Supercharging RV8 flapper

Supercharging RV8 flapper

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V8 Fettler

Original Poster:

7,019 posts

131 months

Wednesday 24th September 2014
quotequote all
I have a Range Rover Classic 3.5 EFi with flapper and Sprintex supercharger. The previous owner told me that it had never run with the supercharger. There is life in the old thing, but I'm confused re: engine breathers. The pipes are run into the plenum/throttle body similar to an NA car, my understanding is that this causes problems with breathing.

I'll get to the point (please!): where do the engine breather pipes for supercharged RV8 Wedges run to? Oil catch can? Atmosphere side of supercharger?

Wedg1e

26,760 posts

264 months

Thursday 25th September 2014
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So is the ECU somehow adjustable to switch between blown and normally aspirated or does it have two ECUs... or something else?

V8 Fettler

Original Poster:

7,019 posts

131 months

Thursday 25th September 2014
quotequote all
2 adjustable pots on the outside of the ECU, although how these operate in conjunction with the mixture adjustment on the AFM I'm not certain.

adam quantrill

11,535 posts

241 months

Thursday 25th September 2014
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What is happening with the blower mechanically?

a) Is it connected to the crank with the drive belt?
b0 Does the engine air run through it?

If neither, then there must be a pipe bypassing it and I guess the throttle body is still remote from the plenum? The breather pipes go to just downstream of the throttle. The vacuum advance pipe goes to the throttle body too.

Some pics might help....

adam quantrill

11,535 posts

241 months

Thursday 25th September 2014
quotequote all
Sorry I understand now - you want to move the pipes to where they should be....

OK here's some pics of mine in that area, first note that the overrun valve on the plenum is a blanking plug:






The pipes for the extra air/overrun go to the atmospheric side of the throttle, the flame trap hose goes on the vacuum side of it.

V8 Fettler

Original Poster:

7,019 posts

131 months

Thursday 23rd October 2014
quotequote all
Thanks Adam, been a long slog with this.

Have re-jigged to something like your arrangement, engine runs but issues with CO or HC for MOT.

Could you please check the pipes marked on your photo.

Yellow (atmospheric) goes to a solid pipe that runs under the plenum but no connection to the plenum, then onto the idle air valve.

Red (atmospheric) appears to go to your flame trap on the passenger side rocker box cover?

Just out of view on the edited photo below (white arrow) is the other side of the idle air valve, connects to the vacuum side of the throttle body?

The engine breather circuit on mine doesn't appear to be complete: flame trap on the pass side rocker cover, pipe now leading to atmospheric side of throttle body, but no visible breather on the driver's side rocker box cover. Do you have a breather on the driver's side rocker cover?


adam quantrill

11,535 posts

241 months

Thursday 23rd October 2014
quotequote all
Yellow (atmospheric) goes to a solid pipe that runs under the plenum but no connection to the plenum, then onto the idle air valve.

Yep. Except that it's the Extra Air Valve - for cold idle only.

Red (atmospheric) appears to go to your flame trap on the passenger side rocker box cover?

Yes but I think that isn't quite atmospheric, it's near the throttle body, so there will be a little vacuum scavenging.

Just out of view on the edited photo below (white arrow) is the other side of the idle air valve, connects to the vacuum side of the throttle body?

Mine doesn't have an idle air valve (unlikely on a flapper). The white arrow is pointing at the supercharger inlet.

The engine breather circuit on mine doesn't appear to be complete: flame trap on the pass side rocker cover, pipe now leading to atmospheric side of throttle body, but no visible breather on the driver's side rocker box cover. Do you have a breather on the driver's side rocker cover?

Yes but only the standard pinhole type with the little foam filter on top.

What are the CO and HC figures you are getting and at what idle speed?

Last MOT my HC was high and the tester revved it to about 2k and read it then.

Edited by adam quantrill on Thursday 23 October 18:43

V8 Fettler

Original Poster:

7,019 posts

131 months

Thursday 23rd October 2014
quotequote all
Thanks Adam, poor description on my part, extra air valve for use when starting from cold.

