Questions concerning tuned V8 engines - Advice sought on engine modifications

mrtask

mrtask

Well-Known Member
The engine in my rustier '73 3500 isn't the original. The previous owner installed an engine from an SD1 after the cylinder liners came loose in the original P6 V8.
He explained that he'd re-built the new engine around an SD1 'short block' (standard P6 heads, P6 water pump, block chemically cleaned, over bored, refaced, crank reground, new +20 thou 10.5:1 CR Pistons, crank/conrod/piston assembly dynamically balanced, late timing cover with uprated oil pump gears, Kent 214 fast road cam, Cloyes timing gear, re-needled SUs, Lumenition, Facet silver top fuel pump) prepared by Rovercraft (now Progress Engineering).
I took it to a rolling road when I bought the car, but the MG tubular steel headers were badly cracked so I couldn't get a maximum power output reading.
It certainly launches and accelerates quicker than the factory-standard V8 in my '72 P6, which feels smoother but more sedate in comparison.
I briefly had a Holley 390 on an Edelbrock manifold fitted to the tuned engine, which changed the character of the beast considerably! I removed it again because it isn't jetted right and was flooding the motor with too much fuel, which consequently exploded in the exhaust middle box! While I had the inlet manifold off I checked the cam and lifters, they all looked fine to my untrained eye.
How do I find out what the correct Holley 390 jets are for the cam, indeed if the cam really is a hotter grind, as I can't see any identification markings. Basically I've got to take the previous owner's word for it, as all the modifications are not visible without disassembly, right?
Is it worth using a '72 P6 block as a basis for my first tuning project, or does a rope oil seal at the back of the crank mean it isn't worth it? Should I rather look for an SD1 block and heads? How do I identify Vitesse cylinder heads? I'd like to try and build an engine myself and learn from scratch, what should I expect to have to pay for a donor engine with a useable block, crank and heads?
What horsepower should it be possible to get out of 3.5 litres with ported and polished 3-angle Vitesse heads, valves & valve gear, a hot cam and suitably-needled SUs on a port-matched inlet, through standard cast iron exhaust manifolds? Basically without the engine appearing in any way different externally, so as to be visually undetectable by the TÜV Inspectors (German for MOT) over here in Berlin!?
 
Hey fellow forum users! I'm surprised I only got the one reply to this thread. Aren't there any knowledgeable V8 owners/fans out there who could shed some light on my questions? Doesn't anybody want to engage in some "bench racing" with me? I want to find out how best to extract maximum power and torque from my engine without it being immediately obviuos that it has been tuned. Surely there are some other V8 P6 owners who have massaged their engines to achieve higher power and greater torque output!? Don't be shy, come on, reply! Anybody else fitted a Holley 390 and got it running right in a street car? Anybody stroked their engine out to 4.2 using a Buick crank? Should I direct my questions elsewhere?
I'm pretty demoralised by the horrible extent of the rust that I'm revealing around the rear arches, D-posts and boot walls. My restoration project is going to take longer than I had initially hoped, looks like I'll have to replace the D posts rather than patch them up, and while I'm sorting out the bodywork I want to get my plans for the engine department over the winter period straight.
So come on chaps, let's have your thoughts! BB, Malreid, IanP6man, Chris York et al. I hope to hear from you
 
There probably are lots of people out there who have done this but if you ask anyone they will tell you the most important thing is what you wan't to do with the car.

It is interesting that you do not wan't any visible mods to the engine to show - given that this is so that it looks standard for MOT purposes it goes without saying that this will apply to the rest of the car.

Personally I find that you can get the best out of a P6 by working on the handling - the V8 even in standard format (but in good order which demands frequentoil changes) is a potent engine and more than powerful enough. The police made no mods to it for their chase cars but instead added strengtheners to the shock mounts and links and spoilers.

i rest my cae.

P6jpe :p
 
You could also have a word with these people :D
Real Steel
Unit 9, Tomo Industrial Estate
Packet Boat Lane
Cowley, Middlesex
England UB8 2JP
Tel: 01895 440505
Fax: 01895 422047
Eml: sales@realsteel.co.uk
They specialise in v8 power :;): and the rover v8
I used them when I had my yank v8 and found them very helpfull, they helped me get 400bhp out of a 289 ci (4.7 ltr) ford v8 in one of my project cars, and that was at the rear wheels.


