3.5 - more beans!

Hi all

first up, it's not in a landy, it's in a 1970 high compression P6. But i figger you people are knowledgeable enough to help

I want a bit more go out of it, it goes pretty well at the moment but I've got modifiers disease so want more! Got some exhaust bits that are better than standard, and going to change the inlet to flow better. Which heads are best? it has the standard 1970 P6 heads on.

Don't really want to do an engine swap for a bigger one cos the one that's in there's only done 19K from an RPI £3K re-con and is in dam good nick. Wouldn't mind a 5 speed if one came along tho. Any ideas on heads/cams?

cheers!

Later heads from an SD1 rover are better, vittesse ones are the best. Edelbrock carb is better than a Holly, and a nice new cam from Piper or similer should start things off! Dont forget the ignition system, there are lots of goodies to upgrade this side of things as well.

seem to remember somthing about sd1 heads not fitting p6 block's , number of bolt's maybe ......

good timing , I am pipe dreaming about building the following motor.

3.5 efi block, with p6 hi comp pistons and 3.5 efi heads and a 3.9 efi cam.

then either a holly, webber or elderbrock- I cant remember which one doesnt work well at an angle? this will oneday go in front of a refurbed lt95 in my 72 range rover.

what do people think of my budget plan and are any of those ideas usefull to the O/P?

I think the holley is no good on an angle. But that's just a hunch.

:5biagree:
Seems to be a problem with them. Normally its to do with the float in the carb. It use to happen all the time when i use to go out 4x4 in the sand dunes with friends in older carb vehicles. Thats why efi and diesel becomes a better option if you into serious off roading. I have heard that the stromberg carbs don't suffer this problem though.

cheers fellas

stuff I've discovered: some of the later heads have got 10 bolts instead of 14, (maybe the 4.2 and bigger?) but they also have smaller combustion chambers to take account of the thicker head gasket, so those on a standard P6 would result in a probably unrunnable comp ratio - it already pinks like a bastid if it's not run on shell vpower + additive. If I was building one i'd go for a slightly lower comp ratio just because it would be less silly.

though the large combustion chamber heads on a composite gasket takes the ratio low enough to think about supercharging...

Not sure about holleys and things, I like SUs and would want to retain the driveability and economy (HA) that they give (and the fact that thy're free cos they're on there already), other than that i'm going to copy fetts idea..

ignition wise the previous chap's fitted mallory twinpoint at some enormous price. Don't quite know how that works but I'll get there.

is a 200 hp flywheel attempt realistic?

I have heard bad things about the mallory ignition, although I havnt used it my self- I knew a guy who took it off again becuase it was such a PITA.

I went for lumention on mine in the end, and after a landrover mechanic I no longer use had fitted it wrong with a 12v coil and broken it I bought some replacement parts and fitted it my self and it works very well now- I wouldnt swap it for anything else as its just so nice and simple.

carb wise I am running a pair of andrew turner refurbished su hif 6's atm and they are ok- again I ended up re-doing them my self after the so called proffesionals couldnt get them right.

Thing is when I bother to build this engine I wont be rushing it so the carbs will be staying on the car running the old motor untill engine swap day and I fancy a 4 barrel for the new engine as there will be less ****in about balencing them.

are you running 10.5:1? and it still pinks on v power?

have you been on the p6 forum as a few of the guys there are running on v power or tesco super and dont have any problems.

It's the 4.0 and 4.6 that have 10 bolts but they do fit the early blocks as its the outside row that cause head gasket problems as they tilt the head over when over tightenead. so they don't drill the holes anymore but the casting is still there. Not sure if you would get 200 bhp from a 3.5 without head work a lumpy cam etc. The 4.2 is 200 from standard so its a better place to start. All depends on what you want it to do , rev like **** or lots of low down grunt! http://www.mez.co.uk/TuningTheRoverV8-pt4.html

I have read that mez site, tis brill!

4.2's slip liners with the best of them though

fanks again all

that mez site is cool.

I'm going for max grunt, got a K-series midget for mad rev stuff

looks like heads is the way forwards, especially if I can get some more modern 10 bolters, and doubly especially if I can keep em if I ever want a bigger engine (when I can afford the insurance hike from the engine swap..)

As for the pinking, i've got it so it only does it very rarely on part throttle, probably trying too much advance tbh. but it's managing a decent 23 mpg with that set at the moment ...

late 3.9 & 4.2s have 10 bolt heads - even on 14 bolts you just don't torque the outer row down too much.

200hp from a 3.5 is possible but just make sure you don't go too wild with the heads as the 3.5 can't flow fast enough.

my recomendation would be to get a 4.3 stroker kit fitted with some merlin heads and light cam which would probably give you arond 260-270hp

v8hotrodboy said:

It's the 4.0 and 4.6 that have 10 bolts but they do fit the early blocks as its the outside row that cause head gasket problems as they tilt the head over when over tightenead. so they don't drill the holes anymore but the casting is still there. Not sure if you would get 200 bhp from a 3.5 without head work a lumpy cam etc. The 4.2 is 200 from standard so its a better place to start. All depends on what you want it to do , rev like **** or lots of low down grunt! Tuning the Rover V8

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how much would that cost though?

fett said:

how much would that cost though?

Click to expand...

1600 for the heads

1000 for the stroker kit

200 for the cam

800 for labour

never said it would be cheap lol

you'd need to do heads and cam to get 200 out of the 3.5 plus 390cfm carm and inlet manifold is going to set you back £800 for heads, £200 for cam, £800 ish for carb.

Yeah it soon gets out of control!! Not the cheapest things to modify. My 4.2 (must be an early one as its got 14 head bolts and a tin gasket) was £275 via ebay (77000 miles). Stripped it, new bearings, rings, gaskets, piper cam, modifled the block to take a cam retaining plate, etc etc, all done at home, Edlebrock manifold and carb from the 3.5 one i took out. Goes well but im just in the middle of changing the auto box because its slipping from 2nd to top when you nail it! Think its just it age. Did keep all the bills etc but dont like to add them up!! Goes well, and because it is all on show due to no bonnet or sides and a re-cored rad and some mods to the inlet manifold water ways to stop hot spots it never gets hot so it shouldnt slip any liners! :doh:

POAH said:

1600 for the heads

1000 for the stroker kit

200 for the cam

800 for labour

never said it would be cheap lol

you'd need to do heads and cam to get 200 out of the 3.5 plus 390cfm carm and inlet manifold is going to set you back £800 for heads, £200 for cam, £800 ish for carb.

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not really worth it for these old things and 200 hp

better of with a lexus or bmw v8 and spening the money to make it fit

or going the cheaper mix and mach i was talking about with the rv8

my opinion of course

POAH said:

1600 for the heads

1000 for the stroker kit

200 for the cam

800 for labour

Click to expand...

Nyaaa price heart attack! I'd love all that stuff but no way can I justify spending that on a £1K car.

Mix and match for cheapness is the way forwards for me, as Fett says

and never ever add up the bills. ever. especially if the missus is watching.

best thing to do would be to get a set of stage 1 heads from v8tuner. this would liberate about 30hp and cost under 1k fitted

30hp for a grand lol :hysterically_laughi

I had my bmw re-mapped and rolling roaded for £190 and got 65 bhp and 72 pounds of torque.

its just not worth the cash with the rv8