Pipe marked white is the other side of the extra air valve to vacuum side of throttle body?



3.5% CO but 2000HC and climbing, can trade lower HC for higher CO.

Edit: I'll recheck, but I can't find any breather on the driver's side rocker box cover, there is a breather on both rocker box covers on my flapper TVR.

adam quantrill

11,535 posts

241 months

Thursday 23rd October 2014
quotequote all
Yeah that's correct but even so it won't affect your CO or HC as the EAV is only open for 12 seconds and that's it.

Mine has a plastic slug where the overrun valve is.

How is your compression? Have you changed the oil if not stick in some fresh 20W/50.

What RPM are you running at idle? I set mine for 1100 for the MoT that's allowable.

V8 Fettler

Original Poster:

7,019 posts

131 months

Thursday 23rd October 2014
quotequote all
Thanks Adam. Oil is fresh, compression unknown but no blue exhaust smoke, heavy breathing or clanking noises. Idle is about 750rpm, will increase to 1100. Was your CO checked at 1100 and HC checked at 2000?

I'll need to create a breather for the driver's side rocker box cover. The oil filler is fitted on that side so might be able to do something with that. Any thoughts on the diameter of hole required?

Oz2

962 posts

187 months

Thursday 23rd October 2014
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Thought more of a plan view might help.
Adam Q has explained it all.
(I'm still here guys, been off air for a while)
Cheers
Adam oz2

V8 Fettler

Original Poster:

7,019 posts

131 months

Thursday 23rd October 2014
quotequote all
Thanks AdamOZ2, does your oil filler cap have a breather?

adam quantrill

11,535 posts

241 months

Thursday 23rd October 2014
quotequote all
I'll double-check mine, maybe it doesn't either.

Yes your idle is far too low (for the MoT anyway), you need more revs as the HC is building up, it will combust it far better at 1100.

V8 Fettler

Original Poster:

7,019 posts

131 months

Thursday 23rd October 2014
quotequote all
Ta, RR is an auto hence idle speed 750 to 850

Edit: but you have the OEM breather fitted to the driver's side rocker box cover to allow air to be drawn into the engine and then out via the throttle body?

Oz2

962 posts

187 months

Friday 24th October 2014
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This is the only breather I have, it's the at the other end of the same rocker cover to the filler cap.
Adam

Oz2

962 posts

187 months

Friday 24th October 2014
quotequote all

This is what the small air filter fits onto, it's a .5 mm hole I think.

Hope this helps
Adam

V8 Fettler

Original Poster:

7,019 posts

131 months

Friday 24th October 2014
quotequote all
Thanks AdamOz, my engine doesn't have the protruding tube with the 0.5mm hole (that is small!), your engine has a breather circuit, mine doesn't.

I'll look at modifying the filler cap to accept a breather. Failing that, it will be off with the rocker cover and out with the drill.

adam quantrill

11,535 posts

241 months

Friday 24th October 2014
quotequote all
V8 Fettler said:
Ta, RR is an auto hence idle speed 750 to 850
Ahhh - got you, above 900 rpm or so the auto box will start pulling in 1st. In that case what you need is a manual transmission. As luck would have it, I have a complete working Rangey 5-speed LT77 with transfer box. It came off my 4.3l '86 Rangey. Interested?

Also - this engine was OK on emissions before the supercharger was connected up, wasn't it? Just wondering.

Edited by adam quantrill on Friday 24th October 07:58

V8 Fettler

Original Poster:

7,019 posts

131 months

Friday 24th October 2014
quotequote all
Thanks for the offer Adam, but I just want it finished, it's been a "challenge" in many ways. Previous owner installed engine and supercharger but vehicle never ran in that configuration. Should be able to increase idle speed when on MOT ramp

adam quantrill

11,535 posts

241 months

Friday 24th October 2014
quotequote all
Did it pass the MoT though before on that engine?

Also - do you have the round rubber gasket inside the lid of the oil reservoir of the blower? (I can see it in the bottom of your photo just to the right of centre.)