4.7 kit for 3.9

[Tree Trimmer]

In doing some reading about the 3.9, I noticed the mention of a kit to rebuild the engine to 4.7. As I am very interested in this, can anyone tell me if this is accurate. If something like this is available where can I find one. I have an engine builder lined up to stroke my engine to 4.6 (just because I want to, I know most of the pros and cons) but want to find out more about this option. Also, does anyone know the HP and torque of one of these engines.

Thanks,
Tim

[Philip A]

AFAIK they are no longer available, although Bruce Davis will do a 5 litre using Falcon pistons.
The 4.7 is available from UK "Real Steel" but it costs landed as much as a new 4.6.
Regards Philip A

[Tree Trimmer]

As I am in the states and have a competent engine builder I need the parts. Anyone know contact info on Bruce Davis or Real Steel? Also, power output?

Or of course, any info on a rebuild like this is greatly appreciated.

Thanks,
Tim

[cloughy]

You can't just quate a power output easily as it varies with how the engine is built. compression ratio, head mods,camshaft all can vary to make 200hp to 500 hp with the same capacity.

[Tree Trimmer]

I can see that, but I guess what I read led me to understand there was a compilation of parts for a 4.7 version of the 3.9 block. If this had been the case I thought there might be a general HP range for the build. There was mention of roller rockers, "last of the 4.7 kits", etc.

Still looking for some good leads, mainly from across the pond, as that is where the 3.9 has been thoroughly researched. I've wanted to do this rebuild for sometime, and now that I am ready, the information has become harder to come by in lieu of the 4.6 being utilized more.

I have contemplated many alternatives to using my 3.9. Diesel, propane only, chevy SB, different trannys, and the list goes on and on, but it always ends up at a built, stroked 3.9 and beefed up ZF. Like I said, I know this may not be optimal, but it's what I want to do.

Any information on a buildup for a fairly strong and reliable, daily driver, off roader, tow vehicle motor ( just occasional) on my current 3.9 for auto tranny would be great. Specific parts, block prep (mods, stiffening, girdling, etc.), supercharging?, anything that has been done but the most exotic high-rev only race engine. I read that a formula team (iirc) ran the 3.5 with a SOC on each bank of pistons. I read about one engine that was under bored and supercharged for production vehicles.(not the 3.9)

I've read lots about the 3.9 and what can be achieved, but have not been able to find the specific parts and procedures. I don't feel that I need to start from scratch and muddle my way through this as there is over 30 years of testing already done. As I said, I have an engine builder ready to undertake the project, we just need leads on parts and specific prep work for this type engine (naturally he's most familiar with chevy's, fords, etc.)

Maybe some would think this is beating a dead horse, but I know I can get what I want out of the 3.9 if I could just get some leads on the specifics. I know there is a wealth of knowledge here, that is why I'm posting this here.

Thanks again,
Tim

[justinC]

I had a John Davis 4.7 motor in my Rangie, (4.67litres actually,) and it was fantastic. It had Ford pistons and a stroker crank made for JD engine works. No vibrations, made some good HP, pulled like a steam train and was ultra reliable. After 160,000km it had a small head gasket leak I stripped it down to find that it was beautifully balanced, port matched etc and the assembly detail/ workmanship was excellent.
I would recommend a 'kit' from Bruce Davis Performance for one of these engines, try them on (02) 96791179, ask for Tony at parts.

Justin Cooper, Hobart, Tasmania.

[Jack Straw]

[Any information on a buildup for a fairly strong and reliable, daily driver, off roader, tow vehicle motor quote]

Just curious, If you're going through all the trouble to go to a 4.7 why not start with a crossbolted block.[/quote]

[Philip A]

If you want to find "real stel" put it in google and their email address comes up.

The reason that the 4.7 died out was that firstly ,after machining it was no cheaper than a new 4.6.
Secondly the 3.9 was the worst engine for sleeve slipping and this was exacerbated by the longer stroke.
Sydney specialist Graeme Cooper (lrexpert.com.au) stopped doing the stroker as soon as the 4.6 became available as he lost a lot of money on warranty failures.
Having said that one of our club members has recently had a 5litre stroker made by JD and is relatively happy so far.
Regards Philip A

[peter r]

G`day Tim ,

Depends which 3.9 you want to use , some will be more suited but if you spend some time with the mobs below .

I tried these on Google and there easy to find .

Rimmer Brothers

RPI engineering

J E engineering

D J E engineering

Above UK

Aluminum V8 ........ D and D Fabrications ... Almont , Mi . 48003 USA

This mob put Buick 300 and maybe 350 cranks in 3.5 s and pretty sure 3.9s , it`s a while since i looked buy it explains pretty clearly what and how they do .


If you feel inclined i`d suggest you have a look at a book called.

" How To Power Tune ROVER V8 Engines by Des Hammill ......... Veloce Publishing .


It will give you an idea of why infomation about Rover V8s is often hard to find .

All the best , peter .

[andrew e]

i have heard a few rumors about stroking the rover v8s, if anyone can confirm, let me know.