If you want some serious fun with the rover v8 you can change the crank and do an oversize rebore this will take it from a 3500 to 5100 and externaly it will look the same, add Nos and hold tight :D
 
Hi Mrtask

There are so many combinations of engine parts RPI and Real Steal would be the best for good advice. But if you want to go bench raceing thats different ! :laugh: .

Your SD1 based engine sounds realy quite sound appart from the P6 heads, I'd go for SD1 with the bigger valves, 3 angle ground. This would open up a bottle neck and take greater advantage of your manifold and cam. Free flow air filters would help as well (and then get you SU's retuned).

How cammy is your cam ? I ask because I put SD1 heads as above on Ron and also put a 3.9 cam in. I chose this cam as, Ron being a auto I wanted plenty of low down power below 2500rpm, or rather I did'nt want to lose any below this. The 3.9 cam was supposed to be better than standard but still mild (cheap to). I often wonder if I could have got another 20 gee gee's with no pain !

For the record, Ron on a rolling road Ron gave 95bhp in 2nd at 4000 rpm. (all tuned and timed up, SD1 heads, electronic ignition, free flow air filters, 3.9 cam). Does'nt sound much, but the auto box must rob a huge amount, Ron certainly stomps on most things when needed !
Does the TUV allow free flow back boxes on the exhaust ? The sound gives your image a HUGE power increase !!
 
You could probably do a lot worse than read This Book

I can't remember the exact details, but as Ron says, there is an ideal combination of either sd1 heads and p6 block, or p6 heads and sd1 block, which gives best compression ratio, I know quite a few grass-track racers that use this setup.

As stated before, you could go to the bigger capacity engines, have the heads ported, fit bigger valves, better cam, etc, and still have it looking totally standard, fit standard P6 rocker covers and twin SU's and hardly anybody will know...

Problem is, the twin SU's probably don't help performance either ! Once you swap them for injection, or a Holley or whatever, it becomes obvious that its not standard.

Richard
 
My perfect P6 motor:
Balanced and Blueprinted 4.6 with webber 500 carb & malory electronic ignition - plenty fast enough for most applications -and I have heard it said that larger than 4.6 and you need to go fuel injection - far too efficient and complicated for my liking, anyway mate this to an R380 gearbox, and a Jag LSD, a bit of suspension jiggery pokery and hey presto the perfect every day driver / weekend sprint/hillclimber! you could even pop in an LPG kit to make it a bit cheaper to run in the week
Cheers
AL
 
The David Hardcastle book is alright but only if you want some pretty picutres to look at while you're sitting on the toilet.

It's pretty thin on the detail and there are certainly no cam specifications etc in there. Might help on the inspiration but if you want a decent book on engine tuning then anything written by David Vizard is worth a look. He has had a long career as an engine tuning and development wiz (unlike David Hardcastle who has had a long career as Airfrieght manager)

Also check out the http://www.v-8.org.uk/forum/
a forum for V8 owners in general but mostly Rover V8.

My advice: A sweet running engine that pulls well throughout the rev range will always be much more satisfying to drive than an engine that gives lots of power but won't idle or run properly on part throttle.
 
A bit bitchy there BB !! :p , but yes after reading David Vizards A Series engine bible, I was most disappionted with the Hardcastle book, not in the same league. David Vizard was an education in engine tuning, Hardcastle is a vague insperation. Agree about smooth power delivery. I also have a highly tuned (badly spec'ed ?, but I only bought the car) mini engine, its orrible to drive in real life, you can never keep it in the power band, and outside you cannot trust it to do as you ask.

I've read that SU's can be OK to just over 200bhp (with work), but what are the Webber/Holly carbs like ? appart from power does the engine behave different ?, and which manifolds fit the P6 ?
 
there is an ideal combination of either sd1 heads and p6 block, or p6 heads and sd1 block, which gives best compression ratio,
Click to expand...

hmmm, not sure what you mean by that since the CR is set by the pistons on this engine; if you want higher CR then fit different pistons; the higer CR ones have valve cut outs.

