Rover V8 3.5L to 4.6L upgrade DYNO TESTED! Rover p6 - Part 7 

I saw this engine in an Osca at an autocross back in 1964, it was called a Buick 215 cu. in., I have always been enamored with that engine.

Cor blimey! Just as well the Rozzers hadn't got one of these! Just kidding, amazing job Graham!.

Very nice! I have a 4.6 with Edelbrock 500cfm carb and Edelbrock intake manifold port matched to a pair of stage 3 ten bolt heads, Stealth cam and mapped ignition (MSD 6AL-2 programmable). With free flowing headers it made 325 ft lbs of torque at 4000 rpm. Over 300 ft lbs between 3000 rpm and 5000 rpm topped out at 315 bhp @ 5800.

Fantastic stuff - just love these engines and have always loved the looks of the P6.

Wow what a difference, nice job guys well impressed 👏

Excellent video

Graham! This is a great vid! Excellent editing and top content. It's been too long since I visited Penguin central. Liked. Subscribed and catch up soon I hope.

Thanks guys, my dad owns a P5B Saloon, I am usong these sounds for a video game! :)

Great video

Sounds wicked and goes well! 3.9 in my mgb is great with edelbrock and headers

What an excellent video

I’ve had several P4’s which I guess are my style of car, a 3 litre coupe’P5 and an SC2000. I did look at a V8 P6 but was put off by the way the guy just started it up and revved it right out. I just thought if that’s the way he treats it I’ll stay away. That’s the closest I got to owning one. Ultimately I was put off the P6 because the one I owned couldn’t handle corners in the snow in the Devon countryside. The P4’s were absolutely brilliant, having been careless enough to put one in a ditch, I was fortunate enough to be able to put it in reverse and get out. The lesson for me at the time I guess was that the P6 wasn’t exactly a country bumpkins car, even a V8. I’m talking now about hills and corners that need a rev to get up in the snow and handling to stay on it, I just felt that the P6 was a little too long in the wheelbase for my needs at the time. The ditch didn’t happen in the winter. Nonetheless the P6 is an absolutely beautiful car to drive, the open roads of West Australia would suit them perfectly, and that V8 is the most beautifully tuned I have ever personally heard, and the way it was respectfully revved is how I would treat my own car cold. Always a pleasure to watch your videos, relaxed, informative, and just really enjoyable. Thanks for that.

I loved the old Rovers... but have also owned 3 TVRs with the RV8s fitted (2 x 390SEs, plus 1x 400SE). Have a look at what TVR and owners of their RV8 cars had done to them, for some extra tips. 👍

Great video. I am looking at buying a 4.6 to replace to 3.5 in my Rover SD1 VDP EFI

Great Video really enjoyed seeing this! We're looking to engine swap a 4.6 Top hat into a 3.9 V8 Range rover classic, so some interesting information here

Nice builds, i also just started my V8 Rover P6 after 20 years :) will see how the engine behaves, maybe will do some mods. Greetings from Vilnius

😎 👍...that mill needs some wildcat heads me thinks

I'm a bit late to the party having just seen this and it's not that different to mine - my knackered 4.6 heads were saved with a set of very very slightly bigger valves (ones that don't need new bigger seats) and like you I used the standard cam, carbs, airfilter, etc off the old 3.5. My 3.5 exhaust manifolds had been built for looks from box section and I thought were awful for flow but I still got the same as you, 201bhp and 291lb/ft so maybe they're not so bad after all. The difference in driving is just staggering, it's definitely the best engine mod you can do IMHO. 4mpg better fuel consumption too :)

I have a TR7 with the 3.5. I would gladly trade up to the 4.6.

Back in the day I owned an SD1 3.5 running twin Strombergs but always looking for a bit more power I bought and fitted a brand new 390 cfm Holley carb, offenhouser manifold and Mallory distributor which straight out of the box really improved the bottom end power but the top end suffered a bit which was a bit surprising. Because dyno's weren't round very corner in these days I was happy enough with the low end gains to live with it.

