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Correct needle for hs2 with Pcv valve

Posted: Fri Jul 02, 2021 8:03 am
by mowogg
Hi

I am just about to fit a Pcv valve to my standard engine as per the late set up with extraction via the tappet cover. I had assumed this would involve a different valve in the carb but none of the are suggesting this is the case. Is this correct or is it indeed a standard needle?

I cannot find any references online.

Thanks

Re: Correct needle for hs2 with Pcv valve

Posted: Fri Jul 02, 2021 8:37 am
by philthehill
Here you go - have a look at the Burlen Fuels chart.

http://sucarb.co.uk/cf/vehicle/list/?ma ... icle=Minor

Re: Correct needle for hs2 with Pcv valve

Posted: Fri Jul 02, 2021 9:16 am
by mowogg
I have been in contact with Burlens. They were not aware of any changes for a Pcv valve and have suggested a standard AN needle. In the back of my mind I thought the needle changed on late cars with crankcase breathers to the carb and presumably different again for breathers to a PCV.

Perhaps this is not the case?

Re: Correct needle for hs2 with Pcv valve

Posted: Fri Jul 02, 2021 10:07 am
by philthehill
There should be no need for a different needle as the PCV valve only operates under certain conditions and throttle openings which do not effect the mixture.

Re: Correct needle for hs2 with Pcv valve

Posted: Tue Jul 06, 2021 8:37 am
by mowogg
Phil. Thanks for the response. I will swap all the bits over and give it a test in the next few days

Re: Correct needle for hs2 with Pcv valve

Posted: Tue Jul 06, 2021 3:02 pm
by kevin s
If you think about it the PCV gasses should not contain oxygen and are fed in after the carb so the only oxygen will be the air going through the carb which will still be the same for the same torque output and need the same amount of fuel.