Simple and relatively cheap are putting on sd1 or vitesse heads. You can then have the heads ported and gitted with larger waisted valves. SD1 block is better for the oil seals and also oil pump gear. A good idea anyway since some p6 engine parts are hard to find thus expensive; quite a few companies who do specilaise in v8 are not interested in anyting older than sd1.
 
Your right Ron, I think I'm stuck in some sort of horrible millitant state of mind due to this problem with Superlite.

Even though the vizard A series book is specific to that engine it is so well written it gives good understanding of tuning principles that will apply to any engine.

I've got a racing Midget (currently rusting away on the in laws farm due to lack of funds) and that runs a 1330 engine 11.5CR, kent 286 cam (fast road) and has standard valves but a beautifully ported head. Gives 130bhp and pulls like a train from 3000rpm. Used to beat a guy running the full race 300 degree BL649 cam simpley becasue he couldn't keep it on the boil.

I've got a weber 500 on my 3.9 RV8 (piper 270/110 cam) in the estate and it does go well but the idle quality is not as good as the SU's and it isn't as smooth on part throttle at the moment. Hopefully just needs some more work on setting it up but I'm going to have to leave it for a while due to other commitments. In retrospect I wish that I'd stuck with the SU's or gone for EFI although probably encouraging a different set of hassles.

There was a rolling road at the Tatton park classic car show last week but I just couldn't pluck up the courage to have a go. The noise of the cars on full chat is just frightening!!
 
Based on the age of these cars, I bet the best thing you could do would be a full rebuild including blue-printing and balancing, valve re-grind and clean out all ports. Fit new rings, big ends and shells. Re-build the carbs with new jets and needles etc, basically just get it back to as-new, plus the blue-printing and balancing can help them to rev a little more freely.

Richard

P.s. I've never read that book, just looked reasonable from the reviews. I have got the vizard A series book and that is very good. I would have recomended Dave Walkers articles in CCC but its no longer in publication, sad really.
 
Dave Walker now write for Practical Performance car I believe. Not often in the news agents but they have a website (google it)

Mag is alright but I only persue it on the news agents shelf!
 
Nice to see my thread liven up a little bit, thanks chaps. Yup, I've read the Hardcastle book but it isn't all that specific to what I want to build. I'll give Mr Vizard a read, thanks for the tip BB.
My engine behaved very differently indeed fitted with a 390cfm Holley on an Edelbrock Performer intake, although it is jetted for a bigger engine; I need to establish what the right set-up would be, any help appreciated. So the SUs should handle as much as 200bhp!? Would that be possible breathing out through standard iron manifolds (alas not even the marginally larger S castings) with SD1 big valve heads and the Kent 214? Who has the most powerful 3500 in the club running SUs, let's hear your boasts/claims then!
 
Not really practical but I have seen a home brewed 3500 fitted with twin turbo's making 350bhp installed into a Morris Minor ( Oh Yes ! )

Richard
 
webmaster said:
Not really practical but I have seen a home brewed 3500 fitted with twin turbo's making 350bhp installed into a Morris Minor ( Oh Yes ! )

Richard
Click to expand...
its not a white one with a blue roof is it? I remember watching that at the pod a few years ago, and inspired me as a younger (just lerning to drive) man to fit a 2 litre fiat twin cam in a rusty old 4 door minor :D allthough I still want to put together a Gale Banks tuned Twin turbo 7 litre corvette powered Minor (somewhere around the 1800 bhp mark) anyone want to give me the money to do it :D :p
 
Just to resurrect this topic, I found a couple of articles on turbo'd rover v8 minors for you all to look at, the first is on the Beardmore Brothers website, I knew Robin Beardmore back when he built the pink version of his minor pickup. And I've seen the wonderfull v8 reliant kitten first hand... Anyway they've got a copy of an article on Nick Mann's 500+bhp rover v8 powered minor HERE

I also found my copy of CCC with the 350bhp twin turbo minor, very similar.

ttminor-sml.jpg


Larger readable Version

Enjoy !

Richard
 
You must log in or register to reply here.
Back
Top