Just shows what it could have been, put together properly!. Nuff said!. 🙂

Just think what it would do with a free flowing heads , cam and 4 barrel webber !!! owe and a nice set of ex manifolds ... knocking on the door of 330 im guessing and not far off that in torque if not a tad more !

Hi Graham, great video and great numbers there!!!. IT is possible to put 4 IDF webers there?

I loved this, what a great video (and series). I've got a '69 Series 1 P6 V8 which has the 3-speed BW35 box. I would take the 4.6 in that set up every time. Why? You can put the 3.5 in '2' which locks the box, and leave it there all the way up to about 65mph from a standing start. It's all torque which still embarrasses a lot of modern cars. Now, with that 4.6, that's rocket ship territory where it all counts from 0-3500 rpms. Then '3' should kick in... I imagine it would pull a p6 easily up to 140mph easy. Not that you would want to without a Police-spec front air splitter.

How about the original Buick engine compared to what has been done to it through Rover.

Be interesting to see what the 3.5 with better breathing can do if you get the chance to do one. 👍🏻

Interesting video, at the moment I'm doing the same with an SD1, I was recently given a 4.6 which was stored in a building which caught fire, rocker covers and plenum top were melted in places, but the short engine seems ok. I'm thinking 4.0 pistons, to give it a bit more compression, 4 barrel carb and intake, mild road cam, I have some ported heads from a 3.5, I have Rimmer bros tubular headers and sports exhaust on the car. In the RR the 4.6 made 220 hp, I'm hoping for 250 hp and 300 lb ft with these mods. Am I being too optimistic? Subscribed.

Great video Graham how's about a standard but stroked pinto

I have mgbgtv8 standard 3.5 engine apart from 4 branch tubular exhaust on the Northampton Motorsport RR produced 160BHP at 5000rpm .

I have a 3.5 and would like to do what you have done. So to be clear: you have replaced the bottom end and heads? Did you keep the upgraded cam from the 3.5? did keep all ancillaries including oil pump?

It's rather interesting to see how you folks down there deal mainly with small displacement engines and rather small power outputs. Where I'm from right in the middle of th U.S., it's hard to find somebody who builds an engine that's less than 325 cid, or for you metric folks, 5.3l. I personally am gathering parts to build a 470 cid engine, and I feel like it's still small.

Is having the correct cc of the engine on the log book a necessity for proper insurance cover?

I would like to see that done to a P5B

Did the bores on P6s exhaust manifolds match the heads on 4.6 ? I had to use a tongue sander on mine similar tho in P5b cast iron but they matched in the end Ps: I had installed a 4.0litre ports were massive compared to standard 10:5;1 P5b which were tiny by comparison

Hi, I have a 4.0 liter long block and some 3.5 heads from a RRC. I was thinking a 4 barrel and a mild cam. I was hoping to replace my tired 3.5 liter on my defender. What carb would you suggest in terms of CFM? How many HPs would you guestimate?

Back in the day at main dealer we would fit offenhauser inlet with 390 cfm with vac secondarys (or 600cfm) drove so much better and about 6mpg better (19-25mpg). Original inlet manifold was absolute shite....

Interesting stuff Graham, I raced a rover V8 powered MK2 Cortina for 30+ years, 3.5 and then 3.9, the final spec was 471 GMC supercharger 650 double pumper Holley, stage 2 high flow heads, blower cam, 7.:1 pistons, Helix clutch and ford T9 4 speed, the best ET was 12.00 @117 mph I never put it on a rolling road but looking at the numbers and the weight of the car I recon it was around 350 - 400 bhp the maximum boost was 5-8 psi , I always wondered what this engine could have been pushed to, what do you think? I sold the car after Shakespeare closed and now have a Camaro.

