3.5 - more beans!

I was going for more like 1bhp per tenner.... Less if possible

yeah by that standard a bugattie veron would cost 1 billion not 1 million

Yeah it has to be said its too expensive to NA tune a RV8.

If you want big power then the money is better spent on FI.

Cheers

turbos are a bit different to N/A engines

fett said:

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

Click to expand...

1396midget said:

I was going for more like 1bhp per tenner.... Less if possible

Click to expand...

heads are the cheapest way to more power with the RV8 - get a nice exhaust system to make it sound better and make sure the carb is well tuned

for us total nuts, thought this sounded nice

[ame=http://www.youtube.com/watch?v=5hLt96QydQM&feature=related]Mad Max's Engine Dyno. 1750 HP 427 TT SBC Sand Rail Motor from Nelson Racing Engines. - YouTube[/ame]

Nelson!!

cheapest option is ditch the 3.5 for a 3.9
bigger capacity and more options on tuning
with the bore shrouding on the 3.5 it does not give much more over 200 bhp and costs more to tune than the bigger capacity rv8 engines in the range

but 3.9 and bigger seem to have bore liner hgf issues, they arnt worth the hassel

I may be wrong when given an experience in a big bore car, but as far as I can see, for what I'm looking for, a tuned 3.5 is perfect. Useable power and low risk of problems.

I just couldn't be doing with the big bore issues!

me too , I will never run a rv8 bigger than 3.5 unless its one of those p76 4.4 jobbies from aus (very unlikely )

I think my 3.5 efi, elderbrock , p6 v8 combo looks like the way ahead

when I retire early Ill get round to it

a-head ? No pun intended?

puh , I dont know

That video....!!!

I'd want a tensioner on that little belt tho. Looks a bit wobbly. It sounds fantastic!

I'll also be sticking with the 3.5, until it goes bang. Presumably 10 bolt heads and the composite gasket is the same compression ratio as the P6 head and tin gaskets?

fett said:

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?

Click to expand...

Why would a dream be to build a stock engine using stock parts when you can achieve so much more with aftermarket parts?

1396midget said:

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?

Click to expand...

The thing with the RV8 is there are loads and loads of options and possibilities.


I've got a 3.5 in my TR7 V8.

On the rollers a number of years ago it was making an est 220-230hp flywheel. No idea if that's correct but I know it'll just about keep pace with a 220hp DC5 Civic Type R in a straight line, so I suspect can't be that far out.


My engine was out of a SD1 though. Although when you say high compression, do you still mean the rather low 9.35:1??? I certainly wouldn't want to run any lower CR on a n/a motor.


Currently mine runs:

-works rally spec long tube exhaust manifolds
-single silencer 3" straight through exhaust system
-Luminition ignition
-Pacet fuel pump
-Weber/Edlebrock 500cfm 4 brl carb
-Offy inlet manifold
-Stage 1 unleaded heads
-Real Steel Hurricane cam (although I'd go for their Typhoon cam if I was doing it again)
-Lt-77 5 speed
-3.90:1 final drive
-leccy fan


It runs very smooth and pulls as well low down as it did stock, but now likes to rev too and will rev smoothly to 6000rpm and really comes on cam nicely at 3000-3500rpm too.

MPG, when I used to use it for commuting it returned 24mpg in normal use. Although a lot less when used purely for fun

Some vids of what it sounds/goes like:
[ame=http://www.youtube.com/watch?v=0njXXhDKjiE]TR7 V8 start up cold.mpg - YouTube[/ame]
[ame=http://www.youtube.com/watch?v=qL928GrFcRM]TR7 V8 giving it some revs.mpg - YouTube[/ame]

This was before the cam and carb swap, so std cam and twin SU's:
[ame=http://www.youtube.com/watch?v=f1HHbMPT3Oc]TR7 V8 Corner clip.mpg - YouTube[/ame]


Personally I think sticking with twin SU's will strangle it, the BL works cars in the 70's used to run quad SU's, but manifolds are hard to get hold of and I think keeping them in balance was a bugger. For road use I see no reason why you wouldn't want a 4 brl carb on there or a swap to EFI.

I wouldn't ditch the SUs just yet. They can run at weird angles and don't take loads of effort to tune up. I've got them on the 3.9, the Tr7V8 and the Etype Try running with out oil in the dash pots for some serious accel, solder the run-on valves shut and play with some needles.

Scott Bevis did a little program called WinSU (WinSU Carburettor Tuning Software) that suggests needles for your build - worked for me.

Try reading Des Hammill's book on tuning SUs as well - interesting stuff...

Edit - btw there is always a trade off on power to mpg. More juice - less miles

MattMatt said:

I wouldn't ditch the SUs just yet.

Click to expand...

I'm not going to, I really like 'em. Had a webber on the Series and just couldn't get on with it. The WinSU program is great as well.

MattMatt said:

Try running with out oil in the dash pots

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hmmm, if you want lumpy running and poor pickup In my experience....

Also the SU's are free, as they're on there already. Hoping for a bit of a real world performance boost from fitting a manual box, when I can find one. Just missed out on one 'cos it was pre payday

360bhp/ton said:

do you still mean the rather low 9.35:1

Click to expand...

No, it's the 'high' P6 type - 10.5:1 with the smaller valves.

300bhp/ton said:

Why would a dream be to build a stock engine using stock parts when you can achieve so much more with aftermarket parts?

Click to expand...

because as we said before its like thousands of pounds to get 100hp

Just not worth it.

1396midget said:

That video....!!!

I'd want a tensioner on that little belt tho. Looks a bit wobbly. It sounds fantastic!

I'll also be sticking with the 3.5, until it goes bang. Presumably 10 bolt heads and the composite gasket is the same compression ratio as the P6 head and tin gaskets?

Click to expand...

the composites are thicker and lower the c/r