Rumor 1 - the poms have a stroker kit for 5.2

Rumor 2 - kiwis have a stroker kit for 6+ litres (used in those jet boat thingies they race around canals)

Rumor 3 - you need buick heads (really old ones from before rover bought the rights to the 3.5) to get enough flow through the ports in a stroker over 5L?

Anyone confirm or deny any of these??????

Andy

[Tree Trimmer]

Thanks Justin, I'll definitely give them a call. Also thanks Peter. I have in the past talked with Chris at RPI, even have one of their chips. I think his main goal, and maybe rightly so, selling me a new engine. I called JE engineering, mainly about a diesel conversion, I didn't ask much about the 3.9. I've also talked with D and D in Altmont. Their catalogue is one of my best sources so far for parts. Don't think I want to go with the old buick crank, although I haven't really researched it that well. I think the biggest problem was getting the crank to hook up to an auto tranny. I hope this would not be an issue with a custom crank? He also tried to steer me toward a 4.6. I'd like to find that book, I think Steve L. has refered to it in some of his writings.

Why not the 4.6 Jack? Probably stupidity. 4.6's are not all that easily to come by cheaply here in the states just to buy one for a rebuild. Then there is the possibility of getting a bad block and spending time and money going through that ordeal. Also I believe most all the 4.6's here are gems. I want to stay with a distributor, (and fuel injection) as a matter of fact I want to keep everything like it is externally. I know the 4.6 can easily be built with a dizzy but I'm wanting to keep the build as simple as possible, on the outside that is. I'll let the engine builder deal with the inside. I just have a thing about keeping the engine I have and working with it. If I were going to put the engine through unusually harsh use I would definitely go with the 4 bolt cross main block. Even though I want more power than the 3.9 has, mainly to tow my camper 3 or 4 times per year, I will not be abusing the engine. I drive fairly conservatively but slightly oversized tires and towing are just out of the 3.9's league.

Maybe I just want to have something a little different from the other US rovers. Who knows.

I hope someone answers these questions Andy. I am hoping I can use my heads by just fitting them with the largest valves possible and porting. Don't think I want to go quite 5.2 or larger though. I've read that to go that large you have to overbore to the point of the block being more prone to failure. Or maybe that was over the 5.2 mark.

Phillip, one thing I've read and think I might do is to have the liners bored out and have new ones heat shrunk in. Just a little insurance for the expense of the rebuild. Steve L. wrote about this but when we spoke about just a straight forward 4.6 rebuild on my block he said it was not necessary. And pardon my ignorance, but what are "the poms"?

Thanks all for the great info,
Tim

[Jack Straw]

[quote="

Why not the 4.6 Jack? Probably stupidity. 4.6's are not all that easily to come by cheaply here in the states just to buy one for a rebuild. [/quote]

I was just referring to the block. You could pick up a 4.0 block as they're crossbolted just the same. If you wanted to use the dizzy just reuse your front cover. Personally, going to a 4.7 without having a crossbolted block is doing a lot of work and spending big $ with a potentially hazardous low end.

[peter r]

G`day Tim ,

Amazon over there sell the book but it`s around $67 US , i think it was .

The book has alot of info on 3.5s through 4.6 and even has a bit on our 4.4 Leyland .

Goes as far as suggesting which blocks to use and why , things like in the crossbolted engines the liners base sits or is supposed to sit on a 360 deg surface of alloy , where as the 3.9 and 3.5 liners only has movement towards the crank stopped by a very small area .

This is where the different 3.9s may come into it , if a long nose crank 3.9 with the casting for the crossbolts but no cross bolts they may have the 360 for the liners but i don`t know if they do or not .

Book also goes into when Rover actually tried to fix the miss alined liners in the blocks .

If the book is taken as read it`s pretty scary what Rover did .

According to the book the pommie armed forces had specially built 3.5 crossbolted motors and they achieved , according to the book an almost 100% failure rate .
And supposidly when any of the blocks be they cracked or whatever are fitted with flanged liners there has been a 100% success Rate , reason being they are sort of like a wet sleeve and are seal at the top and bottom but still fit into the alloy not the water jacket , so it doesn`t really matter what goes on between the seals and the flange at the top limits any movement of the liner .

Have fun ,

peter .

[Tree Trimmer]

Jack, you're making too much sense. I might get on the lookout for a cross bolted block of some kind. Maybe it won't add too much to my project. After all I think I'm going to step back for a little longer and check out that book Peter mentioned. Sounds just like what I need to read. If I still want to do this after reading the book, I know it'll be what I was meant to do.

Thanks all, this has been a very informative series of posts.
Tim

[Philip A]

OK , you want big heads and 6 litres.
How much money have you got?
http://www.roverv8engine.co.uk/index2.htm

Australian slang Pommie, Pom = US slang Limey.
Regards Philip A

[Jack Straw]

Australian slang Pommie, Pom = US slang Limey.

I've scratched my head about that countless times, thanks for clarifying

[Jack Straw]

Gotta work on that quote stuff

[Tree Trimmer]

OK , you want big heads and 6 litres.
How much money have you got?
http://www.roverv8engine.co.uk/index2.htm

Australian slang Pommie, Pom = US slang Limey.
Regards Philip A

Oh I've got the money, I just might be living in a tent beside my rover beast for two or three years after building it!

Tim