The V8 Owners Forum -

Hi everybody, new to here but the old posts have answered some questions already!

I'm just starting a 4l RV8 build, have got an Eaton M112 supercharger that I am going to (try) and machine so I can sit my 4bbl Edelbrock carb on top of it, and mount it on top of an Edelbrock Performer manifold (180deg high rise) but would like to install NOS too- even if its not a big shot.

Assuming the machining all goes ok would I be best off with direct port injection or with a plate or one of these spider things?! Don't see how it would fit unless I get a 360deg inlet manifold which may be best anyway.....

Hopefully you can help before I make a ****up! Thanks

I presume you are after using the intercooling effect of the NOS as much as possable, If this is the case I would use a spray bar under the supercharger and into an open plenum manifold, this would give the NOS the best chance of mixing as evenly with the incoming mixture from supercharger. My understanding is that port injection and spiders are about getting as high a density of nos into the engine as you can.
I am sure there will be someone along soon who can advise better than I.

Mike

Yes that is half the reason, though I am hoping the temperature will keep fairly low by having the fuel mixed whilst being compressed- I think this is 1 reason dragsters have fuel injected before the charger as well as after!
I won't be able to constantly have the NOS flowing to cool the mixture though...
I dont have thousands to spend so a shot big enough to notice but small enough not to have to use a progressive controller would be particularly nice.......

dragsters are arranged like that because that is the rules for many of the classes, topfuel, funny car etc are restricted on blower (size and type) and engine configuration, also both run nitromethanol which has a very high specific latent heat capacity and you use more than twice as much of it so the intercooling effect is more than enough. However it is fairly simple to set up and get running and for low boost set up will work well enough for a rover.
Mike

kiwicar wrote:dragsters are arranged like that because that is the rules for many of the classes, topfuel, funny car etc are restricted on blower (size and type) and engine configuration, also both run nitromethanol which has a very high specific latent heat capacity and you use more than twice as much of it so the intercooling effect is more than enough. However it is fairly simple to set up and get running and for low boost set up will work well enough for a rover.
Mike

Erm what do you mean is easy to set up? The NOS? Would a crossfire plate work ok under the blower as I dont think i have room for a spider thing and looking at other topics in this forum it seems a lot of people dont go for direct port- is it cost?

It depends how much you want to spend, and how much you are worried about overall height. I dont suppose you are that worried about how high the engine is through the bonnet??
If you want the cheapest option go for a plate with 4 WON Crossifre nozzles fitted. And if you limit to a 50hp shot you will get away easily without a controller. You should not have any bother putting 100 fixed hit on the engine, but it will be difficult to control the car. Also, depending how much gas you intend to end up using you need to pay particular attention to piston ring gaps. I've just spent the last two years getting mine sorted. Also, what pistons are you going to use? And if not using a controller, you should make sure you at least get a bottle heater. And a fuel pressure gauge + low pressure cutout switch.
Depending how hard you intend to push the engine on track, you will also need advice on ignition timing while on gas. There are lots of variables to take into account before you decide on final design and system setup.
Hope this helps
Perry

Thanks- I cant be too fussy about height so its not really an issue- I will rarely use the NOS and just want it as a fun car for the odd day to escape every day Land Rover world!!!
Primarily I just want to keep costs as low as possible so as far as engine mods go- was going to rebuild the unit and put a slightly modified cam in, new bearings obviously and probably look to replace the sintered valve spring retainers as I understand they are a weak spot, any other advise? Cheap but effective mods- pistons etc etc?!
Can I get away with a fuel pressure gauge, NOS pressure gauge and keep an eye on it or does it not work like that?
Thanks for all this!

EDIT Sorry just looked at bottle heaters etc it would probably be cheaper to get a basic controller would it not?!?!

Bottle heater more important than a controller for a 50 shot really.
Not sure about sintered valve spring retainers! Never seen any?
Fuel pressure gauge advisable. I hide mine under the bonnet for reference.
Nos pressure gauge can be fitted to the bottle along with the fuel pressure switch so not on show. I dont know anything about supercharging, but wouldn't you need to fit better pistons to handle the higher cylinder pressures? Also using nitrous will increase cylinder pressures, but you can offset this by retarding the ignition.

Thanks, is the fuel pressure swith the one that cuts out the NOS if fuel pressure drops?

Powdered metal retainers, Ooooh I dont like the sound of those!!!!

ian.stewart wrote:Powdered metal retainers, Ooooh I dont like the sound of those!!!!

I thought all the later retainers were sintered? According to the power tuning V8 book they are anyway, so using early buick ones are advisable to increase the rev limit.....?!

Any advice on pistons etc for a reliable blown engine?!?!

Yep!
Fuel switch will shut the nitrous down if pressure drops too low.
Have a word with John Eales about your pistons.

I've got heads from 1975 pre sd1 to 1996 Range EFI and all the spring caps are solid? Have you got a picture of these caps?
I've not heard of them myself.

Who and where is John Eales?! Do you rekon I should just get a new standard profile cam too or go down the 285 or something route?

John Eales is near Lutterworth / Nuneaton.
I'll send you a link.

Decent cam and pistons will cost you the thick end of a grand mate. Depends what you want and what power you expect to get. You could get away with standard pistons if you're running low boost and not a lot of NOS.