What power output do you think you could you expect from a 3.5L Rover V8 in Stage 3 set up with tubular exhausts?

I would be very interested to see what a Ford Essex 3.0 engine can produce without enlargement - back in 1984 i recall reading a copy of a British car mechanics type' magazine where someone un-named fettled an Essex to produce 250HP in old money with a set of triple Carbs and possibly some intake and exhaust tampering but not by enlarging the CC. Having owned a RR Classic 3.9 I have to say the V8 was very under welling in terms of torque/power. Yes the RR was heavy and I made adjustments for that but it was a very flacid engine. I took the engine out and replaced the camshaft and followers etc, etc, and it ran very well on completion but other than the sound that V8 is pretty sluggish in my opinion

Mmmmmm pro charger

whereabouts are you guys, didn't hear you mention and can't see a website address or link

How much do these 3.5s share with the later range rover 4.6 V8?

What sort of price range would it be for an older model Range Rover Classic rebuild, to perhaps 150 hp, and improved torque throughout the range, working mostly with improved efficiency, thus keeping the petrol consumption in the same general region? Is this even possible? :)

I have a question a friend of mine wishes to build a off road buggy. Wants to use a later Rover V8 4.0 EFi . Is this a good way to for power and reliability or should we stick with good old fashion carbs?

Great video, I notice the P6 was a 3500S, does that mean the exhaust manifolds on the test engine were the larger bore ones that were fitted to the 3500S ?

What sort of budget are we talking about going from 3.5 to 4.6? I have a Land Rover 101 with the standard (low mileage) low compression 3.5 V8 and i'm contemplating upping the capacity but don't know whether to just drop a second hand 4.0 or 4.6 into it or having the original engine capacity modified.

want an edelbrock 500 and manifold to test it on it? can drop it round. i got a 3.9 in the escort but my exhausts are horrible, mgb blockhuggers

Can you cure the air starving by fitting 2" SUs off a Jaaag?

What CR and cam are you using? Thanks

I believe this is basically the Buick / Oldsmobile aluminum V8 engine from the early 1960s. Am I correct?

How about changing them nsu carburettors.. into something more advanced?

Hey, will the 3.5 head gasket fit the 3.9 without issues?

Hello sir please help me with the direction of piston most especially where the word front faces for both sides

Enlarged by stroking?

I think that car needs some suspension bushings etc Engine?? A 302 Ford is smaller and makes more power

Buick and the Rover are port limited. They just can not flow the air for higher RPM power.

I feel like im watching a usain bolt trying to breathe through a cigarette. Those twin SUs, omg. 50 hp per litre. Pribably could have got those figures out of a standard rover v8 with some cams and a decent intake system? Im not an expert so maybe im wrong.

Fuel consumption?

Hiya bud great video it's something iv been knocking around in my head for a while now iv got the option of doing a SD1 3.5ltr rebuild or go for the 4.6 option the very thing of doing a 4.6 on su carbs and a cam it's for an off road trialing truck the carbs sounded the simplest of options what I was thinking of doing with the SD1 engine was give it a good freshen up with a full lighten and balanced bottom end a cam and some minor port work similar to what you just described the reason I was looking at the SD1 was I believe it has one of the higher compression ratios as standard and I noticed that the 4.6 is lower compression would I be better starting with the 4.6 with and bumping the compression ratio up abit and a cam straight away instead of looking at the SD1 engine also it would be on a manual box, any advice would be gratefully received and once again good video pal

probably would have picked up more topend power the 4 barrel carb God intended

seems to be alot of lost Horse Power. 9.5:1 pistons, roller lifters and rockers along with a real exhaust probably add 50-100hp if you rev it to 7k

Why go to all that trouble and not put a Holley.4 barrel.on I ran 3.5 in an Mgb.for 15 years

I don't get it. whats the point if the engine can't breath properly? Its crying out for better carbs and cams surely??

there ain't no substitute for cubic inches

Want a 5.0...😂