PCV System with aftermarket Webers Help please.
 

Hello, 17 years away from Volvos and I just knew I'd be back :regular_smile:

I'm now the very proud recent owner of a December registered 1979 245GL

Problem is someone has fitted twin Weber DCOE's to the car and I'm not sure it's been done correctly.

I suspect the engine (crankcase) isn't breathing properly as there is oil all over the front of the engine (although that could be an oil seal) and there was a decent amount of engine oil in the air filters themselves.

There is an aftermarket breather filter on the Valve cover which is fine but on the inlet manifold side below the manifold where I would suspect an oil separator box to be, there is just a big red blanking plate. (Although it does look original to me)

Whereas on the exhaust side near the bell-housing there is just a spout of some sorts poking out which looks like it's spraying misty oil everywhere.

I don't have the original air filter parts so I just want to make sure the crankcase is venting properly and install and oil catch can.

Do I simply run a pipe from this 'spout' near the bell housing into the catch can and all is well or do I need to buy a few more parts?

There are no more vacuum ports on the inlet manifold only the one for the brake servo and the one for the distributor vacuum advance.

As I'm a new member I cannot post pics it seems?? :confused_smile:

Sorry for the essay.

Thank you

for photos just use imagur

You want to run the old breather box to a oil catch can

Thank you for the reply.

There is no original air filter system left on the car only the K&N air filters on the twin webers.

I was hoping I could simply run a pipe from the spout near the bell housing where all this oil seems to be spraying out to an oil catch can?

I believe this spout went to a "Fire Trap" originally, but I'm afraid I don't know what that means.

regarding the distributor vacuum advance, that does not go to the manifold direct , it should go to a dedicated port on one of the carburettors which supplies vacuum all the time except when the throttle is shut idling when it blocks off the port to the distributor , IF the pipe goes direct to the manifold the vacuum at idle will be advancing the ignition timing by at least 10 degrees so when you adjust it with the timing light to the correct 12 degrees, the timing is going to be 10 degrees too retarded under normal driving conditions making it down on power , run hot perhaps and use more fuel ...

The advance for the distributor is in one of the ports for the manifold it looks like someone may have drilled and tapped this part of the manifold for the vacumm advance :Not_Impressed:

oh dear , by someone who did not understand how it worked , it would be better with it disconnected than work like that although you would miss out on some better fuel economy and a quieter engine when cruising...if it was all correct , nice pictures there and i'm sure those massive ports are liking the twin Webers . Have you checked the ignition timing with the vacuum pipe off ?

Hi,

Nice car, I saw it on ebay a few weeks back. A few things:

1.) I have a 1978 245 with a single carb, with all the original parts in place. For cars that early there is one crankcase vent, which is from the cam cover (where you have a mini filter venting to atmosphere), from there a hose takes it to a flame trap, then the hose splits and one side goes to the inlet manifold and one side goes to inside the airbox, inside the filter. The blanking plate you photographed is where Volvo vented the crankcase on (only just) later cars.

This webpage shows both a photo of what a flametrap is and also a line drawing diagram of how the hoses are routed.

https://www.ipdusa.com/products/6860...rmarket-104325

2.) On my car the distributor advance hose goes to a port on the carb. As others have said, perhaps a port for this exists on one/both of your carbs.

3.) The barbed brass hose end you photographed is the coolant system drain, so that won't help you. Oil in that area is coming from something else - I suspect either the cam cover gasket, or the plug at the back of the head.

Cheers

There is no take off on the webers for a vac advance pipe

With the throttle closed to vac pipe is blanked on the original carb so no vac to the dizzy. As the throttle opens the dizzy then starts to see vacuum. How it is fitted you have too much vacuum at idle giving too much advance.

The best long term answer is either going to a company like Aldon who can re-curve the dizzy or go with mapped ignition like this https://www.classicswede.co.uk/123tu..._18275269.aspx

Thank you both for the reply.

So to get this straight in terms of crankcase venting I don't really need to do anything.

The spout outlet thing is for draining coolant and any oil around there is from something else like a leaking seal.

So I don't 'need' to buy number 10 from the diagram the Oil Trap Box used on 81 on wards cars and connect this to an oil catch tank for better crankcase ventilation?

As for the Webers I am going to change for a single Weber 32/36 DGV as this car is to be my daily driver.
The car already has that 123 Distributor so not sure why the last owner connected the vacuum advance.

Correct you could leave your crankcase venting as it is - I'd keep an eye on how much oil mist is coming out and if you feel it's excessive, then perhaps route a hose to a catch can with a vent on the top like this one (preferably a can with just one port, the one I've linked to has two) mounted on the bulkhead somewhere.

https://www.amazon.com/Aluminum-Baff.../dp/B076LXP3JG

Yes the brass barbed fitting is the coolant drain.

I don't think the part labelled 10 will fit your crankcase - willing to be corrected on that though.

If the car already has a programmable distributor fitted, my approach would be to remove the vacuum advance hose and block off the fittings, then get the car set up on a dyno as it is. But if you have experience with the single weber then that might make sense for you... your car and all that.

Cheers