 ran without ever leaving me stranded for 33 years until being retired. By all accounts I could have installed a new camshaft, bearing etc and continued for another 33 years.

It just irks me when people pile criticism on what is without doubt one of the best V8 engines ever made...43 years and counting.

Ron.