RV8 breathing, flame trap, PCV... is there a right way ?!

jonny m · Post by **jonny m** » Sun Feb 24, 2013 9:02 am

I've done a search, and read loads of answers, but still confused:

I've a rebuilt 1980's 3.5 RV8 running a Weber 500:

The hole at the back of the block just has a £5 vent to atmosphere

1 x rocker feeds a pipe to the underside of the air filter

1 x feeds a pipe to the vacuum on the carb

Do I need a flame trap on either, or both ?

(I have a choice of both rounded old, and new square style rockers - the new seem to have something in the vent hole?)

Do I even need a PCV, if so where?

Help & advice appreciated.

Jon

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Cobratone · Post by **Cobratone** » Sun Feb 24, 2013 5:27 pm

Johnny, why not put a post up on the cobra club forum asking the same info?

jonny m · Post by **jonny m** » Sun Feb 24, 2013 5:35 pm

CobraClub tends not to have a big Rover contingent, and from what I've read up so far, there's so many differing opinions; just trying to get a best spread of advice thanks

Robrover · Post by **Robrover** » Mon Feb 25, 2013 7:17 am

I'm using P6 rocker covers on my SD1. RH has a small K/N mushroom type filter plugged into it, LH rocker cover has a small generic Repco PCV plugged into the top with a hose going out of it and into the front port on the Edelbrock.

No flame traps and I've removed the splash guards from inside the tops of the P6 rocker covers tso as to clear the roller rockers. Seems to work ok.

JSF55 · Post by **JSF55** » Mon Feb 25, 2013 9:02 pm

I used the later square ones and used the flame trap and fitted the pcv valve into the top of that ! i used some shrink wrap to seal it up. They only thing i found was the small brass "reducer" in the other rocker cover needed opening up to get rid of this squeek !! no photos but the vid shows most of it

Dixie6789 · Post by **Dixie6789** » Wed Sep 23, 2015 9:36 pm

Robrover wrote:I'm using P6 rocker covers on my SD1. RH has a small K/N mushroom type filter plugged into it, LH rocker cover has a small generic Repco PCV plugged into the top with a hose going out of it and into the front port on the Edelbrock.

No flame traps and I've removed the splash guards from inside the tops of the P6 rocker covers tso as to clear the roller rockers. Seems to work ok.

ditto, same as my set up.

M

sidecar · Post by **sidecar** » Thu Sep 24, 2015 6:46 am

If you want to keep a 'low profile' you can remove the flame traps. My setup has a PCV fitted to one of the rocker covers, a pipe leads from this to the large vacuum port at the front of the carb. I have made and fitted a baffle inside the rocker cover in order to try to keep the oil away from the PCV to reduce the chance of oil going up the pipe! The other rocker has a simple 'mushroom' fitted with a pipe coming off that to the underside of the air filter. You could use a mushroom with an in-built filter and not have the pipe going to the air filter. The usual problem with the mushrooms with an in-built air filter is that the filter is not very good, this could lead to dust and grit getting sucked into the engine by the vacuum that the carb creates within the engine block.

The setup that I use will cause a vacuum within the block due to the fact that the vacuum level at the PCV valve will be much higher than the vacuum at the underside of the air filter, this causes the carb to suck the vapours out of the block and at the same time only lets clean, filtered air into the block.

SimpleSimon · Post by **SimpleSimon** » Thu Sep 24, 2015 8:07 am

sidecar wrote:If you want to keep a 'low profile' you can remove the flame traps. My setup has a PCV fitted to one of the rocker covers, a pipe leads from this to the large vacuum port at the front of the carb. I have made and fitted a baffle inside the rocker cover in order to try to keep the oil away from the PCV to reduce the chance of oil going up the pipe! The other rocker has a simple 'mushroom' fitted with a pipe coming off that to the underside of the air filter. You could use a mushroom with an in-built filter and not have the pipe going to the air filter. The usual problem with the mushrooms with an in-built air filter is that the filter is not very good, this could lead to dust and grit getting sucked into the engine by the vacuum that the carb creates within the engine block.

The setup that I use will cause a vacuum within the block due to the fact that the vacuum level at the PCV valve will be much higher than the vacuum at the underside of the air filter, this causes the carb to suck the vapours out of the block and at the same time only lets clean, filtered air into the block.

And the way it should be rather than just open breathers vented to atmosphere, PCV systems like you have keep the oil cleaner longer too as your already aware I'm sure